ABSTRACT The objective of the study was to assess the effects of including 0, 79.8, 159.8, and 240.0 g kg-1 crude glycerin in the total diet dry matter on the 84 days feedlot performance, nutrient digestibility, blood parameters, and carcass characteristics of crossbred dairy steers. Experimental diets were composed of 98.5 g kg-1 of sorghum silage and 901.5 g kg-1 of concentrate. Twenty-four crossbred dairy steers (337.3±39.8 kg body weight and 15 months of age) were distributed in a completely randomized design with four treatments and six replicates. The intake and digestibility of the dry matter and nutrients were not altered by including crude glycerin in the diet. Crude glycerol levels did not affect the final weight (430.2 kg), daily weight gain (1.38 kg day-1), total weight gain (97.2 kg), hot carcass weight (218.9 kg), cold carcass weight (215.2 kg), hot carcass yield (0.50 kg 100 kg-1 BW), longissimus dorsi area (62.86 cm²), subcutaneous fat thickness (4.05 mm), and carcass physical composition. Concentrations of serum glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol, and creatinine were not altered by including crude glycerin in the diet. Crude glycerin can be added to high concentrate diet up to 240 g kg-1 without changing the animal performance, apparent digestibility of nutrients, the main carcass characteristics, and blood parameters of finishing crossbred dairy steers.

Objetivou-se avaliar os efeitos da inclusão de torta de dendê na dieta sobre o consumo, a digestibilidade das dietas e o desempenho de novilhas leiteiras. Utilizaram-se 16 novilhas leiteiras mestiças Holandês × Zebu, com média de 13 meses de idade e peso vivo inicial de 183,4±32,5 kg, distribuídas em delineamento inteiramente casualizado, com quatro níveis de torta de dendê (0; 11,9; 22,9 e 34,2% da matéria seca total), cada um com quatro repetições. Avaliaram-se os consumos de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), carboidratos não-fibrosos (CNF), extrato etéreo (EE) e nutrientes digestíveis totais (NDT) e as digestibilidades aparentes da MS, PB, FDN, CNF e EE. Houve redução linear no consumo de MS, PB, FDN, CNF e NDT. A digestibilidade aparente da MS e FDN reduziu com a inclusão da torta de dendê na dieta, enquanto a de PB e dos CNF sofreu efeito quadrático. A inclusão de torta de dendê nas dietas promoveu aumento linear da digestibilidade aparente do extrato etéreo. O ganho de peso reduziu linearmente com a inclusão de torta de dendê na dieta, sendo observados valores de 1,06; 0,99; 0,89 e 0,54 kg/dia para as dietas contendo 0; 11,9; 22,9 ou 34,2% de torta de dendê na dieta total, respectivamente. A conversão alimentar não foi afetada pelos níveis de inclusão de torta de dendê na dieta. A inclusão de torta de dendê na dieta reduz o consumo de nutrientes e o desempenho de novilhas leiteiras em crescimento, porém, quando utilizada em níveis de até 24,6% da dieta total, proporciona ganho de peso compatível com os obtidos em programas de recria visando à parição aos 24 meses de idade.

The objective was to evaluate the effects of inclusion of palm kernel cake in the diet on intake, digestibility and performance of dairy heifers. Sixteen dairy Holstein-Zebu crossbred heifers with average age of 13 months and average weight of 183.4±32.5 kg were distributed to four treatments in a completely randomized design with four levels of palm kernel cake (0, 11.9, 22.9 and 34.2% from total dry matter), each one with four replicates. The intake of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), non-fibrous carbohydrates (NFC), ether extract (EE) and total digestible nutrients (TDN), and the apparent digestibility of DM, CP, NDF, NFC and EE were evaluated. There was linear reduction in DM, CP, NDF, NFC, and TDN intake. The apparent digestibility of DM and NDF reduced with the inclusion of palm kernel cake in the diet, while the apparent digestibility of CP and NFC showed quadratic effect. The inclusion of palm kernel cake in the diets resulted in linear increase in the apparent digestibility of ether extract. Weight gain decreased linearly with the inclusion of palm kernel cake in the diet, with values of 1.06, 0.99, 0.89 and 0.54 kg/day for diets containing 0, 11.9, 22, 9 or 34.2% palm kernel cake, respectively. Feed conversion was not affected by the inclusion of levels of palm kernel cake. The inclusion of palm kernel cake in the diet reduces nutrient intake and performance of dairy heifers during growth, but when used in levels up to 24.6% of the total diet, it provides weight gain compatible with growth programs aiming calving at 24 months of age.