Blood concentrations of calcium, phosphorus and magnesium and dietary cation-anion difference in dairy cows / Concentrações sanguíneas de cálcio, fósforo e magnésio e diferença cátion-ânion da dieta de vacas leiteiras

The objective of this study was to identify the effect of pre and postpartum DCAD on serum levels of calcium, phosphorus, and magnesium in peripartum Holstein cows. Blood samples were collected from 56 cows (18 primiparous and 38 multiparous) on days -7, +7, +14 and +28 relative to parturition, to determine serum levels of total and ionized calcium, phosphorus, magnesium, and albumin; diet samples for determination of calcium, phosphorus, magnesium and DCAD were collected at the same moments and urine samples were collected at day -7 for measurement of urinary pH. Prepartum DCAD was positively correlated with total calcium (p = 0.02) and with corrected total calcium (p = 0.01) at day -7. There was a negative correlation between prepartum DCAD and magnesium levels at day -7 (p = 0.02). No influence of prepartum DCAD on phosphataemia was observed. Postpartum DCAD did not correlate with serum mineral levels at any time point. Our results demonstrate that prepartum DCAD can influence calcium and magnesium homeostasis, but not phosphorus. In addition, parity and time period should be considered when evaluating serum levels of these minerals in Holstein cows during transition period.

Objetivou-se identificar o efeito da DCAD pré e pós-parto nos níveis séricos de cálcio, fósforo e magnésio, em vacas Holandesas em periparto. Foram coletadas amostras de sangue de 56 vacas (18 primiparas e 38 multiparas) nos dias -7, +7, +14 e +28 em relação ao parto, para determinação dos níveis séricos de cálcio total e ionizado, fósforo, magnésio e albumina; amostras de alimento foram coletadas nos mesmos momentos para determinação dos níveis cálcio, fósforo, magnésio e DCAD dietético; e amostras de urina foram coletadas no dia -7, para mensuração do pH urinário. A DCAD pré-parto foi positivamente correlacionada com cálcio total (P = 0,02) e com cálcio total corrigido (P = 0,01) no dia -7. Houve correlação negativa entre a DCAD pré-parto e os níveis de magnésio no momento -7 (P = 0,02). Não houve influência da DCAD pré-parto na fosfatemia. A DCAD pós-parto não se correlacionou com os níveis séricos de minerais em nenhum momento. Os resultados demonstram que a DCAD pré-parto pode influenciar na homeostase do cálcio e do magnésio, mas não do fósforo. Além disso, as variáveis paridade e tempo devem ser consideradas ao se avaliarem os níveis séricos desses minerais em bovinos leiteiros da raça Holandesa em transição.

Caracterização pelvimétrica de matrizes caprinas anglonubianas / Pelvimetric characterization of anglo nubian goatdares / Caracterización pelvimétrica de cabras de raza anglonubia

Atualmente, poucos estudos se dedicam a pesquisas mais aprofundadas de aspectoselementares da pelvimetria, sendo estes, ainda mais escassos com a espécie caprina enestesentido, o presente estudo tem como objetivo caracterizar as medidas externas corpóreasdematrizes caprinas e de sua pelve. Foram utilizadas 30 matrizes caprinas da raça Anglonubianaem idade reprodutiva, manejadas em sistema intensivo, pertencentes ao setor decaprinocultura da Universidade Federal do Piauí (UFPI), Campus Professora CinobelinaElvas (CPCE), Bom Jesus, Piauí, Brasil. Durante todo o ciclo produtivo, foramrealizadasmensurações pélvicas das matrizes durante a gestação e no pós-parto, suas medidas corporaise peso vivo. As análises estatísticas foram realizadas pelo Statistical Analysis Softwareabrangendo análise discriminante, correlação, regressão e comparação de médias. Osresultados obtidos para as características de AC (altura de cernelha), CC(comprimentocorporal), PT (perímetro torácico), BII (biilíaca externa), BISQ (biisquiática externa) e ILIOQ(ilioisquiática externa) apresentaram um baixo coeficiente de variação (C.V), o que demonstrauma estabilidade do rebanho com relação a essas características, ocorrendo poucas variaçõesentre os animais. Não foram verificadas diferenças significativas para as medidas de Biilíacaea Ilioisquiática externas com relação ao estágio fisiológico. Já com relação a Biisquiática, foi observado um aumento durante a gestação. De acordo com os dados observados, nãoocorreram diferenças significativas entre as características avaliadas entre cabras primíparasemultíparas. A incorporação de bancos de dados com as medidas corporais e pélvicas de cabrasauxiliam no desenvolvimento de programas de melhoramento genético de diferentes raçascaprinas, reduzindo a ocorrência de eventos de distocia e /ou dificuldade ao parto de modogeral. As amostragens foram incorporadas em um banco de dados, que está sendo construídopara controle e análise genética dos animais do Colégio Técnico de BomJesus, Piauí. Asinformações de produção e reprodução do rebanho também estarão disponíveis nesse bancode dados.(AU)

Currently, few studies are dedicated to more in-depth research of elementary aspectsofpelvimetry, which are even scarcer with the goat species and in this sense, the present studyaims to characterize the external body measurements of goat matrices and their pelvis. ThirtyAnglonubian goats at reproductive age, managed in an intensive system, belonging tothegoat sector of the Federal University of Piauí (UFPI), Campus Professora Cinobelina Elvas (CPCE), Bom Jesus, Piauí, Brazil, were used. During the entire production cycle, pelvicmeasurements of the goats were performed during pregnancy and postpartum, their bodymeasurements and live weight. Statistical analyzes were performed by the Statistical AnalysisSoftware covering discriminant analysis, correlation, regression and comparison of means. The results obtained for the characteristics of AC (height at the withers), CC(bodylength), PT (chest circumference), BII (external biiliac), BISQ (external bischial) and ILIOQ(external ilioschiatic) showed a low coefficient of variation (C.V), which demonstrates a stabilityof theherd in relation to these characteristics, with little variation between animals. No significant differences were found for the external Biiliac and Ilioischiatic measurements in relationtothe physiological stage. Biischiatica, on the other hand, was observed to increase duringpregnancy. According to the observed data, there were no significant differences betweenthecharacteristics evaluated between primiparous and multiparous goats. The incorporationofdatabases with body and pelvic measurements of goats helps in the development of geneticimprovement programs for different goat breeds, reducing the occurrence of dystocia eventsand/or delivery difficulties in general. The samples were incorporated into a database, whichis being built for control and genetic analysis of the animals of the Colégio TécnicodeBomJesus, Piauí. Herd production and reproduction information will also be available inthisdatabase.(AU)

