ABSTRACT The aim of this study was to evaluate intake, digestibility and performance in dairy heifers fed diets containing increasing levels of babassu cake (0, 100, 200 and 300 g kg-1 dry matter - DM) as a substitute for sugarcane treated with calcium oxide. Twenty-four heifers with an initial mean weight of 190.8 + 40.8 kg were used, distributed in a completely randomised design. The dry matter intake (DMI), neutral detergent fibre intake (NDFI) and acid detergent fibre intake (ADFI), as %BW and g BW-0.75 , showed an increasing linear response. The organic matter intake (OMI) showed a linear increase of 40 g day-1, 0.017%BW and 0.66 g BW-0.75 for each 10 g kg-1 increase in babassu cake in the diet. The apparent digestibility of the dry matter (ADDM) and organic matter (ADOM) showed a quadratic response (P < 0.05), with a minimum of 493 g kg-1 DM for 150 g kg-1 DM and 526.5 g kg-1 DM for 320 g kg-1 DM as a substitute for the sugarcane, respectively. The final mean weight was not altered, presenting a value of 299.7 + 45.5 kg. Daily weight gain (DWG) showed a quadratic response, with the highest value at a substitution level of 190 g kg-1 DM. The feed conversion rate of the DM was not affected by the addition of babassu cake, with an average of 4.6 + 0.74 kg DM kg-1 in weight gain. Babassu cake can substitute hydrolysed sugarcane in heifer diets up to 300 g kg-1 DM, with the greatest weight gain seen at a substitution level of 190 g kg-1 DM.

RESUMO A utilização de subprodutos agroindustriais na alimentação de ruminantes apresenta vantagens nutricionais, ambientais e econômicas, contribuindo para a sustentabilidade do sistema de produção. Assim, objetivou-se avaliar o valor nutritivo de dietas contendo torta de babaçu em substituição ao feno de Tifton-85 (70; 140; 210; 280 e 350 g kg-1 de matéria seca; MS). Foram utilizados 25 ovinos machos castrados, com peso corporal médio de 49,6 ± 9,4 kg, alocados em gaiolas metabólicas em delineamento inteiramente casualizado. O consumo voluntário foi obtido pela subtração da quantidade de alimento fornecido pela sobra pesada na manhã seguinte. Para avaliação da digestibilidade dos nutrientes e balanço de nitrogênio (N), amostras de urina e fezes foram coletadas separadamente. O consumo de MS não foi influenciado, contudo o consumo de proteína bruta (PB) e extrato etéreo aumentaram linearmente. A inclusão da torta de babaçu não afetou a digestibilidade da MS (média de 604,6 ± 272,8 g kg-1). A digestibilidade aparente da PB e os teores de nutrientes digestíveis totais apresentaram comportamento linear crescente, enquanto a digestibilidade da fibra em detergente ácido decresceu linearmente. O teor de N retido variou de 9,72 ± 1,12 a 15,51 ± 1,84 g dia-1 e sua relação com o N ingerido variou entre 521,0 ± 26,7 e 578,4 ± 31,8 g kg-1 de N. A inclusão da torta de babaçu, em substituição ao volumoso, incrementou o valor nutritivo da dieta, podendo ser incluída em até 350 g kg-1 da MS na dieta, em substituição ao feno de Tifton-85.

ABSTRACT The use of agro-industrial by-products in feeding ruminants has nutritional, environmental and economic advantages, and helps to sustain the production system. The aim of this study was to evaluate the nutritional value of diets containing babassu cake as a substitute for Tifton-85 hay (70, 140, 210, 280 and 350 g kg-1 dry matter: DM). Twenty-five castrated male sheep with a mean body weight of 49.6 ± 9.4 kg were used, distributed in metabolic cages in a completely randomised design. Voluntary intake was obtained from the difference between the amount of feed provided and the leftovers the following morning. To evaluate nutrient digestibility and nitrogen (N) balance, samples of urine and faeces were collected separately. There was no effect on DM intake; however, crude protein (CP) and ether extract intake increased linearly increased linearly. The addition of babassu cake had no effect on DM digestibility (mean value of 604.6 ± 272.8 g kg-1). Apparent CP digestibility and total digestible nutrient content showed increasing linear behaviour, while the digestibility of acid detergent fibre decreased linearly. The level of retained N varied from 9.72 ± 1.12 to 15.51 ± 1.84 g day-1 with the ratio to ingested N ranging from 521.0 ± 26.7 to 578.4 ± 31.8 g kg-1 N. The addition of babassu cake to replace the roughage, increased the nutritional value of the diet. Babassu cake can be included up to a total of 350 g kg-1 DM in the diet as a substitute for Tifton-85 hay.

