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This study evaluated heterosis and reciprocal effects in across of White Leghorn with Fayoumi, White Leghorn with Koekoek in comparison to their pure line breeds for the productive and reproductive traits. Data were purposively collected from 357 layers based on their genetic groups and each genotype was reared in three replicates on a deep litter system from 20-72 weeks. Results showed that genotype groups were found to have no significant differences (p > 0.05) for age at first egg (AFE) and hen- housed egg production (HHEP). Purebred Koekoek and crossbred of male White Leghorn and female Koekoek were superior for body weight at first egg (BWAFE). Purebred Fayoumi has exhibited the least values for egg number. Purebred White Leghorn was the best by their feed conversion ratio. Effects of heterosis were non-significant (p > 0.05) for AFE and BWAFE, and hen-housed egg production. A negative heterosis percentage was noted for AFE in all crossbred genotypes. Crossing between male Koekoek and female White Leghorn gave the highest heterosis effect for feed intake while crossing between male White Leghorn and female Fayoumi gave the highest estimates of heterosis for total egg number per hen. The main crossbred between male White Leghorn and female Fayoumi hybrids outperformed in AFE and HHEP while the main crossbred between male White Leghorn and female Koekoek outperformed in BWAFE and HHEP. On the contrary, reciprocal crossbreds between male Fayoumi and female White Leghorn and male Koekoek and female White Leghorn had higher feed intake and better feed conversion ratio.(AU)

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Reviewing the current state of knowledge on reproductive performance and productive traits in rams has many advantages. First, the compilation of this information will serve as a literature resource for scientists conducting research around the world and will contribute to the understanding of the data collected and interpreted by researchers on the different hormonal strategies used to improve reproductive performance in rams. Second, it will allow scientists to identify current knowledge gaps and set future research priorities in ram reproduction. Rams play an important role in the global flock economy, but their reproductive analysis has been limited in the use of hormonal technologies to increase the productivity of sheep flocks. In this review, we cite the most important works on six hormones that, in one way or another, modify the hypothalamus-pituitary-gonadal axis, at different doses, in and out of the reproductive season, breeds, application methods, among other factors. The overall aim is to increase the reproductive efficiency of rams in different scenarios and, in some cases, of other species due to the lack of limited information on rams.(AU)

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Andean guinea pig traditionally fed with forages presents low productive and reproductive performance. The aim of this study was to evaluate the effects of fibrous concentrate on the reproductive and productive performance of guinea pigs. A sample of 110 female guinea pigs (963.1 ± 127.3 g) and 22 male guinea pigs (1209.9 ± 159.0 g) of the Peru breed was distributed in 22 breeding modules (1 male/5 females), of which 11 modules were fed with forage (control) and 11 modules with fibrous concentrate (experimental). Each module was a replication. The forage was wholeoat hay, while the fibrous concentrate was a mixture made with chopped hay from the same oats, corn-soybean, vitamin-mineral supplement, common salt, and premix. Both groups received the same amounts of fresh alfalfa as a vitamin C source. Then, 92 young weaning cavies from the control group (248.8 ± 29.9 g) and 106 young cavies from the experimental group (350.5 ± 64.6 g) were fed with the same diets to evaluate their productive performance.The experimental group surpassed the control group in all the variables (p < 0.05): dry matter intake (81.2 ± 4.5 vs 77.9 ± 1.0 g/day), postpartum female weight (1394.0 ± 81.5 vs. 1161.4 ± 50.3 g), male weight (1479.8 ± 125.1 vs. 1287.6 ± 124.4), litter size (2.24 ± 0.45 vs. 1.89 ± 0.68), litter weight (415.1 ± 80.2 vs. 291.3 ± 37.8 g), weaning weight (350.5 ± 64.6 vs. 248.8 ± 29.9 g), weight gain at 60 days of rearing (9.59 ± 1.41 vs. 6.41 ± 0.69 g), and rearing time to commercial weight (60 vs. 105 days), respectively.The fibrous concentrate achieves better reproductive and productive performance than forage and may be a viable alternative for family-commercial breeding of guinea pigs in the Andes.