Actualmente, pocos estudios se dedican a la investigación más profunda de los aspectoselementales de la pelvimetría, que son aún más escasos con la especie caprina y, enestesentido, el presente estudio tiene como objetivo caracterizar las medidas corporales externasde las matrices caprinas y su pelvis. Se utilizaron 30 cabras anglonubias en edad reproductiva, manejadas en sistema intensivo, pertenecientes al sector caprino de la Universidad Federal dePiauí (UFPI), Campus Professora Cinobelina Elvas (CPCE), Bom Jesus, Piauí, Brasil. Durante todo el ciclo de producción se realizaron mediciones pélvicas de las cabras durantelagestación y posparto, sus medidas corporales y peso vivo. Las análisis estadísticasserealizaron mediante el software de análisis estadístico que abarca el análisis discriminante, lacorrelación, la regresión y la comparación de medias. Los resultados obtenidos paralascaracterísticas AC (altura a la cruz), CC (longitud corporal), PT (circunferencia torácica), BII(bilia externa), BISQ (bisquial externa) e ILIOQ (iliosquiática externa) mostraronunbajocoeficiente de variación (C.V), lo que demuestra una estabilidad del rebaño en relaciónaestascaracterísticas, con pocas variaciones entre animales. No hubo diferencias significativas paralas medidas externas Bilíaca e Ilioisquiática en relación al estadio fisiológico. Biischiatica, por otro lado, se observó que aumenta durante el embarazo. De acuerdo con los datosobservados, no hubo diferencias significativas entre las características evaluadas entre cabrasprimíparas y multíparas. La incorporación de bases de datos con medidas corporalesypélvicas de caprinos ayuda en el desarrollo de programas de mejoramiento genéticoparadiferentes razas caprinas, reduciendo la ocurrencia de eventos de distocia y/o dificultadesdeparto en general. Las muestras fueron incorporadas a una base de datos, que está siendoconstruida para el control y análisis genético de los animales del Colégio Técnico deBomJesus, Piauí. La información sobre producción y reproducción del rebaño tambiénestarádisponible en esta base de datos.(AU)

Método de punção guiada por ultrassom no diagnóstico de hematoma de barbela em bovino - relato de caso / Ultrasound-guided puncture method in the diagnosis of dewlap hematoma in bovine - case report / Método de punción por ultrasonidos en el diagnóstico del hematoma de papadas en bovinos - informe de uncaso

Injúrias relacionadas a interação animal/estrutura podem ser encontradas em sistema de confinamento Free-Stall. O hematoma de barbela pode estar relacionado a uma lesãoporcontato sofrido pelo animal com o tronco limitador da cama do Free-Stall no momentoemque ele deita para descansar. O objetivo do presente relato é descrever ummétododediagnóstico e tratamento utilizado em uma fêmea leiteira que apresentou aumento de volumelocalizado na região da barbela. Um bovino ½ HZ, fêmea, primípara, comaproximadamente60 dias em lactação (DEL), acomodada em sistema de confinamento Free-Stall e provenientede fazenda localizada no município de Lavras ­ MG apresentou aumento de volume na regiãoda barbela, sem mais nenhuma manifestação clínica. Durante o exame físico, identificou-seapresença de líquido na região edemaciada da barbela, próximo a região do peito. Foi realizadoexame ultrassonográfico e descartada a presença de pus. Com isso, foi feita uma punçãoguiada por ultrassom no local e confirmado a presença de sangue. Comesses resultados, confirmou-se o diagnóstico de hematoma e determinou-se a etiologia: lesão de contatodoanimal com o limitador da contenção da cama. Foi realizado o tratamento e houverecuperação significativa do animal. A punção guiada por ultrassomproporcionouaverificação da composição do líquido e comprovou a utilidade do exame ultrassonográfico, que foi de extrema importância para o relato.(AU)

Injuries related to animal/structure interaction can be found in Free-Stall confinement systems. The dewlap hematoma may be related to an injury caused by contact suffered by the animal with the restraint structure of the Free-Stall's liyng when it lies down to rest. The objectiveofthe present report is to describe a method of diagnosis and treatment used in a dairy cattle that presented an increase in volume located in the region of the dewlap. A primiparous female ½ HZ cow, with approximately 60 days in milk (DIM), accommodated in a Free-Stall confinement system and coming from a farm located in the municipality of Lavras - MG, presented an increase in volume in the dewlap region, without any further clinical manifestation. During the physical exam, the presence of fluid was identified in the swollenregion of the dewlap, close to the chest region. Ultrasound examination was performedandthe presence of pus was ruled out. Thus, an ultrasound-guided puncture was performedat thesite and the presence of blood was confirmed. With these results, the diagnosis of hematomawas confirmed and the etiology was determined: contact injury of the animal with the restraint structure of the lying. The treatment was carried out and there was a significant recoveryofthe animal. The ultrasound-guided puncture provided the verification of the liquidcomposition and proved the utility of the ultrasound examination, which was extremely important for this report.(AU)

En los sistemas de confinamiento Free-Stall pueden encontrarse lesiones relacionadas conlainteracción entre el animal y la estructura. El hematoma de la papada puede estar relacionadocon una lesión por contacto sufrida por el animal con el tronco limitador de la cama deFree-Stall al acostarse para descansar. El objetivo del presente informe es describir un métododediagnóstico y tratamiento utilizado en una hembra lechera que presentaba una inflamaciónlocalizada en la región de la papada. Un bovino ½ HZ, hembra, primípara, conaproximadamente 60 días de lactancia (DDL), alojada en un sistema de confinamientoFree-Stall y proveniente de una hacienda localizada en el municipio de Lavras - MGpresentóunaumento de volumen en la región de la papada, sin ninguna otra manifestaciónclínica. Durante el examen físico, se identificó la presencia de líquido en la región hinchadadelapapada, cerca de la región del pecho. Se realizó un examen ultrasonográfico y se descartólapresencia de pus. Con esto, se realizó una punción guiada por ultrasonido en el lugar yseconfirmó la presencia de sangre. Con estos resultados, se confirmó el diagnósticodehematoma y se determinó la etiología: lesión por contacto del animal con el limitador delacama. El tratamiento se llevó a cabo y hubo una recuperación significativa del animal. Lapunción guiada por ultrasonido permitió verificar la composición del fluido y demostrólautilidad del examen ultrasonográfico, que fue sumamente importante para el informe.(AU)

Strategic re-use of intravaginal progesterone devices increases conception rate in primiparous Nellore cows / Reutilização estratégica de dispositivo intravaginal de progesterona aumenta a taxa de concepção em vacas Nelore primíparas

In the present study, we investigate the effect of the presence or absence of corpus luteum (CL) at the beginning of a fixed-time artificial insemination (FTAI) protocol and to evaluate the impact of one-time use of intravaginal progesterone device (P4 device) in cows with or without CL. A total of 776 primiparous Nellore cows were subjected to FTAI approximately 45 days postpartum. In Experiment 1, 476 cows were divided into two experimental groups: with (CL-present, n=113) or without (CL-absent, n=363) CL, after ultrasound evaluation. On day 0 (D0), all cows received a new P4 device (1.0 g) and 2.0 mg estradiol benzoate (EB). Eight days later (D8), the P4 devices were withdrawn, and prostaglandin (15 mg), estradiol cypionate (0.5 mg), and eCG (300 IU) were administered i.m. All cows were inseminated 48 h after P4 device withdrawal (D10). In Experiment 2, the cows (n= 300) received (at D0) P4 devices that were previously used once in other cows with (n=109) or without CL (n=191) and 2 mg of EB. The same protocol as that used in Experiment 1 was performed from D8 onwards. In Experiment 1, the overall conception rate after FTAI was 55% (262/476). No difference was found in the conception rate between CL-present and CL-absent cows (52.2 vs. 55.5%). In Experiment 2, the conception rate obtained with P4 devices previously used in cows with CL (58.7%) was greater (P<0.05) than that obtained with P4 devices previously used in cows without CL (42.9%). Thus, this strategy resulted in a 15.8% increase in conception rate. In conclusion, the presence or absence of CL at the beginning of the FTAI protocol did not affect the conception rate in cows synchronized with the new P4 device, but the insertion of P4 devices previously used in cows with CL enhanced the conception rates in cows without CL.

