The influence of artificial shading on environmental variables and on behavioral responses of Nellore steers in an intensive production system was evaluated in this study. The experiment was conducted in the experimental feedlot of the Department of Animal Science at Universidade Estadual de Goiás, from July to October 2014. Forty-eight male Nellore cattle with an average initial weight of 310 kg were kept in double 24-m 2 stalls, in a total of 24 stalls. Of these, six were in the open air; six were covered with black shade netting of 30% light interception; six with black shade netting 50%; and six with black shade netting 80%, providing 6 m 2 of shade per stall. Temperature-humidity index (THI) and respiratory frequency (RF) were assessed twice weekly and behavior was evaluated fortnightly during 12 h, between 06:00 h and 18.00 h. Feeding behavior, rumination, rest, and social activities such as body care and playful and abnormal activities were observed. A significant increase was found in THI and RF as the shading levels decreased, while a significant difference was recorded in rest and in other activities, water intake, and play behavior. Rest time and playful behavior increased significantly, and other activities and water intake decreased with the increase in shading levels. Shading does not change the time spent on feeding behaviors and rumination, or the frequencies of urination, defecation, cleaning other animals, self-cleaning, and social and abnormal types of behavior. The use of black shade netting of 80% light interception provides greater comfort to animals, promoting welfare and quality of life to them. Key words: Ambience. Behavior. Performance. Welfare. ResumoObjetivou-se avaliar a influência dos níveis de sombreamento artificial nas variáveis ambientais e nas respostas comportamentais de machos bovinos nelore em sistema intensivo de produção. O experimento foi realizado no confinamento experimental do curso de Zootecnia da Universidade Estadual de Goiás, no período de julho a outubro de 2014. Utilizaram-se 48 bovinos machos Nelore, com peso médio inicial de 310 kg, mantidos em baias duplas de 24m², sendo utilizados 24 baias, destas, seis a céu aberto, seis com sombrite preto com malha 30%, seis com malha 50% e seis com malha 80%, cobrindo seis m² de sombra por baia. Foi realizado duas vezes por semana avaliação de ITU e frequência respiratória e quinzenalmente a avaliação de comportamento, com duração de 12 horas, com início as 6:00h e término às 18:00h, observou-se o comportamento alimentar, ruminação, descanso, outras atividades, social, cuidados corporais, lúdico e anormal. Observou-se um aumento significativo nos valores de ITU e FR a medida que se reduzia os níveis de sombreamento. Também foi observado uma diferença significativa no tempo de comportamentos de descanso e em outras atividades, e na frequência do consumo de água e comportamento lúdico, com aumento significativo no tempo de descanso e frequência de comportamento lúdico, e redução de outras atividades e ingestão de ág...

The objective of this study was to evaluate the influence of artificial shading on weight gain and meat quality of male Nellore cattle in an intensive production system. The experiment was conducted in the experimental feedlot of the Course of Animal Science at Universidade Estadual de Goiás, from July to October 2014. Forty-eight male Nellore cattle with an average initial weight of 310 kg were kept in double 24-m 2 stalls, in a total of 24 stalls. Of these, six were in the open air; six were covered with black shade netting of 30% light interception; six with black shade netting 50%; and six with black shade netting 80%, providing 6 m 2 of shade per stall. The ration supplied to the animals and the orts left in the trough were weighed daily to determine intake, and the temperature-humidity index (THI) was measured twice weekly. Animals were weighed for the first time at the start of the experiment, and then another three times until the end, which was followed by the slaughter and assessments of performance and meat quality. A difference (p<0.05) was observed between the average THI values, with the highest value found in the stalls without artificial shading. No difference (p>0.05) was observed for feed intake, initial weight, final weight, total weight gain, average daily weight gain, carcass yield, marbling, texture, fatness, backfat thickness, loin-eye area, color, thigh length and circumference, leg length and circumference, or carcass length between the animals on the different treatments. The use of artificial shading does not have a significant effect on performance or meat quality of feedlot Nellore cattle when the ambient temperature is within the thermal comfort zone. Key words: Ambience. Carcass. Intensive system. Quality. ResumoObjetivou-se avaliar a influência do sombreamento artificial no ganho em peso e na qualidade da carne de machos bovinos Nelore em sistema intensivo de produção. O experimento foi realizado no confinamento experimental do curso de Zootecnia da Universidade Estadual de Goiás, no período de julho a outubro de 2014. Utilizaram-se 48 bovinos machos Nelore, com peso médio inicial de 310 kg, mantidos em baias duplas de 24m², sendo utilizados 24 baias, destas, seis a céu aberto, seis com sombrite preto com malha 30%, seis com malha 50% e seis com malha 80%, cobrindo seis m² de sombra por baia. Diariamente era realizada a pesagem da ração fornecida aos animais e das sobras da ração no cocho para determinação do consumo, e duas vezes por semana realizava-se a avaliação inicio do experimento foi realizado a pesagem inicial dos animais e outras três pesagem até o final do experimento, seguido do abate e avaliações de desempenho e qualidade da carne. Observou-se diferença (p<0,05) entre os valores médios de ITU, sendo o de maior índice as baias sem sombreamento artificial. Não houve diferença (p>0,05) entre o consumo de ração, peso inicial, peso final, ganho em peso total, ganho em peso médio diário, rendimento de carcaça, marmoreio, textura, acabamento, espessura de gordura su...