A cobaia criada nos Andes, tradicionalmente alimentadas com forragem, têm baixo desempenho produtivo e reprodutivo. O objetivo do estudo foi avaliar a alimentação com concentrado fibroso no desempenho reprodutivo e produtivo de cobaias. Uma amostra de 110 cobaias fêmeas (963,1 ± 127,3 g) e 22 cobaias machos (1209,9 ± 159,0 g) da raça Peru foi distribuída em 22 módulos de reprodução (1 macho/5 fêmeas), dos quais 11 módulos foram alimentados com forragem (controle) e 11 módulos com concentrado fibroso (experimental). Cada módulo era uma réplica. A forragem foi o feno de aveia integral, enquanto o concentrado fibroso foi uma mistura feita com feno picado da mesma aveia, milho-soja, suplemento vitamínico-mineral, sal comum e pré-mix. Ambos os grupos receberam as mesmas quantidades de alfafa fresca como fonte de vitamina C. Em seguida, foram utilizados 92 coelhos desmamados do grupo controle (248,8 ± 29,9 g) e 106 coelhos do grupo experimental (350,5 ± 64,6 g), resultantes da reprodução, alimentados com as mesmas dietas para avaliar seu desempenho produtivo. O grupo experimental superou o grupo controle em todas as variáveis (p < 0,05): consumo de matéria seca (81,2 ± 4,5 vs. 77,9 ± 1,0 g/dia), peso das fêmeas no pós-parto (1394,0± 81,5 vs. 1161,4 ± 50,3 g), peso do macho (1479,8 ± 125,1 vs. 1287,6 ± 124,4), tamanho da ninhada (2. 24 ± 0,45 vs. 1,89 ± 0,68), peso da ninhada (415,1 ± 80,2 vs. 291,3 ± 37,8 g), peso ao desmame (350,5 ± 64,6 vs. 248,8 ± 29,9 g), ganho de peso aos 60 dias de criação (9,59 ± 1,41 vs. 6,41 ± 0,69 g) e tempo de criação até peso comercial (60 vs. 105 dias), respetivamente. O concentrado fibroso alcança melhor desempenho reprodutivo e produtivo que a forragem, podendo ser uma alternativa viável para a criação familiar e comercial de porquinhos-da-índia nos Andes.

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This study aimed to develop and assess a deterministic mathematical model for predicting the impacts of varying sow replacement rates on the performance of farms producing weaned piglets. Initially, the influence of replacement rate on herd structure was examined using two equations, which accounted for the percentage of sows replaced (55, 45, and 35%), retention rates between parities (13, 9, and 5%), and number of last parities in the herd (6, 7, and 8). The model then estimated sow development throughout the reproductive cycle, starting with an initial weight of 140 kg at first mating and adjusting for weight gains during gestation and losses during lactation, influenced by the varying number of live-born piglets across parities. Energy requirements were calculated using the factorial method, which included maintenance, protein and fat gains, and milk production. The generated data formed various scenarios to derive productive values. These scenarios were analyzed using analysis of variance with the general linear model procedure, treating each scenario as a separate treatment. Early parities (up to P3) contributed 42% in SC-35, 51% in SC-45, and 60% in SC-55. Significant differences were noted in variables such as average parity, birth weight, feed intake during gestation, and average piglet weight gain. The developed model, incorporating replacement gilt modules, gestation, and lactation, can effectively predict herd structure by parity and assess the impact of annual sow replacement rates on the productivity of farms rearing weaned piglets.(AU)

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The objective of the study was to characterize differences in the time to onset of puberty and reproductive variables between East Friesian and Corriedale ewe lambs in an extensive pastoral system. The study was carried out for two consecutive years, and 73 pure-breed ewe lambs were evaluated (35 East Friesian and 38 Corriedale). Plasma progesterone was determined weekly between 4.5±0.5 and 7.2±0.5 months old. The time to onset of puberty was assumed when the progesterone levels were ≥0.6 ng/mL for at least three consecutive blood collections. Body weight and body condition score were also determined. The reproductive variables calculated were fertility (ewe lambs' pregnancy/ewe lambs mated), prolificacy (lambs born/ewe lambs' pregnancy), and fecundity (lambs born/ewe lambs mated). We found that 97.1% of East Friesian lambs and 44.7% of Corriedale reached puberty during the blood-sampling period, and there was no significant age difference between breeds. Average body weight at puberty was significantly higher for East Friesian than for Corriedale ewe lambs (44.2±0.8 and 40.6±0.9 kg, respectively). Fertility significantly differed between breeds (85.7 vs 34.2% East Friesian and Corriedale, respectively) and was not affected by year. Of the pregnant ewe lambs, 88.4% carried a single lamb. Prolificacy did not differ with the breed, year, or dam parity but was significantly higher for those lambs born as twins. Fecundity was significantly higher for East Friesian than for Corriedale lambs. Breeding Corriedale and East Friesian ewe lambs in their first year results in different reproductive outcomes.(AU)

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Reproductive control is one of the biggest challenges in tilapia production and triploidy was developed as an alternative to sterilization. In general, polyploids present chromosomal instability but for triploid Nile tilapia it has yet to be reported. This study evaluated the chromosomal instability from juveniles to adulthood, growth performance and gonadal status of tilapia hatched from eggs submitted or not to heat shock for triploid induction. Nile tilapia oocytes were fertilized (1,476 oocytes), half of the eggs were subjected to a four-minute shock in 41 °C water four minutes after fertilization and the other half were not (Control group). The eggs were incubated (at 27°C) and 160 larvae from the treated group hatched and survived after yolk sac absorption. The determination of ploidy was performed by flow cytometry at 85th (juveniles) and 301st (adults) days of age post yolk sac absorption. At the time of the first cytometry analysis there were 73 surviving juveniles from the treated group, and only 14 were confirmed triploid. However, at the analysis of adult ploidy, one out of 8 surviving adult tilapias from the 14 confirmed triploid juveniles remained triploid. Gonadal histology showed that the non-remaining triploids continued to produce gametes. The growth performance of triploid tilapia was initially superior to that of diploid tilapia during the juvenile phase, but similar in adults. Once the chromosome sets are lost and the tilapias become diploid again, at least in tissues with a high proliferation rate, such as the hematopoietic tissue that was analyzed (and possibly in gonads), all possible advantages of triploids are probably lost. Thus, our results suggest that, due to genomic instabilities, the triploid generation of tilapia has low efficiency.(AU)

