Energy and nitrogen utilisation of sow colostrum and milk by the piglet
Twenty-four newborn piglets were used to evaluate the digestibility of sow colostrum and milk and the efficiency of milk utilisation by the piglet. Within a litter, four piglets were allotted to one of the four treatments: killed at birth, or bottle-fed sow colostrum for 30 h and sow milk thereafter at the rate of 100, 200, or 300 g kg-1 d-1. Piglets were killed on day 8. Faeces and urine were daily collected and heat production (HP) was determined by indirect calorimetry on days 6 and 7, each day during three successive periods of 105–110 min. Energy retention (ER) was calculated as the difference between metabolisable energy intake (ME) and HP. ER was also determined over the 8-d period using the comparative slaughter (CS). There was no effect of level of feeding on energy and nitrogen digestibility. Milk energy digestibility and metabolisability (ME/GE × 100) and nitrogen digestibility were 98.2 ± 1.2 (SEM), 96.8 ± 1.4 and 98.3 ± 1.3%, respectively. Corresponding values for colostrum were lower (P < 0.01), averaging 95.2 ± 2.8, 92.6 ± 3.1 and 95.3 ± 2.9%, respectively. Efficiency of using milk ME for ER determined by indirect calorimetry or CS was similar and averaged 0.72 ± 0.02. The energy cost of 1 kJ of protein deposition was 1.77 (± 0.04) kJ (efficiency, 0.56), whereas the energy cost of 1 kJ of fat deposition was not different to 1 kJ. Key words: Piglet, colostrum, milk, energy, nitrogen