ResumoObjetivou-se avaliar o efeito residual de doses de Nitrogênio (N) aplicadas em pastos de Brachiaria brizantha (cvs. Marandu e Xaraés) por dois anos consecutivos sobre a produção de milho para silagem, em sistema de integração lavoura-pecuária. A adubação nitrogenada dos pastos foi realizada durante dois anos consecutivos, utilizando-se quatro dosagens de Nitrogênio (0, 100, 200 e 300 kg/ha/ano). Estas áreas foram dessecadas para plantio direto do milho. Foi utilizada uma adubação basal de 70 kg de N/ha para o cultivo do milho, aplicado em cobertura. Foram realizadas avaliações agronômicas (estande, altura de plantas e de inserção de espiga, número de espigas, número de grãos na espiga e stay-green) e produtivas do milho (produção de silagem, produção de matéria seca, produção de espigas) colhido em ponto de ensilagem. As dosagens de N aplicadas em pastos afetaram apenas a porcentagem de espigas do milho e o peso do sabugo. Houve interação entre dose e cultivar para a porcentagem de matéria seca das brácteas e a quantidade de fileiras de grãos da espiga. O efeito residual de nitrogênio após cultivo de pastagens de Marandu e Xaraés não afeta os cultivos subsequentes, tornando-se necessária a adubação total da cultura. Palavras-chave: espigas; Marandu; produção de volumoso; silagem; Xaraés. AbstractIt was aimed to evaluate the residual effect of doses of Nitrogen (N) applied in pastures of Brachiaria brizantha (Marandu and Xaraés) for two consecutive years on the production of corn for silage in

The aim of this study was to examine the behavioral, productive, reproductive and thermoregulatory performance of 3/4 and 7/8 Holstein/Gir (HG) dairy cows to identify which genetic composition suffers the least heat stress. A completely randomized design was adopted involving 20 multiparous, lactating crossbred cows from a dairy farm located in the municipality of Turvânia - GO, Brazil. During the experimental period, data on behavioral, productive, reproductive and thermoregulatory traits were collected every 15 days. Bioestat (5.0) statistical software was used for statistical analysis. The mean temperature-humidity index, ambient temperature and relative humidity obtained throughout the experimental period were 74.45, 30.51 ºC and 63.64%, respectively. In terms of reproductive performance, there was a significant difference (p < 0.05) between the genetic compositions for the time from calving to first service, with a longer period shown by the animals with greater Holstein breed genetic composition. Service period and calving interval differed significantly (p < 0.05) during the experimental period between the genetic compositions. A significant difference (p < 0.05) was also detected between the compositions for respiratory rate, with higher values observed in the animals with higher European genetic composition. Benezra thermal comfort index also differed significantly (p < 0.05), with the 7/8 HG animals showing a higher value. Lactating cows with a 7/8 HG genetic composition achieved better results in milk production, whereas those with 3/4 HG genetic composition showed superiority in milk fat composition and reproductive and thermoregulatory performance, indicating greater adaptation to the climatic conditions of the region.

The aim of this study was to evaluate the performance and carcass and meat quality of sheep in an intensive production system with and without artificial shade available. Twenty Santa Inês × Dorper crossbred lambs were allotted to two collective stalls, one of which was covered with a black polypropylene shade net with 80% light interception, providing 2.5 m2 shade animal-1. Performance was evaluated by measuring initial weight, final weight, carcass yield, average daily weight gain, and total weight gain. Carcass and meat traits were evaluated based on the variables of fatness, conformation, loin-eye area, subcutaneous fat thickness, marbling, texture, pH, temperature, and color. Performance and carcass and meat traits were similar between the animals reared in stalls with and without shade available. The groups with and without access to shade showed initial weights of 26.52 and 25.37 kg, final weights of 35.59 and 34.76 kg, carcass yields of 45.73 and 45.50%, loin-eye areas of 14 .11 and 13.61 cm2, and marbling scores of 4.78 and 4.44, respectively. Subcutaneous fat thickness (2.02 cm), texture (3.67), and fatness (2) values were equal for both groups. Based on the results, artificial shading did not affect the performance or carcass and meat quality of the sheep.