RESUMO -Objetivou-se avaliar o efeito de teores crescentes de PB na MS total da dieta (11,5; 13,0; 14,5 e 16,0%) sobre os consumos e a digestibilidade total dos nutrientes e a produção e composição do leite de vacas leiteiras no terço inicial da lactação. O experimento foi constituído de quatro períodos experimentais de 15 dias, sete para adaptação dos animais à dieta e oito para coleta de dados. Foram utilizadas oito vacas, manejadas em cochos individuais, distribuídas em dois quadrados latinos balanceados 4 × 4. Utilizou-se concentrado à base de farelo de algodão e fubá de milho (40%) e, como volumoso, cana-de-açúcar corrigida com 1% de uréia + sulfato de amônio (9:1), na proporção de 60% (% MS). Os consumos médios diários de nutrientes, exceto EE e CNF, diferiram à medida que os teores de PB da dieta aumentaram. Os teores de PB na dieta não afetaram os coeficientes de digestibilidade aparente total dos nutrientes. A produção de leite corrigida ou não para 3,5% de gordura e seus componentes (gordura, PB e lactose), expressa em g/dia, e o nitrogênio uréico no leite (NUL) tiveram efeito linear crescente, enquanto a eficiência de utilização de N sofreu efeito linear negativo dos teores de PB da dieta. A dieta com 16% PB resultou em valores numericamente maiores de consumo e produção do leite e de seus componentes se comparada às dietas com menores teores de PB.Palavras-chave: farelo de algodão, proteína não-degradável no rúmen, terço inicial da lactação Intake and total digestibility of nutrients and milk production and composition in dairy cows fed with increasing crude protein levels in the diet with sugar cane and concentrates ABSTRACT -The objective of this research was to evaluate the effect of increasing levels of CP in the total DM of diet (11.5, 13.0, 14.5 and 16.0%) on the intakes and the total digestibility of nutrients and the milk production and composition of dairy cows in initial third of lactation. The research was constituted by four experimental periods of 15 days each, seven for adaptation of the animals to the diet and eight for data collection. Eight cows, individually fed, were distributed to two balanced 4 × 4 Latin squares. A cottonseed meal, ground corn-based concentrate (40%) was used and, as forage, sugar cane corrected with 1% of urea + ammonium sulfate (9:1), in the proportion of 60% (%DM). The daily average intakes of nutrients, except for EE and NFC, differed as the levels of CP increased in the diet. The protein levels in the diet did not affected the coefficients of total apparent digestibility of the nutrients. Production of fat corrected milk, 3.5% or not and its components (fat, CP and lactose), expressed in g/day, and milk urea nitrogen showed increased linear effect, while the N efficiency showed negative linear effect of the CP levels in the diet. The diet with 16% CP provided values numerically greater for intake and milk production and its components as compared to diets with lower levels of CP.

RESUMO. Objetivou-se neste trabalho avaliar os efeitos da inclusão de ureia em dietas contendo farelo da vagem de algaroba sobre o comportamento ingestivo de ovinos. Os tratamentos constituíram da inclusão de níveis de ureia na dieta, sendo: 0; 0,5; 1,0 e 1,5% da MS total. Foram utilizados oito animais, machos castrados, com peso médio de 33,5 kg, distribuídos em dois quadrados latinos 4 x 4. A avaliação do comportamento ingestivo ocorreu no 17º e 18º dia experimental, sendo registrado o tempo despendido em alimentação, ruminação e ócio. Foram realizadas observações por três períodos, das 10 às 12h, 14 às 16h e 18 às 20h, determinando-se o número de mastigações merícicas bolo ruminal ABSTRACT. Intake behavior of sheep fed mesquite pod meal as a function of urea level. The goal of this work was to evaluate the use of urea in diets containing mesquite pod meal on the intake behavior of sheep. Treatments consisted of the following urea levels in diet: 0, 0.5, 1.0 and 1.5% of total dry matter. Eight gelded males, with mean weight of 33.5 kg, were used in an experimental design with two 4 x 4 Latin squares. (36,209.15), as well as feeding and rumination efficiency, were not affected by urea levels in diet. Intake behavior of sheep is not influenced by up to 1.5% urea in diets containing mesquite pod meal.

This study aimed to evaluate urea excretion, nitrogen balance and microbial protein synthesis in lactating goats fed with diets containing different protein sources in the concentrate (soybean meal, cottonseed meal, aerial part of cassava hay and leucaena hay). Four Alpine goats whose mean body weight was 42.6±6.1 kg at the beginning of the experiment, a mean lactation period of 94.0±9.0 days and a production of 1.7±0.4 kg of milk were distributed in a 4×4 Latin square with four periods of 15 days. Diets were formulated to be isonitrogenous, containing 103.0 g/kg of CP, 400 g/kg of Tifton 85 hay and 600 g/kg of concentrate. Diet containing cottonseed meal provided (p<0.05) increased excretion of urea and urea nitrogen in the urine (g/d and mg/kg of BW) when compared with leucaena hay. The diets affected the concentrations of urea nitrogen in plasma (p<0.05) and excretion of urea nitrogen in milk, being that soybean meal and cottonseed meal showed (p<0.05) higher than the average aerial part of the cassava hay. The use of diets with cottonseed meal as protein source in the concentrate in feeding of lactating goats provides greater nitrogen excretion in urine and negative nitrogen balance, while the concentrate with leucaena hay as a source of protein, provides greater ruminal microbial protein synthesis.

