Effects of Dietary Energy Level and Slaughter Weight on Growth Performance and Grades and Quality Traits of the Carcass in Finishing Pigs

Abstract

ABSTRACT(Y × L) × D-crossbred gilts and barrows weighing 80.2 ± 0.2 kg were fed a "medium-energy" (ME) or "low-energy" (LE) diet (3.2 vs 3.0 M cal DE/kg) and slaughtered at 110, 125, or 138 kg, after which physicochemical and sensory quality traits of major primal cuts of resulting carcasses were analyzed, under a 2 (sex) × 2 (diet) × 3 (slaughter weight; SW) factorial arrangement of treatments. The ADG and ADFI were greater (P<0.01) in barrows than in gilts and also in 125-and 138-kg vs 110-kg SW. Moreover, ADG and gain:feed were greater in ME vs LE (P<0.01), whereas ADFI was greater in LE vs ME (P<0.01). Backfat thickness, which increased with increasing SW (P<0.01), was not affected by sex or diet. Carcass marbling score was greater (P<0.01) in gilts and LE than in barrows and ME, respectively. Carcass quality grade, which was superior in LE vs ME, was not affected by SW, whereas the yield grade decreased abruptly between 125-and 138-kg SW primarily due to the upper limit of carcass weight imposed on the A and B grades. Physicochemical characteristics including pH, drip loss, and variables pertaining to color of belly, ham, and loin were not affected significantly by any of the treatment factors, albeit statistically significant in some cases, in terms of quality criteria. In sensory evaluation, the acceptability of fresh belly was not influenced by any of the treatment factors. Marbling score of fresh ham was greater in LE vs ME (P<0.01) and tended to increase between 110-and 125-kg SW (P=0.10); in loin, the increase of this variable between the two SW was significant (P<0.01). Following cooking, LE was superior to ME in the acceptability in belly and ham, but the effect of SW was insignificant in any of the sensory quality traits evaluated in this study in any of the three major primal cuts. In conclusion, the present results suggest that SW can be increased to up to 138 kg without compromising carcass quality and that LE has some beneficial effects on quality of the whole carcass and the major primal cuts.

Effects of Dietary Energy Level on Growth Efficiency and Carcass Quality Traits of Finishing Pigs

“…The greater carcass marbling and quality grade points in the barrow vs gilt are consistent with previous results (Park et al, 2009). Further, the significant correlation between these two carcass quality variables was also consistent with a result which was observed in the previous study (r=0.80; P<0.01) but was not reported therein.…”

“…The rate of weight gain of the present animals was lower compared with those of the previous studies (Lee et al, 2006;Park et al, 2007Park et al, , 2009). For instance, ADG of the animals fed the medium-energy diet (ME; 3.2 Mcal DE/kg) in the present study was lower than those in the studies cited above by 9%, 6%, and 14%, respectively.…”

“…meat color, fat color and quality, texture, and marbling of the whole carcass, and the quality of the belly including the thickness of the whole cut and its fat layers and the fat:lean balance, marbling score is probably the most significant determinant of the final grade. On the other hand, the greater marbling and quality grade points in the LE vs ME group observed in the previous study (Park et al, 2009) were not apparent in the present study. This suggests that a long period may be necessary for a lowenergy diet to exert its beneficial effects on these quality variables, not only because marbling increases with age as well as with adipose tissue growth (Huff-Lonergan et al, 2003), but because the dietary effects on the variables were apparent only when the age at a fixed slaughter weight increased significantly by feeding the LE vs ME in the previous study.…”

“…These results implicate that the ME and HE are comparable in their influences on growth and are considered to be similar to those of the previous study (Lee et al, 2007), in which all these four variables were not different between the two groups. Moreover, the 10.5% greater ADG in the ME vs LE group, which reflects a greater total energy intake in the former, also was similar to an 11.1% greater ADG in the former (P<0.01) observed in the study of Park et al (2009), although the statistical difference between the ME and LE groups in the present study was rather insignificant. However, the lack of difference in gain:feed between the ME and LE groups in the present study (0.255 vs 0.242; P=0.21) was different from the significantly greater feed efficiency in the former in the previous study (0.268 vs 0.239; P<0.01).…”

“…More lately, Lee et al (2007) have also reported that a 'medium'-and a 'high'-energy diets containing 3.2 and 3.4 Mcal DE/kg, respectively, were comparable in feed efficiency as well as in their effects on growth and carcass quality characteristics of lean-type pigs fed the respective diets from 90 kg to 125 or 135 kg. In contrast, in the study of Park et al (2009), a 'low'-energy diet containing 3.0 Mcal DE/kg was not as effective as the medium-energy diet in supporting weight gain as well as feed efficiency in finishing pigs from 80 kg through 110 to 138 kg. Of note, the carcass marbling and quality grade were superior in the low-vs medium-energy diet in this study, suggesting that a low-energy diet may have some beneficial effects on carcass quality in compensation for its reduced effectiveness on weight gain and its efficiency.…”