Relationships of the Slaughter Weight to Growth Performance and Meat Quality Traits in Finishing Pigs Fed A Low-energy Diet

Abstract

The present study was undertaken to investigate the effects of slaughter weight (SW) of finishing pigs fed a low-energy diet on growth efficiency and carcass quality and thereby to assess the optimal SW. (Yorkshire × Landrace) × Duroc-crossbred gilts and barrows were fed a diet containing 3,060 kcal DE/kg from 80-kg BW and slaughtered at 110, 125, or 135 kg, after which the belly, the most preferred cut in Korea, as well as the least preferred cuts ham and loin were subjected to physicochemical and sensory analyses. Both ADG and ADFI were greater (P<0.05) in the group slaughtered at 125 or 135 kg than in the 110-kg-SW group, whereas the opposite was true for gain:feed (P<0.01). Backfat thickness (BFT), which increased with increasing SW (P<0.01 and P<0.05), was greater in barrows than in gilts (P<0.01); BFT of barrows at 125 kg (24.6 mm) was comparable to that of gilts at 135 kg (24.2 mm). Physicochemical characteristics of the belly, ham and loin were minimally affected, if not affected, by SW; of note, however, the redness of the ham increased between 110-and 125-kg SW (P<0.05). In sensory evaluation of the belly, the fat:lean balance, which is a most important quality trait in this cut, was best (P<0.05) at 125 kg of SW, but the overall acceptability of this cut was not changed by SW. In the ham and loin, the marbling score increased (P<0.01) between 110-and 125-kg SW, whereas color, aroma, off-flavor, and drip were unaffected by SW. In addition, the acceptability of the loin increased (P<0.05) between 110-and 125-kg SW. In cooked meats, none of color, aroma, off-flavor, juiciness, tenderness, taste, and acceptability was changed by SW, except for an increase (P<0.05) in darkness of loin color between 110-and 125-kg SW. In conclusion, the optimal SW for the present subpopulation on the present low-energy diet lie in between 125 and 135 kg for gilts and at 125 kg for barrows.

Feasibility of Increasing the Slaughter Weight of Finishing Pigs

“…The gain:feed ratio of gilts was superior to that of barrows in the studies of Leach et al (1996) and Latorre et al (2004 Table 3), but in Latorre et al (2009) and others (Table 2), it did not differ between the two sexes. Moreover, the gain:feed ratio decreased slightly with increasing SW between 110 and 140 kg in some studies (Latorre et al, 2004, presented in Table 3; Piao et al, 2004;Park et al, 2009a), whereas in others (Cisneros et al, 1996;Leach et al, 1996;Park et al, 2007Park et al, , 2009b, it was not influenced by SW within the similar range of SW. Dressing percentage usually neither differs between the barrow and gilt nor changes with increasing SW (Piao et al, 2004;Lee et al, 2006;Park et al, 2009a,b). However, sometimes, it is slightly greater in gilts than in barrows (Latorre et al, 2004;Lee et al, 2007;Park et al, 2007) and also slightly increases with the increase of SW (Cisneros et al, 1996;Latorre et al, 2008).…”

“…The 24-h muscular pH does not change or slightly decreases with the increase of SW (Corino et al, 2008;Park et al, 2009a,b), with an exception of a slight increase of loin pH with the increase of SW in Park et al (2009a). However, the change in pH unit associated with the increase of SW within a practical range is not large enough to increase the incidence of PSE (pale, soft, and exudative) which can be caused by low postmortem muscular pH (Cisneros et al, 1996).…”

“…Meat color, aroma, off-flavor, and drip of fresh loin and ham judged by sensory panelists are uninfluenced or minimally influenced by sex or SW (Park et al, 2007(Park et al, , 2009a Table 8). However, the increase of marbling of these cuts occurring with increasing SW is considered to be significant in terms of meat quality.…”

“…This was followed by serial studies on various effects of increasing SW up to 138 kg (Lee et al, 2006(Lee et al, , 2007Park et al, 2007Park et al, , 2009a. The main results of these studies have been pooled and analyzed in a previous study to render regressive relationships of SW to the variables associated with growth efficiency and physicochemical and sensory characteristics of major primal cuts.…”

Objective and Subjective Quality Characteristics of Pork Longissimus Muscle as a Function of the Ultimate pH

“…In the Korean pig industry where guidelines for pre-, peri-, and post-slaughter procedures are not standardized, there are presumably many extrinsic factors that could affect ultimate pH including feeding scheme, slaughter weight and post-slaughter process (Park et al, 2009), as well as genetic factors (Hwang et al, 2004). For example, if the glycogen concentration of the muscle tissue is decreased due to feed restriction and stress prior to slaughter, the ultimate pH is higher than 5.5.…”