Estimation of Milk Production in Lactating Sows by Determination of Deuterated Water Turnover in Three Piglets per Litter

Abstract

Estimation of milk production in lactating sows by determination of deuterated water turnover in three piglets per litter.The milk intake in piglets from four lactating sows was measured in three 48 h periods, starting on days 3, 10 and 17 of lactation, using the deuterium oxide (D 2 O) dilution technique. The milk intake was estimated from the water turnover in the piglets corrected for the production of metabolic water. The water turnover was estimated from the water dilution space and the fractional turnover of body water, determined by the rate of D 2 O dilution. To determine the magnitude of isotopic recycling, a randomly selected piglet in each litter was not enriched with D 2 O. Milk production of the four lactating sows was also measured by the weigh -suckle-weigh (WSW) method on days 4, 11 and 18 of lactation. The average daily milk production determined by the D 2 O dilution technique (9.91 9 0.69 kg) was higher (P B 0.05) than that determined by the uncorrected WSW method (8.65 9 0.81 kg). Different procedures for selecting piglets were evaluated to obtain the best possible estimation of total milk production from three piglets in each litter. The total milk production of a sow based on three piglets in the litter was obtained from a quadratic model of the relationship between milk intake and daily gain. When the daily gain of all piglets were known the Pearson correlation between milk production determined for the whole litter (n ¼ 1) and only three median piglets was 0.98.

Milk intake and carbon dioxide production of piglets determined with the doubly labelled water technique

“…According to our previous study (Theil et al, 2002), the BWF of sucking piglets decreases curvilinearly with increasing LW and may be predicted by BWF pred ðwith no unitÞ…”

“…Since the costs of DLW (especially 18 O water) are significant, only three piglets per litter were enriched with DLW. In a previous study, we showed that determination of milk intake of three sucking piglets per litter was sufficient to estimate the milk intake of the whole litter and thereby the milk production of the sow (Theil et al, 2002). In four of eight litters, piglets that were not enriched with DLW were labelled with D 2 O to determine milk intake.…”

“…The atomic fraction (AF) of deuterium in water hydrogen was measured in serum ultrafiltrate as described by Theil et al (2002). In Experiment 1, the 18 O enrichment was analysed as the delta 46/44 m/z value in CO 2 in expired air without any sample preparation (analysed by John Speakman, Aberdeen, Batch #240).…”

“…The D 2 O enrichment was quantified absolutely as an atomic fraction of 2 H relative to 1 H in serum ultrafiltrate, as described by Theil et al (2002). In contrast, the determination of 18 O enrichment is more problematic, because an m/z ratio of 46/ 44 can be obtained not only by a single 18 O atom in CO 2 but also by two 17 O atoms or by one 13 C and one 17 O atom in combination with the most abundant isotopes ( 12 C and 16 O).…”

“…The D 2 O dilution technique used to assess piglet milk intake, the chemical analyses of milk components, the underlying assumptions of the technique and calculations are described in detail by Theil et al (2002).…”