José Fernando Coelho da Silva

Ingestive behavior in Holstein calves fed diets with different concentrate levels

ABSTRACT - The effects of different concentrate levels on the ingestive behavior were studied with five rumen and abomasum fistulated Holstein bull calves, with average initial age of 10.8±0.8 months and average 233.4±26.1 kg BW. The animals were housed in individual stalls and ad libitum fed diets containing 30, 45, 60, 75 and 90% of concentrate, on DM basis. The diets contained, approximately, 16% CP were formulated for body weight gain of 1.0 kg/day and constituted of soybean meal corn ground grain in the concentrate and coast-cross grass hay as forage. A randomized complete blocks design, with five treatments, throughout 20 days, 12 days of adaptation and four periods of two days, relative to the data collection, was used. The eating and ruminating time decreased, while the idle time linearly increased, as the concentrate levels in the diets increased. The feeding efficiency in g DM/h showed quadratic behavior, and the maximum estimated value was 826.81 g NDF/h, for the level of 60.77% of concentrate. The rumination efficiency, g DM/h, and g NDF/h increased and decreased linearly, respectively, as the concentrate levels in the diets increased. The number of ruminate boli and the ruminating chews per day linearly decreased. The number and the ruminating chews per bolus showed a quadratic behavior, and maximum values of 73.79 ruminating chews and 66.61 seconds, per ruminate boli, were estimated for the levels of 48.51 and 54.44% of concentrate, respectively.

Consumo e digestibilidade aparente total e parcial em bezerros holandeses alimentados com dietas contendo diferentes níveis de concentrado

ABSTRACT - This work was conducted to evaluate the effects of different concentrate levels on the voluntary intake and the apparent total and partial digestibilities of dry matter (DM), organic matter (OM), ether extract (EE), neutral detergent fiber (NDF) and total carbohydrates (TCH), in the rumen and in the intestines. Five rumen and abomasum fistulated Holstein calves, with initial average age of 5.8±0.7 months and initial average of 107.4±11.0 kg LW were allotted to a 5x5 Latin square design (treatment x period). The animals were housed in individual stalls and full fed diets (DM basis) containing 30.0, 45.0, 60.0, 75,0 and 90.0% of concentrate. The diets were based on coast-cross grass hay as forage and soybean meal and ground corn grain in the concentrate. The chromic oxide was used as marker to estimate the fecal and abomasal DM flows. The intakes of DM, OM, CP and TCH, in kg/day, were not affected by diets, while that of EE intake increased and NDF intake linearly decreased, when expressed in %LW and g/kg.75 as the dietary concentrate levels increased. Total apparent digestibilities of DM, OM, EE and TCH linearly increased as the dietary concentrate levels increased, but NDF digestibility was not affected. Ruminal digestibilities of DM, NDF and TCH did not vary as the dietary concentrate levels increased, but the OM digestibility increased and that of EE linearly decreased as the dietary concentrate levels increased. The intestinal digestibility of DM did not vary, but that of OM and TCH linearly increased. The EE and NDF digestibilities were not affected by the inclusion of crescent concentrate levels in the diets.

Composição corporal e exigências líquidas de proteína e energia para ganho de peso de bovinos F1 Simental x Nelore

Avaliaram-se os efeitos de cinco niveis de concentrado nas racoes sobre a composicao corporal e as exigencias liquidas de proteina e energia para ganho de peso. Vinte e nove bovinos, nao-castrados, F1 Simental x Nelore com, em media, 17 meses de idade e 354 kg PV inicial, foram usados. Cinco animais foram abatidos ao inicio do experimento, como referencia, para estimar o peso de corpo vazio (PCV) inicial e as concentracoes iniciais de gordura, proteina e energia. Os animais restantes foram distribuidos nos tratamentos, de forma inteiramente casualizada, de acordo com o nivel de concentrado nas racoes: 25; 37,5; 50; 62,5; e 75%. Os animais foram alimentados a vontade ate atingirem o peso de abate preestabelecido de 500 kg. Equacoes de regressao foram ajustadas, para cada nivel de concentrado e em conjunto, do logaritmo das quantidades de gordura, proteina ou energia, em relacao ao logaritmo do PCV. Derivando-se as referidas equacoes de regressao, obteve-se a composicao do ganho de PCV. A quantidade de gordura e o conteudo de energia no peso ganho aumentaram, a medida que se elevou o PV do animal. O conteudo corporal de proteina elevou-se com o aumento do PV, mas a concentracao em g/kg de PCV diminuiu. As exigencias liquidas de energia para um animal de 400 kg PCV para 1 kg PCV foram, em media, 3,96 Mcal/dia. As exigencias de energia liquida para ganho em peso aumentaram e as de proteina reduziram, com o aumento do peso corporal.