No presente estudo, investigamos o efeito da presença ou ausência de corpo lúteo (CL) no início de um protocolo de inseminação artificial em tempo fixo (IATF) e avaliamos o impacto do uso único de dispositivo intravaginal de progesterona (dispositivo P4) em vacas com ou sem CL. Um total de 776 vacas Nelore primíparas, aproximadamente 45 dias pós-parto foram submetidas à IATF. No Experimento 1, após avaliação ultrassonográfica, 476 vacas foram divididas em dois grupos experimentais: com (CL-presente, n=113) ou sem (CL-ausente, n=363) CL. No dia 0 (D0), todas as vacas receberam um novo dispositivo de P4 (1,0 g) e 2.0 mg de benzoato de estradiol (BE). Após 8 dias (D8), os dispositivos P4 foram retirados e prostaglandina (15 mg), cipionato de estradiol (0,5 mg) e eCG (300 UI) foram administrados i.m. Todas as vacas foram inseminadas 48 horas após a retirada do dispositivo de P4 (D10). No Experimento 2, as vacas (n= 300) receberam (no D0) um dispositivo de P4 previamente utilizado uma única vez em outras vacas com (n=109) ou sem CL (n=191) e 2 mg de BE. O mesmo protocolo utilizado no Experimento 1 foi realizado a partir do D8. No experimento 1, a taxa geral de concepção após IATF foi de 55% (262/476). Não foi encontrada diferença na taxa de concepção entre as vacas com CL presente e CL ausente (52,2 vs. 55,5%). No Experimento 2, a taxa de concepção obtida com dispositivos P4 previamente utilizados em vacas com CL-presente (58,7%) foi maior (P<0,05) quando comparada aos dispositivos P4 previamente utilizados em vacas com CL-ausente (42,9%). Essa estratégia resultou em aumento de 15,8% na taxa de concepção. Em conclusão, a presença ou ausência de CL no início do protocolo de IATF não afetou a taxa de concepção em vacas sincronizadas com dispositivo novo de P4; e a eficácia dos dispositivos de P4 previamente utilizados em vacas com CL é maior durante seu segundo uso em vacas sem CL.

Ceftiofur efficacy in the intramammary extended treatment of staphylococcal subclinical mastitis in primiparous cows / Eficácia do ceftiofur no tratamento estendido intramamário da mastite subclínica por estafilococos em vacas primíparas

Extended therapy is an alternative approach to treat nonresponsive staphylococcal mastitis, although it has been used mainly in adult cows. This study investigated the efficacy of intramammary ceftiofur in the treatment of staphylococcal subclinical mastitis in primiparous cows. Sixty primiparous cows Holstein were divided into four groups (G1 = Group negative to staphylococci infection, G2 = Group positive to staphylococci infection untreated with intramammary ceftiofur, Group, G3 = Group treated with intramammary ceftiofur early lactation, G4 = Group treated with intramammary ceftiofur late lactation group) with milk samples collected at five moments (M0 = diagnosis of subclinical mastitis, M1 = 7 days after diagnosis of subclinical mastitis and early extended therapy, M2 = 14 after the diagnosis of subclinical mastitis, M3 = 21 days after diagnosis of mastitis) and M4 = 28 days after diagnosis of mastitis). In groups G3 and G4, which were treated with intramammary ceftiofur, the microbiological cure was evidenced by a reduction in SCC of 73.3% and 46.7%, respectively. Thus, in the treated groups (G3 + G4) and untreated (G2), cure rates were 60% and 26.7%, respectively (P <0.05). Forty-five strains of staphylococci were Motta, R. G. et al.1958Semina: Ciênc. Agrár. Londrina, v. 43, n. 5, p. 1957-1974, set./out. 2022isolated, with a predominance of S. aureus (51,1%) and S. intermedius (48,8%). The in vitro antimicrobial susceptibility pattern showed higher sensitivity indices of isolates for oxacillin (80%), ceftiofur (77.8%), cephalexin (77.8%), ciprofloxacin (66.7%), and gentamicin (60%). In contrast, cloxacillin (24.4%), penicillin (35.6%), and tetracycline (44.5%) were ineffective antimicrobials for staphylococci isolates. Among the milk samples taken when M0 and M1 (7 days after isolation), 13.3% were positive for the detection of the inhibiting substances (antimicrobials) in Delvotest™ and all negative in the Snap test™, whereas in the M2 (14 days after isolation), 55% were positive in Delvotest™ and 46.7% in the Snap test™. Twenty-one days after diagnosis (M3), 16.7% revealed positive results in Delvotest™ and 11.7% in the Snap test™. For M4 (28 days after isolation), 11.7% showed positive results in Delvotest™, and 8.3% revealed positive results in the Snap test™. There was a reduction in SCC among all cured animals. Significant results were identified for milk production in the M0, so G1 produced more milk than the other three groups, G2, G3, and G4. A statistical association was observed between the reduction in the volume of daily milk and production in animals with subclinical mastitis, denoting losses in milk production in primiparous bovines infected during lactation by staphylococci. Extended intramammary therapy with ceftiofur in bovine primiparous cows subclinically affected by staphylococcal mastitis is effective mainly in cases treated at the beginning of lactation, showing microbiological cure and reduction in SCC.(AU)

O estudo presente investigou a eficácia do ceftiofur intramamário no tratamento da mastite subclínica por estafilococos em primíparas bovinas. Foram utilizados 60 animais da raça holandesa, divididos em quadro grupos (G1 = Grupo negativo, G2 = Grupo positivo não tratado com ceftiofur intramamário, G3 = Grupo tratado com ceftiofur intramamário no início da lactação, G4 = Grupo tratado com ceftiofur intramamário no final da lactação), com amostras de leite coletadas em cinco momentos (M0 = diagnóstico da mastite subclínica, M1 = 7 dias após diagnóstico e início da terapia estendida, M2 = dia 14 após o diagnóstico da mastite subclínica, M3 = dia 21 após o diagnóstico da mastite, M4 = dia 28 após o diagnóstico da mastite). Nos grupos tratados com ceftiofur intramamário, foi evidenciada a cura microbiológica com redução na CCS em 73,3% no G3 e 46,7% no G4. Nos grupos tratados (G3+G4) e não tratado (G2), as taxas de cura foram, respectivamente, 60% e 26,7% (p<0,05). Foram isoladas 45 linhagens de estafilococos, com predomínio de S. aureus (51,1%) e S. intermedius (48,8%). O perfil de sensibilidade microbiana "in vitro" dos isolados apresentou maiores índices de sensibilidade para oxacilina (80%), ceftiofur (77,8%) e cefalexina (77,8%), ciprofloxacino (66,7%) e gentamicina (60%). Em contraste, cloxacilina (24,4%), penicilina (35,6%) e tetraciclina (44,5%) foram os antimicrobianos menos efetivos diante dos estafilococos isolados. Nas amostras de leite colhidas nos momentos M0 e M1, 13,3% foram positivas para o teste de detecção de substâncias inibidoras na prova de Delvotest™ e todas negativas no Snap test™. Já, no M2, 55% foram positivas no Delvotest™ e 46,7% no Snap test™. No M3, 16,7% positivas no Delvotest™ e no 11,7% no Snap test™. No M4, 11,7% positivas no Delvotest™ e 8,3% no Snaptest™, dois dias após o término do tratamento (M2). Foram identificados nos grupos G3 e G4 a presença de animais positivos em 96,7% para o Delvotest™ e 90% para o Snap test™. Ocorreu redução na CCS em todos os animais curados. Foram identificados resultados significativos para a produção de leite no MO, posto que o G1 produziu mais leite se comparado aos outros três grupos G2, G3 e G4. Foi observada associação estatística entre a redução no volume de leite diário e a produção nos animais com mastite subclínica, denotando prejuízos na produção de leite em primíparas bovinas infectadas na lactação por estafilococos. A terapia intramamária estendida com ceftiofur em primíparas com mastite estafilocócica é eficaz principalmente nos casos tratados no início da lactação, mostrando cura microbiológica e redução da CCS, indicando que esta abordagem terapêutica alternativa pode ser utilizada para o tratamento de novilhas.(AU)

