Ingestive behavior of Holstein × Zebu cows managed on deferred supplemented pasture

This study aimed to evaluate the ingestive behavior of F1 Holstein × Zebu cows grazing on deferred pasture receiving different supplementation strategies. The experimental design was completely randomized, in a 3×4 factorial, with three supplementation strategies and four evaluation periods. The ingestive behavior of 24 cows divided into three groups of supplementation provided at milking was observed, and two of these groups received protein in the pasture. Ingestive behavior was monitored every 10 minutes for 24 hours and analyzed in the form of periods (morning, afternoon, night, and dawn) and total time. The animals remained longer grazing during the afternoon when the BGHI presented values of 83.8. Protein consumption did not influence grazing time but interfered with forage consumption. For the total grazing time, the animals in group 2 spent less time grazing. The groups of animals presented no difference concerning the time spent on rumination and idleness. During night and dawn, when the climate was characterized as thermal comfort, the animals spent more time ruminating. The climatic conditions did not influence the ingestive behavior, as the grazing peak was observed at times of higher BGHI. However, supplementation of the animals in group 2 modified the ingestive behavior of F1 H × Z cows.

Effect of solar radiation on Holstein heifers' physiological variables and grazing behavior

The objective was to assess the physiological and behavioral variables of pasture-raised Holstein heifers on the basis of their coat color. Eight heifers were used, four with black coat, and four with white coat. In the morning and afternoon periods, their physiological variables were measured, namely respiratory rate (RR, mov min. -1), rectal temperature (TR, ºC), and coat surface temperature (TS, ºC). The behavior analysis considered the site (sun or shade), position (standing or lying down), and activities (idleness, rumination, grazing, and others). The data of the physiological variables were assessed through analysis of variance, and significance, through Tukey's test at 5%, while behavioral data were assessed using the Chi-squared test (SAS Software). There was a difference for all of the heifers' physiological variables as a function of coat color (p < 0.0001) and period (p < 0.0001), with black ones showing greater results than white ones as to all physiological variables in the afternoon period (p < 0.0001). Grazing behavior is reduced during the hottest hours of the day. We conclude that solar radiation changes the physiological variables and grazing behavior of pasture-raised Holstein heifers.(AU)

Geographical distribution of zebu breeds and their relationship with environmental variables and the human development index

The environment is vital to the agricultural sector since it can cause adversities throughout the entire productive chain. This study evaluated the geographical distribution of zebu breeds in Brazil and correlated their occurrence with environmental variables and the human development index. Herds of purebred zebu cattle (Bos indicus) in Brazil were classified as beef, dairy, and dual-purpose breeds, and all breeds were spatialized in the ArcGIS program. Environmental (precipitation, temperature, relative humidity index) and the human development index (HDI) were examined. We conducted regression and logistic analyses. Zebu cattle showed a lower distribution in the Northeastern states compared to other locations, possibly due to harsh weather conditions, namely long periods of high temperatures and lower precipitation, directly affecting local livestock. Beef breeds were evenly spread throughout the country in regions influenced by environmental variables of higher precipitation, normalized difference vegetation index (NDVI), temperature, relative humidity (RH), and temperature humidity index (THI), as well as properties without smallholder farmers and rivers and streams with riparian vegetation. The regions for dual-purpose and dairy breeds were predominantly cultivated with cutting forages (e.g., sugarcane - Saccharum officinarum), with the integration of crops, livestock and/or forestry (i.e., combining different activities in the same area) and areas with a rotational grazing system (i.e., grazing management), indicating a higher occupation in fertile lands. The Gir breed, the only dairy breed evaluated in this study, was seen in establishments with smallholder farmers, characterized by small to medium farms, and in regions at higher altitudes.

Anthelmintic resistance against gastrointestinal nematodes in beef cattle: effect on liveweight gain of grazing livestock in Mexico / Resistência anti-helmíntica em nematódeos gastrointestinais de bovinos de corte em uma região tropical: efeito no ganho de peso vivo do gado de pasto no México

This study aimed to determine the efficacy and parasite resistance of levamisole (LV) and ivermectin (IVM) in beef cattle naturally infected with gastrointestinal nematodes, as well as the effect on the liveweight gain in a tropical wet region of Oaxaca, Mexico. From November 2019 to January 2020, sixty-six grazing calves were randomly allocated into three groups of twenty-two animals each, treated with LV or IVM or an untreated control group (day 0). Feces were collected 1 day before treatment and 15 days after treatment. The liveweight gain from each animal was recorded at days 0, 15, 30 and 45 post treatment. The LV group presented the highest reduction of eggs per gram (EPG) of feces, followed by the IVM group. Resistance to IVM was detected, although LV resistance was also suspected. The IVM group had significantly higher effective treatment at 93.5%, resulting in an increase (P<0.05) of liveweight gain of 16.1kg, followed by the LV group (92.4%) with 17.1kg, compared to the untreated control group. A significant (P < 0.05) negative correlation was observed between EPG and weight gain for the LV (r = -0.46) and IVM groups (r = -0.32). LV and IVM showed a lack of efficacy against gastrointestinal nematodes, as well as an adequate capacity for EPG reduction but with IVM resistance and detrimental effects on growth performance in grazing beef cattle.

