Beef cows' milk yield is typically determined by measuring milk yield once daily and then doubling this value to estimate daily production. However, it is not known whether this is accurate. Thus, we aimed to determine the association between morning and afternoon milk yield in grazing Nellore cows. Eighty Nellore cows were used, with initial weight of 516.0 ± 1.0 kg. The experiment was a completely randomized factorial scheme, with 20 replications and four treatments (i.e., + or - pre-partum supplementation in combination with + or - post-partum supplementation): PRMM-1 kg of supplement/cow/day for 90 days pre-partum; MMPS-1 kg of supplement/cow/day for 90 days post-partum; PRPS-1 kg of supplement/cow/day for 90 days pre-partum and 90 days post-partum; and MM-only mineral mix ad libitum during pre- and post-partum. Milk was sampled on days 45, 135, and 225 post-partum (early, middle, and late lactation, respectively). No effects were observed of pre- and post-partum supplementation on milk yield (P > 0.05). The afternoon/morning proportion of 0.45 in the early third of lactation was higher than other stages, which had a proportion of 0.41 (P < 0.05). Post-partum supplementation increased milk protein in the morning and afternoon milking (P < 0.05). There was also no effect of pre- and post-partum supplementation on afternoon-morning proportion other milk components (P> 0.05). We conclude that estimating daily milk production of grazing beef cattle by multiplying a once daily milking amount times two is not accurate. Under the conditions of this study, proportion of total daily production represented by the ratio of afternoon/morning milking was 0.45 in early lactation (first third) and 0.41 in mid- and late lactation.

-The study assessed performance, microbial protein synthesis, intake and digestibility of nutrients by beef heifers receiving levels of multiple supplements or nitrogen salt, in a self-controlled intake, on pasture, during the dry season. Thirty-five beef heifers, from 6 to 9 months of age and average initial body weight of 203.4 + 4.5 kg, were used. Study factors were: control -mineral mixture; nitrogen salt -50% of urea + mineral mixture, at proportion of 1:1, and 50% of corn (75% of crude protein); levels of multiple supplementation -multiple supplements with different percentages of intake controller mixture (urea + mineral mixture, at the proportion of 1:1), corn and soybean meal (45% of crude protein). Supplement consumptions observed were: 115, 173, 572 and 1214 g/animal/day for animals fed on nitrogen salt, low, medium and high levels of multiple supplement, respectively. Supplemented animals had greater average daily gain, evidencing the positive linear effect of the levels of multiple supplementation on average daily gain. Overall, there were no significant differences between average daily gain of animals fed on multiple supplements or nitrogen salt. Supplementation increased the intake and digestibility of nutrients, except for digestibility of neutral detergent fiber, although the intake of digested neutral detergent fiber increased. Supplementation increased the production of microbial nitrogen as well as nitrogen losses in urine, although the quantity of nitrogen assimilated by bacteria, proportionally to intake, was higher.Supplementation improves nutritional parameters and weight gain.

RESUMO -Avaliaram-se os efeitos de suplementos múltiplos com diferentes níveis de uréia sobre o desempenho produtivo e os parâmetros nutricionais de bovinos em fase de terminação mantidos em pastagem diferida de capim-braquiária (Brachiaria brizantha cv. Marandu) no período de transição águas-seca. A disponibilidade estimada de matéria seca das pastagens variou de 16.360 a 9.358 kg/ha. Para avaliação do desempenho produtivo, utilizaram-se 20 novilhos mestiços não-castrados, com 20 meses de idade e 376 kg de peso vivo. Os animais foram agrupados em lotes com pesos semelhantes, segundo um delineamento inteiramente casualizado, em quatro piquetes de 1,5 ha, onde receberam 1,5 kg/dia de suplemento isoprotéico (20% de PB), constituído de grãos de milho e soja moídos, mistura mineral e uréia nos níveis 0,0; 1,6; 3,2 ou 4,8% na matéria natural. O ganho médio diário -valor médio foi de 0,570 kg/dia -não foi influenciado pelos níveis de uréia do suplemento. Os parâmetros nutricionais foram avaliados utilizando-se quatro animais mestiços Holandês × Zebu, não-castrados, com peso médio inicial de 320 kg, fistulados no esôfago, rúmen e abomaso. Os animais receberam as mesmas quantidades de suplemento fornecidas aos animais do experimento de desempenho. Os níveis de uréia não afetaram significativamente o pH e a concentração de amônia ruminal. Para obtenção de ganhos de 0,5 a 0,6 kg/dia, pode-se utilizar apenas milho, uréia e mistura mineral em suplementos múltiplos para terminação de bovinos em pasto diferido.Palavras-chave: consumo, digestibilidade, milho, soja integral, suplementação Urea levels in multiple supplements for finishing beef cattle on palisade grass pasture during the rainy to dry transition ABSTRACT -The effects of multiple supplements with different urea levels on the productive performance and nutritional characteristics, for finishing beef cattle kept in deferred pasture of palisade grass (Brachiaria brizantha cv.Marandu) in the transition period of rainy to dry season were evaluated. The estimated dry matter availability of the pasture ranged from 16,360 to 9,358 kg/ha. In the performance trial, 20 crossbreed bulls, 20 months old and initial 376 kg BW were used. The animals were grouped in lots of similar weights to a completely randomized design, in four paddocks of 1.5 ha, where they received 1.5 kg/d of isoproteic supplements (20% CP), consisting with corn grain, grounded soybean, mineral mix and urea in the levels of 0.0; 1.6; 3.2 and 4.8% as-is basis, respectively. The average daily gain (mean value of 0.57 kg/d) was not affected by the urea levels in the supplements. The nutritional characteristics were evaluated using four crossbred (Holstein × Zebu) bulls, with initial 320 kg BW, with esophageal, ruminal and abomasal cannula, were used. The animals were fed the same amounts of supplements fed to the animals of the experimental performance. Urea levels did no affect the ruminal pH and the ammonia concentration. Weight gains 0.5 to 0.6 kg/d could be obtained using only corn, urea and mineral mix in ...