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This study evaluated two surgical sterilization techniques in free-ranging female capybaras (n = 21). The first group underwent uterine horn ligature (HL; n = 11), while the second was subjected to partial salpingectomy (S; n = 10). We assessed total operative time, incision length, the ease of identifying reproductive structures, the adequacy of exposure for surgical performance through flank or midline approaches, and the extent of abdominal viscera manipulation for each method. The HL method emerged as faster, with an average operative time difference of 16 minutes. In the S group, a flank mini-laparotomy over the ovarian topography facilitated easy exposure of the ipsilateral ovary and uterine tube, enabling ligature and partial resection of the uterine tube but not the uterine horn exposure. However, accessing the contralateral uterine tube without a bilateral incision was impractical, thus prolonging the total operative time due to the need for patient repositioning and new antisepsis procedures. Conversely, a post-umbilical approach for the HL method necessitated only one mini-laparotomy incision, offering ample uterine exposure for hysterotomy in pregnant females. Both methods involved minimal abdominal viscera manipulation and resulted in no fatalities or postoperative complications. Although direct comparison is limited by the distinct sterilization techniques and surgical approaches, this study underscores the challenges and surgical access of each method. Our findings endorse the HL technique as an effective contraception method for female capybaras to prevent the birth of seronegative offspring that could amplify Rickettsia sp., the causative agent of Brazilian spotted fever.(AU)

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Goat breeding is an economic activity carried out in the rural areas of the Eastern Mediterranean region of Türkiye. The small ruminants breeding project carried out in extensive farmer conditions was a project which aimed to improve the quality and quantity of meat and milk yields of domestic goat breeds of Anatolia since 2015. The genetic improvement study of indigenous Hair goats was started in 2015 and ended in 2020, using 5985 does and 252 bucks, with the participation of 60 local volunteer farmers in the rural farming system of Eastern Anatolia of Türkiye. At the end of the study, it was found that the birth rate, twinning rate, prolificacy, litter size, and survival rate varied between, 81.88 to 98.18%, 5.26 to 13.54%, 103.00 to 111.00%, 1.11 to 1.27 and 92.67% to 99.06%, by years respectively. As a result of the breeding study, it was determined that the birth weight, weaning weight, and daily body weight gain of the offspring were increased from 2.60 to 3.07 kg, from 8.21 to 10.77 kg, and from 107.74 to 149.15 g, respectively. It was determined that the growth characteristics of kids differed significantly over the years (P < 0.001). As a result of this study, it was determined that production based on local gene resources with improved genetic capacity in rural areas is important for sustainability. Simple recording schemes for the objective assessment of performance traits and planned mating schemes will help enhance animals' production performances in traditional farming systems.

A criação de cabras é uma atividade econômica nas zonas rurais da região mediterrânica oriental da Anatólia, na Turquia. O projeto de criação de pequenos ruminantes em condições de exploração extensiva é um projeto destinado a melhorar a qualidade e a quantidade da produção de carne e leite das raças de cabras autóctones da Anatólia desde 2015. Um destes projetos, o melhoramento genético das cabras indígenas da Anatólia, teve início em 2015 e terminou em 2020, utilizando 5985 fêmeas e 252 machos, com a participação de 60 agricultores voluntários locais no sistema agrícola rural da Anatólia Oriental da Turquia. No final do estudo, observou-se que a taxa de natalidade por ano variou entre 81.88 e 98.18%, enquanto a taxa de gemelaridade foi entre 5.26 e 13.54%, a prolificidade foi entre 103.00 e 111.00%, o tamanho da ninhada foi entre 1.11 e 1.27 e a taxa de sobrevivência foi entre 92.67% e 99.06%. Além disso, observou-se que o peso ao nascer dos cabritos variou entre 2.60 kg e 3.07 kg, o peso ao desmame foi entre 8.21 kg e 10.77 kg e o ganho de peso vivo foi entre 107.74 e 149.15 g. As diferenças observadas por anos em termos de características de crescimento dos cabritos foram observadas como significativamente diferentes umas das outras (P < 0.001). No final deste estudo, concluiu-se que melhores estratégias de criação de raças locais, esquemas simples de registro para a avaliação objetiva de características de desempenho e esquemas de acasalamento planeados ajudarão a melhorar o desempenho da produção animal em sistemas agrícolas tradicionais.

