Examination of the effect of ACTH on cow milk yield and composition

摘要

Five 4-5 year old Polish Black Pied Lowland cows in months 3-4 of lactation received 6 intramuscular injections of ACTH at 6 h intervals. Milk samples were taken from these cows during morning milkings during the ACTH administration period, and after ACTH administration, for 6 days. During ACTH administration, blood cortisol concentration increased from 13.52deg 2.48 to 169.74deg 14.94 nmol/litre. Average contents of total protein, fat, lactose, DM, Na, K and Cl were 3.19, 4.05, 4.56, 12.52, 0.033, 0.142and 0.090% respectively before ACTH administration. Peak values for the contents of total protein, fat, lactose, DM, Na and Cl were recorded on day 2 of the experimental period (4.13, 6.06, 4.80, 12.94, 0.063 and 0.164% respectively), while the K content decreased during ACTH administration but increased again to 0.147% by day 4. Somatic cell count (SCC) also increased, from 370deg 191 X 103/ml before ACTH treatment to 690deg 298 X 103/ml after ACTH treatment. It is concluded that stimulation of the adrenalcortex, evident from the increase in cortisol concentrations, may be the reason for changes in milk yield, milk composition and SCC in milk following the administration of ACTH.