Interrelationships between dietary lysine, sex, and porcine somatotropin administration on growth performance and protein deposition in pigs between 80 and 120 kg live weight.

Abstract

Sixty male and 60 female crossbred pigs were allocated to an experiment to investigate the effects of porcine somatotropin (pST) administration (0 or 6 mg/d) and dietary lysine content on growth performance, tissue deposition, and carcass characteristics over the live weight range of 80 to 120 kg. Pigs receiving pST were given diets containing 6.9, 7.8, 8.8, 9.7, 10.6, or 11.5 g lysine/kg, whereas control pigs received diets containing 4.8, 5.8, 6.9, 7.8, 8.8 or 9.7 g lysine/kg. These dietary levels ranged from 0.40 to 0.70 g available lysine/MJ of DE for pST-treated pigs and from 0.28 to 0.58 g available lysine/MJ of DE for control pigs. Pigs were individually housed in pens, and there were five replicates of each treatment. All diets contained 14.5 MJ of DE/kg and were offered for ad libitum consumption to pigs between 80 and 120 kg live weight. Growth rate increased exponentially and food conversion ratio (FCR) decreased exponentially with increasing levels of lysine. In addition, there was a significant sex x pST interaction such that pST reduced the sex difference in FCR. Growth rate was faster in boars than in gilts and was increased by pST at the higher levels of dietary lysine. Similarly, FCR was lower for boars than for gilts and was decreased by pST at the higher dietary lysine levels. The optimum growth rate and FCR were defined as the lysine level at which growth rate and FCR were 95% and 105%, respectively, of the lysine plateau. The optimum growth rate and FCR were achieved at similar dietary lysine contents and were approximately 0.35 and 0.52 g available lysine/MJ of DE for control and pST-treated pigs, respectively. Protein deposition in the carcass increased exponentially with increasing dietary lysine level, was higher in boars than in gilts, and was increased by pST at the higher dietary lysine contents. Sex had no effect on dietary lysine required to maximize protein deposition. The dietary lysine contents required to ensure 95% of plateau protein deposition of 104 and 153 g/d were 0.39 and 0.55 g available lysine/MJ of DE for control and pST-treated pigs, respectively. The increase in lysine requirement with pST seems to be commensurate with the increase in protein deposition.

The effect of immunization against GnRF on nutrient requirements of male pigs: a review

“…However, studies from the early 2000s suggested that, although the daily protein deposition and growth potential of entire males was greater than that of gilts, there was little difference in the lysine (g/kg feed) requirement of grower and finisher entire males and gilts O'Connell et al, 2005 and. King et al (2000) found that there was no difference in the lysine requirement to maximize protein deposition and minimize FCR in heavy (80 to 120 kg BW) finisher entire males and gilts. O'Connell et al (2005) found that, in three studies in grower entire males and gilts (20 to 68 kg BW), there were no differences in the lysine requirements (g/kg) to maximize growth and minimize FCR.…”

“…per MJ digestible energy (DE)). The studies used in these analyses included those reported by Batterham et al (1985), Giles et al (1986and 1987, Hansen and Lewis (1993), King et al (2000), O'Connell et al (2005 and, Moore et al (2012) and Rikard-Bell et al (2012) with some publications containing more than one study. The meta-analysis indicated that entire males have a higher dietary lysine requirement than gilts (0.600 v. 0.549 g SID lysine/MJ DE, P 5 0.009) over the finisher stage.…”

Assessment of statistical models describing individual and group response of pigs to threonine intake

“…Experiments studying the dose-response relationships in pigs fed diets providing a broad range of amino acid intake showed that the group response diminished as the limiting amino acid intake approached requirement (Gahl et al, 1994;King et al, 2000). Whether the response of individuals is rectilinear or curvilinear is not clear.…”

Effect of growth hormone on fatty acid synthase gene expression in porcine adipose tissue cultures

“…Treatment with pGH also enhanced protein deposition in well-nourished growing pigs (Vann et al, 2000) and increased lysine requirements, which is commensurate with increased protein deposition in boars (King et al, 2000). Sows treated with growth hor-mone at some time during, or even late in, gestation showed an increase in progeny size at birth (Rehfeldt et al, 2004).…”