Evaluation of the Gross Energy Content in the Milk of the Equine

Abstract

Seven Quarter Horse mares were fed a balanced diet and milked at discrete intervals throughout a ISO-day lactation. Samples were obtained by hand milking and were analyzed for gross energy concentration by oxygen bomb calorimetry. Average milk energy concentration for seven observations on seven mares was 438.4 cal/gm ranging from 576.5 to 336.8 cal/gm. Highest energy concentration was observed at 10-days post-partum and the energy concentration tended to decline linearly over the course of lactation. Total milk energy production averaged 5.110 meal/day and ranged from 7.841 to 4.104 meal/day. This curve also tended to decline linearly. Simple correlation analyses showed milk energy concentration to be highly positively correlated with milk yield (r=.71, P<.01), fat (r=.65, P<.01), protein (r=.81, P<.01) and total solids (r=.72, P<.01). The results of this study shows that milk energy concentration and total energy supply declines throughout lactation in mares and its variation is highly correlated to yield and organic milk components.