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This study evaluated the productive and reproductive performances of Santa Inês sheep and their Dorper crossbreeds during the lactation period amidst the dry season in the semi-arid region of Paraíba, Brazil. Conducted at the experimental goat farm of the State University of Paraíba (UEPB), Campus IV, Catolé do Rocha, the investigation included a cohort of 24 ewes (12 Santa Inês and 12 Dorper crossbreeds [comprising 87.5% Dorper and 12.5% Santa Inês]) and 30 lambs (10 males and 20 females). Observations were recorded from birth and continued at 30-day intervals up to 90 days. Using a two-way ANOVA with a 2 x 2 factorial design (two genetic groups and two sexes), the study monitored both ewes and lambs. The animals adhered to traditional regional management, grazing in paddocks by day and secured in shelters by dusk. The study found that both Santa Inês and Dorper crossbred ewes produced similar quantities of milk (P=0.8310) for the first 60 days of lactation. There was no discernible effect of the ewes' genetic backgrounds on their live weights, body condition scores at lambing, throughout the subsequent 30, 60, and 90 days of lactation, or on the overall productive efficiency and total weight of weaned lambs per ewe. In contrast, Dorper lambs demonstrated a higher weaning weight (P=0.0349) and greater weight gain (P=0.0403). The study also noted that the sex of the lambs did not notably influence their performance within the first 90 days of suckling.

Objetivou-se avaliar o desempenho produtivo e reprodutivo de ovinos da raça Santa Inês e mestiços da raça Dorper criados em sistema tradicional de produção durante a fase de amamentação na época seca do ano no semiárido paraibano. O experimento foi conduzido no Setor de Caprinovinocultura da Universidade Estadual da Paraíba/UEPB/Campus-IV, Catolé do Rocha/PB. Foram utilizadas 24 ovelhas multíparas, sendo 12 da raça Santa Inês e 12 mestiças da raça Dorper (87,5% Dorper + 12,5% Santa Inês) paridas com 30 ovinos jovens, sendo 10 machos e 20 fêmeas. O período experimental se iniciou no momento do parto e os dados foram coletados ao nascimento, aos 30, 60 e 90 dias de idade. Foi utilizada análise de variância para as ovelhas e para os cordeiros esquema fatorial 2 x 2 (dois grupos genéticos e dois sexos). Os cordeiros permaneceram com suas mães em piquetes durante o dia e à noite no aprisco, manejo tradicional da região. As ovelhas Santa Inês e mestiças Dorper produziram quantidades de leite semelhantes (P=0,8310) até os 60 dias de lactação. O grupo genético das ovelhas não influenciou os pesos vivos e escore de corporal ao parto, 30, 60 e 90 dias de lactação, como também a eficiência produtiva e peso total de crias desmamadas por ovelha. Os cordeiros e cordeiras Dorper apresentaram maiores pesos vivos (P=0,0349) e ganhos de peso (P=0,0403), por outro lado, o sexo dos ovinos jovens não influenciou o desempenho até os 90 dias de amamentação.

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When applied at growing phase, lighting program aims to obtain quails with body weight and physiological maturity suitable for the beginning of laying. This study evaluated lighting programs at growing phase on performance, sexual maturity and egg quality of meat quail breeders (Coturnixcoturnix) at laying phase. From 7 to 49 days of age, 300 female meat quails were subjected to three lighting programs (natural, intermittent and continuous), with 5 replicates of 20 birds each. At 49 days of age, 240 quails were transferred to a shed, maintaining the same experimental conditions. Meat quails submitted to continuous and intermittent lighting programs had higher weight of reproductive system and lower ages for first egg production and to reach 50% of egg production (P < 0.05). Quails submitted to natural lighting had lower feed intake from 49 to 70 and 71 to 92 days of age and worse feed conversion up to 114 days of age. Continuous and intermittent lighting programs resulted in more precocious quails compared to natural lighting program. Quails submitted to natural lighting at growing phase presented lower egg production during all periods, not differing for birds submitted to continuous and intermittent programs from the second period (71 to 92 days of age). Intermittent and continuous lighting result in better feed conversion of breeding quails up to 114 days and a higher percentage of laying (49 to 136 days), reducing the number of days to produce the first egg and to reach 50% of laying, in relation to natural lighting.

