Influence of Energy and Protein Intake during Lactation on Body Composition of Primiparous Sows

Abstract
The effects of energy and protein intakes by 32 primiparous sows during a 28-d lactation on sow and litter performance and sow body composition and bone properties were examined. Dietary treatments were energy intakes of 8 (LE) and 16 (HE) Meal of ME/d and protein intakes of 380 (LP) and 760 (HP) g of CP/d in a 2 × 2 factorial arrangement. Sows fed diets that were inadequate in either energy or protein lost more weight than did sows fed the HE-HP diet, but backfat losses were greater when energy intake was deficient than when protein was deficient. Carcass measurements were influenced in a similar manner, with energy intake affecting (P < .001) backfat thickness and protein intake affecting (P < .05) longissimus muscle area. Heart, kidneys and liver of sows fed LP diets weighed less (P < .01) and contained less water and protein (P < .05) than those of sows fed HP. Sows fed LE had heart, liver and viscera that weighed less (P < .05) than those of sows fed HE. There was less fat (P < .05) in the heart, lung, liver and viscera of sows fed LE than in those of sows fed HE. Carcass components of the supraspinatus muscle and standardized sections through the longissimus muscle and right shoulder weighed less (P < .05) from sows fed LP rather than HP, and these components contained less water and protein. Sows fed the LE diets had less fat in the loin soft tissue section, right shoulder section and supraspinatus muscle than sows fed HE. Bone composition and strength were not influenced by dietary treatment. The composition of weight lost during lactation was diet-dependent. Sows fed diets that were deficient in protein but adequate in energy lost large amounts of protein from muscles and internal organs. Energy deficiency resulted primarily in fat loss. Copyright © 1989. American Society of Animal Science . Copyright 1989 by American Society of Animal Science