The absence of nutrient replacement, especially nitrogen (N), is one of the main causes of grazing system underutilization and tropical climate pasture degradation. Therefore, N is a very important nutrient in the pasture maintenance; however, it is necessary to know the maximum limit to be used of this nutrient, since fertilization increases production cost. Thus, the objective of this study was to identify the N dose that provides the highest production of marandu palisadegrass (Brachiaria brizantha cv. Marandu), and the fertilization effect on pasture degradation process and forage nutritive value. Treatments consisted in the application of : 0 (control), 25, 50, 75 and 100 kg N ha −1 cycle −1 of regrowth. The evaluations were carried out during the summers (November to April) of 2015/2016 and 2016/2017. The highest dry matter yield (DMY) and forage accumulation rate (FAR) occurred between doses of 50 and 75 kg ha −1 cycle −1 , with no change in productive potential at higher doses. The reduction in mineral content and the increase in crude protein (CP) are the main changes in the nutritional value of marandu palisadegrass, with no pronounced effect on in vitro dry matter digestibility (IVDMD), indigestible neutral detergent fiber (iNDF) and potentially digestible dry matter proportions of CP in the cell wall (CP CW) and in cellular content (CP CC).The productive effect of nitrogen fertilization under marandu palisadegrass is the increase in DMY and FAR. Thus, the use of nitrogen fertilizers in pasture systems with marandu palisadegrass has a greater impact on the area gain than the individual gain, assuming these systems, the use of nitrogen doses of 50 to 75 kg ha −1 cycle −1 .

The performance of female calves in creep feeding under different strategies of supplementation and milk production, intake, and digestibility of grazing Nellore and crossbred cows (Nellore × Holstein) during the dry-rainy transition season were assessed. Forty-four female beef suckling calves, with initial age between 90 and 150 days and average initial body weight of 117.7 ± 4.3 kg, and their respective dams (24 Nellore and 20 crossbred) with average initial body weight of 417.5 ± 8.3 kg, were used. The experimental treatments consisted of: control group--mineral mixture only; strategy 1--supplementation from 112 days prior to weaning (0.375 kg/animal/day); strategy 2--supplementation from 112 days prior to weaning, in increasing amounts of 0.15, 0.30, 0.45, and 0.60 kg/animal/day through the four experimental periods, respectively; and strategy 3--supplementation from 56 days prior to weaning (0.750 kg/animal/day). Calves from strategy 1 had greater (P < 0.05) average daily gain (0.672 kg/day) than control animals (0.582 kg/day) and greater (P < 0.05) efficiency of supplement use than the other groups. Crossbred cows produced more milk than Nellore cows (P < 0.05). Crossbred cows presented greater (P < 0.05) dry matter intake (DMI) than Nellore cows. However, no differences were found (P > 0.05) for nutrient digestibility among genetic types. It can be concluded that strategies of supplementation that present an equitable distribution of supplement provides greater weight gain in suckling female beef calves. Crossbred cows produce more milk and present greater DMI than Nellore cows. There are no differences in the nutrient digestibility between Nellore and Nellore × Holstein crossbred cows.