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商品豬早期因素在預測存活率、后期生長性能和胴體品質中的應用

發布單位:天津瑞孚農牧科技集團有限公司

查看次數：8029

時間：2019-08-21

Zhikai K Zeng，Pedro E Urriola，Jenelle R Dunkelberger，John M Eggert，Roos Vogelzang，Gerald C Shurson，Lee J Johnston
翻譯&校對：上海亙泰實業集團

      隨著對母豬多產仔數的選育，現代高產母豬通常比低產母豬的產仔數更多，但是低初生重仔豬占比也逐漸提高。然而多大比例的低出生重仔豬會有補償生長，以及如何在早期鑒定這些豬只，相關的研究幾乎沒有。本試驗的目的在于研究仔豬初生重和早期生長性能對斷奶前死亡率、后期生長性能和胴體品質的影響。
      試驗收集7654頭商品豬數據進行分析。使用區組回歸模型分析初生重對斷奶前存活率的影響，使用一系列混合模型分析初生重（n=7654）對斷奶重（n=6777）、保育末期重（n=4805）和出欄重（n=1417）、胴體重和瘦肉率（n=4572）的影響。生長速度根據斷奶前＜225g/d和≥225g/d分組，保育階段根據＜424g/d和≥424g/d分組。斷奶前死亡率、生長速度、體重和胴體性狀根據標準日齡進行校正，日增重和瘦肉率通過計算得到。
      結果顯示，區組回歸模型的結果表明初生重低于0.99kg和高于0.99kg時，斷奶前死亡率和初生重回歸方程的斜率有顯著差異（P＜0.05）。混合模型的分析結果發現初生重和校正后出欄重、胴體重、瘦肉率之間有正線性相關關系（P＜0.05），母豬胎次與校正后出欄重、胴體重、瘦肉率之間有二次線性相關關系。與哺乳期日增重較高的豬相比，日增重較低的豬初生重提高對校正后出欄重、胴體重的提高更多（P＜0.05）。保育期日增重越大的豬，校正后出欄重和胴體重越大（P＜0.05）。
      總之，初生重低于1kg的仔豬斷奶前死亡率越高。低初生重仔豬如果在哺乳階段生長速度低于平均水平可能會喪失補償生長的能力。

      As a result of genetic selection for increased litter size, modern, highly prolific sows often produce large litters with an increased percentage of light birth weight (BiW) piglets compared with less prolific females. However, there is limited information elucidating what proportion of light BiW piglets that express compensatory growth and how these pigs might be identified at a young age. The objective of this study was to analyze the effect of birth weight and early phase growth on preweaning mortality, subsequent growth performance, and carcass characteristics of pigs. Individual records collected on 7,654 commercial crossbred pigs were used for analyses. A segmented regression model was used to analyze the effect of birth weight on preweaning survival and a series of mixed models were used to analyze the effect of birth weight (n = 7,654) group on weights recorded at: weaning (n = 6,777), nursery exit (n = 4,805), and finishing exit (n = 1,417); hot carcass weight (HCW), and lean percentage (n = 4,572). The effect of growth rate group was defined during suckling (< 225 or ≥ 225 g/d) or the nursery phase (< 424 or ≥ 424 g/d). Preweaning mortality, growth rate, BW, and carcass traits were adjusted to a standard age, and ADG and lean percentage were calculated. Results of segmented regression analysis showed that the slope of preweaning mortality on birth weights below 0.99 kg differed (P < 0.05) from the slope of preweaning mortality regressed on birth weights above 0.99 kg. The mixed model analyses showed a positive linear effect (P < 0.05) of BiW and quadratic effect (P < 0.05) of sow parity on age-adjusted finishing weight (FiW), HCW, and lean percentage. The positive influences of increasing BiW were greater (P < 0.05) in age-adjusted FiW and HCW for pigs with slow suckling growth rate compared with those with fast suckling growth rate. Pigs with fast nursery growth rate had greater (P < 0.05) age-adjusted FiW and HCW compared with the slow growing nursery contemporaries. In conclusion, piglets born weighing less than 1 kg were at a higher risk of preweaning mortality than piglets born weighing 1 kg or greater. Light BiW pigs, but not heavy BiW pigs, may lose compensatory growth capability if growth rate during the suckling phase is below the average level.（轉自：豬營養國際論壇）