Quando aplicado na fase de crescimento, o programa de luz visa obter codornas com peso corporal e maturidade fisiológica adequados para o início da postura. Este estudo avaliou programas de iluminação na fase de crescimento sobre o desempenho, maturidade sexual e qualidade dos ovos de codornas de corte reprodutoras (Coturnix coturnix) na fase de postura. Durante o período de sete a 49 dias de idade, 300 codornas de corte fêmeas foram submetidas a três programas de iluminação (natural, intermitente e contínuo), com cinco repetições de 20 aves cada. Aos 49 dias de idade, 240 codornas foram transferidas para um galpão, mantendo a mesma distribuição experimental e submetidas às mesmas condições. As aves submetidas aos programas de iluminação contínuo e intermitente na fase de crescimento apresentaram maiores peso relativo do sistema reprodutivo e consequentemente menores idades para produção do primeiro ovo e para atingir 50% da produção de ovos (P < 0.05). As aves que receberam apenas iluminação natural apresentaram menor consumo de ração nos períodos de 49 a 70 e 71 a 92 dias de idade e pior conversão alimentar até 114 dias de idade. Os programas de iluminação contínua e intermitente na fase de crescimento resultaram em codornas mais precoces quando comparados as aves submetidas ao programa de iluminação natural. Codornas submetidas a programa de luz natural na fase de crescimento apresentaram menor produção de ovos durante todos os períodos, não diferindo das aves submetidas a programas contínuos e intermitentes a partir do segundo período (71 a 92 dias de idade). A iluminação intermitente e contínua na fase de crescimento resulta em melhor conversão alimentar de codornas reprodutoras até 114 dias e maior percentual de postura (49 a 136 dias), reduzindo o número de dias para produzir o primeiro ovo e atingir 50% de postura, em relação a iluminação natural.

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This observational study describes the short- and long-term effects of maternal factors in 226 Holstein heifers and their offspring. We obtained maternal data and information from the dairy register. Young heifers were assessed in the window of 60 to 105 days of life to perform the Calf Health Scoring System and performance index, and blood samples to measure inflammatory biomarkers. Prospective data on reproduction were obtained from dairy farm registers. The eutocic weight was higher than the dystocic calving heifers. Plasma total protein and weight were higher in the offspring of multiparous dams than in those of primiparous dams. Calves that were born lighter and in summer had lower concentrations of total protein and performance indices. The punctuation of the fecal score was higher in calves born in summer and cold months for BRD. Offspring from multiparous dams born at term exhibited greater precocity in terms of age at first artificial insemination and first parturition. Finally, seasonality at birth affected pregnancy loss and age at first calving. Heifers born in winter had lower rates of pregnancy loss than those born in summer. In addition, these animals were more precocious than animals born during the cold seasons.

Este estudo observacional descreve os efeitos de curto e longo prazo de fatores maternos em 226 novilhas Holandesas e suas proles. Foram obtidos dados maternos e informações do registro leiteiro. Novilhas jovens foram avaliadas, na janela de 60 a 105 dias de vida, com o escore de saúde, índice de desempenho e amostras de sangue para medir biomarcadores inflamatórios. Dados prospectivos sobre reprodução foram obtidos dos registros da fazenda. O peso das novilhas eutócicas foi superior ao das novilhas que nasceram de parto distócico. A proteína total plasmática e o peso foram maiores nas proles de vacas multíparas do que nas proles das primíparas. Bezerras que nasceram mais leves e no verão apresentaram menores concentrações de proteína total e índices de desempenho. A pontuação do escore fecal foi maior em bezerras nascidas no verão e nos meses frios para DRB. A prole de vacas multíparas nascidas a termo apresentou maior precocidade em relação à idade à primeira inseminação artificial e ao primeiro parto. Finalmente, a sazonalidade ao nascimento afetou a perda de prenhez e a idade ao primeiro parto. As novilhas nascidas no inverno tiveram menores taxas de perda de gestação do que as nascidas no verão. Além disso, esses animais eram mais precoces do que os nascidos nas estações frias.

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Abstract Livestock is a fundamental part of the agriculture industry in Pakistan and contributes more than 11.53% to GDP. Among livestock species, the buffaloes are regarded as the black gold of Pakistan. Being the highest milk producers globally, Nili-Ravi buffaloes are the most famous ones. Buffaloes are affected by many endemic diseases, and "Hemorrhagic septicemia" (HS) is one of them. This study was designed to ascertain the effects of experimental exposure ofP. multocida B:2 (oral) and its immunogens, i.e., LPS (oral and intravenous) and OMP (oral and subcutaneous) on reproductive hormonal profiles in Nili-Ravi buffaloes. Repeated serum samples were collected from the jugular vein of experimental animals for 21 days (0, 02, 04, 08, 12, 16, 20, 24, 36, 48, 72, 120, 168, 216, 264, 360, 456 and 504 hours). Hormonal assays to determine the serum concentrations of Gonadotropin-releasing hormone (GnRH), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Estrogen (E2) and progesterone (P4) were performed using (MyBioSource) commercial Elisa kits. The hormonal profile of all treatment groups of the buffalo heifers exhibited significant (P<0.05) variations as compared to the control group (G-1). These results indicate suppression in Nili-Ravi buffaloes' reproductive hormonal profile on exposure to P. multocida B:2 and its immunogens. This influence warrants that exposure to H.S may be a possible reason for delayed puberty and poor reproduction performance in Nili-Ravi buffaloes.

