D.C. Alves Filho

Características dos componentes não integrantes da carcaça de novilhos superjovens da raça Devon, terminados em diferentes sistemas de alimentação

O objetivo do estudo foi avaliar as caracteristicas dos componentes nao integrantes da carcaca de novilhos Devon terminados em confinamento (CONF), em pastagem de clima temperado (pastagem de azevem - Lolium multiflorum Lam - PTEM) ou em pastagem de clima tropical (associacao de pastagem de milheto - Pennisetum americanum (L.) Leeke - e capim-papua - Bracharia plantaginea - PTRO). Os novilhos, ao inicio da terminacao, estavam com 320kg e 15 meses de idade. Os animais confinados foram alimentados com relacao volumoso:concentrado de 60:40; o volumoso era constituido de silagem de milho, e o concentrado de farelo de trigo, milho e minerais. Os animais foram abatidos com pesos semelhantes de 388,3; 386,7 e 375,8kg no CONF, na PTEM e na PTRO, respectivamente. Os animais da PTRO apresentaram maior (P<0,10) rendimento de carcaca quente (RCQ) relativo a 100kg de peso corporal vazio (RCQPCV) do que os da PTEM, 64,6 versus 62,6%, e os do CONF apresentaram RCQPCV intermediario, 63,7%. Os pesos absolutos do figado, 5,22; 4,43 e 3,87kg, do conjunto dos orgaos internos, 12,81; 11,37 e 10,83kg, do rumen-reticulo, 7,62; 6,54 e 6,06kg, da gordura do coracao, 1,26; 0,65 e 0,30kg, e dos intestinos, 9,97; 7,13 e 7,49kg, foram mais altos (P<0,05) nos animais da PTEM, em relacao aos do CONF e da PTRO, respectivamente. A mesma ordem de grandeza ocorreu com os pesos relativos desses orgaos. A PTRO e o CONF originaram animais com maior (P<0,05) peso de conteudo gastrintestinal em relacao a PTEM, respectivamente, 60,27; 55,32 e 41,21kg. O CONF proporcionou animais com pesos absolutos mais elevados (P<0,05) do omaso, 5,17kg, em relacao aos da PTEM, 3,70kg, e este peso foi intermediario nos animais da PTRO, 4,77kg. A mesma ordem de grandeza ocorreu com os pesos relativos do omaso, 1,61; 1,12 e 1,54%.

Características da carcaça e do corpo vazio de bovinos Charolês de diferentes categorias abatidos com similar grau de acabamento

The carcass characteristics and empty body of Charolais steers n=9, cull heifers n= 10, and cull cows n=10, feedlot finished with similar subcutaneous fat thickness were evaluated. The slaughter weight and empty body weight (EBW) were similar between steers (480.2 and 417.4kg) and cows (516.2 and 405.8kg), which were higher than for heifers (368.3 and 306.1kg). Hot carcass dressing was significantly different among categories, being 57.2, 53.3 and 50.5%, respectively, for steers, heifers and cows. When carcass dressing was expressed in relation to EBW the differences became smaller among categories, being significant only between steers and heifers. The digestive tract content of cows was 34 and 45% higher than for steers and heifers, respectively, being correlated (P<0.05) with slaughter weight (r=0.66) and hot carcass dressing (r=-0.41). Hot carcass weight was similar for steers (274.9kg) and cows (260.8kg), both superior to heifers (196.4kg). Carcass length was higher for cows, intermediate for steers and lower for heifers. The Longissimus dorsi area was smaller for heifers. Steers showed better carcass conformation score than females, which did not differ between themselves.

Composição física da carcaça e qualidade da carne de novilhos Charolês e Nelore que receberam diferentes proporções de concentrado na dieta

Avaliaram-se a composicao fisica da carcaca e a qualidade da carne de 22 novilhos contemporâneos, com media de idade de 22 meses, das racas Charoles ou Nelore, terminados em confinamento, e que receberam diferentes proporcoes de concentrado na dieta. A fracao volumosa da dieta foi composta pelas silagens de milho e sorgo em partes iguais. Os animais foram distribuidos em tres tratamentos constituidos por 35, 50 ou 65% de concentrado na materia seca. Nao houve efeito (P>0,05) da porcentagem de concentrado na dieta sobre a composicao fisica da carcaca. A proporcao de inclusao do concentrado influenciou (P=0,0013) positivamente a maciez da carne, aumentando em 0,026 pontos a cada ponto percentual de aumento do concentrado. As demais caracteristicas qualitativas da carne nao foram influenciadas (P>0,05) pelo aumento do concentrado na dieta. A carne dos novilhos Charoles apresentou textura mais fina, 4,15 x 3,14 pontos, foi mais macia, 6,85 x 5,71 pontos, mais suculenta, 7,17 x 5,77 pontos, e apresentou menor resistencia das fibras ao cisalhamento, 3,79 x 5,79kgF. A carcaca dos novilhos Charoles apresentou maior deposicao muscular, 65,5 x 61,5%, e a dos novilhos Nelore apresentou maior percentagem de gordura, 23,3 x 20,3%.

