Thermal Comfort of Nelore Cattle (Bos indicus) Managed in Silvopastoral and Traditional Systems Associated with Rumination in a Humid Tropical Environment in the Eastern Amazon, Brazil.

The objective of this study was to evaluate the thermal comfort of Nelore cattle (Bos indicus) managed in silvopastoral and traditional systems associated with rumination behavior in a humid tropical environment in the Eastern Amazon, Brazil. The study was carried out on a rural property in Mojuí dos Campos, Pará, Brazil, during the transition period of the year, from June to July 2023. Over these two months, six consecutive data collection days were held. We selected 20 clinically healthy non-castrated male Nelore cattle, aged between 18 and 20 months, with an average weight of 250 kg and body condition score of 3.5 (1-5). These animals were randomly divided into two groups: traditional system (TS) and silvopastoral system (SS). The physiological variables evaluated included RR, RT and BST. The variables were analyzed using the linear mixed model. For agrometeorological variables, higher values were observed between 10:00 a.m. (33 °C) and 6:00 p.m. (30 °C), with the highest temperature observed at 4:00 p.m. (40 °C). The RR showed interactions (p = 0.0214) between systems and times; in general, higher RR were obtained in the Traditional. The animals' RT showed no significant difference (p < 0.05) between the production systems, but there was a statistically significant difference in relation to the time of collection (p < 0.0001). In the BGHI, it was possible to observe that there was mild stress in the period from 22:00 at night to 6:00 in the morning and moderate stress in the period of greatest increase in temperature, from 10:00 in the morning to 18:00 at night. BST showed no statistical difference between the regions studied or between the SP (35.6 °C) and TS (36.25 °C) systems. RT in the TS showed a positive correlation with AT (r = 0.31507; p = 0.0477). RT in the SP showed a positive correlation with THI (r = 35583; p = 0.0242). On the other hand, RT in the SP (r = 0.42873; p = 0.0058) and ST (r = 0.51015; p = 0.0008) showed a positive correlation with BGHI. RR in the TS showed a positive correlation with BGHI (r = 0.44908; p = 0.0037). The greatest amounts of rumination were carried out by animals in the SP system, generally ruminating lying down (p < 0.05). With regard to rumination behavior in the morning and afternoon, there were higher numbers of WS and LD in the TS (p > 0.05). Most of the time, the cattle were LD during the morning and afternoon shifts, and at night and dawn they were WS in the TS. Therefore, the SP offers more thermal comfort advantages compared to the TS system.

Nutritional and productive performance of purebred Nellore heifers and crossed with Brangus and Braford finished in a feedlot system.

This study evaluated the nutritional and productive performance of Nellore purebred heifers and crossbred Brangus x Nellore (BGNE) and Braford x Nellore (BFNE) in a feedlot system. Thirty heifers (10 of each genetic group) with an average age of 18 months and an initial body weight of 261 kg were used. The experiment was structured and conducted according to a completely randomized design, with three treatments. Heifers received two diets (60 days each) during the experimental period. The experiment lasted 120 days with four experimental periods. Nellore heifers had a lower intake than crossbred heifers (P <0.05). There were no differences between BGNE and BFNE heifers, which had higher final body weight, average daily gain, feed efficiency, hot carcass weight and carcass length than NE heifers. Crossed heifers presented better fat cover than NE heifers. However, NE heifers had higher carcass dressing Despite presenting lower carcass yields than Nellore heifers, crossed heifers are more efficient and have higher performance and better fat cover on the carcass than purebred Nellore heifers. Crossbreeding synthetic breeds, such as Brangus and Braford breeds, with the Nellore breed is an effective way to increase the productivity and efficiency of feedlot heifers in tropical regions.

Thermographic Profiles in Livestock Systems under Full Sun and Shaded Pastures during an Extreme Climate Event in the Eastern Amazon, Brazil: El Niño of 2023.

The El Niño represents a substantial threat to pastures, affecting the availability of water, forage and compromising the sustainability of grazing areas, especially in the northern region of Brazil. Therefore, the objective of this study was to characterize the thermographic profile of three production systems in the Eastern Amazon, Brazil. The study was conducted on a rural cattle farm in Mojuí dos Campos, Pará, Brazil, between August and November 2023. The experiment involved livestock production systems, including traditional, silvopastoral and integrated, with different conditions of shade and access to the bathing area. An infrared thermographic (IRT) camera was used, recording temperatures in different zones, such as areas with trees, pastures with forage and exposed pastures. The highest mean temperatures (p = 0.02) were observed in pastures with full sun from August to November. On the other hand, the lowest average temperatures were recorded in areas shaded by chestnut trees (Bertholletia excelsa). The highest temperature ranges were found in sunny areas and the lowest were recorded in shaded areas. The highest temperatures were observed in the pasture in full sun, while the lowest were recorded in areas shaded by chestnut trees (p < 0.0001). The interaction between the systems and treatments revealed significant temperature differences (p < 0.0001), with the native trees showing an average temperature of 35.9 °C, lower than the grasses and soil, which reached 61.2 °C. This research concludes that, under El Niño in the Eastern Amazon, areas shaded by Brazil nut trees had lower temperatures, demonstrating the effectiveness of shade. Native trees, compared to grasses and soil, showed the ability to create cooler environments, highlighting the positive influence on different species such as sheep, goats and cattle.

Perspectives of economic losses due to condemnation of cattle and buffalo carcasses in the northern region of Brazil.