Os nematódeos gastrointestinais do gado de pastoreio causam perdas econômicas substanciais em todo o mundo. Este estudo teve como objetivo determinar a eficácia e a resistência parasitária do levamisol (LV) e da ivermectina (IVM) em bovinos de corte naturalmente infectados com nematódeos gastrointestinais, bem como o efeito no ganho de peso vivo, em uma região tropical úmida de Oaxaca, México. De novembro de 2019 a janeiro de 2020, 66 bezerros de pasto foram distribuídos aleatoriamente em três grupos de 22 animais cada um, tratados com LV ou IVM, ou em um grupo controle sem tratamento (dia 0). As fezes foram coletadas 1 dia antes do tratamento e 15 dias após o tratamento. O ganho de peso vivo de cada animal foi registrado nos dias 0, 15, 30 e 45 pós-tratamento. O grupo do LV apresentou a maior redução de ovos por grama de fezes (EPG), seguido pelo grupo IVM. A resistência à IVM foi detectada, embora também se suspeitasse de resistência ao LV. O grupo IVM teve um tratamento eficaz significativamente maior, com 93,5%, resultando em um aumento (P < 0,05) do ganho de peso vivo de 16,1kg, seguido pelo grupo LV (92,4%), com 17,1kg, em comparação com o grupo controle sem tratamento. Foi observada uma correlação negativa (P < 0,05) entre o EPG e o ganho de peso para os grupos LV (r = -0,46) e IVM (r = -0,32). LV e IVM mostraram falta de eficácia contra nematódeos gastrointestinais, assim como uma capacidade adequada de redução de EPG, mas com resistência IVM e efeitos prejudiciais no desempenho de crescimento em gado de corte em pastagem.

Energy supplements for beef heifers on cool season pastures: a database analysis / Uso de suplemento energético para novilhas de corte em pastagens de estação fria: análise de banco de dados

Pooled data analysis is an analytical method that combines results from multiple studies. This technique provides a more robust estimate of the effects of an investigation. We performed a database analysis from seventeen experiments developed at Federal University of Santa Maria, Rio Grande do Sul state, Brazil, between 1999 and 2017 to characterize individual performance per area and stocking rate with or without supplementation of replacement heifers grazing winter pastures. Data were separated into two groups: with and without energy supplement provision, and into five subgroups based on supplement levels. Heifers from both groups were maintained under similar forage biomass and leaf blade allowance. Statistical analyses were run on R software using a 'meta' package. Supplement supply increased average daily gain and gain of body condition scores by 11.1% and 20.0%, respectively. Supplement levels higher than 1.2% of body weight resulted in higher weight gain per area, with the stocking rate increasing with higher supplement levels.

Análise conjunta de dados é um método analítico que integra os resultados de muitos estudos. Essa técnica fornece uma estimativa mais robusta sobre os efeitos de uma investigação. Com o objetivo de caracterizar o desempenho individual, por área e a taxa de lotação com uso ou não de suplementos para novilhas de reposição mantidas em pastagem de inverno, foi realizada uma análise de banco de dados de dezessete experimentos conduzidos na Universidade Federal de Santa Maria (UFSM), RS, Brasil, entre 1999 e 2017. Os dados foram estratificados em dois grupos: com e sem suplemento energético e cinco subgrupos de acordo com o nível de suplemento. As novilhas de ambos os grupos foram mantidas em similar massa de forragem e oferta de lâminas foliares. As análises estatísticas foram executadas no software R, pacote 'meta'. O fornecimento de suplemento aumentou o ganho médio diário em 11.1% e em 20.0% o ganho no escore de condição corporal. Níveis de fornecimento maiores que 1.2% do peso corporal proporcionaram o maior ganho de peso por área e a taxa de lotação aumenta à medida que os níveis de suplemento aumentam.

Association of additives in supplemented grazing cattle during the finishing phase at the rainy season

The objectives were to evaluate the effects of monensin and virginiamycin, alone or combined, on supplemented Nellore cattle grazing tropical grass during the rainy season. Two experiments were conducted simultaneously to evaluate intake, digestibility, CH4 emissions, blood parameters, performance, and carcass characteristics (Exp. 1), and ruminal fermentation and relative abundance of ruminal microorganisms (Exp. 2). Animals (n = 92 Exp. 1 and n = 12 Exp. 2) were distributed in a completely randomized design and allocated in twelve paddocks composed of Urochloa brizantha (A. Rich.) Stapf. cv. Xaraés. A protein-energetic supplementation of 3 g/kg of BW per day was provided to all animals. Supplements were: without additives (WA), monensin alone at 80 mg/kg of product (MN), virginiamycin alone at 150 mg/kg of product (VM), and monensin (80 mg/kg of product) combined with virginiamycin (150 mg/kg of product; MNVM). Treatments did not affect intakes of total dry matter (DM), supplement DM, and nutrients. However, the intakes of forage DM and crude protein decreased in cattle fed MNVM compared with animals fed WA, MN, and VM. Total volatile fatty acids increased in animals fed VM. Ruminal NH3-N decreased, and pH increased in animals fed MN, VM, and MNVM. Relative abundance of total F. succinogenes and S. ruminantium decreased and R. flavefaciens increased in animals fed MN and VM at d 118. Treatments had no effect on enteric CH4 emissions. The average daily gain (ADG) and total gain were greater in cattle fed MNVM than in cattle fed MN. Combination of monensin and virginiamycin altered the rumen microbial populations but did not decrease enteric CH4 emissions. However, it decreased forage dry matter intake without altering the ADG and total weight gain, leading to an increase in feed efficiency. Results from this study indicate an advantage in including feed additives combined in the diet of supplemented Nellore cattle grazing tropical grass during the rainy season.