Frequências do fornecimento do alimento no desempenho de vacas e novilhas em confinamento

The effect of frequency of supply of forage (V) and concentrate (C) on the performance of cows and heifers in feedlot was studied. The treatments were the following frequencies in the supply: 2 V/C= V and C twice daily; 1 V/C= V and C once daily; 1 V/2C= once V and C twice daily, 1 V/3C= once V and C three times a day, for the cows or heifers. The experimental design was completely randomized in factorial arrangement 4 x 2, with four replications. There was no significant interaction between frequency of supplying and category animal. The dry matter intake (DMI) was superior for the animals fed 1 V/2C or 1 V/3C a day in relation with the supply of 2 V/C and 1 V/C, presenting values of 11.7; 11.4; 10.6 and 10.7 kg, respectively. The average daily gain (ADG) was not influenced by the frequency of supplying. The DMI was higher in cows (12.6 kg) than heifers (9.57 kg), having no difference in the weight gain. Increasing frequency of feeding the concentrate to two or three times a day, provided greater consumption, not influencing the weight gain of cows and heifers confined.

Órgãos internos e trato digestório de novilhos superprecoces não castrados ou castrados, de dois grupos genéticos

Avaliaram-se as caracteristicas dos orgaos e do trato gastrintestinal de novilhos com duas condicoes sexuais - castrados e nao castrados -, com predominio genetico Charoles ou Nelore com idade e peso medios iniciais de 12 meses e 267kg, respectivamente. Os novilhos foram confinados ate o peso de abate medio preestabelecido de 400kg. A dieta alimentar continha relacao volumoso:concentrado de 50:50 (base na materia seca), com 10% de proteina bruta. O delineamento experimental utilizado foi o inteiramente ao acaso, em arranjo fatorial de 2x2 (duas condicoes sexuais x dois predominios geneticos). Para o peso absoluto do omaso, observou-se interacao significativa de genotipo versus condicao sexual dos novilhos. Animais nao castrados apresentaram maiores pesos absolutos dos rins (0,81 versus 0,66kg), do abomaso (1,20 versus 1,00kg) e dos intestinos, nas diferentes formas de expressao, em comparacao aos castrados. Os animais com predominio Charoles apresentaram maiores pesos absolutos do omaso (4,24 versus 3,46kg), dos intestinos (8,18 versus 6,84kg) e do total do trato digestorio (16,88 versus 14,90kg) em relacao aos animais com predominância Nelore. Nao houve correlacao entre o rendimento de carcaca e os componentes nao integrantes da carcaca.

Silagem de híbridos de sorgo associado a percentagens de concentrado no desempenho de novilhos

The feedlot performance of steers fed forage sorghum and double purpose hybrids silage associated with concentrate levels was evaluated. A total of 60 steers, initial age 20 months and body weight of 322.45±5.58kg, were randomized in the treatments: three concentrate levels and two types of sorghum silage. The interaction of sorghum silage versus concentrate levels was observed for dry matter intake and average daily weight gain, which increased with the increase concentrate level in diets with forage sorghum silage, but was not altered in diets with double purpose silage. Steers fed forage sorghum silage presented a lower average intake of digestible energy (27.89Mcal/day-1) than those fed double purpose sorghum silage (31.42Mcal/day-1). The average feed conversion was not affected by the type of silage used. The increase of concentrate level in diets with lower forage quality increases the biological efficiency of feedlot beef cattle.

Performance of feedlot steers finished with different fat sources in diet

The objective of this study was to evaluate the effect of different fat sources in finishing diets on performance of feedlot steers. Twenty steers, with average age of 20 months and initial live weight of 260 ± 41.3 kg, were feedlot fed during 126 days. The animals received corn silage as roughage and the tested concentrates were: basic concentrate (BC); basic concentrate + whole rice bran and rice oil (WRB); basic concentrate + 3 % of fatty acids calcium salts (M3) and basic concentrate + 6 % of fatty acids calcium salts (M6). Each treatment had animals with the following genetic group: 1 pure Charolais (CH), 1 pure Nellore (NE), 2 11/16 CH 5/16 NE, 1 21/32 NE 11/ 32 CH. No significant differences were observed for crude protein, digestible energy, neutral and acid detergent fibers intakes. The animals that consumed 6 % of fatty acid calcium salts presented higher ether extract intake (0.77 kg/day), while those that consume 3 % or whole rice bran and oil showed intermediate value (0.51 kg/day) and the ones that consumed basic concentrated presented lower value (0.25 kg/day). Similar averages were observed for average daily weight gain (1.142, 1.199, 1.365 and 1.391 kg/day, for BC, WRB, M3 and M6, respectively) and final weight (421 kg).

Suplementação com gordura protegida para vacas de corte desmamadas precocemente mantidas em pastagem natural

The objective of this work was to evaluate the productive and reproductive performance of beef cows, as well as the performance of their calves according to the following dietary treatments: PRE: supplemented with protected fat (PF) during 45 days prepartum; PREPOS: supplemented with PF during 45 days prepartum and 63 days postpartum; POS: supplemented with PF during 63 days postpartum; PN: without supplementation. The productive performance of cows was not influenced by feed management (P>0.05), except for body condition score (BCS), which was lower for PRE and PREPOS cows at the end of mating season, with the latter cows having similar BCS POS and PN. The calving interval (CI) was shorter for cows supplemented in PREPOS  376 days , and did not differ in cows maintained in PN  383 days. Supplemented PREPOS cows weaned 4.4% more pounds of calf per 100kg of cow at calving  22.6kg  than the PRE and POS cows  21.6kg and 21.6kg, respectively  and 8,4% more pounds of calf per 100 of cow at calving than the cows maintained in native pasture  20.7kg. The fat protected supplementation during pre and/or postpartum periods did not affect the performance of cows and calves.