The work aims to study the economical losses of the condemnation of bovine and buffalo carcasses, in order to estimate the losses in animals slaughtered in Santarém-Pará, Brazil, between 2016 and 2018, with data obtained from the Municipal Department of Agriculture and Fisheries. Sex, age, origin, total number of animals slaughtered and causes of condemnation of carcasses were considered. All analyzes were performed in RStudio version 1.1.463. In this study, 71,277 bovine carcasses and 2,016 buffalo carcasses were inspected, of which 300 bovine and 71 buffalo were condemned. The highest prevalence of causes of condemnation in cattle was recorded for brucellosis (0.0020%) and tuberculosis (0.0019%). In buffaloes, tuberculosis (0.0307%) peritonitis (0,0019%) were the main causes of condemnations. Economical losses were more evident in females, for both species. The projection of economical losses related to the condemnation of carcasses showed a sharp growth for the next three years, if the average growth remains constant. The biggest projected loss was for bovine females, with an accumulated projection of $ 5,451.44. The smallest estimated loss was for buffalo males, projected at more than thirty-two thousand reais. The most important causes of condemnation report the diseases brucellosis and tuberculosis, as the ones with the greatest impact. In the buffalo species this was even more accentuated, even though the number of buffaloes slaughtered is more than 35 times smaller than the number of cattle.

Mixed Models in Nonlinear Regression for Description of the Growth of Nelore Cattle.

Body weight records were used to characterize the growth curve of Nelore cattle. Body weight was regressed as a function of age, for both sexes, by using nonlinear models through the functions of Brody, Gompertz, Logistic, Richards, Meloun 1, Von Bertalanffy, and Von Bertalanffy. The quality of the model arrangements was evaluated by employing Akaike and Bayesian Schwarz information criteria. The Brody function provided the best adaptations by the evaluators and, considering the asymptotic weight and the maturation rate as random, a reduction in residual variance of 79% for males and 83% for females was obtained in relation to the models under fixed contexts. In males, the absolute and relative growth rates ranged from 0.921 to 0.261 kg/day and 2.39 to 0.08%, respectively. For the same rates, under another approach, females ranged from 0.922 to 0.198 kg/day and 2.55 to 0.06%, respectively. Males showed greater growth acceleration at the beginning of the growth trajectory, being equal to females at 397 days of age and from that age onward they presented lower estimates. The nonlinear regression model approach under the mixed-models context allows reduction of residual variance, increasing model accuracy.

The impact of heterogeneity of variances on the genetic evaluation of performance traits in Nellore cattle

The objective was to evaluate the existence of heterogeneity of variances and its impact on the genetic evaluation of ponderal performance in sires of the Nellore breed. We used records of adjusted body weights at 210 (W210), 365 (W365), and 450 (W450) days of age. Both W365 and W450 were combined by principal component analyses using the first component (PC). Average daily gain (ADG) was obtained by difference between W450 and W210. The classes of standard deviations (SD) for W210, PC, and ADG were obtained by the standardization of means of herd-year means subclasses, with positive values composing the high SD and values equal and less than zero composing the SD. The model included the fixed effects of contemporary group and age at calving as a covariate, random genetic additive, and maternal genetic (except for PC) effects, and the permanent maternal environment. Variance components were obtained by Gibbs sampling. Posterior means of heritability in analyses without considering heterogeneity of variances ranged from 0.15±0.01 to 0.31±0.01. Posterior means of genetic correlations between the two classes of SD for W210, PC, and ADG were equal to 0.85±0.04, 0.83±0.03, and 0.71±0.08, respectively. Spearman correlation to breeding values of sires for ADG as the selection intensity increased in them, and the correlations between breeding values in general analyses were more correlated with those predicted in the high DP. Therefore, when there is a higher selection intensity on the sires only for the ADG criterion, there is a significant presence of the heterogeneity of variances and impact on the genetic evaluation of the sires. Thus, for ADG, the predictions of breeding values obtained by the genetic evaluation model in which the heterogeneity of variances are not considered are more weighted by the class of greater heterogeneity.(AU)

Dried distillers grains with solubles in diets during late gestation affects behavior and maintains the performance of sows

We examined the effect of dried distillers grains with solubles (DDGS) in diets for late gestating sows on sow and litter performance, colostrum chemical composition, and sow behavior. Sixty gestating sows of 3.77±1.65 parity were divided into three groups of 20 animals, in a randomized block design with 0 (corn-soybean meal diet), 150, or 300 g kg−1 DDGS from 84 days of gestation until farrowing. Sows fed 300 g kg−1 DDGS presented a lower frequency of standing position and eating activity. The lying lateral position was more frequent in the first 40 min post-feeding for sows fed the highest DDGS level. There was no effect of diets on sow and litter performance; however, DDGS inclusion tended to increase lactation feed intake. Inclusion of DDGS was inclined to produce more lactose and less protein in colostrum, but did not affect colostrum fat, total solids, and ash contents. Inclusion of up to 300 g kg−1 DDGS in the diet of late gestation sows does not change sow and litter performance and colostrum composition compared with corn-soybean meal diets, but it favored animal welfare.(AU)

Cottonseed and Soy-bean agro-industrial by-products used in feedlot cattle diet: effects on beef fatty acid profile and quality parameters / Subprodutos agroindustriais de caroço de algodão e soja utilizados na dieta de bovinos confinados: efeitos no perfil de ácidos graxos e parâmetros de qualidade da carne bovina