Resumo A pecuária é uma parte fundamental da indústria agrícola no Paquistão e contribui com 11,53% do PIB nacional. Entre as espécies de gado, os búfalos são considerados o ouro negro do Paquistão. Sendo os maiores produtores de leite em todo o mundo, os búfalos Nili-Ravi são os mais famosos. Os búfalos são afetados por muitas doenças endêmicas, entre as quais a "septicemia hemorrágica" (SH). Este estudo busca verificar os efeitos da exposição experimental de P. multocida B:2 (oral) e seus imunógenos, ou seja, LPS (oral e intravenoso) e OMP (oral e subcutâneo), nos perfis hormonais reprodutivos em búfalos Nili-Ravi. Amostras de soro repetidas foram coletadas da veia jugular de animais experimentais por 21 dias (0, 2, 4, 8, 12, 16, 20, 24, 36, 48, 72, 120, 168, 216, 264, 360, 456 e 504 horas). Os ensaios hormonais para determinar as concentrações séricas do hormônio liberador de gonadotrofina (GnRH), hormônio foliculoestimulante (FSH), hormônio luteinizante (LH), estrogênio (E2) e progesterona (P4) foram realizados usando kits comerciais Elisa (MyBioSource). O perfil hormonal de todos os grupos de tratamento das novilhas bubalinas apresentou variações significativas (P < 0,05) em relação ao grupo controle (G-1). Esses resultados indicam supressão no perfil hormonal reprodutivo de búfalos Nili-Ravi na exposição a P. multocida B:2 e seus imunógenos. Essa influência garante que a exposição à SH possa ser uma possível razão para o atraso da puberdade e o baixo desempenho reprodutivo em búfalos Nili-Ravi.

Resumo

The aim was to identify predictive traits of relatively easy measurement and which can be recorded early in life (age at first conception - AFCo), besides estimating its genetic correlations with growth and carcass traits in Nellore cattle. Age at first conception was considered the age at which the female had the first positive diagnosis for pregnancy. The estimation of (co)variance components and genetic parameters was performed using a linear animal model in two-trait analysis. The estimates of heritability were moderate, enabling genetic selection for growth-, carcass-, and sexual precocityrelated traits. The genetic correlation obtained between AFCo and age at first calving (AFCa) was high (0.88), indicating the feasibility of using AFCo as a selection criterion for early calving heifers. Genetic correlation estimates between AFCo and AFCa with weight at 120, 210, 365, and 450 days of age and carcass traits were moderate and negative (-0.33 to -0.62). Thus, genetic selection for animals with early AFCo and AFCa would enhance carcass yield, fat deposition, and growth performance, despite not affecting birth weight or daily weight gain. The results of this study encourage the use of AFCo in Nellore cattle since this trait displayed enough genetic variability in Nellore cattle, and can be used as selection criteria to improve sexual precocity. When the objective of genetic selection is to increase heifer sexual precocity, we could use the first trait as a criterion, as the measurement of this trait occurs at a lower AFCa.

Objetivou-se identificar características indicadoras de precocidade sexual de fácil mensuração e que podem ser registradas em menor idade (idade à primeira concepção - IPC), além de estimar as correlações genéticas dessa característica com aquelas de crescimento e carcaça em bovinos Nelore. A IPC foi considerada a idade em que a fêmea apresentou o primeiro diagnóstico positivo de prenhez. A estimativa dos componentes de (co)variância e dos parâmetros genéticos foi realizada usando modelo animal linear em análises bicaracterísticas. As estimativas de herdabilidade foram moderadas, indicando viabilidade de seleção genética para características de crescimento, carcaça e precocidade sexual. As correlações genéticas obtidas entre o IPC e a idade ao primeiro parto (IPP) foram altas (0,88), indicando a viabilidade do uso de IPC como critério de seleção para parto em idade precoce de novilhas. As estimativas de correlações genéticas entre IPC e IPP com peso aos 120, 210, 365 e 450 dias de idade e características de carcaça foram moderadas e negativas (-0,33 a -0,62). Assim, a seleção genética para animais com IPC e IPP precoces aumentaria o rendimento de carcaça, a deposição de gordura e o peso corporal, embora não afete o peso ao nascer e o ganho de peso diário. Os resultados deste estudo encorajam o uso de IPC em bovinos Nelore, uma vez que esta característica apresentou variabilidade genética em bovinos Nelore, podendo ser utilizada como critério de seleção para melhorar a precocidade sexual. Quando o objetivo de seleção genética é aumentar a precocidade sexual das novilhas, indica-se o uso de IPC como critério, pois a mensuração desta característica ocorre em idade menor IPP.