Consumo e digestiblidades aparentes totais e parciais de dietas contendo diferentes níveis de concentrado, em novilhos Nelore

ABSTRACT - The objective of this experiment was to evaluate the effects of the concentrate level in the diets on the intakes andtotal and partial apparent digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neu tral detergentfiber (NDF) and total carbohydrates (CHO). The effect of collections carried out during the day and the night, for the DM and O M totaland partial apparent digestibilities, was also evaluated. Four Nellore bulls, fistulated in the rumen, abomasum and ileum, fed diets ad libitumwith 25.0; 37.5; 50.0; 62.5; and 75.0% of concentrate, were randomly allotted to a completely randomized block design. The chro mium oxidewas used as indicator, in the dose of 20 g/day. The intakes of DM, OM, total digestible nutrients (TDN) and EE increased and th at of NDFdecreased linearly with the increase of the concentrate in the diets. The minimum estimated total apparent digestibilities of 6 7.27% for DMand 68.31% for OM were with 36.71 and 41.5% of concentrate in the diets, respectively. The ruminal apparent digestibilities of DM and OMaveraged 63.35 and 71.42%, respectively. The increase of concentrate in the diets reduced the ruminal digestion of NDF, but res ulted in linearincrease in TDN and total DM digestibility of the diets. There were no differences for the total and partial apparent digestibi lities of DM andOM obtained in collections accomplished during the day or the night.Key Words: bulls, concentrate, digestibility, intake

Níveis de concentrado em dietas de novilhos mestiços F1 Simental x Nelore: 1. Consumo e digestibilidades

An experiment was carried out to evaluate the dietary concentrate levels on the intake, total and partial apparent digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrates (CHO), neutral detergent fiber (NDF) and non structural carbohydrates (NEC). The effects of samples collections, realized on the day or the night, on the total and partial apparent digestibilities of DM and OM, were studied. Five F1 Simental x Nellore bulls fistulated in the rumen, abomasum and ileum, full fed diets with 25.0, 37.5, 50.0, 62.5, and 75.0% of concentrate and allotted to 5 x 5 Latin square, were used. The hays of brachiaria (Brachiaria decumbens, Stapf) and coast-cross grasses (Cynodon dactylon) were used in the same proportions. The chromic oxide was used as indicator to determine the digesta flows and fecal excretion. The addition of increasing amounts of concentrate to the diet resulted in linear increases in the DM, OM, CP, EE, CHO, NEC and TDN intakes and reduction in the NDF intake. The total apparent digestibilities of DM, OM, CP, EE, CHO, NEC and TDN linearly increased with the increasing concentrate levels. The concentrate levels did not influence the NDF apparent digestibilities in the rumen and post-rumen. The reduction in the dietary NDF levels resulted in TDN linear increases and DM total apparent digestibility. Feces and abomasum and ileum digesta representative samples can be obtained using collections only during the day.

Consumo, conversão alimentar, ganho de peso e características da carcaça de bovinos F1 Simental x Nelore

The effects of different dietary concentrate levels on the intakes of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), ether extract (EE), total carbohydrates (TC), total digestible nutrients (TDN), calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na) and potassium (K) were evaluated. The live weight (LWG) and the empty body gains (EBG), feed:gain ratio (F:G), carcass gain (CG) and the carcass productivity in relation to live weight (LWCP) and to empty body weight (EBW) were also evaluated. Twenty nine F1 Simental x Nelore bulls, averaging 17 months of age and initial live weight of 354 kg, were used. In the beginning of the experiment, five animals were slaughtered, as reference, to estimate the initial empty body weight (IVBW). The remaining animals were allotted to a completely randomized design according to the concentrate level in the diets: 25, 37.5, 50, 62.5, and 75%. Animals were fed full until a pre-established slaughter weight of 500 kg. As forage, the coast-cross (Cynodon dactylon) and brachiaria (Brachiaria decumbens) hays were used. The intakes of DM, CP, EE and TDN increased while that of NDF reduced linearly with the concentrate increase in the diets. The intakes of P, Mg and K were influenced linearly and that of Ca on a quadratic way by the dietary concentrate levels. LWG, VBG and CG increased and FC decreased linearly as a function of the dietary concentrate levels, whereas LWCP and VBCP were not affected by the dietary concentrate levels. The animal performance was improved with the use of higher concentrate contents in the diets

Níveis de concentrado em dietas de novilhos mestiços F1 Simental x Nelore: 2. Balanço nitrogenado, eficiência microbiana e parâmetros ruminais

The effects of dietary concentrate levels were evaluated on the microbial synthesis efficiency, the nitrogenous compounds balance, the ammonia concentrations and the ruminal fluid pH, the ruminal digesta passage rate and the endogenous losses of nitrogen compounds (N). Five F1 Simental x Nellore bulls fistulated in the rumen, abomasum and ileum, full fed diets with 25.0; 37.5; 50.0; 62.5; and 75.0% of concentrate and allotted to 5x5 Latin square, were used. The ammonia concentrations and the ruminal pH were determined in ruminal fluid samples immediately collected before and 2; 4; 6; and 8 hours after feeding. The unicompartimental model, using chromic oxide as indicator, determined the passage rate. The microbial synthesis efficiency, express in relation to the organic matter degraded in the rumen (OMDR), to the total carbohydrates degraded in the rumen (CHODR) and to TDN, was influenced in quadratic way by the concentrate levels in the diet, estimating maximum values of 41.22 gNmic/kg OMDR, 39.89 gNmic/kg CHODR and 17.33g CPmic/100 g NDT, estimated for 52.16, 60.44, and 56.63% of concentrate in the diet, respectively. When express in DMmic/kg CHODR, the efficiency linearly increased as the concentrate level increased. Values of 5.15 g N/kg ingested DM for the fecal metabolic nitrogen and 422 mg N/kg0,75 for the total endogenous losses were estimated. The maximum ammonia concentrations for all treatments were observed at 3,6 hours after feeding. The passage rates of .052, .052, .055, .055, and .042.h-1 were obtained for all treatments with 25.0, 37.5, 50.0, 62.5, and 75.0% of concentrate, respectively. The maximum microbial efficiency ranged from 52 to 60% of concentrate.