Beef composition are directly influenced by the dietary fat, particularly in ruminants, due to rumen biohydrogenation, which promotes alterations in the dietary fatty acid (FA) profile and affects the meat quality. Beef sensorial, chemical, and FA compositions of intramuscular and subcutaneous fat were evaluated, from 40 Nellore males finished on feedlot diet based, containing cottonseed (CSB) and soybean by-product (SOB) as agro-industrial by-product fat sources. CSB as a fat source, did not alter the beef pH, shear force, chemical composition, or subcutaneous FA profile compared with the SOB diet. Differences were observed at yellow and red beef color, with low and high CSB diet inclusion; on the contrary, inclusion of SOB in the diet led to an intensely unpleasant aroma in aged and cooked meats. Regarding beef FA profile, CSB with 3% dietary fat produced steaks with a lower proportion of C 17:0 , having 1.359 and 3.238 g/100 g of intramuscular FA, whereas CSB with 5% dietary fat led to an increase in C 18:2 n -6 , with 0.298 and 0.132 g/100 g of intramuscular FA in steaks from animals fed with CSB and SOB, respectively. CSB produced more intense red beef color, unpleasant aroma, and higher linoleic acid content; however, the color and aroma of the meat produced from cattle fed with CSB in the diet were less intense and were like those observed in cattle fed with SOB; these could therefore be recommended for use as agro-industrial by-products in beef cattle diet.(AU)

A composição da carne bovina é influenciada diretamente pela gordura da dieta, principalmente em ruminantes, devido à biohidrogenação ruminal, que promove alterações no perfil de ácidos graxos dietéticos e afeta a qualidade da carne. Foram avaliadas às composições sensoriais, químicas e de ácido graxo da carne, da gordura intramuscular e subcutânea, de 40 machos Nelore terminados em dieta de confinamento contendo caroço de algodão (CSB) e subproduto de soja (SOB) como fontes de gordura de subprodutos agroindustriais. CSB, não alterou o pH da carne, força de cisalhamento, composição química ou perfil de ácido graxo subcutâneo em comparação com a dieta SOB. Diferenças foram observadas na cor amarela e vermelha da carne bovina, com baixa e alta inclusão de CSB na dieta; a inclusão de SOB na dieta levou a um aroma intensamente desagradável em carnes envelhecidas e cozidas. Em relação ao perfil de ácido graxo da carne bovina, CSB com 3% de gordura dietética produziu bifes com menor proporção de C 17: 0 , tendo 1.359 e 3.238 g / 100 g de ácido graxo intramuscular, enquanto CSB com 5% de gordura dietética levou a um aumento de C 18: 2n- 6 , com 0,298 e 0,132 g / 100 g de ácido graxo intramuscular em bifes de animais alimentados com CSB e SOB, respectivamente. CSB produziu cor vermelha bovina mais intensa, aroma desagradável e maior teor de ácido linoléico; entretanto, a cor e o aroma da carne produzida em bovinos alimentados com CSB na dieta foram menos intensos e semelhantes aos observados em bovinos alimentados com SOB; estes poderiam, portanto, ser recomendados para uso como subprodutos agroindustriais na dieta de bovinos de corte.(AU)

Effect of sample size on kinetic parameters of roughage and concentrated feeds by a semi-automated in vitro gas production system / Efeito do tamanho da amostra nos parâmetros cinéticos de alimentos volumosos e concentrados por meio de um sistema de produção de gases in vitro semi-automatizado

This study aimed to evaluate the effect of different amounts of incubated samples on the kinetic parameters of in vitro fermentation of roughage and concentrated food used for feeding ruminants. Samples were prepared using 200, 300, 400, and 500 mg of air-dried roughage and concentrated sample, ground to 1 mm, and placed in 120 mL glass flasks. Next, inoculum and McDougal solution were added, and the readings were obtained using a semi-automated pressure transducer up to 96 h after the beginning of the incubations. Gas production of the non-fibrous fraction increased linearly (P < 0.05) for sugarcane, Marandu grass silage, corn silage, dried corn distillers' grains with solubles, dried brewer's yeast, bean residue, wet brewer's grains, sunflower meal, and Jatropha meal; quadratically (P < 0.05) for Napier grass silage and cottonseed meal; and cubically (P < 0.05) for castor meal and soybean meal. The degradation rate of the non-fibrous fraction reduced linearly (P < 0.05) for sugarcane, Napier grass silage, and castor meal; quadratically (P < 0.05) for Marandu grass silage; and cubically (P < 0.05) for corn silage, soybean meal, dried corn distillers' grains with solubles, bean residue, and cottonseed meal. Gas production of the fibrous fraction increased linearly (P < 0.05) for Napier grass silage, Marandu grass silage, corn silage, dried corn distillers' grains with solubles, bean residue, wet brewer’s grain, cottonseed meal, and sunflower meal; quadratically ( < 0.05) for Jatropha meal; and cubically (P < 0.05) for sugarcane, castor meal, and soybean meal. The degradation rate of the fibrous fraction increased linearly (P < 0.05) for Napier grass silage, dried corn distillers’ grains with solubles, dried brewer’s yeast, wet brewer’s grains; quadratically (P < 0.05) for corn silage and castor meal; and cubically (P < 0.05) for sugarcane, Marandu grass silage, and bean residue. The lag time reduced linearly (P < 0.05)...

Objetivou-se com este trabalho avaliar o efeito de diferentes quantidades de amostras incubadas sobre os parâmetros cinéticos de fermentação in vitro de alimentos concentrados e volumosos disponíveis para alimentação de ruminantes. O preparo das amostras foi realizado utilizando 200, 300, 400 e 500 mg de amostra seca ao ar, moída a 1 mm, alocadas em frascos de vidro com capacidade de 120 mL, e adicionados inóculo e solução McDougal, seguidos das leituras, por meio de um transdutor de pressão semi-automatizado, até 96 horas após o inicio das incubações. A produção de gases da fração não-fibrosa apresentou comportamento linear crescente (P < 0,05) para a cana-de-açúcar, silagem de capim marandu, silagem de milho, grão seco da destilaria do milho, resíduo de cervejaria desidratado, resíduo de feijão, resíduo úmido de cervejaria, torta de girassol e farelo de pinhão manso, quadrático (P < 0,05) para silagem de capim napier e torta de algodão, e cúbico (P < 0,05) para farelo de mamona e farelo de soja. A taxa de degradação da fração não-fibrosa apresentou redução linear (P < 0,05) para a cana-de-açúcar, silagem de capim napier e farelo de mamona, quadrático (P < 0,05) para a silagem de capim marandu, e cúbico (P < 0,05) para a silagem de milho, farelo de soja, grão seco da destilaria do milho, resíduo de feijão e torta de algodão. A produção de gases da fração fibrosa apresentou comportamento linear crescente (P < 0,05) para a silagem de capim napier, silagem de capim marandu, silagem de milho, grão seco da destilaria do milho, resíduo de feijão, resíduo úmido de cervejaria, torta de algodão e torta de girassol, quadrático (P < 0,05) para farelo de pinhão manso, e cúbico (P < 0,05) para a cana-de-açúcar, farelo de mamona, farelo de soja. A taxa de degradação da fração fibrosa apresentou comportamento linear decrescente (P < 0,05) para a silagem de capim napier, grão seco da destilaria do milho, resíduo...