Application of PGF2α at the moment of fixed-time artificial insemination in crossbred beef cows

Although studies have shown positive effects of gonadotropin releasing hormone (GnRH) or prostaglandin F2α (PGF2α) at the moment of fixed-time artificial insemination (FTAI) in the conception rate (CR) of cattle, its effects on treatments based on progesterone (P4) and estradiol benzoate (EB) is still not conclusive. The objective of this study was (1) to evaluate the effect of a PGF2α analogue at FTAI in the CR of crossbred beef cows submitted to a 11d FTAI protocol based on P4 and EB; and (2) to describe the CR between PGF2α-treated and control cows in different body condition scores (BCS) and parity categories. Crossbred (½ Nellore and ½ Angus) beef cows were submitted to a synchronization protocol and randomly assigned into 2 groups: Control (n = 163), at FTAI cows received 2 mL of saline solution as a placebo, and PGF2α (n = 163), at FTAI cows were treated with PGF2α analogue (10 mg of dinoprost tromethamine). Pregnancy diagnosis was performed 33d post-FTAI. Binary logistic regression model was used to analyze the effect of PGF2α treatment on CR. There was no difference in CR between PGF2α and control groups (P > 0.05; odds ratio (OR) = 0.92; confidence interval (CI) = 0.59-1.4). A greater CR was found in heifers (P = 0.0006, OR = 2.65, CI = 1.61 - 4.38) and multiparous (P = 0.0006, OR = 2.12, CI = 1.04 - 4.3) when compared to primiparous cows. Cows with low BCS (4; 9-point scale) showed lower CR when compared with moderate BCS (5-6; 9-point scale) (P < 0.05; OR = 0.10; CI = 0.06 - 0.18). There was no numerical difference on CR between PGF2α-treated and control cows in different BCS and parity categories. The results suggested that the CR in this study was not influenced by 10 mg PGF2α analogue at FTAI.(AU)

Effect of stocking management and nitrogen supplementation on pasture milk yield / Efeito do manejo do pastejo e suplementação nitrogenada sobre a produção de leite a pasto

This study aimed to evaluate the effect of the first and last stocking strategies combined with a partial substitution of the protein from the supplement for urea nitrogen on nutrient intake and digestibility, milk composition, and nitrogen balance of primiparous Girolando cows. The cows were allocated to a double 4 × 4 Latin square composed of four animals and four treatments in a 2 × 2 factorial arrangement. Supplements were formulated to provide an intake of 0.6% body weight, with and without the inclusion of 21% urea nitrogen in their composition. The first stocking management method improved nutrient intake and digestibility. Supplementation with urea led to a 47% higher excretion of urine N (g/day) than the urea treatment. The combination of the supplement without urea and the first stocking provided higher intake and retention of nitrogen and higher retained-N levels (%digested N). The combination of a supplement containing 21% urea nitrogen and the first stocking can be used without compromising the nutritional and productive parameters of the cows.

Objetivou-se avaliar os efeitos dos manejos do pastejo ponta e repasse combinados a substituição parcial da proteína do suplemento por nitrogênio ureico sobre o consumo e digestibilidade dos nutrientes, composição do leite e balanço de nitrogênio de vacas primíparas da raça Girolanda. As vacas foram alocadas em dois quadrados latinos 4 x 4 compostos de quatro animais cada e quatro tratamentos em um esquema fatorial 2 x 2. Os suplementos foram formulados para um consumo de 0,6% do peso corporal: sem utilização de nitrogênio ureico; ou com 21% de nitrogênio ureico em sua composição. O manejo do pastejo de ponta melhorou o consumo e a digestibilidade dos nutrientes. O suplemento contendo ureia excretou 47% a mais de N urina (g/dia) em comparação ao suplemento sem ureia. A combinação entre o suplemento sem ureia e o manejo de pastejo ponta apresentou maior ingestão e retenção de nitrogênio e maior N retido (%N digerido). A combinação entre o suplemento contendo 21% de nitrogênio ureico e o pastejo de ponta pode ser utilizada sem prejuízos aos parâmetros nutricionais e produtivos das vacas.

Management of dairy calves and heifers and the economic impact on first lactation / Manejos de bezerras e novilhas leiteiras e seu impacto econômico na primeira lactação

Management of calves and heifers directly influence the future productivity of dairy animals. However, the pre-production stage is often neglected by farmers, as young cows do not yet produce milk and, therefore, revenue, while representing an important part of the total cost of the property. This study aimed to identify and determine the economic value of factors influencing the production in the first lactation of heifers in a herd. This was a case study carried out on a family property in the municipality of Patrocínio, state of Minas Gerais, using data from 54 heifers. Qualitative characteristics (sire, maternal grandsire, amount of colostrum consumed, antibiotics use on the first day of life; application of prostaglandin to induce estrus, application of prostaglandin for resynchronization, use of progesterone implant for resynchronization, occurrence of retention of placenta and/or abortion, induction of lactation) and quantitative characteristics (weight at 90 days, average daily gain at 90 days and age at first mating) were evaluated. Variables influencing the production in the first lactation were the application of antibiotics, retained placenta, induction of lactation and age at mating. The differences in milk revenue were -R$ 2,381.21 for the use of antibiotics in each female, -R$ 299.85 for each heat loss for the first mating, -R$ 5,043.11 for each lactation induction, -R$6,841.16 for each retained placenta with abortion and - R$1,060.96 for each case of retained placenta without abortion. Knowing the productive and economic consequences of each of these items provides the producer with subsidies for decision making, such as planning management strategies that avoid such losses, and choosing options to maximize the economic efficiency of production.

O manejo e os cuidados com as bezerras e novilhas influenciam diretamente a produtividade futura das fêmeas leiteiras. No entanto, muitas vezes a fase pré-produtiva é negligenciada pelos produtores, pois ao mesmo tempo que representam uma parcela importante do custo total da propriedade, as fêmeas jovens ainda não produzem leite e, portanto, receita. Objetivou-se identificar e determinar o valor econômico de fatores que influenciam na produção na primeira lactação de novilhas em um rebanho. O estudo de caso foi realizado em uma propriedade familiar na cidade de Patrocínio/MG, utilizando os dados de 54 novilhas. Foram avaliadas características qualitativas (pai, avô materno, quantidade de colostro consumida, uso de antibiótico no primeiro dia de vida; aplicação de prostaglandina para indução do cio, aplicação de prostaglandina para ressincronização, uso de implante de progesterona para ressincronização, ocorrência de retenção de placenta e/ou aborto, indução de lactação) e quantitativas (peso aos 90 dias, ganho médio diário aos 90 dias e idade à primeira cobertura). As variáveis que influenciaram a produção na primeira lactação foram a aplicação de antibióticos, retenção de placenta, indução à lactação e idade cobertura. As diferenças na receita do leite foram de -R$ 2.381,21 para o uso de antibióticos em cada fêmea, -R$ 299,85 para cada cio perdido para a primeira cobertura, -R$ 5.043,11 para cada indução de lactação, de -R$ 6.841,16 para cada ocorrência de retenção de placenta com aborto e de -R$ 1.060,96 para cada caso de retenção de placenta sem aborto. Conhecer as implicações produtivas e econômicas de cada um destes itens fornece ao produtor tem subsídios para tomadas de decisão, como planejar estratégias de manejo que evitem tais prejuízos, e escolher as opções que maximizem a eficiência econômica da produção.

