The effects of porcine somatotropin and dietary lysine on growth performance and carcass characteristics of finishing swine.

Abstract

Seventy-two finishing pigs (initial weight = 57.6 kg) were utilized to determine the effects of porcine somatotropin (pST) and dietary lysine level on growth performance and carcass characteristics. Pigs were injected daily with 4 mg pST in the extensor muscle of the neck and fed either a pelleted corn-sesame meal diet (.6% lysine, 17.8% CP) or diets containing .8, 1.0, 1.2 or 1.4% lysine provided by additions of L-lysine.HCl. All diets were formulated to contain at least twice the required amounts of other amino acids. Control pigs received a placebo injection and the .6%-lysine diet. Increasing levels of dietary lysine resulted in increased ADG and improved feed conversion (quadratic, P less than .01) for pST-treated pigs. The calculated daily lysine intake was 16.6, 13.6, 19.6, 25.1, 29.6 and 33.6 g for the control and pST-treated pigs fed .6, .8, 1.0, 1.2 and 1.4% lysine, respectively, over the entire experiment. Breakpoint analysis indicated that cumulative ADG and feed conversion were optimized at 1.19 and 1.22% lysine, respectively. Longissimus muscle area and trimmed ham and loin weights increased as dietary lysine was increased among pST-treated pigs (quadratic, P less than .01). Breakpoint analysis indicated that 1.11% lysine maximized longissimus muscle area, whereas trimmed ham and loin weights were maximized at .91 and .98% lysine, respectively. Adjusted backfat thickness was not affected by dietary lysine, but pST-treated pigs had less backfat (P less than .05) than control pigs did. Percentage moisture of the longissimus muscle increased (linear, P less than .05), as did percentage CP (quadratic, P less than .05), whereas fat content decreased (linear, P less than .05) as lysine level increased. Similar trends in composition were observed for muscles of the ham (semimembranosus, semitendinosus, and biceps femoris). Shear-force values from the longissimus and semimembranosus were lowest for control pigs, but they increased as dietary lysine level increased among pST-treated pigs. Sensory panel evaluations indicated that juiciness and tenderness decreased (linear, P less than .05) as dietary lysine level increased. Plasma urea concentrations decreased linearly (P less than .01) on d 28 as lysine level increased, whereas plasma lysine and insulin were increased (quadratic, P less than .01). Plasma glucose and free fatty acid concentrations on d 28 tended to increase (quadratic, P less than .10) with increasing dietary lysine level.(ABSTRACT TRUNCATED AT 400 WORDS)

The effects of porcine somatotropin, gender and porcine stress syndrome on growth, carcass composition and pork quality

“…These data compare favorably with the results reported by Chung et al (1985), Etherton et al (1986), Evock et al (1988), Goodband et al (1990) and Krick et al (1992). Treatment with pST depressed ADF (-7%; P < 0.01), consistent with the findings of Evock et al (1988), Goodband et al (1990) and Krick et al (1992).…”

“…Solomon et al (1991) reported a tremendous effect of pST treatment on PSE meat development, with 62% of pST-treated animals developing PSE meat versus 0% for controls. LT shear forces from pST-treated animals were also 30% higher than in controls, and this is supported by the work of Goodband et al (1990) where LT shear forces increased for pST-treated pigs, while juiciness and tenderness decreased for pSTtreated animals receiving high levels of dietary lysine. More recently, Boles et al (1991) were unable to demonstrate an interaction between pST treatment and PSS genotype; however, pST treatment was found to reduce scores for tenderness, juiciness and flavor.…”

The effect of dietary protein supply on carcass composition, size of organs, muscle properties and meat quality of pigs

“…In the present study, the absolute weights of the kidneys were heavier in pigs fed the high-protein diet (P b 0.05), which differs from the results of Goodband et al (1990), but is in line with a finding by Chiba et al (2002), who found an increase in kidney weight after feeding the pigs a high-amino acid diet. In the study by Chiba et al (2002), the livers were also heavier in pigs fed the high-amino acid finisher diet than in those fed the low-amino acid diet.…”

Effects of Dietary Lysine Levels on Apparent Nutrient Digestibility and Serum Amino Acid Absorption Mode in Growing Pigs

“…However, in some cases, a high level of one amino acid is associated with a decline in other amino acids (Goodband et al, 1990; Henry et al, 1992; Roy et al, 2000; Barea et al, 2009). Roy et al (2000) have reported that, with increasing dietary lysine levels, the plasma concentration of free lysine increased, whereas the concentrations of isoleucine, threonine, and valine decreased.…”

“…Roy et al (2000) have reported that, with increasing dietary lysine levels, the plasma concentration of free lysine increased, whereas the concentrations of isoleucine, threonine, and valine decreased. Increasing levels of dietary lysine also caused an increase in the serum content of lysine, but these increasing lysine levels caused a decrease in the concentrations of other amino acids in pST-treated pigs (Goodband et al, 1990). Dietary lysine supplementation resulted in an increase in the plasma concentrations of free lysine, and a decrease in the concentrations of threonine, tyrosine, and some nonessential amino acids (Henry et al, 1992).…”