Resumo

As a positional and geometrical isomer of linoleic acid, trans 10, cis 12 conjugated linoleic acid (t10c12-CLA) reduces white fat by reducing food intake, modulating lipid metabolism, and stimulating energy expenditure. However, the t10c12-CLA products are mostly mixtures, making it difficult to obtain accurate results. Studies are needed to investigate the effects of pure t10c12-CLA on animals and humans. In this study, we used the biallelic transgenic (tg) mice, which could produce t10c12-CLA itself, to investigate the effects of pure t10c12-CLA on female reproductive ability. The results showed that the body and relative ovary weights had no significant difference between tg and wild-type (wt) littermates at ages 3 or 10 weeks. While the fecundity test found that tg mice had a significantly longer first litter time (32.0 ± 4.70 days vs. 21.3 ± 2.31 days, P<0.05), and a significantly lower number of litters (4.75 ± 2.75 vs. 6.67 ± 0.57, P<0.05) when compared with wt mice during continuous mating within seven months. Hormone profiles showed that serum estradiol levels did not change in tg mice; however, significantly (P<0.05) decreased progesterone and increased prostaglandin E2 levels were observed in tg mice compared with those of wt mice. Hematoxylin-eosin staining showed no pathological characteristics in tg ovaries, except for the increased atresia follicles (P<0.05). Moreover, the tg mice had a significantly more extended diestrus period than the wt mice (48.4 ± 6.38% vs. 39.6 ± 3.81%, P<0.05). In summary, t10c12-CLA could affect serum progesterone and prostaglandin E2 levels, lead to a disordered estrus cycle, and impact the reproductive performance of female mice. This study provided theoretical and biosafety recommendations for applying t10c12-CLA in female mammals.(AU)

Resumo

Abstract Livestock is a fundamental part of the agriculture industry in Pakistan and contributes more than 11.53% to GDP. Among livestock species, the buffaloes are regarded as the black gold of Pakistan. Being the highest milk producers globally, Nili-Ravi buffaloes are the most famous ones. Buffaloes are affected by many endemic diseases, and "Hemorrhagic septicemia" (HS) is one of them. This study was designed to ascertain the effects of experimental exposure ofP. multocida B:2 (oral) and its immunogens, i.e., LPS (oral and intravenous) and OMP (oral and subcutaneous) on reproductive hormonal profiles in Nili-Ravi buffaloes. Repeated serum samples were collected from the jugular vein of experimental animals for 21 days (0, 02, 04, 08, 12, 16, 20, 24, 36, 48, 72, 120, 168, 216, 264, 360, 456 and 504 hours). Hormonal assays to determine the serum concentrations of Gonadotropin-releasing hormone (GnRH), Follicle-stimulating hormone (FSH), Luteinizing hormone (LH), Estrogen (E2) and progesterone (P4) were performed using (MyBioSource) commercial Elisa kits. The hormonal profile of all treatment groups of the buffalo heifers exhibited significant (P 0.05) variations as compared to the control group (G-1). These results indicate suppression in Nili-Ravi buffaloes' reproductive hormonal profile on exposure to P. multocida B:2 and its immunogens. This influence warrants that exposure to H.S may be a possible reason for delayed puberty and poor reproduction performance in Nili-Ravi buffaloes.

Resumo A pecuária é uma parte fundamental da indústria agrícola no Paquistão e contribui com 11,53% do PIB nacional. Entre as espécies de gado, os búfalos são considerados o ouro negro do Paquistão. Sendo os maiores produtores de leite em todo o mundo, os búfalos Nili-Ravi são os mais famosos. Os búfalos são afetados por muitas doenças endêmicas, entre as quais a septicemia hemorrágica (SH). Este estudo busca verificar os efeitos da exposição experimental de P. multocida B:2 (oral) e seus imunógenos, ou seja, LPS (oral e intravenoso) e OMP (oral e subcutâneo), nos perfis hormonais reprodutivos em búfalos Nili-Ravi. Amostras de soro repetidas foram coletadas da veia jugular de animais experimentais por 21 dias (0, 2, 4, 8, 12, 16, 20, 24, 36, 48, 72, 120, 168, 216, 264, 360, 456 e 504 horas). Os ensaios hormonais para determinar as concentrações séricas do hormônio liberador de gonadotrofina (GnRH), hormônio foliculoestimulante (FSH), hormônio luteinizante (LH), estrogênio (E2) e progesterona (P4) foram realizados usando kits comerciais Elisa (MyBioSource). O perfil hormonal de todos os grupos de tratamento das novilhas bubalinas apresentou variações significativas (P 0,05) em relação ao grupo controle (G-1). Esses resultados indicam supressão no perfil hormonal reprodutivo de búfalos Nili-Ravi na exposição a P. multocida B:2 e seus imunógenos. Essa influência garante que a exposição à SH possa ser uma possível razão para o atraso da puberdade e o baixo desempenho reprodutivo em búfalos Nili-Ravi.

