Effect of Somatotropin on Milk Yield of Ewes

Abstract
The effect of daily intramuscular injections with 25 mg. of Somatotropin in 5 cc. of physiological saline in lactating ewes was studied. In the first trial the treated ewes produced about 40 percent more milk following the treatment period than the control ewes. A highly significant increase in fat test and a non-significant decrease in non-fat solids occurred following the treatment period. In the second trial milk yield increased approximately 22 percent during the period when Somatotropin was injected. The fat test increased an average of 2.3 percentage units during the 21 days of Somatotropin treatment. The increase in both milk yield and fat test during the treatment period was highly significant. In both trials milk yield and fat test returned to near pretreatment levels three to ten days after terminating treatment. Feed consumption during the treatment period increased in three of the four ewes. Copyright © . .