Effect of sample size on kinetic parameters of roughage and concentrated feeds by a semi-automated in vitro gas production system / Efeito do tamanho da amostra nos parâmetros cinéticos de alimentos volumosos e concentrados por meio de um sistema de produção de gases in vitro semi-automatizado

This study aimed to evaluate the effect of different amounts of incubated samples on the kinetic parameters of in vitro fermentation of roughage and concentrated food used for feeding ruminants. Samples were prepared using 200, 300, 400, and 500 mg of air-dried roughage and concentrated sample, ground to 1 mm, and placed in 120 mL glass flasks. Next, inoculum and McDougal solution were added, and the readings were obtained using a semi-automated pressure transducer up to 96 h after the beginning of the incubations. Gas production of the non-fibrous fraction increased linearly (P < 0.05) for sugarcane, Marandu grass silage, corn silage, dried corn distillers' grains with solubles, dried brewer's yeast, bean residue, wet brewer's grains, sunflower meal, and Jatropha meal; quadratically (P < 0.05) for Napier grass silage and cottonseed meal; and cubically (P < 0.05) for castor meal and soybean meal. The degradation rate of the non-fibrous fraction reduced linearly (P < 0.05) for sugarcane, Napier grass silage, and castor meal; quadratically (P < 0.05) for Marandu grass silage; and cubically (P < 0.05) for corn silage, soybean meal, dried corn distillers' grains with solubles, bean residue, and cottonseed meal. Gas production of the fibrous fraction increased linearly (P < 0.05) for Napier grass silage, Marandu grass silage, corn silage, dried corn distillers' grains with solubles, bean residue, wet brewers grain, cottonseed meal, and sunflower meal; quadratically ( < 0.05) for Jatropha meal; and cubically (P < 0.05) for sugarcane, castor meal, and soybean meal. The degradation rate of the fibrous fraction increased linearly (P < 0.05) for Napier grass silage, dried corn distillers grains with solubles, dried brewers yeast, wet brewers grains; quadratically (P < 0.05) for corn silage and castor meal; and cubically (P < 0.05) for sugarcane, Marandu grass silage, and bean residue. The lag time reduced linearly (P < 0.05)...(AU)

Objetivou-se com este trabalho avaliar o efeito de diferentes quantidades de amostras incubadas sobre os parâmetros cinéticos de fermentação in vitro de alimentos concentrados e volumosos disponíveis para alimentação de ruminantes. O preparo das amostras foi realizado utilizando 200, 300, 400 e 500 mg de amostra seca ao ar, moída a 1 mm, alocadas em frascos de vidro com capacidade de 120 mL, e adicionados inóculo e solução McDougal, seguidos das leituras, por meio de um transdutor de pressão semi-automatizado, até 96 horas após o inicio das incubações. A produção de gases da fração não-fibrosa apresentou comportamento linear crescente (P < 0,05) para a cana-de-açúcar, silagem de capim marandu, silagem de milho, grão seco da destilaria do milho, resíduo de cervejaria desidratado, resíduo de feijão, resíduo úmido de cervejaria, torta de girassol e farelo de pinhão manso, quadrático (P < 0,05) para silagem de capim napier e torta de algodão, e cúbico (P < 0,05) para farelo de mamona e farelo de soja. A taxa de degradação da fração não-fibrosa apresentou redução linear (P < 0,05) para a cana-de-açúcar, silagem de capim napier e farelo de mamona, quadrático (P < 0,05) para a silagem de capim marandu, e cúbico (P < 0,05) para a silagem de milho, farelo de soja, grão seco da destilaria do milho, resíduo de feijão e torta de algodão. A produção de gases da fração fibrosa apresentou comportamento linear crescente (P < 0,05) para a silagem de capim napier, silagem de capim marandu, silagem de milho, grão seco da destilaria do milho, resíduo de feijão, resíduo úmido de cervejaria, torta de algodão e torta de girassol, quadrático (P < 0,05) para farelo de pinhão manso, e cúbico (P < 0,05) para a cana-de-açúcar, farelo de mamona, farelo de soja. A taxa de degradação da fração fibrosa apresentou comportamento linear decrescente (P < 0,05) para a silagem de capim napier, grão seco da destilaria do milho, resíduo...(AU)

The effect of transport density and gender on skin temperature and carcass and meat quality in pigs / Efeito da densidade de transporte e de gênero na temperatura da pele e qualidade de carcaça e carne em suínos

Pre-slaughter handling of pigs established properly is very important, not only from the point of view of welfare, but also for the quality of meat. The aim of present research was to evaluate the effect of gender and density of pigs during their transport to the abattoir on the skin temperature and carcass and meat quality. Were used 192 (115.54 ± 6.03 kg) finishing pigs to investigate the effects of gender (barrows and gilts) and transport densities for slaughter (236, 251, and 275 kg/m²) on the skin temperature and carcass and meat quality. Average skin temperature between genders and transport densities at any point of time during pre-slaughter did not differ. Skin temperatures before unloading had the highest average value relative to all other time points, followed by immediately after unloading and remaining the same for the next 2 h. Lowest skin temperature value was registered on pigs at the pre-slaughter time followed by farm and at loading times. Pigs transported with different densities did not show differences for the skin carcass lesions. Meat from pigs transported at 275 kg/m² presented higher frequency of red, soft, exudative (RSE) and lower of red, firm, non-exudative (RFN) classes as compared to those for other densities. Animals transported at 236 and 251 kg/m² did not differ as the frequency of RSE and RFN meat. Skin temperature of pigs oscillate along the pre-slaughter times and the pre-slaughter transport of pigs at 236 and 251 kg/m² generates less frequency classes of faulty pork, although difference in the densities did not have any effect on the skin temperature and skin lesions.