RESUMO. Objetivou-se neste trabalho avaliar os efeitos da inclusão de ureia em dietas contendo farelo da vagem de algaroba sobre o balanço de nitrogênio, N-ureico no plasma e parâmetros ruminais em ovinos. Foram utilizados oito animais, machos castrados, com peso médio de 33,5 kg, distribuídos em dois quadrados latinos 4 x 4. Os tratamentos constituíram da inclusão de níveis de ureia na dieta, sendo: 0; 0,5; 1,0 e 1,5% da MS total. A dieta foi fornecida como dieta total na relação volumoso:concentrado de 40:60 com base na MS total da dieta. Foi realizada a coleta total de urina e fezes e determinada a excreção de nitrogênio. Foi coletado sangue, seguido com a extração do plasma e determinação do N-ureico. Para avaliação do pH e N-amoniacal no líquido ruminal foram utilizados quatro animais fistulados no rúmen. A ingestão de N (31,68 g dia -1 ) e perdas vias fecal (7,94 g dia -1 ) e urinária (9,95 g dia -1 ) não sofreram alterações. As concentrações de N-amoniacal e N-ureico no plasma aumentaram de forma linear. O pH ruminal foi semelhante entre os tratamentos. A inclusão de ureia não influencia o balanço de nitrogênio, porém eleva as concentrações de N-amoniacal no rúmen e N-ureico no plasma podendo influenciar o gasto de energia no organismo.Palavras-chave: alimento alternativo, confinamento, metabolismo, nitrogênio não-proteico, pequenos ruminantes.Mesquite pod meal associated with levels of urea on feeding sheep: nitrogen balance, plasma urea-N and ruminal parameters ABSTRACT. The goal of this study was to evaluate the effects of including urea in diets containing mesquite pod meal on nitrogen balance, plasma urea-N and ruminal parameters. Eight gelded males, with mean weight of 33.5 kg, were divided into two 4 x 4 Latin squares. Treatments consisted of following urea levels in diet: 0, 0.5, 1.0 and 1.5% of total dry matter. The diet was provided as total diet a 40:60 forage: concentrate ratio based on total diet DM. Total urine and feces were collected and nitrogen excretion was determined. Blood was collected, followed by plasma extraction and quantification of urea nitrogen. To evaluate pH and ammonia-N in rumen fluid, four rumen fistulated animals were used . Intake of N (31.68 g day -1 ) and losses through feces (7.94 g day -1 ) and urine (9.95 g day -1 ) did not change. The concentrations of ammonia-N and plasma urea-N increased linearly. Rumen pH was similar among treatments. The inclusion of urea does not influence the nitrogen balance, but increases the concentrations of rumen ammonia-N and urea nitrogen in plasma, which may influence energy expenditure in the body.Keywords: alternative feed, confinement, metabolism, non-proteic nitrogen, small ruminants. IntroduçãoA alimentação racional dos animais domésticos visa fornecer os nutrientes capazes de manter e assegurar as exigências de mantença e o nível de produção pretendido. A proteína tem sido um dos nutrientes mais pesquisados na nutrição de ruminantes, sendo que, em razão de sua natureza diversificada, a ela têm sido atribuídos ganhos diferenciad...

-The objective of this study was to evaluate the effects inclusion of 0%, 33.3%, 66.7% and 100% natural matter (NM) of mesquite pod meal (MPM), in substitution of corn, on the intake, digestibility and feeding behavior of lactating Saanen goats. The forage:concentrate ratio in the diet was 40:60, using elephant grass silage as a forage source. Eight adult lactating goats with about 60 days in milk and weighting 50 kg were divided into two 4 × 4 latin squares and four 17-day experimental periods. Dry matter (DM), crude protein (CP) and total digestible nutrient (TDN) intakes were not influenced by MPM levels. Ether extract (0.51; 0.34; 0.36; 0.20 kg/day) and non-fiber carbohydrate (NFC) (0.54; 0.53; 0.49; 0.36 kg/day) intakes showed a linear effect with increased MPM. Organic matter (OM) and NDF intakes presented a quadratic behavior. The maximum OM intake was estimated with the replacement of 40.5%. The maximum estimated intakes for NDF were 0.665 kg/day and 14.8 g/kg body weight, with a replacement close to 60%. Nutrient digestibility coefficients and TDN levels (655.0 g/kg) were not affected, except for NFC. The time spent eating, ruminating and idle was not influenced by the addition of MPM. The feeding rate of DM had a linear decrease which reflected the intake restriction. Corn replacement with MPM should not exceed 40.5%, although its total replacement does not interfere with the intake of DM, CP and TDN on the apparent digestibility of nutrients and most ingestive behavior parameters.

