Jonatas Cattelam

Efeitos da frequência de fornecimento do volumoso e concentrado no comportamento ingestivo de vacas e novilhas em confinamento

ABSTRACT - The present study was conducted with the objective of evaluating the influence of frequency ofroughage and supplement supply and/or animal category on the ingestive behavior of cattle. Sixteen heifers and sixteencows, with average initial age of 20 and 66 months and average initial weight of 338 and 432 kg, respectively, were used.Treatments were represented by the frequencies of roughage and concentrate supply: 2 R/C – roughage and concentratetwo times per day; 1 R/C – roughage and concentrate one time per day; 1 R/2C – roughage one time per day and concentratetwo times per day; 1 R/3 C – roughage one time per day and concentrate three times per day, offered to cows and heifers.Diet was composed of 60% maize silage and 40% concentrate, on a dry matter basis (DM). The complete randomizedexperimental design was used, with a 4 × 2 factorial arrangement (frequencies × category). The data were submitted tovariance analysis and averages were compared by “t” test. The interaction between supply frequencies and animal categorywas significant for rumination and idle times, efficiencies of dry matter rumination and of neutral detergent fiberrumination, number of ruminated bolus and daily time of chew. Heifers showed longer idle periods and daily time of chewwhen compared with cows that received food once in a day. Duration of feed intake did not vary with frequencies. Cowsshowed longer period of feed intake and ingestive rate in relation to heifers (4.38 vs. 4.09 hours and 2.91 vs. 2.35 kgof DM/hour of intake, respectively). The increase in food frequency stimulated animals to intensify feed intake at themoment of supply.Key Words: animal category, chews, food handling, food intake, idleness, rumination

Profile of ingested fatty acids and in the duodenal digest of steers fed different diets

It was evaluated in this study the effect of the type of the diet on duodenal flow of long-chain fatty acids in steers. The tested diets were the following: conventional (feedlot diet composed of 60% corn silage and 40% of concentrate); winter forage silage - rye grass (Lolium multiflorum, Lam); or tropical forage silage - association of millet (Pennisetum americanum, Leeke + alexander grass, Brachiaria plantaginea). Six Charolais × Nellore crossbred steers with cannulas in duodenum were used in a 3 × 3 double Latin square. Dry material intake was similar among the groups (mean of 4,037 g/day), but the intake of total fatty acids and saturated fatty acids were higher in the group fed tropical pasture silage. On the other hand, the animals which received the conventional diet consumed higher quantity of unsaturated fatty acids. Tropical pasture silage provided higher consumption of vacenic acid (C18:1 t-11) and the winter forage silage offered higher consumption of conjugated linoleic acid. The intake of omega-6 fatty acids was higher in the group fed conventional diet and for omega-3, intake was higher in the group fed tropical pasture diet. The total fatty acid flow in the duodenum was not affected by the diets, but in all treatments it was higher than the consumed one. The animals fed diet with concentrate show the greatest changes on the profile of fatty acids during the ruminal fermentation. Conventional diets provide the highest intake of unsaturated fatty acids and the highest availability of vacenic acid in the small intestine, but they do not increase the supply of intestinal conjugated linoleic acid.

Características dos componentes externos e das gorduras descartadas de novilhos superprecoces não-castrados ou castrados de dois genótipos terminados em confinamento

The objective of this study was to evaluate the characteristics of external components and discard fat of young steers with two different sexual conditions and two different genotypes, finished in feedlot. Average age and weight of the animals at the beginning of the experimental period were 12 months and 267.0 kg, respectively. The steers were in feedlot until reaching pre-established slaughter weight of 400 kg. Diet contained roughage:concentrate ratio of 50:50, on dry matter basis, with 10% crude protein. It was used a complete randomized experimental design, in a 2 × 2 factorial arrangement, composed of two sexual conditions and two genetic groups. Empty body weight (EBW), carcass dressing in relation to empty body weight and the relationship between empty body weight and slaughter weight were similar among genotypes and sexual conditions. For absolute weight of ears, it was observed significant interaction between genotypes and sexual conditions of steers. Castrated animals showed greater values of intestinal fat in relation to empty body weight (1.62 versus 1.18%). Animals with Charolais predominance showed greater absolute values to tail broom (0.16 versus 0.11 kg) and Nellore steers predominance presented greater weight related to rawhide and renal fat. There is no correlation among carcass dressing and non-integrant components of carcass.

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.

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).

Qualitative characteristics of meat from cull cows of different genotypes and age class slaughter under different finishing systems: a meta-analytic approach

The aim of this study was to evaluate, by meta-analysis, the quality of the meat of the cows according to genotype, termination system and age class slaughter. During an online research were identified 15 articles with information related to meat quality of slaughtered cows. The data were grouped according of the genotype of cows being: zebu or continental defined, crossed zebu x british or zebu x continental; according to termination system: feedlot or grassland; according to age of slaughter, where: up to 4 years old (young), 4-8 years old (adult) or more than 8 years old (old). The meat of the continental crossbred cows was softer than the other genotypes, both panel of evaluators and by Shear. The meat of cows finished in feedlot showed higher marbling degree in relation to meat of females finished on grassland. The reduction of the slaughter age of cows improved the meat color. The cows genotype affects the organoleptic aspects of meat while the finished system and slaughter age affects the sensory aspects of meat.

Comportamento social, frequência respiratória e escore de limpeza de novilhos confinados com diferentes espaços individuais

Objetivou-se avaliar o comportamento social, a frequencia respiratoria e o escore de limpeza de novilhosconfinados em diferentes espacos individuais. Foram utilizados 48 novilhos com idade e pesos medios iniciaisde 20 meses e 243,4 kg, respectivamente. Os animais foram confinados coletivamente de acordo como espaco individual disponivel, 2,5; 5,0 ou 10 m2. A dieta continha relacao volumoso:concentrado de 39:61(base na materia seca). O delineamento experimental utilizado foi o de blocos ao acaso. As analises foramefetuadas atraves do proc MIXED. As medias foram classificadas pelo teste “F” e os parâmetros comefeito significativo comparados pelo “teste t”, com α = 0,05. As interacoes agressivas atraves de cabecadasou ameacas, medias de 15,8 e 5,1 ocorrencias diarias, respectivamente, e o numero total de disputas, com21,9; 21,5 e 19,7 ocorrencias entre animais mantidos em espacos de 2,5; 5,0 e 10 m2, citados na mesmaordem, nao foram influenciadas pelo espaco individual disponivel. Do mesmo modo, o numero de interacao nao-agonisticas foi similar entre os diferentes espacamentos avaliados. Novilhos confinados com 5,0 e 10m2 estenderam seus membros 8,8 e 9,7 vezes por dia, respectivamente, superiores aos animais mantidoscom disponibilidade individual de 2,5 m2, que realizaram esse comportamento 4,3 vezes ao dia. O escore delimpeza diferiu entre os espacamentos – 3,2; 2,4 e 1,1 – para novilhos com espacos individuais de 2,5; 5,0 e10 m2, respectivamente, assim como a frequencia respiratoria, com 27,1; 24,8 e 22,7 movimentos/ minuto,citados na mesma ordem.