O manejo pré-abate estabelecido adequadamente é importante, não apenas do ponto de vista de bemestar, mas também para qualidade da carne. O objetivo com o presente estudo foi avaliar o efeito do gênero e da densidade de transporte de suínos para o abatedouro sobre a temperatura da pele, qualidade de carcaça e carne de suínos. Foram utilizados 192 (115,54 ± 6,03 kg) suínos em terminação para avaliar os efeitos de gênero (machos castrados e fêmeas) e densidades de transporte para abate (236, 251, e 275 kg / m²) sobre a temperatura da pele e qualidade de carcaça e carne de suínos. Os valores médios de temperatura da pele entre os gêneros e densidades de transporte não diferiram no pré-abate. A temperatura da pele dos animais antes do descarregamento foi maior, seguidos pelo momento imediatamente após a descarga e mantendo o mesmo para as próximas duas horas. O menor valor de temperatura da pele foi registrado em suínos no momento pré-abate seguido pelos momentos à granja e ao carregamento. Os suínos transportados com diferentes densidades não apresentaram diferenças para as lesões na carcaça. Carne de suínos transportados a 275 kg / m² apresentaram maior frequência de carne vermelha, flácida e exsudativa (RSE) e menores de carne vermelha, firme e nãoexsudativa (RFN) em comparação com outras densidades. Os animais transportados à 236 e 251 kg/m² não diferem quanto a frequência de carne RSE e RFN. A temperatura de pele de suínos oscila ao longo dos momentos pré-abate, e transporte de suínos pré-abate com 236 e 251 kg/m² geram menor frequência de classes anormais de carne, embora diferenças nas densidades não tiveram efeitos sobre a temperatura da pele e lesões de pele.

Impacto da distribuição de número desigual de progênies por reprodutor na avaliação genética de animais, em ambientes com presença de heterogeneidade de variância ambiental / Impact of the uneven distribution of the number of progenies by sires in the genetic evaluation of animals in environments with presence of heterogeneity of environmental variance

A progeny test representing the milk yield was simulated to evaluate the effect of heterogeneity of environmental variance on genetic evaluation of sires in situations of unequal number of progeny per sire between herds, eliminating, at random, daughters per sires in environments of low and high environmental variability. In all situations involving loss of information in the environment of lower environmental variability, there was larger overestimation of the residual variance component, resulting in lower estimates of heritability. On the other hand, the decrease in the amount of information of herds from high environmental variability led to greater overestimation of additive genetic variance and lower overestimation of environmental variance. Although there were alterations in breeding values regarding sires, Spearman and Pearson correlations between breeding values, in all situations, were higher than 0.90. The uneven number of progeny per sire in the presence of heterogeneity of environmental variance led to the overestimation of variance components and changes in absolute breeding values of the sires, without, however, changing the classification values.

Foi simulado um teste de progênie com o objetivo de avaliar o efeito da heterogeneidade de variância ambiental sobre a avaliação genética de reprodutores, em situações de número desigual de progênie por reprodutor entre rebanhos. A situação do número desigual de progênie por reprodutor foi representada eliminando-se, de forma aleatória, o número de progênies por reprodutor em ambientes de baixa e alta variabilidade ambiental. Nas situações que envolveram perda de informação no ambiente de menor variabilidade ambiental, houve maiores superestimações na estimação da variância residual, ocasionando menores estimativas de herdabilidade. Por outro lado, quando se diminuiu a quantidade de informação proveniente de rebanhos de alta variabilidade ambiental, houve maior superestimação da variância genética aditiva e menor superestimação da variância ambiental. Embora, tenham ocorrido alterações na magnitude dos valores genéticos para os reprodutores, as correlações de Spearman e Pearson entre os valores genéticos dos mesmos, em todas as situações, foram maiores do que 0,90. O número desigual de progênie por reprodutor na presença de heterogeneidade de variância ambiental provoca superestimação das estimativas de componentes de variância e valores absolutos de predição de valores genéticos dos reprodutores, sem, contudo, alterar a classificação dos mesmos.

Impacto da distribuição de número desigual de progênies por reprodutor na avaliação genética de animais, em ambientes com presença de heterogeneidade de variância ambiental / Impact of the uneven distribution of the number of progenies by sires in the genetic evaluation of animals in environments with presence of heterogeneity of environmental variance

A progeny test representing the milk yield was simulated to evaluate the effect of heterogeneity of environmental variance on genetic evaluation of sires in situations of unequal number of progeny per sire between herds, eliminating, at random, daughters per sires in environments of low and high environmental variability. In all situations involving loss of information in the environment of lower environmental variability, there was larger overestimation of the residual variance component, resulting in lower estimates of heritability. On the other hand, the decrease in the amount of information of herds from high environmental variability led to greater overestimation of additive genetic variance and lower overestimation of environmental variance. Although there were alterations in breeding values regarding sires, Spearman and Pearson correlations between breeding values, in all situations, were higher than 0.90. The uneven number of progeny per sire in the presence of heterogeneity of environmental variance led to the overestimation of variance components and changes in absolute breeding values of the sires, without, however, changing the classification values.(AU)