Influence of irrigation and supplementation on performance and ingestive behavior of beef cattle on mixed grass pastures

The purpose of this study was to evaluate the performance of beef cattle with two levels of energy-protein supplementation of low-consumption on African Bermudagrass pasture, overseeded in winter with oat and ryegrass, with or without irrigation. Twenty-four castrated Angus steers (11 months old and had an initial average of 220 kg body weight (BW)) were used in experimental area of 3.6 ha. The experiment was completely randomized in a 2×2 factorial design, with three replicates. The evaluation period was 249 days (July/2019 to March/2020). The treatments were: irrigated pasture with supplementation of 1 g/kg BW or 2.7 g/kg BW and non-irrigated pasture with 1 g/kg BW of supplement or 2.7 g/kg BW. The grazing method was continuous with a variable stocking rate. Irrigation provided pastures with better chemical composition in winter and spring. Irrigation increased the daily accumulation rate in winter (84.6 vs. 45.9 kg DM/ha/day), providing a greater stocking rate (1,702 vs. 1,385 kg/ha) and, consequently, body weight gain per hectare. Supplementation of 2.7 g/kg BW provided a greater stocking rate in winter (1,652 vs. 1,435 kg/ha) and spring (3,096 vs. 2,811 kg/ha), not changing in summer. The association of irrigation and supplementation of 2.7 vs. 1.0 g/kg BW improves the intake pattern by the animal in summer without changing productivity parameters. Irrigation increases productivity and the nutritional value of pasture with higher livestock production per area in periods of water deficit. The supply of 2.7 vs. 1.0 g/kg BW provides a greater stocking rate and body weight gain per hectare.(AU)

Strategic grazing management decreases nitrogen excretion intensity of dairy cows

ABSTRACT: There is limited information regarding both nitrogen (N) and energy partitioning of dairy cows grazing wellmanaged tropical pastures. The objective of this study was to investigate the N and energy partitioning of midlactation dairy cows on rotationally grazed elephant grass using two pregrazing targets: 95 % or maximum canopy light interception (LI95% or LIMax) during regrowth. The study used 26 Holstein × Jersey dairy cows arranged in a randomized complete block design with three 40day periods of sampling. Grazing at LI95% increased organic matter and crude protein intake by 20 % (p 0.05) which resulted in a 9 % increase in fat corrected milk yield (p 0.05) relative to LIMax. Cows grazing at LI95% had greater concentration of total volatile fatty acids, butyrate and valerate (p 0.05), and smaller acetate (p 0.05) than those grazing at LIMax. Intake of net energy for lactation (NEL) and NEL secreted in milk were greater (p 0.05), while partitioning of NEL towards maintenance tended to be greater (p = 0.07) for cows grazing at LI95% than those grazing at LIMax. Milk urea nitrogen and both urine and fecal N excretion were greater for cows grazing at LI95% (p 0.05), but N excretion intensity was lower than in cows grazing at LIMax (p 0.05). Strategic grazing management using the LI95% pregrazing target increases N losses through both urine and feces; however, it reduces N excretion intensity of dairy cows by 9 %.

Strategic grazing management decreases nitrogen excretion intensity of dairy cows

There is limited information regarding both nitrogen (N) and energy partitioning of dairy cows grazing well–managed tropical pastures. The objective of this study was to investigate the N and energy partitioning of mid–lactation dairy cows on rotationally grazed elephant grass using two pre–grazing targets: 95 % or maximum canopy light interception (LI95% or LIMax) during regrowth. The study used 26 Holstein × Jersey dairy cows arranged in a randomized complete block design with three 40–day periods of sampling. Grazing at LI95% increased organic matter and crude protein intake by 20 % (p ≤ 0.05) which resulted in a 9 % increase in fat corrected milk yield (p ≤ 0.05) relative to LIMax. Cows grazing at LI95% had greater concentration of total volatile fatty acids, butyrate and valerate (p ≤ 0.05), and smaller acetate (p ≤ 0.05) than those grazing at LIMax. Intake of net energy for lactation (NEL) and NEL secreted in milk were greater (p ≤ 0.05), while partitioning of NEL towards maintenance tended to be greater (p = 0.07) for cows grazing at LI95% than those grazing at LIMax. Milk urea nitrogen and both urine and fecal N excretion were greater for cows grazing at LI95% (p ≤ 0.05), but N excretion intensity was lower than in cows grazing at LIMax (p ≤ 0.05). Strategic grazing management using the LI95% pre–grazing target increases N losses through both urine and feces; however, it reduces N excretion intensity of dairy cows by 9 %.

