Influence of porcine somatotropin on endocrine and histological variables in gilts1

Autor: T. R. Cline, J A Clapper, Thomford Pj, M L Green, Andres Cj, Mark A. Diekman
Rok vydání: 1993
Předmět:
Zdroj: Journal of Animal Science. 71:1552-1560
ISSN: 1525-3163
0021-8812
DOI: 10.2527/1993.7161552x
Popis: Thirty-six crossbred gilts (71.7 +/- .9 kg and 140.1 +/- .9 d) were assigned to one of three doses (0, 35, or 70 micrograms.kg BW-1 x d-1) of recombinant porcine somatotropin (rpST). The doses of rpST were adjusted weekly, and i.m. injections continued until d 50. Gilts were pen fed (six gilts/pen) a 17% CP corn-soybean diet (1.2% lysine and 3.2 Mcal of ME/kg). At d 50, feed intake, feed:gain ratios (P = .02), and blood urea nitrogen were decreased (P .05) conception rate, age, or weight at puberty. Numbers of blastocysts or corpora lutea observed at d 10.4 +/- 1.5 of gestation (42.2 d after final rpST injection) were unaffected (P > .05) by rpST treatment. Anterior and posterior pituitary weights were increased (P .05) by rpST. After a withdrawal period of 42.2 +/- 2.0 d, rpST increased (P < or = .02) the estimated percentage of lean by 5.8% and longissimus muscle area by 10.4%. Eighteen hours before the initial rpST injection (d 0), 10 gilts per rpST dose were catheterized. Catheterizations were repeated on d 40. The rpST or diluent was given i.m. in the extensor muscle of the neck 1 h after initiation of blood collection. Adrenocorticotropic hormone (1.4 IU/kg BW) was administered through the catheter 3 h after initiation of blood collection.(ABSTRACT TRUNCATED AT 250 WORDS)
Databáze: OpenAIRE