Foi simulado um teste de progênie com o objetivo de avaliar o efeito da heterogeneidade de variância ambiental sobre a avaliação genética de reprodutores, em situações de número desigual de progênie por reprodutor entre rebanhos. A situação do número desigual de progênie por reprodutor foi representada eliminando-se, de forma aleatória, o número de progênies por reprodutor em ambientes de baixa e alta variabilidade ambiental. Nas situações que envolveram perda de informação no ambiente de menor variabilidade ambiental, houve maiores superestimações na estimação da variância residual, ocasionando menores estimativas de herdabilidade. Por outro lado, quando se diminuiu a quantidade de informação proveniente de rebanhos de alta variabilidade ambiental, houve maior superestimação da variância genética aditiva e menor superestimação da variância ambiental. Embora, tenham ocorrido alterações na magnitude dos valores genéticos para os reprodutores, as correlações de Spearman e Pearson entre os valores genéticos dos mesmos, em todas as situações, foram maiores do que 0,90. O número desigual de progênie por reprodutor na presença de heterogeneidade de variância ambiental provoca superestimação das estimativas de componentes de variância e valores absolutos de predição de valores genéticos dos reprodutores, sem, contudo, alterar a classificação dos mesmos.(AU)

IMPACTO DA DISTRIBUIÇÃO DE NÚMERO DESIGUAL DE PROGÊNIES POR REPRODUTOR NA AVALIAÇÃO GENÉTICA DE ANIMAIS, EM AMBIENTES COM PRESENÇA DE HETEROGENEIDADE DE VARIÂNCIA AMBIENTAL

Abstract A progeny test representing the milk yield was simulated to evaluate the effect of heterogeneity of environmental variance on genetic evaluation of sires in situations of unequal number of progeny per sire between herds, eliminating, at random, daughters per sires in environments of low and high environmental variability. In all situations involving loss of information in the environment of lower environmental variability, there was larger overestimation of the residual variance component, resulting in lower estimates of heritability. On the other hand, the decrease in the amount of information of herds from high environmental variability led to greater overestimation of additive genetic variance and lower overestimation of environmental variance. Although there were alterations in breeding values regarding sires, Spearman and Pearson correlations between breeding values, in all situations, were higher than 0.90. The uneven number of progeny per sire in the presence of heterogeneity of environmental variance led to the overestimation of variance components and changes in absolute breeding values of the sires, without, however, changing the classification values.

Resumo Foi simulado um teste de progênie com o objetivo de avaliar o efeito da heterogeneidade de variância ambiental sobre a avaliação genética de reprodutores, em situações de número desigual de progênie por reprodutor entre rebanhos. A situação do número desigual de progênie por reprodutor foi representada eliminando-se, de forma aleatória, o número de progênies por reprodutor em ambientes de baixa e alta variabilidade ambiental. Nas situações que envolveram perda de informação no ambiente de menor variabilidade ambiental, houve maiores superestimações na estimação da variância residual, ocasionando menores estimativas de herdabilidade. Por outro lado, quando se diminuiu a quantidade de informação proveniente de rebanhos de alta variabilidade ambiental, houve maior superestimação da variância genética aditiva e menor superestimação da variância ambiental. Embora tenham ocorrido alterações na magnitude dos valores genéticos para os reprodutores, as correlações de Spearman e Pearson entre os valores genéticos dos mesmos, em todas as situaçãoes, foram maiores do que 0,90. O número desigual de progênie por reprodutor na presença de heterogeneidade de variância ambiental provoca superestimação das estimativas de componentes de variância e valores absolutos de predição de valores genéticos dos reprodutores, sem, contudo, alterar a classificação dos mesmos.

Bovine leukosis virus and antibodies against bovine herpesvirus type-1 and bovine viral diarrhea virus and in bufaloes of the State of Pará, Brazil / Ocorrência do vírus da leucose enzoótica dos bovinos (BLV) e de anticorpos contra herpesvírus bovino tipo-1 (BoHV-1) e vírus da diarreia viral bovina (BVDV) em búfalos no Estado do Pará

Background: Viral diseases affecting reproduction cause economic losses in cattle, as reproductive failure interrupts the production cycle, thus reducing herd productivity. Buffaloes are susceptible to most of the diseases that affect cattle. Some of the viral diseases of reproductive importance are infectious bovine rhinotracheitis (IBR), bovine viral diarrhea (BVD), and bovine leukosis (BL). The objective of this study was to determine the seroprevalence of IBR virus (bovine herpes virus-1, BoHV-1), BVD virus (BVDV), and BL virus (BLV) in female buffaloes living in wetland areas or plains in the state of Pará, as well as the seroprevalence of BoHV-1, BVDV, and BLV in females of different age groups. Materials, Methods & Results: It were used 225 crossbred buffaloes from 4 buffalo exclusive farms. The buffaloes reared on farms A (n = 50) and B (n = 89) were kept in wetland areas on Marajó Island (n = 139), Pará. On farms C (n = 30) and D (n = 56) buffaloes were kept in plains (n = 86) in a northeastern mesoregion of Para. Animals were categorized into age groups: I: 0-3 years (n = 34), II: 3-6 years (n = 58), III: 7-9 years (n = 55), and IV: over 9 years (n = 78). Blood samples were collected and sera were sent for processing at the Bovine Virus Laboratory, Biological Institute of São Paulo, Brazil. The presence of IBRV and BVDV was determined by neutralization and BLV [...](AU)