Strategic grazing management decreases nitrogen excretion intensity of dairy cows

There is limited information regarding both nitrogen (N) and energy partitioning of dairy cows grazing well­managed tropical pastures. The objective of this study was to investigate the N and energy partitioning of mid­lactation dairy cows on rotationally grazed elephant grass using two pre­grazing targets: 95 % or maximum canopy light interception (LI95% or LIMax) during regrowth. The study used 26 Holstein × Jersey dairy cows arranged in a randomized complete block design with three 40­day periods of sampling. Grazing at LI95% increased organic matter and crude protein intake by 20 % (p ≤ 0.05) which resulted in a 9 % increase in fat corrected milk yield (p ≤ 0.05) relative to LIMax. Cows grazing at LI95% had greater concentration of total volatile fatty acids, butyrate and valerate (p ≤ 0.05), and smaller acetate (p ≤ 0.05) than those grazing at LIMax. Intake of net energy for lactation (NEL) and NEL secreted in milk were greater (p ≤ 0.05), while partitioning of NEL towards maintenance tended to be greater (p = 0.07) for cows grazing at LI95% than those grazing at LIMax. Milk urea nitrogen and both urine and fecal N excretion were greater for cows grazing at LI95% (p ≤ 0.05), but N excretion intensity was lower than in cows grazing at LIMax (p ≤ 0.05). Strategic grazing management using the LI95% pre­grazing target increases N losses through both urine and feces; however, it reduces N excretion intensity of dairy cows by 9 %.

Twenty-five-centimeter pre-grazing canopy height in palisade grass and forage peanut

Short-term grazing behavior variables are sensitive to the canopy structure and have an impact on daily forage intake. This study evaluated the effect of pre- and post-grazing canopy heights on the forage harvesting process at a patch scale in a mixture of Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. syn. Urochloa brizantha R.D. Webster cv. Marandu (palisade grass) and Arachis pintoi Krapov. & W.C. Greg. cv. Belomonte (forage peanut). Treatments were allocated to a split-plot arrangement in a completely randomized design. The plots, in their entirety, consisted of two pre-grazing canopy heights: 25 cm (CH25) and 35 cm (CH35); subplots consisted of three levels of defoliation severity: no defoliation (DS0); 20% depletion of pre-grazing canopy height (DS20); and 40% depletion of pre-grazing canopy height (DS40), with eight replications. Heifers were allowed to graze the patches (0.7 × 0.7 m) and their grazing behavior was recorded. Canopy structure measurements were taken both before and after grazing. Patches from CH35 presented greater stem mass for grass (p = 0.001) and legume (p = 0.002) than did patches from CH25. Bite rate, bite mass and instantaneous intake rate were greater for CH25 than for CH35 (p < 0.001, p = 0.068, and p = 0.074), and bite mass and instantaneous intake rate were lower for DS20 compared to DS0 (p = 0.032 and p = 0.016). Greater stem mass in the grazing strata negatively influenced the instantaneous intake rate.

Ethological behavior of Bos taurus, Bos indicus,and Caqueteño Creole cattle in three tree cover systems of Brachiaria decumbenspaddocks at the Amazon foothills in Colombia / Comportamento etológico do gado Bos taurus, Bos indicuse crioulo Caqueteño em três sistemas de cobertura de árvores de Brachiaria decumbenspaddocks no sopé da Amazônia na Colômbia

The study was conducted at the Amazon Research Center CIMAZ -MACAGUAL of the University of Amazonia, Colombia, with a tropical rain forest climate (Af). The behavior of Bos taurus, Bos indicus, and Caqueteño Creole cattle, the animals were observed in paddocks with three levels of scattered tree cover density. The pasture was composed of Braquiaria decumbenswith 35 days of regrowth. Direct observations were made from 9:00 a.m. to 5:00 p.m. with 10-minute intervals between the recording of the activities. The activity performed most often during the day by all of the animals was grazing under the sun, and those who pasture the most arethe Caqueteño Creole, followed by the Bos indicusand, finally, the Bos taurus. Ruminating was the second most important activity performed by the cattle, having presented the same tendency. In the paddocks with a low level of tree cover, the animals pasture more in the shade; this trend is more relevant among B. taurus cattle.Caqueteño Creole cattle dedicate less time to water consumption and rest, spending more time grazing, in the high and medium cover levels, they interrupt the grazing at noon for a shorter time compared to B. indicusand B. taurus; after 2 p.m., the creoles vertiginously increase grazing. At the high cover level, the peak of grazing of the Caqueteño Creoles is at 9 a.m. and from 1-1:30 p.m., while at the medium tree cover level, the peak of pasturing was at noon, 1:30 p.m., and 4:30 p.m., at the high tree level of cover, the peak for the three breeds was at 11 a.m. Only at the average tree level of cover did the Caquetaño creoles and B. indicuspresent a similar peak. In 9-9:30 a.m. and 4-5 p.m., the breeds substantially reduce rumination.(AU)

