Department of Large Animal Sciences, Faculty of Life Science, University of Copenhagen, Grønnegaardsvej 2, DK-1870 Frederiksberg C, Denmark.
Prev Vet Med. 2011 Aug 1;101(1-2):73-8. doi: 10.1016/j.prevetmed.2011.05.002. Epub 2011 Jun 8.
In several countries slaughter pigs are paid for individually, according to slaughter weight and lean meat percent (LMP). Production of uniform batches of pigs within the optimal weight and LMP limits will obtain the best price. Therefore, all pigs should have a similar growth rate (average daily gain, ADG) and reach an appropriate slaughter weight within the same time period. LMP may serve as a proxy for ADG since pigs with low LMP have significantly higher ADG than pigs with high LMP and vice versa. Both breeding strategy and feeding system may influence the range of variation among pigs. The aim of this study was to test the two following hypotheses: (1) Herds purchasing breeding gilts have a higher mean value and a lower variation (standard deviation) in LMP than herds producing their own breeding gilts and (2) Herds using restricted feeding of finishers have a higher mean value and a lower variation (standard deviation) in LMP than herds with ad libitum feeding of finishers. The study included 72 herds and a total of 345,132 pigs slaughtered during one year. Among the 72 herds, 40 were home-breeders and 32 purchased breeding gilts from a breeding company. Nineteen herds used restricted feeding, of which 8 (42%) were home-breeders. Fifty-three herds used ad libitum feeding, of which 32 (60%) were home-breeders. Breeding strategy had a significant effect on SDLMP (p=0.003), where purchase of breeding gilts resulted in a significantly lower standard deviation of the monthly LMP compared to home-bred gilts (a difference in median SDLMP of 0.2 percentage points or 8% difference between groups). Feeding system had a significant effect on the meanLMP (p<0.001), with a significantly higher meanLMP in herds using restrictive feeding compared to ad libitum feeding (60.7% versus 60.0%). Restrictive feeding also resulted in a significantly lower SDLMP (p<0.001) compared to ad libitum feeding (2.2% versus 2.5% or a 12% difference between groups).
在一些国家，生猪屠宰是根据屠宰重量和瘦肉百分比（LMP）单独付费的。生产符合最佳体重和 LMP 限制的均匀批次的猪将获得最佳价格。因此，所有猪的生长速度（平均日增重，ADG）应该相似，并在同一时间段内达到适当的屠宰体重。LMP 可以作为 ADG 的替代指标，因为 LMP 较低的猪的 ADG 明显高于 LMP 较高的猪，反之亦然。繁殖策略和饲养系统都可能影响猪之间的变异范围。本研究的目的是检验以下两个假设：（1）购买繁殖母猪的畜群的 LMP 平均值较高，变异（标准差）较低，而生产自己繁殖母猪的畜群则相反；（2）使用限制育肥猪饲料的畜群的 LMP 平均值较高，变异（标准差）较低，而自由采食育肥猪饲料的畜群则相反。该研究包括 72 个畜群和一年内屠宰的 345132 头猪。在 72 个畜群中，40 个是自繁畜群，32 个从繁殖公司购买繁殖母猪。19 个畜群使用限制饲养，其中 8 个（42%）是自繁畜群。53 个畜群使用自由采食，其中 32 个（60%）是自繁畜群。繁殖策略对 SDLMP 有显著影响（p=0.003），购买繁殖母猪导致每月 LMP 的标准差明显低于自繁母猪（中位数 SDLMP 差异为 0.2 个百分点或两组之间差异为 8%）。饲养系统对平均 LMP 有显著影响（p<0.001），限制饲养的畜群的平均 LMP 明显高于自由采食的畜群（60.7%比 60.0%）。限制饲养还导致与自由采食相比，SDLMP 显著降低（p<0.001）（2.2%比 2.5%或两组之间差异为 12%）。
