Performance and carcass traits of early-weaned steers receiving either a pasture growing period or a finishing diet at weaning.

Abstract

A 2-yr study was conducted to evaluate 1) steers fed ad libitum high concentrate after weaning (CONC), or 2) steers grown on pasture for 82 d, followed by high-concentrate finishing (PAST), on the performance and carcass traits of 74 early-weaned (117 d of age) steers. Potential breed differences were evaluated using crossbred steers of three types: 1) 3/4 Angus x 1/4 Simmental (BRI), 2) 3/4 Simmental x 1/4 Angus (CON), and 3) 1/2 Wagyu x 1/4 Angus x 1/4 Simmental (WAG). Steers were randomly assigned within breed to the two treatments. There was no interactions (P > .10), so the data were pooled over years. The CONC steers had an ADG that was .17 kg/d higher (P = .0001), intake 1.09 kg/d lower (P = .0001), and gain:feed ratio .013 unit better (.190 vs .177, P = .008) than PAST steers overall. Growing treatment did not affect total concentrate consumed (P = .97). The BRI steers required 31 d less than did CON steers (P = .008), and 23 d less than WAG steers (P = .05) when fed to a constant fat end point (1.1 cm). The BRI steers exhibited an ADG .16 kg/d higher (P = .0003), tended (P = .07) to have an ADG intake .49 kg/d higher, and exhibited gain:feed .01 unit better (.189 vs 180) than WAG steers. When compared with CON steers, BRI steers consumed 310 kg less total concentrate (P = .0003). No differences (P > .38) were observed between growing treatments for carcass characteristics or sensory attributes except that CONC steers tended (P = .11) to improve percentage of steers grading Average Choice or higher by 47% over PAST steers. The WAG steers had a 76-unit higher marbling score (1,000 = Small00, 1,100 = Modest00) (P = .006) than BRI steers, resulting in 19% more (P = .09) steers grading > or = Choice and 82% more (P = .03) grading > or = Average Choice. Liver (P = .15) and rumen (P = .01) weights as a percentage of hot carcass weight were reduced for CONC steers. The CONC steers had higher gain, lower intake, better efficiency, reduced liver and rumen weights, and consumed the same amount of total concentrate when compared with PAST steers. The BRI steers had less finishing days and lower daily intake compared with CON steers. The WAG steers had more days finishing, lower gain, lower intake, more undesirable efficiencies, consumed the same amount of total concentrate, and improved quality grades compared with BRI steers.

Effect of management strategy on growth performance, carcass characteristics, fatty acid composition, and palatability attributes in crossbred steers

“…This is in agreement with other studies comparing beef from steers exclusively fed high grain diets vs. cattle consuming alfalfa silage ad libitum or cattle backgrounded on pasture (Myers et al 1999) followed by high grain finishing. In contrast, Dikeman et al (1985) reported higher shear scores for steers that were backgrounded before finishing vs. steers directly finished on grain.…”

“…Age and weight at start of test and weight at slaughter were similar (P > 0.36) between management strategies. Weight at slaughter was also not affected in previous studies comparing steers fed a high grain diet vs. steers initially consuming alfalfa silage ad libitum or grazed on pasture before high grain finishing (Myers et al 1999). In contrast, other researchers (Rompala et al 1984;Vaage et al 1998) reported heavier slaughter weights in backgrounded cattle when compared with cattle started on a high grain diet after weaning and slaughtered at a common backfat endpoint.…”

“…Larger LMA in grain-fed cattle relative to forage-fed cattle were previously reported after feeding to a constant time on feed (Mandell et al 1998a) or backfat thickness (Crouse et al 1984), and these results were attributed to diet differences in ME (Mandell et al 1998a). In contrast, LMA did not differ between management strategies when cattle were slaughtered at a constant backfat thickness after feeding high grain diets or diets based on forages followed by high grain finishing (Rompala et al 1984;Vaage et al 1998;Myers et al 1999).…”

Produção do Superprecoce a Partir de Bezerros Desmamados aos 72 ou 210 Dias de Idade

“…Este provável aumento da capacidade digestiva deve ter sido um dos fatores que colaboraram para o maior consumo de matéria seca dos animais do T 210 durante a terminação. Myers et al (1999) concluíram que animais desmamados precocemente (117 dias) e mantidos em pastagem por 82 dias apresentaram maiores peso do retículo-rúmen e consumo de alimentos durante a fase de terminação em confinamento que animais submetidos a confinamento logo após o desmame.…”

“…Já Myers et al (1999) observaram maior GMD e melhor CA em animais também desmamados precocemente e abatidos com idade similar à do presente experimento, porém com níveis mais altos de concentrado na dieta.…”