Objetivou-se avaliar o comportamento ingestivo durante 24 horas em oito períodos do dia, de 24 tourinhos Limousin x Nelore terminados em confinamento, alimentados com quatro níveis do subproduto gérmen de milho integral na dieta (0, 15, 30, 45%). O fornecimento de alimento (25% de volumoso e 75% de concentrado) foi realizado diariamente às 9:00 e 16:30 horas. A adição de gérmen de milho integral às dietas não influenciou os tempos despendidos em alimentação, dormindo e em outras atividades, nem as frequências de procura por água, micção e defecação. Os animais alimentaram-se mais nos períodos em que foram arraçoados, gastando em média 137,10 minutos por dia. Os animais dormiram mais à noite, das 2 às 5 horas, enquanto, o tempo despendido em outras atividades foi maior das 17 às 20 horas. Os níveis de gérmen de milho integral influenciaram o tempo de ruminação e de ócio de forma quadrática, com o nível de 30% apresentando maior tempo de ruminação (28,30% do tempo diário) e menor de ócio (42,24% do tempo diário). As atividades ruminação, ócio, alimentação, dormindo e outras atividades, além das frequências de ingestão de água, micção e defecação, comportaram-se de forma distinta para os diferentes períodos do dia. A inclusão de gérmen de milho integral à dieta de bovinos proporciona maior tempo de ruminação e modifica a distribuição desta atividade durante o dia.

This research was conducted to assess the ingestive behavior during 24 hours in eight periods of the day of 24 Limousin x Nellore young bulls in feedlot, fed with diets containing 0; 15; 30 and 45% of whole corn germ. At 9 a.m. and 4:30 p.m., the animals were fed with a roughage:concentrate ration of 25:75. The inclusion of whole corn germ in the diets did not affect the time spent with food intake, sleeping and other activities, neither the frequencies of water drinking, urination and defecation. Food intake occurred more often during the periods when animals were fed, spending in average 137.10 minutes with this activity. Animals slept more during the night, from 2 to 5 a.m., whereas the time spent with other activities was higher from 5 to 8 p.m. Whole corn germ levels affected the rumination and leisure time in a quadratic form, with the 30% level showing higher rumination time (28.3% of the daily time), and lower leisure time (42.24% of the daily time). Animals submitted to different levels of whole corn germ showed distinct behavior for rumination, leisure, food intake, sleeping and other activities, and frequencies of water drinking, urination and defecation, during the different periods of the day. The inclusion of whole corn germ to the diet of bovines provides greater rumination time and modifies the distribution of this activity during the day.

Nutrient intake and digestibility and productive performance of 30 feedlot young bulls fed diets containing babassu mesocarp bran in replacement of corn were evaluated. Animals were distributed in a completely randomized design with five levels of replacement of corn by babassu mesocarp bran (BMB): 0, 250, 500, 750 and 1000 g/kg of dry matter, and six replications. The dry matter (DM) intake in kg/day, g/kg body weight (BW) and g/kgBW0.75 increased as the corn was replaced by BMB. The intake of neutral detergent fiber (NDF) and crude protein (CP) increased linearly, whereas the intake of non-fibrous carbohydrates (NFC) had quadratic behavior. The digestibility of DM, CP, NDF and NFC and the total digestible nutrients (TDN) showed quadratic behavior with points of minimum digestibility of 850.0, 638.0, 867.0, 638.0 and 833.0 g/kg dry matter of replacement of corn by BMB, respectively. The final weight (476.82 kg) and average daily gain (1.55 kg/day) were not affected by experimental diets. The feed efficiencies of DM and CP decreased with increase in the levels of BMB, but the feed efficiency of TDN was not changed. Babassu mesocarp bran enables satisfactory performance, and depending on the price and opportunity cost, it can be utilized in the feeding of feedlot cattle totally replacing the corn of the diet.