Effect of Immunization against Somatostatin (SS) in Cattle: A Review of Performance,Carcass Composition and Possible Mode of Action

Abstract

A review of the effects of immunization against somatostatin in cattle is given. In most experiments (8 out of 9; no information in 2), significant antibody formation was reported in immunized animals but antibody formation may vary between individuals. Only a few have reported data on antibody affinity, but available data indicate that the antibodies formed may act to neutralize SS rather than function as binding proteins. Meta-analysis on weighted group averages showed that anti-SS animals consumed 4.2 ± 1.4% more feed (P = 0.03), had a 11.4 ± 2.3% higher daily gain (P < 0.001) and had a 4.7 ± 2.1% lower feed conversion ratio (P = 0.06), indicating improved feed efficiency. Increased fat deposition has been observed following immunization against SS, but more studies are needed in order to quantify the changes. Immunization does not seem to affect dressing percentage or carcass conformation score. The mode of action of immunization against SS seems to be associated with IGF-I and not GH, but more studies are needed to clarify fully the mechanisms by which immunization modifies performance in cattle.