The effects of dietary protein and energy levels of diets offered during lactation on the lactational and subsequent reproductive performance of first-litter sows

Abstract

A total of 315 first parity sows were used in two experiments to establish the lactational and subsequent reproductive performance of first-litter sows in response to varying levels of dietary amino acids and digestible energy (DE) offered during lactation. In the first experiment, sows were offered five diets ranging in lysine content from 6·2 to 15·1 g/kg. In the second experiment sows were offered five diets with a similar lysine: DE ratio (0·88 to 0·85 g/MJ) but ranging in DE content from 12·6 to 15·1 MJ/kg. Voluntary food intake during lactation was unaffected by lysine or DE content of the diets. Piglet pre-weaning growth was similarly unaffected by dietary DE content but responded in a curvilinear manner with increasing dietary lysine. Sow body-weight loss during lactation was unaffected by dietary lysine but declined with increasing DE content up to 13·8 MJ/kg. Backfat loss was lowest for sows offered the lowest lysine diet and tended to reach a plateau at a dietary level of 10·6 g lysine per kg. In response to dietary DE content, backfat loss tended to be highest for sows offered the diet of lowest DE content and declined with increasing DE content up to 15·1 MJ DE per kg. The subsequent weaning to remating interval was unaffected by dietary DE content. Subsequent litter size was similarly unaffected by dietary DE content but was significantly higher for sows offered the two higher, compared with the two lower, lysine diets (10·7 v. 9·6 born alive, s.e.d. 0·5, P < 0·05). The results suggest that current amino acid recommendations for lactating first-litter sows are inappropriate and may be constraining both milk production and subsequent reproductive performance.

Response to dietary protein during lactation of Meishan synthetic, Large White and Landrace gilts given food to achieve the same target backfat level at farrowing

“…This is in agreement with much of the literature, but recent data from Tritton et al (1996) and Richert et al (1994, cited by Foxcroft et al, 1995 has shown an increase in litter size (1-1 pigs and 1-2 pigs respectively) in response to increases in dietary lysine at lower food intake levels (37 to 68 and 28 to 45 up to 61 g lysine per day respectively). This is in agreement with much of the literature, but recent data from Tritton et al (1996) and Richert et al (1994, cited by Foxcroft et al, 1995 has shown an increase in litter size (1-1 pigs and 1-2 pigs respectively) in response to increases in dietary lysine at lower food intake levels (37 to 68 and 28 to 45 up to 61 g lysine per day respectively).…”

Estimation of the optimal standardized ileal digestible lysine requirement for primiparous lactating sows fed diets supplemented with crystalline amino acids

“…Several studies have been conducted to estimate the effect of Lys (protein) levels in diets on the performance of lactating sows (Knabe et al 1996;Tritton et al 1996;Sauber et al 1998;Touchette et al 1998;Yang et al 2000) with Lys supplied from intact protein sources. However, for economic and environmental reasons, a reduction in dietary crude protein (CP) and supplementation with crystalline amino acids (AA) is a desirable goal for the pig industry (Kerr et al 1995).…”

Consequences for body composition at farrowing and nutrient partitioning during lactation of a choice-feeding regime during rearing and pregnancy in gilts of different genotypes

“…The effect of nutritional treatment on litter size might be attributable to both pre-and postconception effects. A reduced dietary protein intake prior to service has been shown to decrease ovulation rate in gilts and second litter size in young sows (Tritton et al, 1996). In general, increases in gestation feed intake have not been accompanied by adverse effects on litter performance (Mullan and Williams, 1989;Dourmand, 1991;Weldon et al, 1994;Sinclair et al, 2001) although Xue et al (1997) did observe a decrease in numbers born alive when intake was increased from 2 to 3.1 kg.…”