O estudo foi realizado no Centro de Pesquisa Amazônica CIMAZ -MACAGUAL da Universidade da Amazônia, Colômbia, com um clima de floresta tropical úmida (Af). O comportamento do gado Bos taurus, Bos indicuse Caqueteño crioulo, os animais foram observados em cercados com três níveis de densidade de cobertura arbórea dispersa. A pastagem era composta de Braquiaria decumbenscom 35 dias de recrescimento. Observações diretas foram feitas das 9h às 17h com intervalos de 10 minutos entre o registro das atividades.A atividade mais executada durante o dia por todos os animais era o pasto sob o sol, e aqueles que mais pastam são os Caqueteñocrioulo, seguido pelo Bos indicuse, finalmente, o Bos taurus. A ruminação foi a segunda atividade mais importante desempenhada pelo gado, tendo apresentado a mesma tendência. Nos cercados com um baixo nível de cobertura arbórea, os animais pastam mais à sombra; esta tendência é mais relevante entre o gado B. taurus.O gado crioulo Caqueteñodedica menos tempo ao consumo de água e descanso, passando mais tempo pastando, nos níveis de cobertura alta e média, interrompem o pastoreio ao meio-dia por um tempo mais curto em comparação com o B. indicuse B. taurus; depois das 14 horas, os crioulos aumentam vertiginosamente o pastoreio. No nível de cobertura alta, o pico de pastagem dos Caqueteñocrioulosé às 9h e das 13h30, enquanto no nível médio de cobertura de árvores, o pico de pastagem era ao meio-dia, 13h30 e 16h30, no nível alto de cobertura de árvores, o pico para as três raças era às 11h. Nas 9-9h30 e16-17h, as raças reduzem substancialmente a ruminação.(AU)

Beef cattle behavior in integrated crop-livestock systems / Comportamento de novilhos de corte em sistemas integrados de produção agropecuária

Temperament often depends on the animals' reaction to people, social and environmental conditions. However, little is known about the influence of changes in the pasture environment on cattle temperament. Thus, this study was designed to evaluate if an animals' temperament changes in response to being kept in a silvopastoral system. This study evaluated the effect of the tree components in a pasture environment on the temperament of any grazing cattle in integrated crop-livestock systems. A total of thirty-two Angus steers were allocated to either a livestock (L) or livestock-forest (LF) system and observed from December 2019 to February 2020. Each animal was evaluated for their reactivity score, flight speed, and number of vocalizations. The statistical model established that the animals were random effects and that the treatments and periods were fixed effects using the MIXED procedure, and the means were compared using LSMeans. The flight speed and number of vocalizations were similar in both production systems, while the reactivity score was lower for animals kept in the LF system when compared to those in the L system. This suggested that the LF system interferes positively with the animal's temperament in relation to the L production system. However, additional research is needed to understand the influence of the production system on animal temperament.

As divergências no temperamento dependem da reação dos animais às pessoas e à diferentes situações sociais e ambientais. Contudo, pouco se sabe acerca da influência de alterações no ambiente pastoril sobre o temperamento dos bovinos. Com isso, a hipótese de trabalho é de que o temperamento dos animais pode ser alterado se mantidos em sistemas pastoris arborizados. Para tanto, objetivou-se avaliar o efeito do componente arbóreo em ambiente pastoril sobre o temperamento de bovinos em pastejo em sistemas integrados de produção agropecuária. Foram avaliados 32 novilhos da raça Angus alocados em dois sistemas pecuária (PEC) e pecuária-floresta (PF) durante o período de dezembro de 2019 a fevereiro de 2020, no qual foi mensurado: o escore de reatividade dos animais; a velocidade de fuga e o número de vocalizações. O modelo estatístico utilizado considerou como efeito fixo de tratamentos e períodos e efeitos aleatórios dos animais, utilizando o procedimento MIXED, as médias foram comparadas pelo recurso lsmeans. A velocidade de saída e número de vocalizações foram similares entre os sistemas de produção. O escore de reatividade foi menor para os animais mantidos no sistema PF quando comparados aos do tratamento PEC. O sistema PF interfere positivamente no temperamento animal em relação ao sistema de produção PEC, observado pelo menor escore de reatividade nos animais mantidos neste sistema. Contudo, o estudo sobre a influência da integração de sistemas sobre o temperamento animal exige mais pesquisas para revelar o potencial deste modelo de produção sobre o comportamento animal.

Forage performance and cattle production as a function of the seasonality of a Brazilian tropical region

This study aimed to evaluate forage yield, tiller population density, canopy height, nutritional value as well as cattle performance in alternate stocking from three tropical forage cultivars. The experiment followed a randomized block design, in a 3 x 3 factorial scheme with three replications. Three forage cultivars (Marandu, Massai and Xaraés) distributed in nine hectares were evaluated in three dry season periods (transition wet/dry, dry, and end of dry season), with repeated measures over time. The following variables were evaluated: canopy height, leaf: stem ratio, forage mass, leaf mass, stem mass and dead material mass. Total digestible nutrients, crude protein and in vitro dry mass digestibility were evaluated regarding forage nutrition. Animal performance, using 36 eleven-month-old animals (half-blood Nelore), was evaluated by the daily average gain and weight gain by area. During pre-grazing, canopy height presented interaction among forage cultivars and the evaluated periods. The average daily gain showed no interaction among cultivars and period of the year the similarity in animal performance among the cultivars Marandu and Massai show that the Massai grass can be used as an alternative for forage diversification under an alternate management system.(AU)

Prevalence and risk factors of cysticercosis in cattle tracking / Prevalência e fatores de riscos da cisticercose no rastreamento de bovinos

