EFFECT OF RECOMBINANT PORCINE SOMATOTROPIN AND MONOCLONAL-ANTIBODY DIRECTED TO OVINE SOMATOTROPIC HORMONE ON NITROGEN-RETENTION AND IMMUNE PARAMETERS IN PIGS
W. Vanderhel et al., EFFECT OF RECOMBINANT PORCINE SOMATOTROPIN AND MONOCLONAL-ANTIBODY DIRECTED TO OVINE SOMATOTROPIC HORMONE ON NITROGEN-RETENTION AND IMMUNE PARAMETERS IN PIGS, Journal of animal science, 72(11), 1994, pp. 2820-2827
Single and combined effects of administration and withdrawal of recomb
inant porcine somatotropin (rpST) and an enhancing murine anti-ovine g
rowth hormone monoclonal antibody (OA15) on nitrogen retention, and se
rological and immunological measurements in Pigs were examined in a pl
acebo-controlled experiment. Thirty-six barrows were allotted to one o
f four treatments: control, rpST, OA15, and OA15+rpST. The trial phase
was four balance periods: a preperiod, two periods of treatment, and
a postperiod. Weight- and nitrogen gain were higher for the rpST group
by 13% (P < .01) and 15% (P < .001), for the OA15 group by 8% (P < .0
5) and 9% (P < .05), and for the OA15+rpST group by 25% (P < .001) and
20% (P < .001), respectively compared with the control group. During
the postperiod, weight gain of the OA15- and the OA15+rpST group was 2
3% (P < .001) and 22% (P < .001) lower than that of the control group.
Nitrogen gain during the postperiod was decreased by 19% (P < .01) fo
r the OA15 group compared with the control group. Single or combined a
dministration of rpST or OA15 did not affect (P > .10) cellular consti
tuents in the blood of all groups during the periods of observation. A
nimals treated solely with rpST mounted a humoral immune response dire
cted to rpST. This anti-rpST antibody response was, however, decreased
(P < .01) in barrows treated with rpST and OA15 simultaneously. Also,
a slight anti-rpST antibody response was noticed in barrows solely tr
eated with OA15. Barrows treated with OA15 mounted an anti-mouse immun
oglobulin antibody response that correlated with a decrease (P < .001)
in gain in the second period of treatment. These titers were lower th
an those found in pigs treated with a non-relevant mouse immunoglobuli
n of similar isotype as OA15. The OA15 mimicked effects of rpST. This
may have implications for application in pig industry.