Dietary effects on beef composition: I. Quantitative and qualitative carcass traits

Abstract

Suppressed development of edible portion in carcasses from cattle fed hay during the early feeding period (216-340 kg live weight) was followed by compensatory growth during the intermediate (341-409 kg live weight) and final (410-454 kg live weight) periods. However, when silage in the early feeding period was followed by corn concentrate in the intermediate period, no increased 'edible portion' development was achieved beyond that produced by continuous silage. The final feeding period (corn concentrate) resulted in a decline in ' edible portion' percentage in cattle that previously received concentrate in the intermediate period whereas those that previously received silage remained at about the same percentage.Cattle fed hay during the early period had less (P < 0-01) carcass weight, less (P< 0'01) fat cover, and more (P < 0-01) reticulo-rumen weight than those fed corn silage for the same period, regardless of slaughter weight.In the heavy (409 and 454 kg) slaughter groups, cattle fed silage in the early period had higher (P < 0-05) marbling scores than those fed hay. Feeding silage in the intermediate period resulted in lower colour (P < 0-01) and firmness (P < 0-01) scores in the longissimus dorsi muscle than feeding concentrate at that time. The dietary regimes used in these studies resulted in widely varying growth rates among treatments with consequential differences in the average age of the animal groups at slaughter. Therefore, the treatment effects observed seem to be easily explicable on the basis of age differences.

Bodyweight and carcass characteristics of somali goats fed hay supplemented with graded levels of peanut cake and wheat bran mixture

“…In the present study, the meat to bone ratio was 3.3 at 23.82 kg of slaughter weight, which is within the range reported. The higher content of fat in supplemented animals in the current study is similar to that reported by Garrigus et al (1969), whereby animals on concentrate feed had higher weight of fat than those fed hay based diets.…”

Dietary effects on beef composition: II. Quantity and distribution of fat

“…Inhibition of fat deposition by hay feeding in the early period was not evident until the cattle reached 409 or 454 kg weights (Table 2). These results indicate that restricted growth, resulting from feeding hay (Garrigus et al 1969), did not affect intramuscular fat deposition during the early feeding period but growth restrictions during this period delayed the tendency for fat to be deposited in the muscles when higher density rations were subsequently fed. It is possible that the compensatory muscle growth occuring during the later feeding periods (Garrigus et al 1969) reduced the energy available for intramuscular fat deposition.…”

“…These results indicate that restricted growth, resulting from feeding hay (Garrigus et al 1969), did not affect intramuscular fat deposition during the early feeding period but growth restrictions during this period delayed the tendency for fat to be deposited in the muscles when higher density rations were subsequently fed. It is possible that the compensatory muscle growth occuring during the later feeding periods (Garrigus et al 1969) reduced the energy available for intramuscular fat deposition. These results are in agreement with those of Carroll, Ellsworth & Kroger (1963) who reported that ration restrictions which resulted in a loss of carcass fat did not reduce longissimus dorsi ether extract; when these restrictions were followed by realimentation, the cattle had less intramuscular fat than those which had been continuously grown.…”

“…However, hay feeding reduced the fat in the mesentary only when the cattle were slaughtered at light weights (284 and 340 kg). The expansion of the digestive tract in hay-fed cattle (Garrigus et al 1969) may have permitted later deposition of large…”