ABSTRACT. This study aimed to evaluate whether different fertilization strategies influence the morphogenic, structural, and production characteristics of Megathyrsus maximus cv. Mombaça. The experimental design adopted was a randomized block design with a 4 × 3 factorial scheme having five replications. The treatments were as per the following fertilization recommendations: 5th Approach Guide (5AP), Pará Guide (PG), Nutrient Replacement (RP), and the Michaelis and Menten adapted model (MM), applied for three days after application of the nitrogen (N) source following defoliation (days 0, 3, and 6). The interaction between factors affected the following variables: leaf appearance rate (LAR), leaf elongation rate (LER), and leaf senescence rate (LSR). The highest stem elongation rate (SER) was observed for the 5AP recommendation treatment with N application on day 0 (0.113 cm). The highest leaf area index (LAI; 5.33) and tiller population density (TPD; 421.5 tillers m-2) were observed for the 5AP recommendation. The 5AP recommendation with N application on day 0 and on the sixth day after defoliation, and the MM recommendation with fertilization on day 0 showed the best LAR and LER, as well as a greater number of cycles and greater absolute values of leaf blade dry mass.

ABSTRACT The objective of this study was to evaluate performance, apparent digestibility, blood parameters, and quantitative characteristics of carcass and internal organs of crossbred dairy calves fed different levels of crude glycerin in corn grain-based diets. Twenty-four calves of three months of age and average initial weight of 95.5±11.8 kg were used. The experimental design was completely randomized with four treatments (0, 80, 160, and 240 g kg−1 of crude glycerin of DM of diets). The calves were fed in feedlot until six months of age (195.68±2.38 kg of BW). Dry matter (4.14, 4.11, 3.80, and 3.49 kg day−1) and apparent digestible energy intake (0.43, 0.41, 0.37, and 0.35 MJ kg−1 BW) decreased with increasing levels of glycerin in the diets. There was no effect on the apparent digestibility of nutrients, average daily gain, feed efficiency, carcass characteristics, and blood parameters. The diets did not influence the weights [g kg−1 of empty body weight (EBW)] of lungs, heart, kidneys, liver, omasum, abomasum, and large intestine. The reticulorumen weight (g kg−1 EBW) increased, whereas the small intestine weight decreased with increased levels of glycerin in the diets. The area, height, and width of the rumen papillae were not changed with increasing levels of glycerin. The rumen wall thickness increased with increasing levels of glycerin in the diets. The inclusion up to 240 g kg−1 DM of crude glycerin of in corn grain-based diets for the production of dairy calves does not alter animal performance, carcass characteristics, and weights of internal organs.

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.

ABSTRACT The objective of this study was to assess the effects of including crude glycerin in the diet on intake, performance, rumen development, and carcass traits of dairy crossbred veal calves fed starter concentrate containing 0, 80, 160, and 240 g kg−1 crude glycerin. Twenty-eight calves with an average weight of 38.03±6.7 kg and five days of age were distributed in a completely randomized design with four treatments with seven replications. Calves were individually housed in covered stalls equipped with feeders and drinkers for 56 days. The calf response to inclusion of crude glycerin in the concentrate changed over the weeks and the inclusion level of 240 g kg−1 resulted in greater dry matter intake and average daily gain. There was no effect on the final weight and total weight gain of the animals, with mean values of 73.60 and 35.16 kg, respectively. The weight of the rumen-reticulum adjusted for body weight, empty body weight, and total stomach weight increased linearly with the inclusion of crude glycerin. Blood total protein, globulin, urea, cholesterol, gamma glutamyl transferase, aspartate aminotransferase, and alkaline phosphatase concentrations did not differ among treatments. Carcass traits and meat color were not affected. Crude glycerin can be added to dairy calf starter concentrate up to 240 g kg−1 dry matter because it benefits concentrate intake, performance, and rumen development without affecting animal health.

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.

Objetivou-se avaliar o consumo, a digestibilidade aparente de nutrientes e o balanço de nitrogênio de dietas contendo farelo de mesocarpo de babaçu (FMB) em substituição à silagem de capim elefante (0; 21; 38; 62 e 78%). Utilizaram-se 20 ovinos alojados em gaiolas metabólicas individuais e distribuídos em delineamento inteiramente casualizado com quatro repetições. Foram coletados e registrados o consumo de alimentos e excreções de fezes e urina. Os consumos de matéria seca, matéria orgânica, proteína bruta, cinzas, fibra em detergente neutro, fibra em detergente ácido, hemicelulose e carboidratos totais não foram influenciados pelas dietas experimentais. Foi observada alteração nos consumos de carboidratos não fibrosos (CCNF) e redução nos consumos de extrato etéreo em % do PV e em gramas por unidade de tamanho metabólico (g UTM-1). O consumo de nutrientes digestíveis totais (CNDT) teve comportamento quadrático com pontos de máximo em 37,3 e 37,9% de FMB expressos em %PV e g UTM-1, respectivamente. As digestibilidades aparentes da matéria orgânica, fibra em detergente neutro, fibra em detergente ácido, proteína bruta e carboidratos não fibrosos reduziram na medida em que o FMB aumentou nas dietas. As digestibilidades aparentes da matéria seca (DAMS), extrato etéreo e carboidratos não fibrosos tiveram comportamento quadrático, com máxima DAMS estimada em 10% de FMB. O NDT reduziu 0,28% para cada ponto percentual de inclusão de FMB nas dietas. A adição do FMB reduziu a digestibilidade das frações fibrosas e aumentou o CCNF e o CNDT, o que indica que este subproduto pode ser utilizado como fonte energética em dietas para ruminantes.

The objective of this study was to evaluate the intake, apparent digestibility of nutrients and the nitrogen balance of diets containing babassu-mesocarp meal (BMM) as a replacement for elephant-grass silage (0, 21, 38, 62 and 78%). Twenty sheep were used, housed in individual metabolic cages and distributed in a completely randomized design with four replications. Food intake was noted and faeces and urine excretions were collected and recorded. Intake of dry matter, organic matter, crude protein, ash, neutral-detergent fibre, acid-detergent fibre, hemicellulose, and total carbohydrate was not affected by the experimental diets. Changes were observed in the non-fibrous carbohydrates intake (INFC) and a reduction in the intake of ether extract as a % of live weight (LW) and grams per unit of metabolic body size (g MBS-1). Total digestible nutrient intake (ITDN) presented quadratic behaviour, with maximum points at 37.3% and 37.9% of BMM expressed as %LW and g MBS-1 respectively. The apparent digestibility of organic matter, neutral-detergent fibre, acid-detergent fibre, crude protein and non-fibrous carbohydrate decreased with the increase in BBM in the diet. The apparent digestibility of dry matter (ADDM), ether extract and non-fibrous carbohydrates showed a quadratic response, with maximum ADDM estimated at 10% of BMM. The TDN decreased by 0.28% for each percentage point of BMM added to the diet. The addition of BMM reduced digestibility of the fibres and increased both INFC and ITDN, indicating that this byproduct can be used as an energy source in ruminant diets.

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.