Resumo

This study aimed to evaluate the productive and reproductive performance and the nutritional metabolic condition of ewes supplemented at different stages of gestation in a synchronized reproduction system. Fourty Santa Inês × Dorper crossbreed ewes, pregnant with an average age of ten months and two previous births, were distributed in a completely randomized design, with four treatments: mineral salt, supplementation started 20 days before the estrus synchronization (ES) protocol, supplementation from confirmation of pregnancy (60 days after ES), and supplementation in the final third of gestation (90 days after ES). The adoption of supplementation strategies during the beginning, middle, or end of pregnancy changed the intake and digestibility of dry matter (g/day), with a reduction of 10.53 and 9.14%, respectively, for the mineral salt treatment, in addition to organic matter, crude protein, neutral detergent fiber, acid detergent fiber, non-fibrous carbohydrates, ether extract, and total digestible nutrients, as well as protein, energy, and mineral profiles. There was no difference in the number of ovulations and reproductive and productive performance using supplementation alternatives. Supplementation strategies during the gestation stages influence the intake and digestibility of nutrients, as well as the animal metabolic profiles. However, it does not change reproductive and productive performance.(AU)

Resumo

The female reproductive function is coordinated by the endocrine system driven by the hypothalamic-pituitary-gonadal (HPG) axis. While not directly part of the female reproductive system, the gut microbiome plays a crucial role in overall health, including reproductive health. The gut microbiome communicates bidirectionally with the brain via the gut-brain axis, influencing stress levels, mood, and hormonal balance, which can impact reproductive health and fertility. In addition to that, the vaginal and uterine microbiome are directly involved with the reproductive success of farm animals, including female fertility and offspring development. In this paper, we summarize some of the effects of bacterial contamination in the female reproductive tract and their association with reproductive performance in farm animals.(AU)

Resumo

Treating lactating sows with chorionic gonadotropins may allow controlling their post-weaning reproductive function, despite the occurrence of anestrous during lactation. This article reviews the potential effectiveness of treatment with both equine and human chorionic gonadotropins (eCG and hCG, respectively) during lactation on the control of estrus expression and ovulation in weaned sows. The use of 1,000 IU hCG at 24 and 48 h postpartum may induce ovulation in the treated sows, but the ovulation rate may be variable. Pregnancy rates may be improved with combined treatment after the second week of lactation with both chorionic gonadotropins: 1,500 IU eCG plus 500 - 1,000 hCG; or 1,000 IU eCG plus 1,000 IU hCG. Treatment with eCG (1,000 - 2,000 IU) at the end of lactation may result in acceptable estrus expression and ovulation rates, although with marginal benefit for pregnancy rates. The subsequent response to treatments with chorionic gonadotropins during lactation is likely influenced by the treatment period, the suckling frequency during lactation, and the boar exposure during the weaning-to-estrus interval. A better understanding of the efficiency of such steroid-free treatments is increasingly relevant due to the constraints of the use of steroid hormones in livestock reproductive management.(AU)

Resumo

This review elucidates the physiological and endocrinological processes intrinsic to puberty and ovulation induction protocols in Bos indicus and Bos taurus beef heifers. Puberty is a complex physiological event involving gonadotropic and metabolic changes that lead to sexual maturity, first ovulation, and regular reproductive cycles, enabling females to reproduce. Exposure to progesterone-based hormonal protocols, with or without additional hormones, can reduce the age at first ovulation and improve sexual maturity through stimuli in the hypothalamus-pituitary-gonadal (HPG) axis and uterine development. However, inducing puberty differs from inducing ovulation, as it does not ensure the heifer will continue cycling or be ready to establish and maintain pregnancy after hormonal exposure. Regardless of the pharmacological basis, studies consistently report that beef heifers that had a corpus luteum (CL) prior to the timed-artificial insemination (TAI) protocol, have greater expression of estrus in response to synchronization and greater pregnancy per AI compared to heifers without a CL. The combination of P4 and E2 significantly impacts uterine development, increasing reproductive efficiency. Exposure to P4 causes a positive effect on inducing ovulation. However, studies indicate that the addition of E2 esters at the time of P4 device removal increases the ovulation rate. In general, the studies showed that fertility varied according to the type of the ovulation induction protocol used, but with inconsistent results. Although ovulation induction protocols are strategic tools to accelerate sexual maturity, a holistic view of the entire system is extremely important, combining integration with genetics and nutrition to enhance the reproductive outcomes of beef heifers. Future research is needed to understand and refine these protocols, driving the efficiency of beef cattle production systems.(AU)

Resumo

The objective of this study was to evaluate the effect of palm kernel cake and ram effect on reproductive activity of postpartum and lactating ewes. Twentymultiparous ewes,five to eleven days postpartum,were separated into four different treatments: control, control-ram, palm and palm-ram. Body weight, difference in body weight recorded between days 0 and 42 of the experiment, diameter of the largest follicle at day zero of the study, number of ewes bearing a corpus luteum and pregnancy rate were measured in ewes. Average daily weight gain was measured in lambs. There was no effect (p≥0.05) of palm kernel supplementation, ram stimulation, or their interactions on the weights of ewes and lambs. A greater number of ewes with corpus luteum (p<0.05) were observed in ewes stimulated by rams than those not stimulated. The number of pregnant ewes was not affected by ram effect or palm kernel supplementation (p≥0.05). In conclusion, the use of the ram effect increases the incidence of corpus luteum in postpartum and lactating ewes. In addition, palm kernel cake in the diet doesnot affect body weight of postpartum ewes and lambs.(AU)