Revell D K, Williams I H, Mullan B P, Ranford J L, Smits R J
Animal Science, Faculty of Agriculture, The University of Western Australia, Nedlands.
J Anim Sci. 1998 Jul;76(7):1738-43. doi: 10.2527/1998.7671738x.
Sows that were either fat or lean at farrowing (340 or 280 g of body fat/kg BW, respectively) were offered either a low-protein (LP; 7.9% CP and 15.5 MJ DE/kg as fed) or a high-protein (HP; 19.0% CP and 15.6 MJ DE/kg as fed) diet on an ad libitum basis throughout a 4-wk lactation to test the hypothesis that the amount of milk and its composition are responsive to the supply of endogenous (body reserves) and exogenous (diet) substrates. Pigs were weighed at birth and weekly during lactation, milk yield was estimated using deuterium oxide in early (d 4 to 8) and late lactation (d 24 to 28), and milk samples were collected to determine composition in early (d 4 to 6) and late lactation (d 25 to 27). Throughout lactation, milk yield and composition were mainly associated with differences in litter size. Milk yield was about 15% higher in lean than in fat sows and in sows fed HP rather than LP, but large CV (17 to 32%) prevented these differences from attaining significance (P > .273). The responses in milk yield were reflected in pig growth. Differences in milk composition between treatment groups were not significant; however, during early lactation there was a tendency for fat sows to produce milk with a fat content 21% higher, and a protein content 12% lower, than that of lean sows. Changes in the protein:energy ratio of milk during the course of lactation and small changes in milk yield composition collectively suggested that in early lactation, sow body composition affected milk production but, as lactation progressed, the dietary supply of precursors for milk synthesis became more important.
分娩时体脂含量分别为340或280克/千克体重的肥瘦母猪，在整个4周的哺乳期内自由采食低蛋白（LP；7.9%粗蛋白和15.5兆焦消化能/千克风干饲料）或高蛋白（HP；19.0%粗蛋白和15.6兆焦消化能/千克风干饲料）日粮，以检验牛奶产量及其成分对体内（体储备）和体外（日粮）底物供应有反应这一假设。仔猪出生时称重，哺乳期每周称重一次，在泌乳早期（第4至8天）和晚期（第24至28天）使用氧化氘估算产奶量，并采集乳样以测定泌乳早期（第4至6天）和晚期（第25至27天）的成分。在整个哺乳期，产奶量和成分主要与窝仔数差异有关。瘦母猪的产奶量比肥母猪高约15%，采食HP日粮的母猪比采食LP日粮的母猪高约15%，但较大的变异系数（17%至32%）使这些差异未达到显著水平（P>.273）。产奶量的反应反映在仔猪生长上。各处理组间乳成分差异不显著；然而，在泌乳早期，肥母猪所产牛奶的脂肪含量比瘦母猪高21%，蛋白质含量比瘦母猪低12%。泌乳过程中牛奶的蛋白质:能量比变化以及产奶量成分的微小变化共同表明，在泌乳早期，母猪体组成影响产奶量，但随着泌乳进展，日粮中用于合成牛奶的前体物质供应变得更为重要。