Passage rates and ruminal degradation kinetics in Holstein calves fed diets with different concentrate levels.

ABSTRACT - This work was conducted to evaluate the effects of different concentrate levels on the liquid passage rates, using Co-EDTA, and particulate, using ytterbium chloride and Cr-mordant, and the in situ ruminal degradation kinetics of dry matter (DM) and crude protein (CP). Five rumen and abomasum fistulated bull Holstein calves, with an initial average age of 5.8±0.7 months and initial average of 107.4±11.0 kg LW were allotted to a 5x5 Latin square design (treatment x period). The animals were housed in individual stalls and full fed diets (DM basis) containing 30.0, 45.0, 60.0, 75,0 and 90.0% of concentrate. The diets were based on coast-cross grass hay as forage and soybean meal an corn ground grain in the concentrate. The passage rate of fluids showed a quadratic behavior, with the maximum value of 9.73%/h, with the 61.69% of concentrate in the diet. The particulate passage rate of the soybean meal in the reticulum-rumen linearly decreased, while the concentrate levels in the diets did not affect the passage rate in proximal cecum-colon. The concentrate levels in the diet did not affect the passage rates of the coast-cross grass hay in the reticulum-rumen and in the proximal cecum-colon. The effective degradation of the DM of the soybean meal was not affected, while those of the corn ground grain increased and coast-cross grass hay linearly decreased, respectively. The effective degradation of the CP of the soybean meal and coast-cross grass hay did not vary, however, that of the corn ground grain linearly increased as the dietary concentrate levels increased.

Eficiência de utilização da energia metabolizável para ganho de peso e exigências de energia metabolizável e nutrientes digestíveis totais de bovinos F1 Simental x Nelore

O objetivo deste trabalho foi estimar a eficiencia de utilizacao da energia metabolizavel (EM), para ganho de peso, e as exigencias de energia metabolizavel e nutrientes digestiveis totais de bovinos F1 Simental x Nelore, nao-castrados, alimentados com racoes contendo diferentes niveis de concentrado. Foram utilizados 29 animais com, em media, idade de 17 meses e peso vivo inicial de 354 kg. Cinco animais foram abatidos ao inicio do experimento, como referencia, e o restante foi alimentado a vontade e distribuido nos tratamentos, de forma inteiramente casualizada, de acordo com o nivel de concentrado na racao: 25; 37,5; 50; 62,5; e 75%. Os animais foram abatidos quando atingiram o peso de 500 kg. As concentracoes de energia liquida das racoes foram calculadas e as eficiencias de utilizacao da energia metabolizavel para ganho de peso foram estimadas, por analise de regressao, entre as energias liquidas para ganho, em relacao a energia metabolizavel (EM) das racoes. As exigencias de EM para ganho de um quilograma de peso de corpo vazio aumentaram, a medida que se elevou o peso corporal dos animais e diminuiram, para mesmo peso vivo, a medida que se elevaram os niveis de concentrado nas racoes. Estimaram-se as eficiencias de utilizacao da energia metabolizavel para ganho de peso em: 0,27; 0,26; 0,36; 0,39; e 0,42. O nivel de concentrado melhorou a eficiencia de utilizacao da EM para ganho de peso.

Composição corporal e exigências líquidas de macroelementos minerais de bovinos F1 Simental x Nelore

The effects of different dietary concentrate levels on the net requirements of Ca, P, Mg, Na and potassium (K) were studied. Twenty-nine F1 Simental x Nellore bulls, averaging 17 months of age and initial LW of 354 kg, were used. Five animals were slaughtered at the beginning of the experiment as a reference and the remainders were allotted to a completely randomized design, according to the different dietary concentrate levels: 25.0, 37.50, 50,0, 62.5, and 75.0%. The animals were were full fed until a pre-established slaughter weight of 500 kg. The logarithm of mineral macroelement amounts were regressed on the logarithm of empty body weight (EBW). By deriving those regression equations, the net requirements for 1 kg EBW were found. The net requirements of Ca, P, Mg, Na and K for 1 kg EBW gain for an animal of 400 kg LW, using the overall equation, were, respectively: 10.33, 4.68, 0.30, 1.25, and 1.46 g. The mineral concentrations decreased, in the empty body weight, as the EBW increased