Estrus expression and pregnancy rates in heifers primiparous and multiparous Nelore cows subjected to timed artificial insemination with strategic use of gonadotropin-releasing hormone / Expressão de estro e taxas de prenhez em novilhas, primíparas e multíparas Nelore submetidas à inseminação artificial em tempo fixo com uso estratégico de hormônio liberador de gonadotrofina

We evaluated the effects of nulliparous, primiparous, and multiparous conditions on the estrus and pregnancy rates in females that did not show estrus but were treated with gonadotropin-releasing hormone (GnRH) at the time of timed artificial insemination (TAI). Nelore females (n = 531) were allocated according to the following categories: nulliparous (n = 144), primiparous (n = 132), and multiparous (n = 255). The animals received a conventional TAI protocol, and estrus expression was identified by the absence of paint in the sacrococcygeal region on the day of TAI. Females that did not show estrus were treated with 10 µg of GnRH together with insemination. The rates of estrus and pregnancy were analyzed using a logistic regression model (P < 0.05). The estrus expression was lower (P = 0.006) in the primiparous (61.36%) group than in the nulliparous (76.39%) and multiparous (75.69%) groups. Similar pregnancy rates were observed in females that showed estrus (nulliparous 84.54%, primiparous 86.42%, and multiparous 80.31%; P = 0.39) and in females that did not show estrus and received GnRH (nulliparous 41.18%, primiparous 56.86%, and multiparous 58.06%; P = 0.24). The total pregnancy rates were also similar (P = 0.98) among the categories (nulliparous 74.3%, primiparous 75.0%, and multiparous 74.9%). The primiparous females had a lower rate of estrus, and the pregnancy rates were similar among the categories that received GnRH.(AU)

O objetivo do trabalho foi avaliar o efeito das categorias nulíparas, primíparas e multíparas sobre a taxa de manifestação de estro e a taxa de prenhez de fêmeas que não manifestaram estro, mas foram tratadas com GnRH no momento da inseminação artificial em tempo-fixo (IATF). Foram utilizadas 531 matrizes, todas da raça Nelore, alocadas de acordo com a categoria: nulíparas (n = 144), primíparas (n = 132) e multíparas (n = 255). As matrizes foram submetidas a um protocolo reprodutivo para inseminação artificial em tempofixo (IATF) e tiveram a expressão do estro identificada pela ausência de tinta na região sacrococcígea no dia da inseminação. As fêmeas que não apresentaram estro receberam 10 µg de GnRH no momento que foram inseminadas. As taxas de estro e prenhez foram analisadas por meio de um modelo de regressão logística (P < 0,05). A expressão do estro foi menor (P = 0,006) no grupo de primíparas (61,36%) do que nos grupos de nulíparas (76,39%) e multíparas (75,69%). Taxas de prenhez semelhantes foram observadas em fêmeas que apresentaram estro (nulíparas 84,54%, primíparas 86,42% e multíparas 80,31%; P = 0,39) e em fêmeas que não apresentaram estro e receberam GnRH (nulíparas 41,18%, primíparas 56,86% e multíparas 58,06%; P = 0,24). As taxas de prenhez total também foram semelhantes (P = 0,98) entre as categorias (nulíparas 74,3%, primíparas 75,0% e multíparas 74,9%). As fêmeas primíparas apresentaram menor taxa de estro e as taxas de prenhez foram semelhantes entre as categorias que receberam GnRH.(AU)

Influência da progesterona injetável na taxa de prenhez e perda gestacional de fêmeas nelore de distintas categorias reprodutivas submetidas a inseminação artificial em tempo fixo / Influence of injectable progesterone on the pregnancy rate and gestational loss of Nellore females of different reproductive categories undergoing fixed-time artificial insemination

Progesterone (P4) is essential for embryonic development and maintenance of pregnancy when deficiency causes early embryonic loss. In this study, we investigated the ability of hormonal supplementation to improve the fertility of Nellore females subjected to fixed-time artificial insemination (IATF) protocols. Here, we evaluated the effect of long-acting injectable progesterone (iP4) supplementation in the D4 after IATF on pregnancy rate and pregnancy loss in Nellore females (Bos taurus indicus) from different reproductive categories in Western Amazonia. Eight hundred thirteen Nellore females from 5 farms were selected and distributed into 2 groups: control [GC; administration of 0.5 mL of 0.9% saline solution, intramuscularly - IM] (n = 407) and a group that received injectable progesterone (iP4) that was long-acting [GiP4; administration of 0.5 mL of iP4, 300 mg, via IM four days after IATF] (n = 406). Each group contained 3 subgroups: heifers, primiparous cows, and multiparous cows. Of the 407 animals in the CG, 103 were heifers, 107 primiparous, and 197 multiparous. Of the 406 animals in the GiP4 group, there were 101 heifers, 107 primiparous, and 198 multiparous. On a random day of the estrous cycle (D0), an intravaginal device containing 1 g of P4 and 2 mg of estradiol benzoate (BE) was inserted by intramuscular injection. On D8, the P4 device was removed and 150 µg of D-cloprostenol (PGF2α), 300 IU eCG, and 1 mg BE were administered IM. Cows were inseminated at D10, 48-52 h after procedure on D8. Pregnancy diagnosis was made between 35 and 40 days after insemination through ultrasound examination. Between 80 and 90 days after insemination, a new ultrasound examination was performed to assess early pregnancy loss. The data were processed using the SAS 9.2. The conception rate, pregnancy loss, and final conception rate were analyzed using PROC GLIMMIX according to groups (CG and GiP4), categories (heifers, primiparous and multiparous), and their interactions as variables. The differences in the means of least squares were adjusted using the Tukey­Kramer method. Statistical significance was defined as P < 0.05. The general conception rate was 46% (375/816). Regardless of the animal class, GiP4 animals (51.97%) had higher conception rates (P < 0.05) than CG (40.29%). In the subgroups (heifers, primiparous and multiparous cows), there was a difference (P < 0.05) between animals treated with iP4 (52.48%, 57.94%, and 48.48%, respectively) and those who were not (39.81%, 41.12%, and 40.10%, respectively). Gestational losses, regardless of the animal class, were higher in females in the CG (7.93%) [P < 0.05] compared to those in the GiP4 group (2.84%). Regardless of treatment with iP4, the percentage of gestational loss in heifers was significantly higher (10.64%) than that in primiparous and multiparous cows (3.77% and 2.86%, respectively). The final conception rates were higher in animals that received long-acting iP4, which increased the final pregnancy in all parity categories. In the present study, the use of iP4 increased the pregnancy rate in Nellore females, regardless of the category. Although there has been no consensus on the use of iP4, there is an agreement that increases in the pregnancy rate are related to the moment of exogenous P4 application. In addition to influencing the pregnancy rate, reduction in pregnancy losses is also attributed to iP4 treatment, a fact demonstrated in the present study, where animals treated with iP4 had a lower pregnancy loss rate than normally occurs in beef cattle. Supplementation with long-acting iP4 increased the pregnancy rate at D35-40, reduced pregnancy losses, and increased the conception rate on D80-90 days in Nellore females reared in the Western Amazon, regardless of the animal category.(AU)

