S. G. Cornelius

A refinement and evaluation of the isotope dilution method for estimating milk intake by piglets

Piglets (49) were removed from their dams at 1–3 days of age and trained to drink from artificial nipples. Estimates of milk replacer consumption of individual piglets over periods of 1 or 3 days were made by an isotope (deuterium) dilution method and by disappearance. Estimates by isotope dilution averaged 0.4% higher (P > 0.10) in 1-day periods and 2.9% higher (P < 0.05) in 3-day periods than estimates by disappearance. Various sources of error were evaluated. The most likely sources of error appear to be in measurement of the dose of deuterium injected (as D2O) and in the measurement of deuterium concentration in water extracted from blood samples. Milk analyses, except for dry matter, can be eliminated. Measurement of deuterium space at the end of the milk consumption measurement period is not necessary. We conclude that the isotope dilution method for measuring the milk consumption of piglets is acceptably accurate and precise.

Influence of postpartum feeding method on performance of the lactating sow

Data on the effect of postpartum feeding methods on sow and litter performance and the incidence of lactation failure in the sow are presented. One hundred and sixteen sows were allowed either ad libitum consumption within 16 h postpartum (AL) or restricted to a gradual increase in feed, starting with 0.45 kg on Day 0 and increasing to 0.91 kg each day reaching ad libitum by Day 6 of lactation (R). The AL sows consumed more feed from Day 0 to Day 6 (P<0.01) and during total lactation period (P<0.10) than R sows. Litter performance was not affected by treatment. Loss of sow body weight and condition during lactation and the weaning-to-estrous interval were not affected by treatment. Lactation failure was minimal and not affected by treatment. Rectal temperatures of AL sows were generally higher than R sows, but were not related to incidence of lactation failure. Fecal consistency scores revealed more normal defecations from the AL sows. Neither AL nor R could be identified as the preferred feeding method.