저에너지 사료 급여가 거세 비육돈의 성장과 도체 품질에 미치는 영향 = Effects of a low-energy diet on growth and carcass quality of finishing barrows

다국어 초록 (Multilingual Abstract)

Barrows eat excessively more feed than gilts and as a result, their carcass grades are, in general, lower than those of the latter. The present study was conducted to investigate the effect of a low-energy diet on growth and carcass quality in finishing barrows and thereby to draw a guideline for the usage of it. In experiment I(Exp. I), 60 LYYD cross-bred barrows weighing ~70kg were randomly assigned into four pens and fed ad libitum either of two finishing diets containing 103%(control diet) and 87%(low-energy diet) of the NRC digestible energy(DE) requirements, respectively, up to slaughter at ~105kg. Exp. Ⅱ was same as Exp. Ⅰ except that average initial weight of the barrows(48 heads) was ~60kg and feed intake was measured.
In Exp. I, by feeding the low-energy diet, average daily gain(ADG) was decreased(P＜0.05); backfat thickness corrected for 110kg of live weight tended to be decreased(P=0.11); and the ratio of A,B grade carcass was not apparently affected[93%(low-energy diet) vs 90%(control)]. In Exp. II, as in Exp. I, ADG was decreased by feeding the low-energy diet vs control, which is interpreted to have resulted primarily from a 14% decrease in total DE intake. Compared with control, low-energy diet group had a similar average daily feed intake(3.10 vs 3.04kg) and a 14% higher feed/gain. In somewhat contrast to the result of Exp. I, backfat thickness corrected for the live weight was not different between the two groups in Exp. II, which is presumed to have resulted mainly from a genetic ununiformity of the animals with respect to this trait. The A,B carcass ratio, on the other hand, was not appreciably different between the two groups(73 vs 83%).
In summary, under the current domestic carcass grading system allowing a relatively wide range of backfat thickness for A and B grades, a low-energy diet is considered to be useful only for a barrow population where the A, B carcass ratio is too low for excessive fackfat. More studies are needed, however, to determine whether a low-energy diet will be useful under the situation of international pork market demanding a higher lean meat ratio.