Effect of recombinant porcine somatotropin on growth and carcass quality in growing pigs: interactions with genotype, gender and slaughter weight.

Abstract

Effects of recombinant porcine somatotropin (rpST) on growth, lean tissue growth, feed intake, feed conversion, lean tissue feed conversion, backfat thickness and lean percentage were examined in 96 growing pigs. The experiment used barrows and gilts from the genotypes Duroc, F1 (Dutch Yorkshire x Dutch Landrace) and Pietrain. Half the pigs received 14 mg rpST i.m. twice each week starting at 60 kg; others received a placebo. Pigs had ad libitum access to a diet containing 2,162 kcal net energy and 182 g crude protein per kilogram and were slaughtered at either 100 or 140 kg live weight. From 60 to 100 and from 100 to 140 kg, live weight responses to rpST averaged as follows: daily gain, +4.5 and +19.9%; feed intake, -4.4 and +3.5%; feed conversion, -8.4 and -13.9%; backfat thickness, -13.8 and -22.8%; lean percentage, +4.4 and +8.7%; lean tissue growth rate, +8.6 and +35.8%; and lean tissue feed conversion, -13.1 and -24.9%. No gender x rpST interaction was detected. However, a genotype x treatment interaction was significant for backfat thickness at both slaughter weights, showing a higher response to rpST in Duroc than in Pietrain and F1. Growth performance was improved more by rpST in F1 and Pietrain than in Duroc, especially at higher weights, but carcass traits were improved more by rpST in Duroc. The response to rpST in lean tissue growth rate from 60 to 100 kg was highest in fatter animals (Duroc, barrows), whereas from 100 to 140 kg, response in lean tissue growth rate to rpST was highest in leaner animals (Pietrain, F1, gilts).

Growth performance and carcass quality of immunocastrated and surgically castrated pigs from crossbreds from Duroc and Pietrain sires1

“…In contrast, Kanis et al (1990) and Ellis et al (1996) failed to show any difference in growth performance between DU and PI crossbreds. The discrepancies reported may be explained by differences in the matemal line used in these experiments or by differences in the objectives of the genetic selection applied to the 2 sire lines used (Latorre et al, 2003a).…”

The interrelationship between and the regulation of hepatic growth hormone receptors and circulating GH binding protein in the pig

“…Growth and serum IGF-I (Table 1 ) Older pGH treated animals showed a tendency to lesser weight gain over the 12 days compared to their control group, presumably reflecting greater fat loss than pro¬ tein deposition as previously shown with GH treatment (30,31); however, this did not achieve statistical significance. Porcine GH treatment increased the weight of the liver relative to body weight (p = 0.02), and this ratio also increased with age (p = 0.001).…”

Feasibility of Increasing the Slaughter Weight of Finishing Pigs

“…Similarly, in the study of Corino et al (2008), ADG between 114 and 161kg BW (1.06 kg) was only marginally less than that between 78 and 111 kg (1.17 kg). In non-lean pigs, however, a negative effect of increasing BW on ADG is evident even at above 100 kg (Kanis et al, 1990;Latorre et al, 2004, presented in Table 3). …”