The aim of this study was to identify the prevalence and the main risk factors related to the transmission of bovine cysticercosis based on tracking animals sent for slaughter and coming from properties located in the micro-region of Uberlândia, Minas Gerais, Brazil. The properties were previously evaluated for the occurrence of cysticercosis during post-mortem inspection in the 12 months prior to the beginning of the research, and those with animals with bovine cysticercosis found at least once during this period were considered positive. A cross-sectional study was carried out on 87 properties, from which 1024 bovine serum samples were collected. Indirect ELISA performed serological diagnosis and Immunoblot confirmed positive sera. The prevalence found in this study was 5.1% (95% CI = 3.74-6.42). The risk factors identified were cattle origin (RC = 4.9), grazing (RC = 6.4) and sewage destination on the property (RC = 3.6). These environmental factors suggest that sanitation control measures and the restriction of pastures beyond the property boundary can help prevent disease in the study area. A control system based on risk analysis was discussed and proposed as a strategy to control bovine cysticercosis in the Triângulo Mineiro region and other regions of the country.

Este estudo teve por objetivo identificar a prevalência e os principais fatores de risco relacionados com a transmissão da cisticercose bovina em animais enviados para abate e provenientes de propriedades localizadas na microrregião de Uberlândia, Minas Gerais, Brasil. As propriedades foram previamente avaliadas quanto à ocorrência de cisticercose durante a inspeção post mortem nos 12 meses antecedentes ao início da pesquisa; aquelas que revelaram animais com cisticercose bovina pelo menos uma vez durante esse período foram consideradas positivas. Foi realizado um estudo de corte transversal em 87 propriedades, onde foram coletadas 1024 amostras de soro bovino. O diagnóstico sorológico foi realizado por triagem pelo teste ELISA indireto, e os soros positivos foram confirmados pelo Immunoblot. A prevalência identificada neste estudo foi de 5,1% (IC 95%= 3,74-6,42). Os fatores de risco identificados foram: a origem dos bovinos (RC=4,9), o pastejo (RC=6,4) e o destino do esgoto da propriedade (RC=3,6). Esses fatores ambientais encontrados sugerem que medidas de controle do saneamento e restrição a pastagens além do limite da propriedade possam auxiliar na prevenção da doença na área de estudo.

Nutritional and productive performance of grazing system beef heifers receiving multiple supplementation in the dry season / Desempenho nutricional e produtivo de novilhas de corte em sistema de pastejo recebendo suplementação múltipla na estação seca

This research was conducted to evaluate the effects of supplementation multiple on intake, digestibility, and microbial protein synthesis and, productive performance of grazing system receiving multiple supplementation in the dry season. Twelve Nellore heifers (averaging 214.6 ± 7.3 kg initial BW and 8.0 ± 0.10 months) were distributed to a completely randomized design in two treatments: unsupplemented (only mineral) and; supplemented (1 kg per animal day-1 of multiple supplement). Only the crude protein (CP) intake was increased by supplementation (P < 0.05). In addition, the supplementation increased the digestibility of organic matter (OM), CP, ether extract (EE), non-fibrous carbohydrates (NFC) and dietary content of digested OM (DOM) (P < 0.05). The supplementation decreased microbial nitrogen to ingested nitrogen ratio (MICNR) (P < 0.05) and increased the serum urea nitrogen (SUN) concentration and urinary nitrogen excretion (UNE) (P < 0.05) in the animals. Finally, average daily gain (ADG) and final BW (FBW) were not affected by supplementation (P > 0.05). In summary, the provision 1 kg per animal day-1 of multiple supplement for beef heifers in grazing system does not improve productive performance in dry season when there is adequate qualitative and quantitative availability of forage mass. However, provision of supplement increases the total nutrients digestibility and nitrogen statuses in the animals.(AU)

Esta pesquisa foi conduzida para avaliar os efeitos da suplementação múltipla sobre o consumo, digestibilidade e síntese de proteína microbiana e, desempenho produtivo de novilhas de corte em sistema de pastejo na época seca. Doze novilhas Nelore (média de 214,6 ± 7,3 kg de peso corporal inicial e 8,0 ± 0,10 meses) foram distribuídas em delineamento inteiramente casualizado em dois tratamentos: não suplementado (apenas mistura mineral) e; suplementado (1 kg por animal dia-1 de suplemento múltiplo). Apenas o consumo de proteína bruta (PB) aumentou com a suplementação (P < 0,05). Além disso, a suplementação aumentou a digestibilidade da matéria orgânica (MO), PB, extrato etéreo (EE), carboidratos não fibrosos (CNF) e teor dietético de MOD (P < 0,05). A suplementação diminuiu a relação nitrogênio microbial nitrogênio ingerido (MICNR) (P < 0,05) e aumentou a concentração de nitrôgeno ureico no soro (NUS) e excreção urinário de ureia (ENU) (P < 0,05) nos animais. Finalmente, o ganho médio diário (GMD) e o peso corporal final (PCF) não foram afetados pela suplementação (P > 0,05). Em resumo, o fornecimento de 1 kg por animal dia-1 de um suplemento múltiplo para novilhas de corte em sistema de pastejo não melhora o desempenho produtivo na época seca, quando existe uma adecuada disponibilidade qualitativa e quantitativa da massa de forragem. No entanto, o fornecimento do suplemento múltiplo aumenta a digestibilidade total dos nutrientes e status de nitrogênio dos animais.(AU)