Relationship between metabolic profile, diseases, productive and reproductive performance in highproducing Holstein cows in the postpartum period / Relação entre o perfil metabólico, doenças, desempenho produtivo e reprodutivo de vacas Holandesas recém-paridas de alta produção

The present study aimed to monitor Holstein cows in the postpartum period, and to evaluate the occurrence of clinical diseases and their relationship with metabolic profile, milk yield and composition, and reproductive performance. One hundred and five Holstein cows, 32 primiparous and 73 multiparous, from two dairy herds in Arapoti, Paraná State, were clinically monitored up to ten days after calving. The clinical occurrences diagnosed were: dystocia, metritis, retained placenta, clinical hypocalcemia, displaced abomasum, mastitis, pneumonia, and digital dermatitis. Blood samples were collected at one, two, five, and ten days postpartum for analysis of non-esterified fatty acids (NEFA), ß-hydroxybutyrate (BHB), and total calcium. Individual milk yield was measured up to 100 days in milk (DIM), and the first test-day was evaluated for milk composition. Statistical analyses were conducted using the MIXED procedure of SAS, and the fixed effects of farm (A and B), parity (primiparous and multiparous), and occurrence of clinical diseases (sick and healthy cows) were included. Forty-eight cows (45.7%) had one or more clinical occurrences. In these sick cows, the BHB concentration at five DIM was higher (P = 0.06) than in healthy cows; 0.78 and 0.57 mmol L-1, respectively. Regarding milk yield, cows with one or more clinical occurrences had lower (P < 0.01) daily milk yield up to 30 DIM, and had a tendency of lower (P = 0.09) accumulated production up to 100 DIM than healthy cows. Sick cows had a tendency to show lower (P = 0.08) milk total solids content than healthy cows; 12.04 and 12.60%, respectively. There were no significant differences between sick and healthy animals in the remaining milk components, or the reproductive parameters assessed. The differences observed for days in the first artificial insemination (AI), AI number, and days open occurred due to the effect of the herd.(AU)

O objetivo deste estudo foi monitorar vacas Holandesas no pós-parto e avaliar a ocorrência de doenças clínicas e sua relação com o perfil metabólico, a produção de leite e sua composição e o desempenho reprodutivo. Foram monitoradas clinicamente durante 10 dias após o parto, 105 vacas da raça Holandesa, 32 primíparas e 73 multíparas, de dois rebanhos leiteiros em Arapoti, Paraná. As ocorrências clínicas diagnosticadas foram: distocia, metrite, retenção de placenta, hipocalcemia clínica, deslocamento de abomaso, mastite, pneumonia e dermatite digital. Amostras de sangue foram coletadas nos dias 1, 2, 5 e 10 após o parto para análises de ácidos graxos não-esterificados (AGNE), ß-hidroxibutirato (BHB) e cálcio total. A produção de leite individual foi mensurada até 100 dias em leite (DEL) e para a composição do leite foi avaliado o primeiro controle leiteiro oficial após o parto. As análises estatísticas foram conduzidas pelo procedimento MIXED do SAS e foram incluídos os efeitos fixos de fazenda (A e B), paridade (primíparas e multíparas) e ocorrência de doenças clínicas (vacas doentes e saudáveis). Quarenta e oito vacas (45,7%) apresentaram uma ou mais doenças clínicas. Nestas vacas doentes a concentração de BHB no 5o dia pós-parto foi superior (P = 0,06) a de vacas saudáveis; 0,78 e 0,57 mmol L-1, respectivamente. Em relação a produtividade, vacas com uma ou mais doenças clínicas apresentaram menores (P < 0,01) produções diárias até 30 DEL e tendência de menores (P = 0,09) produções acumuladas até 100 DEL em relação a vacas sadias. Vacas doentes apresentaram uma tendência de menor (P = 0,08) porcentagem de sólidos totais no leite do que vacas saudáveis; 12,04 e 12,60%, respectivamente. Não houve diferenças significativas entre animais doentes e saudáveis para os outros componentes do leite, bem como nos parâmetros reprodutivos avaliados. As diferenças observadas para dias até a primeira inseminação artificial (IA), número de IA e dias abertos ocorreram devido ao efeito de rebanho.(AU)

Influence of caprine arthritis encephalitis on milk production and quality along the lactation curve in primiparous dairy goats / Influência da artrite encefalite caprina na produção e qualidade do leite ao longo da curva de lactação em cabras leiteiras primíparas

The aim of this study was to examine the influence of caprine arthritis encephalitis (CAE) on the production of milk and its components (protein, fat and total solids) along the lactation curve of primiparous goats. The study was developed using a database from the years 2014 to 2018. Sixty-one animals were subjected to the serological test for CAE, whose result indicated that 42 were seropositive and 19 seronegative, and milk production and quality data were compiled. To adjust the curve for production of milk, fat, protein and total solids during lactation, the following nonlinear model developed by Wood (1967) was used: Y = atb e-ct, where Y represents the observations of milk, fat, protein or total solid production at time t; a is the parameter associated with the initial production; b is the parameter associated with the rate of rise in production until the peak; c is the parameter associated with the rate of decline of the lactation curve; and t is the representative time of the day in milk. The parameters were compared by the confidence interval considering 95% probability. Peak production was calculated using the following formula: a(b/c)b e-b. There was no statistical difference (p > 0.05) between seropositive and seronegative primiparous goats for initial production and the rates of rise and decline of the parameters of milk, fat, protein and total solid production. However, at their peak, these variables were 26, 27, 23 and 23% higher, respectively, in the seronegative goats than in their seropositive counter parts. In conclusion, CAE does not affect milk production or the production of fat, protein and total solids along the lactation curve, but seropositive goats produce less milk and respective components at the peak of the lactation curve than seronegative goats.

Objetivou-se avaliar a influência da artrite encefalite caprina (CAE) sobre a produção leiteira e seus constituintes (proteína, gordura e sólidos totais) ao longo da curva de lactação de cabras primíparas. O estudo foi realizado a partir do banco de dados dos anos de 2014 a 2018. Foram utilizados um total de 61 animais, todos submetidos ao teste de sorologia para CAE, sendo 42 cabras soropositivas e 19soronegativas, e os dados foram compilados de produção e qualidade do leite. Para o ajuste da curva para a produção de leite, gordura, proteína e sólidos totais ao longo da lactação foi utilizado o modelo não linear de Wood (1967): Y = atb e-ct, no qual: Y representa as observações de produção de leite, gordura, proteína ou sólidos totais no tempo t, a é o parâmetro associado à produção inicial, b é o parâmetro associado à taxa de ascensão da produção até o pico, c é o parâmetro associado à taxa declínio da curva de lactação e t é o tempo representativo do dia em lactação. Os parâmetros foram comparados pelo intervalo de confiança considerando 95% de probabilidade. A produção no pico foi calculada pela fórmula: a(b/c)b e-b. Não houve diferença estatística (p > 0,05) entre cabras primíparas soropositivas e soronegativas para a produção inicial, taxa de ascensão e taxa de declínio dos parâmetros para a produção de leite, de gordura, de proteína e de sólidos totais. Porém a produção no pico das variáveis em cabras soronegativas foi de26%, 27%, 23% e 23%, respectivamente, mais altas que em soropositivas. Conclui-se que a CAE não afeta a produção leiteira, bem como a produção de gordura, proteína e sólidos totais ao longo da curva de lactação, entretanto cabras soropositivas têm menor produção de leite e de seus componentes no pico da curva de lactação em relação às soronegativas.