ABSTRACT. This study aimed to evaluate the ingestive behavior of sheep fed increasing levels of mesquite pod meal (0, 15, 30 and 45% in total dry matter diet), replacing grass silage elephant. Eight noncastrated Santa Inês sheep with average weight of 32 kg were divided into two 4 x 4 Latin squares, each lasting 15 days. The sheep were submitted to visual observation every ten minutes, for 24 hours, in the 13 th day of each experimental period. There was no significant regression (p > 0.05) relative to the time spent on feeding, rumination and resting, depending on the levels of substitution of mesquite pod meal. The average time spent on feeding, rumination and resting was 5.64, 10.88 and 8.8h day -1 , respectively. There was a positive linear effect (p < 0.05) regarding the levels of replacement of elephant grass silage by mesquite pod meal on dry matter intake (DMI), neutral detergent fiber intake (NDFI), feeding efficiency of DM, rumination efficiency of DM, rumination efficiency of NDF. The use of observation intervals of up to 30 minutes does not alter the assessment of time spent on feeding, rumination and resting.

ABSTRACT. Eight Santa Ines sheep were assigned to two 4 x 4 Latin squares, to evaluate the effects of replacing elephant grass silage with different levels of mesquite pod meal (MDM) (15, 30 and 45% DM) on intake, apparent digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), acid detergent fiber (ADF), neutral detergent fiber (NDF), total carbohydrates (TC) and non-fiber carbohydrates (NFC) and the nitrogen balance. There was a linear increase (p < 0.05) in the intake of DM, OM, CP, ADF, NDF, NFC and TC according to the addition of MPM to the diet. The digestibility of DM, OM and CP increased (p < 0.05) with the addition of MDM. We observed a positive linear effect (p < 0.05) for the nitrogen intake. The addition of mesquite pod meal up to 45% increased the intake of DM, NDF, ADF, CP, OM, NFC and TC but reduced the digestibility of EE and NDF. MPM at 30 and 45% propitiated a positive nitrogen balance.Keywords: forage conservation, Prosopis juliflora, silage.Farelo de vagem de algaroba em dietas de ovinos: consumo, digestibilidade aparente dos nutrientes e balanço de nitrogênio RESUMO. Foram utilizados oito ovinos da raça Santa Inês, distribuídos em dois quadrados latinos 4 x 4, com o objetivo é avaliar os efeitos da adição do farelo de vagem de algaroba -FVA (15, 30 e 45% da MS) em substituição à silagem de capim elefante sobre o consumo, digestibilidade aparente da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra de detergente ácido (FDA), fibra em detergente neutro (FDN), carboidratos totais (CT) e carboidratos não fibrosos (CNF) e balanço de nitrogênio. Foi observado efeito linear crescente (p < 0,05) dos níveis de FVA sobre os consumos de MS, MO, PB, FDA, FDN, CNF e CT. Os coeficientes de digestibilidade da MS, MO e PB aumentaram (p < 0,05) com a adição de FVA. Observou-se efeito linear positivo (p < 0,05) para a ingestão, excreção fecal e retenção de nitrogênio, enquanto que a excreção de N na urina não variou (p > 0,05) em função dos níveis de substituição. A adição de FVA em até 45% proporcionou o aumento do consumo de MS, FDN, FDA, PB, MO, CNF e CT, mas, reduziu o coeficiente de digestibilidade do EE e de FDN. Os níveis 30 e 45% de FVA proporcionaram balanço de nitrogênio positivo.Palavras-chave: conservação de forragem, Prosopis juliflora, silagem.

This study aimed to evaluate intake, digestibility, ingestive behaviour, and body weight variation in lambs fed mesquite pod meal (0, 30, 60 and 90%) in substitution of ground corn grains (as-fed basis) in pelleted diets. Twelve Santa Ines×Dorper lambs with average body weight of 25.0±1.8 kg were distributed through three 4×4 Latin Squares consisting of four periods and four treatments. Diets consisted of 30% alfalfa hay and 70% concentrate. The experimental period was 60 days, divided into 15-day periods. The intakes of dry matter (DM), total carbohydrates (TC) and total digestible nutrients (TDN) were not influenced (P>0.05) by the different levels of mesquite pod meal added in substitution of corn. The digestibility coefficients of DM, organic matter (OM), ether extracts (EE), neutral detergent fibre free of ash and protein (NDFap), TC and the TDN decreased linearly (P<0.05) as the level of mesquite pod meal in the diet was increased. Feed efficiency [g DM and neutral detergent fibre (NDF)/hour] was not influenced (P>0.05) by the mesquite pod meal levels; contrastingly, this feedstuff caused a reduction of 12.13 and 1.9 g in rumination efficiency (g DM and NDF/hour, respectively) for every percentage unit added. The average weight gain showed quadratic behaviour (P<0.05) as a result of the substitution level, and maximum weight gain was estimated at 275.9 g/day at the substitution level of 47.5%.