Forage performance and cattle production as a function of the seasonality of a Brazilian tropical region

This study aimed to evaluate forage yield, tiller population density, canopy height, nutritional value as well as cattle performance in alternate stocking from three tropical forage cultivars. The experiment followed a randomized block design, in a 3x3 factorial scheme with three replications. Three forage cultivars (Marandu, Massai and Xaraés) distributed in nine hectares were evaluated in three dry season periods (transition wet/dry, dry,and end of dry season), with repeated measuresover time. The following variables were evaluated: canopyheight, leaf: stem ratio, forage mass, leaf mass, stem mass and dead material mass. Total digestible nutrients, crude protein and in vitrodry mass digestibility were evaluated regarding forage nutrition. Animal performance, using 36 eleven-month-old animals (half-blood Nelore),was evaluated by the daily average gain and weight gain by area. During pre-grazing, canopy height presented interaction among forage cultivars and the evaluated periods. The average daily gain showed no interaction amongcultivarsand period of the year the similarity in animal performance amongthe cultivars Marandu and Massai show that the Massai grass can be used as an alternative for forage diversification under an alternate management system.(AU)

Effects of thermal environment on dairy cattle under a grazing system in the Western Amazon, Brazil / Efeitos do ambiente térmico em bovinos leiteiros em sistema de pastejo na Amazônia Ocidental, Brasil

This study aimed to evaluate the thermal conditions to which animals are exposed and their effect on the comfort/discomfort of dairy herds in a grazing system in the municipality of Sena Madureira, Acre State, Brazil. Eight farms and a total of 113 lactating crossbred cows were evaluated. Dry-bulb temperature (DBT, °C), relative humidity (RH, %), black globe temperature (BGT, °C), and wind speed (v, km h¹) were measured in January, February, and March (rainy season) to calculate temperature-humidity index (THI), black globe-humidity index (GTWBI), and radiant heat load (RHL). Moreover, the animals were measured for the physiological variables: rectal temperature (RT), heart rate (HR), and respiratory rate (RR). Significant differences (P<0.05) were observed for THI, GTWBI, and RHL. THI reached a mean value of 80 on farm G in January. Farm F had a GTWBI value of 79 in February. RHL reached the highest value (510 W m²). RT and HR showed no differences among the analyzed months. Thus, the environmental conditions in which dairy cows are housed at milking time rarely promoted thermal discomfort, with farm G being the most affected by THI.

Objetivou-se avaliar as condições térmicas a que os animais estão submetidos, seu efeito no conforto/desconforto de rebanhos leiteiros em sistema de pastejo, no município de Sena Madureira-Acre. Foram avaliadas oito propriedades e o total de 113 vacas mestiças em lactação. As medições ocorreram nos meses: janeiro, fevereiro e março (inverno amazônico), mensurando-se: temperatura do bulbo seco (TBS, °C), umidade relativa do ar (UR, %) e temperatura de globo negro (TGN, °C), velocidade do vento (v, km/h) para cálculos dos índices da temperatura e umidade (ITU), índice da temperatura de globo e umidade (ITGU) e carga térmica radiante (CTR), além da temperatura retal (TR), frequência cardíaca (FC), frequência respiratória (FR). Entre as propriedades analisadas, houve diferenças significativas (P<0,05) para ITU, ITGU e CTR. Destaca-se que o ITU na propriedade G, em janeiro, atingiu o valor médio de 80. A propriedade F, em fevereiro, teve valor de 79 para o ITGU. A CTR apresentou carga elevada (510 W.m³). A TR e a FC não apresentaram diferença entre os meses analisados. Concluiu-se que o ambiente ao qual as vacas leiteiras estão alojadas na hora da ordenha encontraram-se poucas vezes em situação de desconforto térmico, sendo a propriedade, a mais afetada pelo ITU.

Protein-energy supplementation on productive and nutritional performance of grazing beef heifers / A suplementação proteico-energética no desempenho produtivo e nutricional de novilhas de corte em pastejo

This study was conducted with the aim of evaluating the effect of protein-energy supplementation on productive performance, intake, digestibility, and microbial protein synthesis in heifers fed tropical forage. Twelve Nellore heifers at 11 months of age, with a mean initial body weight of 248.8 ± 11.40 kg were used. The animals were distributed in a completely randomized design with two treatments and six replicates. The treatments evaluated were: control (without supplementation); and supplementation in the amount of 1.5 kg animal-1 day-1. Forage samples were collected to evaluate the chemical composition and the total availability of dry matter of the pasture consumed by the animals. To evaluate the intake and forage digestibility, a trial was performed using internal and external markers. In this study no effect of supplementation was observed on the intakes of dry matter (DM), organic matter (OM), forage DM, or neutral detergent fiber corrected for ash and protein (NDFap; P > 0.10). However, supplementation increased (P < 0.01) the intakes of crude protein (CP), ether extract (EE), and non-fibrous carbohydrates (NFC). Additionally, an upward trend (P=0.076) was observed in the intake of digested OM (DOM) with supplementation. On the other hand, supplementation increased (P < 0.01) the digestibility coefficients of OM, CP, EE, and NFC, although supplementation did not affect the ruminal synthesis of nitrogen compounds (MICN), efficiency of protein microbial synthesis (EMS), relative microbial nitrogen (RMICN) or urine urea nitrogen (UUN) excretion (P > 0.57). Lastly, supplementation increased (P=0.050) the average daily gain of the animals, although no effect (P > 0.10) was observed on their final body weight. These results suggested that protein-energy supplementation improves the productive performance and nutritional characteristics of grazing beef heifers.(AU)