Influence of caprine arthritis encephalitis on milk production and quality along the lactation curve in primiparous dairy goats / Influência da artrite encefalite caprina na produção e qualidade do leite ao longo da curva de lactação em cabras leiteiras primíparas

The aim of this study was to examine the influence of caprine arthritis encephalitis (CAE) on the production of milk and its components (protein, fat and total solids) along the lactation curve of primiparous goats. The study was developed using a database from the years 2014 to 2018. Sixty-one animals were subjected to the serological test for CAE, whose result indicated that 42 were seropositive and 19 seronegative, and milk production and quality data were compiled. To adjust the curve for production of milk, fat, protein and total solids during lactation, the following nonlinear model developed by Wood (1967) was used: Y = atb e-ct, where Y represents the observations of milk, fat, protein or total solid production at time t; a is the parameter associated with the initial production; b is the parameter associated with the rate of rise in production until the peak; c is the parameter associated with the rate of decline of the lactation curve; and t is the representative time of the day in milk. The parameters were compared by the confidence interval considering 95% probability. Peak production was calculated using the following formula: a(b/c)b e-b. There was no statistical difference (p > 0.05) between seropositive and seronegative primiparous goats for initial production and the rates of rise and decline of the parameters of milk, fat, protein and total solid production. However, at their peak, these variables were 26, 27, 23 and 23% higher, respectively, in the seronegative goats than in their seropositive counter parts. In conclusion, CAE does not affect milk production or the production of fat, protein and total solids along the lactation curve, but seropositive goats produce less milk and respective components at the peak of the lactation curve than seronegative goats.(AU)

Objetivou-se avaliar a influência da artrite encefalite caprina (CAE) sobre a produção leiteira e seus constituintes (proteína, gordura e sólidos totais) ao longo da curva de lactação de cabras primíparas. O estudo foi realizado a partir do banco de dados dos anos de 2014 a 2018. Foram utilizados um total de 61 animais, todos submetidos ao teste de sorologia para CAE, sendo 42 cabras soropositivas e 19soronegativas, e os dados foram compilados de produção e qualidade do leite. Para o ajuste da curva para a produção de leite, gordura, proteína e sólidos totais ao longo da lactação foi utilizado o modelo não linear de Wood (1967): Y = atb e-ct, no qual: Y representa as observações de produção de leite, gordura, proteína ou sólidos totais no tempo t, a é o parâmetro associado à produção inicial, b é o parâmetro associado à taxa de ascensão da produção até o pico, c é o parâmetro associado à taxa declínio da curva de lactação e t é o tempo representativo do dia em lactação. Os parâmetros foram comparados pelo intervalo de confiança considerando 95% de probabilidade. A produção no pico foi calculada pela fórmula: a(b/c)b e-b. Não houve diferença estatística (p > 0,05) entre cabras primíparas soropositivas e soronegativas para a produção inicial, taxa de ascensão e taxa de declínio dos parâmetros para a produção de leite, de gordura, de proteína e de sólidos totais. Porém a produção no pico das variáveis em cabras soronegativas foi de26%, 27%, 23% e 23%, respectivamente, mais altas que em soropositivas. Conclui-se que a CAE não afeta a produção leiteira, bem como a produção de gordura, proteína e sólidos totais ao longo da curva de lactação, entretanto cabras soropositivas têm menor produção de leite e de seus componentes no pico da curva de lactação em relação às soronegativas.(AU)

Relationship between reproductive performance and meteorological variables in French Alpine goats in the northwestern part of Croatia

The study aimed to determine the relationship between reproductive performance, kidding distribution, and birth weight of French Alpine goats and meteorological variables in the northwestern part of Croatia throughout six consecutive years (from 2013 until 2018). During the study, French Alpine goats (n=948) on the 6 dairy goat farms, birthed 1025 goat kids after 893 successful matings (55 matings were unsuccessful) during six consecutive years. The average birth weight was 3.46±0.48 kg for females (n=478) and 3.71±0.51 kg for male kids (n=547). French Alpine does with single kids accounted for 85.89% (n=767), with twins 13.44% (n=120) and triplets 0.67% (n=6). The average litter size was 1.15, and the average parity was 2.95. The birth weight of goat kids in primiparous and pluriparous goats was not significantly different. Survival rate (until 1 month of age) was 93.66 % (n=960). French Alpine does fertility in northwestern Croatia, through six years was 94.18%. Seasonal kidding of French Alpine was distributed mostly on two seasons: winter (73.57%) and spring (24.52%) in the northwestern part of Croatia during six consecutive years 2013-2018. Observed differences in the kidding distribution per month during the years of observation were statistically significant (P = 0.018). The highest number of kidding was recorded in February in all years of observation. It can be concluded that there was not any relationship between monthly air temperature and precipitation amounts with tested reproductive performances in French Alpine dairy goats in the NW part of Croatia during the observed period.(AU)

Relationship between reproductive performance and meteorological variables in French Alpine goats in the northwestern part of Croatia

The study aimed to determine the relationship between reproductive performance, kidding distribution, and birth weight of French Alpine goats and meteorological variables in the northwestern part of Croatia throughout six consecutive years (from 2013 until 2018). During the study, French Alpine goats (n=948) on the 6 dairy goat farms, birthed 1025 goat kids after 893 successful matings (55 matings were unsuccessful) during six consecutive years. The average birth weight was 3.46±0.48 kg for females (n=478) and 3.71±0.51 kg for male kids (n=547). French Alpine does with single kids accounted for 85.89% (n=767), with twins 13.44% (n=120) and triplets 0.67% (n=6). The average litter size was 1.15, and the average parity was 2.95. The birth weight of goat kids in primiparous and pluriparous goats was not significantly different. Survival rate (until 1 month of age) was 93.66 % (n=960). French Alpine does fertility in northwestern Croatia, through six years was 94.18%. Seasonal kidding of French Alpine was distributed mostly on two seasons: winter (73.57%) and spring (24.52%) in the northwestern part of Croatia during six consecutive years 2013-2018. Observed differences in the kidding distribution per month during the years of observation were statistically significant (P = 0.018). The highest number of kidding was recorded in February in all years of observation. It can be concluded that there was not any relationship between monthly air temperature and precipitation amounts with tested reproductive performances in French Alpine dairy goats in the NW part of Croatia during the observed period.