Bovine leukosis virus and antibodies against bovine herpesvirus type-1 and bovine viral diarrhea virus and in bufaloes of the State of Pará, Brazil / Ocorrência do vírus da leucose enzoótica dos bovinos (BLV) e de anticorpos contra herpesvírus bovino tipo-1 (BoHV-1) e vírus da diarreia viral bovina (BVDV) em búfalos no Estado do Pará

Background: Viral diseases affecting reproduction cause economic losses in cattle, as reproductive failure interrupts the production cycle, thus reducing herd productivity. Buffaloes are susceptible to most of the diseases that affect cattle. Some of the viral diseases of reproductive importance are infectious bovine rhinotracheitis (IBR), bovine viral diarrhea (BVD), and bovine leukosis (BL). The objective of this study was to determine the seroprevalence of IBR virus (bovine herpes virus-1, BoHV-1), BVD virus (BVDV), and BL virus (BLV) in female buffaloes living in wetland areas or plains in the state of Pará, as well as the seroprevalence of BoHV-1, BVDV, and BLV in females of different age groups. Materials, Methods & Results: It were used 225 crossbred buffaloes from 4 buffalo exclusive farms. The buffaloes reared on farms A (n = 50) and B (n = 89) were kept in wetland areas on Marajó Island (n = 139), Pará. On farms C (n = 30) and D (n = 56) buffaloes were kept in plains (n = 86) in a northeastern mesoregion of Para. Animals were categorized into age groups: I: 0-3 years (n = 34), II: 3-6 years (n = 58), III: 7-9 years (n = 55), and IV: over 9 years (n = 78). Blood samples were collected and sera were sent for processing at the Bovine Virus Laboratory, Biological Institute of São Paulo, Brazil. The presence of IBRV and BVDV was determined by neutralization and BLV [...]

Parâmetros nutricionais de novilhas Nelore em pastejo de capim marandu recebendo suplemento energético, proteico e múltiplo no período de transição seca-águas / Nutritional parameters of Nellore heifers grazing in grass marandu receiving energy, protein and multiple supplement the dry-rainy transition period

O objetivo foi avaliar o consumo e a digestibilidade dos nutrientes, a concentração de nitrogênio amoniacal (N-NH3) no rúmen e nitrogênio ureico no soro (NUS) em novilhas Nelore recriadas em capim Marandu durante o período de transição seca-águas recebendo suplementos concentrados. Foram utilizadas quatro novilhas Nelore com peso corporal e idade inicial média de 189,5kg e 12 meses, respectivamente, distribuídas em quatro piquetes de 0,25 ha cada. O delineamento utilizado foi o quadrado latino (quatro suplementos e quatro períodos de 14 dias). Os suplementos avaliados foram: suplemento energético (SE), proteico (SP) e múltiplo (SM), fornecidos na quantidade de 1 kg animal dia-¹, além do suplemento contendo mistura mineral comercial ad libitum (MM). A suplementação concentrada não influenciou os consumos de matéria seca, de matéria orgânica total e da forragem. O suplemento SP proporcionou maior (P<0,0001) consumo de proteína bruta (PB). Os suplementos SE e SP resultaram em maior consumo de extrato etéreo. A digestibilidade da PB foi maior (P<0,0001) para os animais suplementados com SP e SM. Imediatamente antes e quatro horas após o fornecimento da suplementação observaram-se maiores concentrações de N-NH3 ruminal para os suplementos SP e SM. Não verificou-se diferença quanto ao nitrogênio uréico no soro (NUS). A utilização de suplemento proteico e múltipo proporcionaram melhor adequação do ambiente ruminal de novilhas no período de transição seca-águas alimentadas com capim Marandu.(AU)

The objective was to evaluate thein take and digestibility of nutrients, ammonia nitrogen (NH3-N) in the rumen and serum urea nitrogen (BUN) in Nellore heifers in grass Marandu recreated during the transition period dry energy supplement receiving waters, protein and multiple. We used four heifers with average body weight and initial age of 189.5 kg and 12 months respectively, distributed in four paddocks of 0.25 ha each. The design was a 4x4 Latin square (four supplements and four periods of 14 days). The supplements were: energy supplement (ES) protein (PS) and multiple (MS), provided the amount of 1 kg animal day-¹ in addition to supplement containing commercial mineral mixture ad libitum (MM). The concentrate supplementation did not increase intakes of dry matter, total organic matter and forage. The additional SP provided greater (P<0,0001) intake of crude protein (CP). The SE and SP supplement resulted ingreater ether extract intake. The CP was higher (P< 0.0001) in animals supplemented with SP and SM. Immediately before and four hours after supplementation higher concentrations of ruminal NH3-N were observed for the SM and SP supplements. There were no differences for ser um urea nitrogen (BUN). The use of protein supplement and multiple provided the best fit of the rumen of heifers during the transition period dry-rainy fed on grasses Marandu environment.(AU)

Bioeconomic efficiency of beef cattle at feedlot / Eficiência bioeconômica de bovinos de corte em confinamento

It was aimed to evaluate the dry matter intake (DMI), total weight gain (TWG) and the bioeconomic efficiency of feedlot beef cattle with different body weights in dry and rainy season. Records of DMI, TWG, feed conversion (FC), feed efficiency (EA), lot size and feedlot length of stay (LS) of 13,686 beef cattle males with predominance of Nelore blood finished the year 2009, were used to discriminate possible differences in input weight (up to 350kg or above 350kg) and the season (dry or water). There was no effect on the season (rainy x dry) to DMI and TWG of independent animals, regardless of weight class that showed differences, with the lighter animals presented lower DMI and higher TWG and therefore higher efficiency than animals with higher higher starting weights of feedlot. The purchase price per head affects highly on value per head for the exit of feedlot which is dependent on dry matter intake and total weight gain for maximizing revenue.(AU)