Este estudo foi conduzido com o objetivo de avaliar o efeito da suplementação proteico-energético sobre o desempenho produtivo, consumo, digestibilidade e sínteses de proteína microbiana em novilhas de corte alimentadas com forragem tropical. Doze novilhas Nelore com 11 meses de idade e peso corporal médio inicial de 248,8±11,40 kg foram utilizadas. Os animais foram distribuídos em delineamento inteiramente casualizado com dois tratamentos e seis repetições. Os tratamentos avaliados foram: controle (não suplementado); e suplementado na quantidade de 1,5 kg animal-1 dia-1. Amostras de forragem foram coletadas para avaliar a composição química e a disponibilidade total de matéria seca do pasto consumido pelos animais. Para avaliar o consumo e digestibilidade da forragem, um ensaio foi conduzido usando marcadores internos e externos. Neste estudo não foi observado efeito da suplementação sobre o consumo de matéria seca (MS), matéria orgânica (MO), MS da forragem, ou fibra em detergente neutro corrigida para cinzas e proteína (FDNcp; P > 0,10). No entanto, a suplementação incrementou o consumo de proteína bruta (PB), extrato etéreo (EE) e carboidratos não fibrosos (CNF). Além disso, foi observada uma tendência de aumento (P=0,076) no consumo de MO digerida (MOD) com a suplementação. Por outro lado, a suplementação aumentou (P < 0,01) os coeficientes de digestibilidade da MO, PB, EE e CNF, embora a suplementação não tenha afetado a síntese ruminal de compostos nitrogenados (NMIC), eficiência de síntese de proteína microbiana (EFM), nitrogênio microbiano relativo (NMICR) ou excreção de nitrogênio ureico na urina (NUU) (P > 0,57). Finalmente, a suplementação aumentou (P < 0,050) o ganho médio diário dos animais, embora nenhum efeito (P > 0,10) tenha sido observado no peso corporal final. Esses resultados sugerem que a suplementação proteico-energética melhora o desempenho produtivo e as características nutricionais de novilhas de corte em pastejo.(AU)

Does first and last stocking could "fits" Campos grassland structure to improve beef cattle production? / O método de pastoreio rotativo "ponta" e "rapador" pode moldar a estrutura das pastagens naturais para aumentar a produção de bovinos de corte?

This study evaluated the structure of vegetation and the performance of rearing heifers and cull cows in Campos grasslands managed in the rotational stocking method with first-last stocking in the spring-summer period. The treatments were different rest intervals of 402 and 252 degrees-day, which favor the growth of different functional groups of grasses. A completely randomized block design with two treatments and three repetitions was used. The test animals were 24 heifers in the "first" group and 24 cows in the "last" group. In the stratum between tussock grasses, sward heights greater than 0.16 m were predominant in both treatments, it was 1.3 times more frequent in the 402 DD treatment compared to the 252 DD treatment. Average stocking rate was 22% higher in the 252 DD treatment. Although, no differences were observed for the average daily gain of heifers (0.227 kg.day-1) and cows (0.336 kg.day-1) between treatments, the weight gain per area in the experimental period was greater in the 252 DD treatment. Despite the management system with first and last stoking does not provide significant changes in the structure of the pasture, it allowed to achieve satisfactory performance goals in areas of Campos grassland.

Este estudo teve como objetivo avaliar a estrutura da vegetação e o desempenho de novilhas em recria e vacas de descarte em pastagens naturais manejadas em sistema de pastejo rotacionado com lotes "ponta" e "rapador" no período primavera-verão. Os tratamentos foram diferentes intervalos de descanso de 402 e 252 graus-dia (GD), os quais favorecem o crescimento de gramíneas de diferentes grupos funcionais. O delineamento experimental foi em blocos ao acaso com dois tratamentos e três repetições. Os animais de teste foram 24 novilhas no grupo "ponta" e 24 vacas no grupo "rapador". No estrato entre touceiras, as alturas do pasto maiores que 16 cm foram predominantes em ambos os tratamentos, sendo 1.3 vezes mais frequente no tratamento 402 GD em relação ao tratamento 252 GD. A taxa de lotação média foi 22% maior no tratamento com 252 GD. Embora não tenham sido observadas diferenças para o ganho médio diário de novilhas (0,227 kg.dia-1) e vacas (0,336 kg.dia-1) entre os tratamentos, o ganho de peso por área no período experimental foi maior no tratamento 252 GD. Apesar do sistema de manejo com lotes "ponta" e "rapador" não proporcionar mudanças significativas na estrutura da pastagem, ele permite atingir metas de desempenho satisfatórias em áreas de pastagens naturais.