Effect of different rearing condition on early age in the maze, open-field, and aversive behaviours in the dairy cow during the first lactation

The aim of the study was to tested hypotheses that the primiparous cows behaviour is impacted by the method of rearing from the second day of life to weaning. 53 Holstein primiparous cows were used. They were reared in different ways during milk nutrition. Calf-heifers were assigned to one of five rearing groups on the second day after having nursed their mothers for 24 hours: H) hutch; HA) hutch, from 7 days pen with an automated drinking machine (ADM); MA) with mother, from 7 days pen with an ADM; MH) with mother, from 7 days hutch; MN) with mother, from 4 days with nursing cows. After weaning (56 days), all heifers were kept in group pens, after calving in free-stall housing. Maze learning ability was tested in the third month of lactation. In the 5th month, cows were observed in the open-field, in the seventh month they were subjected to an aversion test (AT). Group MN was the slowest in solving all tasks and HA the fastest. Differences were recorded among groups in the first-day evaluation (P < 0.01). No differences in open field tests were found. In the AT traversing, the slowest were groups H and HA, the fastest MH and MA (P < 0.01). The time of the first return was different (P < 0.001). On the first day, the most vocalized cows of the MN group (P < 0.05). The results show that the method used to rear heifers may have a significant impact on their maze and aversive behaviour.(AU)

Effect of different rearing condition on early age in the maze, open-field, and aversive behaviours in the dairy cow during the first lactation

The aim of the study was to tested hypotheses that the primiparous cow’s behaviour is impacted by the method of rearing from the second day of life to weaning. 53 Holstein primiparous cows were used. They were reared in different ways during milk nutrition. Calf-heifers were assigned to one of five rearing groups on the second day after having nursed their mothers for 24 hours: H) hutch; HA) hutch, from 7 days pen with an automated drinking machine (ADM); MA) with mother, from 7 days pen with an ADM; MH) with mother, from 7 days hutch; MN) with mother, from 4 days with nursing cows. After weaning (56 days), all heifers were kept in group pens, after calving in free-stall housing. Maze learning ability was tested in the third month of lactation. In the 5th month, cows were observed in the open-field, in the seventh month they were subjected to an aversion test (AT). Group MN was the slowest in solving all tasks and HA the fastest. Differences were recorded among groups in the first-day evaluation (P < 0.01). No differences in open field tests were found. In the AT traversing, the slowest were groups H and HA, the fastest MH and MA (P < 0.01). The time of the first return was different (P < 0.001). On the first day, the most vocalized cows of the MN group (P < 0.05). The results show that the method used to rear heifers may have a significant impact on their maze and aversive behaviour.

Estimation of heritability and genetic correlations between milk yield and linear type traits in primiparous Holstein-Friesian cows

Estimation of genetic variability and genetic correlations between production traits (milk yield, fat yield, fat content, protein yield, and protein content) and selected type traits (angularity, fore udder height, rear udder height, front teat placement, teat length, and udder depth) was done using data sets of 10,860 first-calving Holstein-Friesian cows raised in the territory of the Republic of Serbia. Genetic variance and covariance were obtained using the Restricted Maximum Likelihood (REML) method, VCE v6 software, and the multi-trait mixed model. To enable more precise estimates of values for genetic variances and covariance, a relationship matrix was formed for the individual model (animal model), encompassing 21363 animals. The highest heritability values were obtained for milk yield (0.182), fat yield (0.134), and protein yield (0.170). The lowest heritability estimates were for teat length, front teat placement, rear udder height, and udder depth, all being under 0.110. Genetic correlations between production traits and linear type traits were between −0.131 (fat content and front teat length) and 0.307 (protein yield and fore udder attachment). The largest number of traits shows a positive genetic correlation with the traits of milk yield, which thus indicates possibility of genetic improvements of milk yield in cattle without jeopardizing the type traits or vice versa.

Associations of days open with milk urea nitrogen and other herd traits in dairy cows

We evaluated the association of monthly milk urea N (MUN) concentrations before conception and days open in high-producing dairy cows from commercial herds in Southern Brazil. Other herd traits were also investigated regarding their relationship with days open. A database containing 16,569 monthly test-day records (obtained from 3,926 lactations of 2,145 cows) for productive, reproductive, and milk quality data was assembled from three different herds. Maximum MUN before conception was divided into quartiles as follows: ≤15.5 mg/dL (1), from 15.6 mg/dL to 18.0 mg/dL (2), from 18.1 to 20.5 mg/dL (3), and >20.5 mg/dL (4). When cows calved in spring and winter, days open averaged (mean±SE) 171.2±2.71 and 155.4±2.31, corresponding to an increase in 12 and 2%, respectively, related to cows that calved in summer (152.7±2.44). When cows calved in fall, a 12% reduction in days open (135.5±1.79) compared with cows that calved in summer was observed. The estimated regression coefficients showed that multiparous cows are expected to have an increase of 12 and 6% in days open when compared with primiparous and secondiparous cows, respectively. Days open were positively associated with the highest MUN value obtained until conception. Cows in the highest quartile of maximum MUN (>20.5 mg/dL) had more days open (184.6±2.93) than cows in quartiles 1, 2, and 3 (123.7±2.12, 150.2±2.16, and 160.5±2.29, respectively), which represents reductions of 40, 21, and 14%, respectively. These results suggest that a maximum MUN concentration before conception higher than 15.5 mg/dL may negatively impact the fertility of high-producing dairy cows.

Atualidades nos efeitos do fotoperíodo em leitoas de reposição e os impactos na performance reprodutiva / Updates on the effects of photoperiod on replacement gilts and the impacts on reproductive performance

A mudança de luminosidade claramente possui um grande impacto no ciclo reprodutivo em diferentes espécies, principalmente espécies reprodutoras sazonais. Apesar de o suíno doméstico ser capaz de se reproduzir com sucesso no decorrer do ano, os efeitos da sazonalidade têm sido estudado por diversos anos visto que, ainda hoje, existem reduções de taxas reprodutivas em leitoas e porcas, principalmente nas épocas de verão e outono. Além dos efeitos do estresse por calor que acometem granjas durante o verão, efeitos do fotoperíodo podem ser identificados em dinâmicas hormonais, e alguns resultados de desempenho dependendo das estações do ano. Há indícios que o fotoperíodo em associação com o estresse causado pelas altas temperaturas do ambiente sejam as principais causas do processo de infertilidade sazonal em suínos. Estudos mais recentes demonstram efeitos negativos na fertilidade de leitoas e primíparas quando expostas a ambientes com baixa luminosidade durante o período de cobertura. Apesar de ainda existir grande espaço para mais investigações a respeito dos efeitos de duração e intensidade do fotoperíodo artificial e para melhorias em termos de ambiência, os órgãos responsáveis pela regulamentação de animais de produção sugerem uma intensidade e tempo mínimo de exposição à iluminação artificial para os suínos em confinamento.

The changes in photoperiod clearly impact the reproductive cycle in different species, especially in seasonal breeders. Although the domestic pig can successfully reproduce throughout the year, the seasonal effects have been studied for years, and still today, reduction in reproductive rates exist in gilts and sows, mainly during summer and fall periods. Besides the high temperatures during summer causing detrimental effects due to heat stress in swine, changes in photoperiod effects can be identified by hormonal changes and performance results depending on the season. There is evidence of photoperiod associated with heat stress being the leading causes of seasonal infertility in swine. Recent studies demonstrate adverse effects on gilts and primiparous sows fertility when exposed to an environment with low lighting intensity during the breeding period. Although further investigation on the effects of intensity and duration of artificial photoperiod and improvements in terms of ambient is still needed, the guidelines and regulations for animal production suggest a minimum exposure of artificial light intensity and duration for confined swine.