Kristensen L, Therkildsen M, Aaslyng M D, Oksbjerg N, Ertbjerg P
Department of Food Science, Royal Veterinary and Agricultural University, DK-1958 Frederiksberg C, Denmark.
J Anim Sci. 2004 Dec;82(12):3617-24. doi: 10.2527/2004.82123617x.
Compensatory growth is a phenomenon observed in pigs given free access to feed following a period of restricted feeding that results in increased growth rates. Compensatory growth is believed to increase protein turnover and thereby the proteolytic potential at the time of slaughter, leading to faster tenderization rates of meat. Nine litters of three gilts and three barrows were allocated within litter and gender to three dietary treatment groups. Pigs had ad libitum access to feed from d 28 to slaughter at d 140 (ALA) or were restricted to 69% ad libitum from d 28 to d 80 or 90, and then given ad libitum access to the diet until slaughter at d 140 (RA80 and RA90, respectively). Pigs in the RA80 and RA90 treatment groups had a 9.7% higher (P < or = 0.001) fractional growth rate in the second feeding period than those in the ALA group. Growth rate was correlated to the activity of m-calpain (r = 0.37; P < or = 0.01), beta-glucuronidase (r = 0.48; P < or = 0.001), and cathepsins B (r = 0.47; P < or = 0.001) and B+L (r = 0.31; P < or = 0.04). The LM of RA80-gilts received higher tenderness scores than the LM of ALA gilts, but tenderness scores were similar among barrows regardless of treatment (gender x treatment; P = 0.02). Conversely, tenderness scores were higher for the biceps femoris of ALA barrows than either ALA gilts or RA90 barrows (gender x treatment; P = 0.02). Desmin and troponin-T degradation, as well as myofibrillar fragmentation index, of the LM were not (P > or = 0.24) affected by treatment. No dietary treatment effects were observed on the activities of mu-calpain (P = 0.15), m-calpain (P = 0.74), or calpastatin (P = 0.91) at slaughter. The cathepsin inhibitors, cystatins, tended to be increased (P = 0.06) in RA80 and RA90 pigs. Sarcomere length was longer (P = 0.003) in the LM of gilts than barrows. Barrows in the RA80 group had lower i.m. fat concentrations than ALA; however, no differences were found in the LM of gilts (gender x treatment; P = 0.03). The underlying hypothesis that compensatory growth leads to an increased proteolytic potential at the time of slaughter could not be verified in this study.
补偿性生长是一种在猪身上观察到的现象，即在一段时间的限饲后让猪自由采食，这会导致生长速度加快。补偿性生长被认为会增加蛋白质周转率，从而在屠宰时提高蛋白水解潜力，使肉的嫩化速度加快。将9窝仔猪（每窝3头小母猪和3头小公猪）按窝别和性别分配到三个日粮处理组。从第28天到第140天屠宰期间，猪自由采食（ALA组）；或者从第28天到第80天或第90天限制采食量为自由采食量的69%，然后从那时起直到第140天屠宰期间自由采食（分别为RA80组和RA90组）。RA80组和RA90组的猪在第二个采食期的生长分数率比ALA组高9.7%（P≤0.001）。生长速度与m-钙蛋白酶的活性相关（r = 0.37；P≤0.01）、β-葡萄糖醛酸酶（r = 0.48；P≤0.001）、组织蛋白酶B（r = 0.47；P≤0.001）和组织蛋白酶B + L（r = 0.31；P≤0.04）。RA80组小母猪的腰大肌嫩度评分高于ALA组小母猪，但无论处理如何，小公猪之间的嫩度评分相似（性别×处理；P = 0.02）。相反，ALA组小公猪的股二头肌嫩度评分高于ALA组小母猪或RA90组小公猪（性别×处理；P = 0.02）。日粮处理对腰大肌的结蛋白和肌钙蛋白-T降解以及肌原纤维破碎指数没有影响（P≥0.24）。在屠宰时，日粮处理对μ-钙蛋白酶（P = 0.15）、m-钙蛋白酶（P = 0.74）或钙蛋白酶抑制蛋白（P = 0.91）的活性没有影响。组织蛋白酶抑制剂胱抑素在RA80组和RA90组猪中倾向于增加（P = 0.06）。小母猪腰大肌的肌节长度比小公猪长（P = 0.003）。RA80组小公猪的肌内脂肪浓度低于ALA组；然而，小母猪的腰大肌中未发现差异（性别×处理；P = 0.03）。本研究无法验证补偿性生长会导致屠宰时蛋白水解潜力增加这一潜在假设。