Objetivou-se avaliar o consumo de matéria seca, o ganho de peso total e a eficiência bioeconômica de bovinos de corte terminados em confinamento com diferentes pesos corporais ao início do confinamento nos períodos de seca e de chuvas. Registros de CMS, ganho de peso total (GPT), conversão alimentar (CA), eficiência alimentar (EA), tamanho de lote e tempo de permanência (TP) no confinamento de 13.686 bovinos de corte machos com predominância de sangue nelore terminados no ano de 2009, foram utilizados para discriminar possíveis diferenças quanto ao peso de entrada (até 350kg ou acima de 350kg) e da época do ano (seca ou águas). Observou-se ausência de efeitos da época do ano (chuvas x seca) para o CMS e o GPT dos animais independente da classe de peso que apresentaram diferenças, com os animais mais leves apresentando menores CMS e maiores GPT e, consequentemente, maior eficiência que os animais mais pesados ao início do confinamento. O valor de compra por cabeça interfere altamente sobre valor por cabeça na saída do confinamento que é dependente do consumo de matéria seca e do ganho de peso total para maximização da receita.(AU)

Bioeconomic efficiency of beef cattle at feedlot / Eficiência bioeconômica de bovinos de corte em confinamento

It was aimed to evaluate the dry matter intake (DMI), total weight gain (TWG) and the bioeconomic efficiency of feedlot beef cattle with different body weights in dry and rainy season. Records of DMI, TWG, feed conversion (FC), feed efficiency (EA), lot size and feedlot length of stay (LS) of 13,686 beef cattle males with predominance of Nelore blood finished the year 2009, were used to discriminate possible differences in input weight (up to 350kg or above 350kg) and the season (dry or water). There was no effect on the season (rainy x dry) to DMI and TWG of independent animals, regardless of weight class that showed differences, with the lighter animals presented lower DMI and higher TWG and therefore higher efficiency than animals with higher higher starting weights of feedlot. The purchase price per head affects highly on value per head for the exit of feedlot which is dependent on dry matter intake and total weight gain for maximizing revenue.

Objetivou-se avaliar o consumo de matéria seca, o ganho de peso total e a eficiência bioeconômica de bovinos de corte terminados em confinamento com diferentes pesos corporais ao início do confinamento nos períodos de seca e de chuvas. Registros de CMS, ganho de peso total (GPT), conversão alimentar (CA), eficiência alimentar (EA), tamanho de lote e tempo de permanência (TP) no confinamento de 13.686 bovinos de corte machos com predominância de sangue nelore terminados no ano de 2009, foram utilizados para discriminar possíveis diferenças quanto ao peso de entrada (até 350kg ou acima de 350kg) e da época do ano (seca ou águas). Observou-se ausência de efeitos da época do ano (chuvas x seca) para o CMS e o GPT dos animais independente da classe de peso que apresentaram diferenças, com os animais mais leves apresentando menores CMS e maiores GPT e, consequentemente, maior eficiência que os animais mais pesados ao início do confinamento. O valor de compra por cabeça interfere altamente sobre valor por cabeça na saída do confinamento que é dependente do consumo de matéria seca e do ganho de peso total para maximização da receita.

Desempenho, crescimento e características de carcaça de linhagens alternativas de frangos de corte criados com acesso a piquete / Performance, growth and carcass characteristics of alternatives lineages of broiler chickens created with access to paddock

Objetivou-se com este estudo avaliar o desempenho de linhagens alternativas de frangos de corte, criados em sistema com acesso a piquete. Foram utilizados 312 pintos de corte de um dia de idade, alojados com uma densidade de 6,4 aves/m2 na área interna e 2 m2/animal na área de pastejo. Os tratamentos adotados corresponderam a cada linhagem: Redbro Cou Nu, Gris Barré Cou Nu, Master Gris Cou Plumé e Gris Barré Cou Plumé. O delineamento estatístico adotado foi inteiramente casualizado, com quatro tratamentos e seis repetições. Para o estudo do crescimento a equação de Gompertz apresentou melhor ajuste, quando comparadas ás demais. A linhagem Master Gris Cou Plumé obteve maior peso assintótico, taxa de crescimento absoluto máximo e menor viabilidade, maiores valores de peso médio e ganho de peso, quando comparada à linhagem Gris Barré Cou Nu. Mesmo com as diferenças de desempenho zootécnico entre as linhagens estudadas, não a diferenças significativas entre médias de peso do corpo após o jejum e peso das carcaças evisceradas. Foram observados maiores pesos de carcaça, peito, coxa+sobrecoxa, dorso e asa para a linhagem Master Gris Cou Plumé, quando comparado a Gris Barré Cou Nu e Gris Barré Cou Plumé.

The aim of this study was to evaluate the performance of alternative lineages of broiler chickens created with access to paddock. Were used 312 one day broiler chickens, house data density of 6.4birds/m2in the internal area and 2m2/animal in the pasture area. The treatments consisted of each lineage used in the experiment: Redbro Cou Nu, Gris Barré Cou Nu, Master Gris Cou Plume and Gris Barré Cou Plume. The statistical design was completely randomized with four treatments and six repetitions. For study the growth, the Gompertz equation showed a better adjustment compared with others. The lineage Master Gris Cou Plume got the greatest asymptotic weight, absolute growth rate and lowest viability, higher average weight and weight gain when compared to lineage Gris Barré Cou Nu. Even with the differences in zoo technical performance among the lineages studied, not the significance of differences between means indicates there is a ratio of body weight after fasting and weight of the eviscerated carcass.Showed highercarcass weight, chest, thigh + drumstick, wing and backin the lineage Master Gris Cou Plume, compared to Gris Barré Cou Nu and Gris Barré Cou Plume. The lineages Redbro Cou Nu and Master Gris Cou Plume had similar performance, but the Redbro Cou Nu, showed growth characteristics more suitable to alternative creations with access to paddock area.