Compensatory nitrogen retention in growing pigs following a period of N deprivation

Abstract

1. Semi-synthetic diets, with dried microbial cells (Pruteen) as the nitrogen source, were used to measure N retention in 50 kg pigs given different combinations of N intake involving periods of deprivation and enhanced 2. Metabolic faecal N losses were 1.92 g/d (1.26 g/kg dry matter eaten) and endogenous urinary losses were Many pigs undergo a period of growth during which deposition of protein proceeds at below the potential rate; for example, as a result of depressed feed intake following weaning or as a consequence of imperfect matching of dietary protein supply to protein requirements for growth. It is therefore of biological and economic importance to ascertain whether or not pigs can compensate for a temporary reduction in protein deposition rate by undergoing a period of enhanced nitrogen retention when dietary protein supply is more liberal. A previous paper (Whittemore et al. 1978) demonstrated that compensatory protein retention (as measured by N balance) was possible in growing pigs following a 12 d period of N deprivation, and that enhanced N retention rates were associated with improved efficiency of utilization of dietary N. The aim of the present experiment was to examine the phenomenon in more detail by providing growing pigs with a sequence of three diets. The four diets used contained low, medium, high or extravagant levels of protein, and they were offered in combinations to test the effects of changes on N balance during the first three and the following 7 d. These were compared with values obtained from control pigs which received one of the four diets throughout the experiment. It was also of interest to examine possible changes in the biological value of proteins when provided at different levels in the diet.Conventional balance techniques were used to measure N balance after profound changes in N intake. Control treatments involved the provision of very low, moderate, high and very high daily N intakes, the very high level being included to test N-retention response at an extreme level of N supply. While compensatory N retention was observed, the results indicated that this mechanism accords more closely with the short-term replenishment of variable body lean (Fowler, 1976) or labile N stores (Boorman, 1980), than the acceleration of N deposition in carcass muscle growth to allow growing pigs to compensate for previous dietary misfortunes and catch up with unchecked contemporaries. * For reprints.

Lysine restriction during grower phase on growth performance, blood metabolites, carcass traits and pork quality in grower finisher pigs

“…Previous studies have also reported that pigs subjected to dietary restrictions utilized feed more efficiently during the realimentation phase than unrestricted pigs . In other studies, the faster growth did not last throughout realimentation, but it was significantly exhibited throughout four to six weeks after the change in diet (Tulis & Whitemore, 1986;Skiba et al, 2001), while Therkildsen et al (2002) had proposed that at least 42 days of realimentation was required for full compensation.…”

Physiological aspects of compensatory growth in pigs

“…In the cited literature, both ad libitum and restricted feeding were applied during realimentation, which proves that feeding regime and change in feeding behaviour are not the most important factors that influence the compensatory growth of animals. The faster growth rate does not last throughout realimentation, but it is significantly exhibited throughout 4-6 weeks after the change in diet (Tulis et al, 1986;Skiba et al, 2001). In most cases of compensatory growth, pigs characterize better the feed conversion ratio as compared with non-restricted animals.…”

Compensatory growth and nitrogen balance in grower-finisher pigs1

“…Compensatory N retention following the N deprivation in pigs has been demonstrated (Whittemore et al, 1978;Tullis et al, 1986), but a long-term effect of dietary restrictions on N balance in grower-finisher pigs has not been elucidated fully. The present study was conducted to investigate the effect of dietary amino acid restrictions during the grower phase on growth performance, serum metabolites, carcass and meat quality, and N balance in grower-finisher pigs.…”