Effects of Abortion and Stage of Lactation on Chemical Composition and Mineral Content of Goat Milk from Mixed-breed Goat on Rangeland

Abstract

The objective of this study was to analyze the chemical and mineral composition of aborted goats as well as goats with normal kidding for an entire lactation (five months; rainy season under range conditions), and the effect of stage of lactation on various raw milk components. Thirty one multiparous goats of mixed-breed goats were used, 16 carried their pregnancy to term and 15 aborted about the fourth month of pregnancy. Percentage of milk fat fluctuated greatly (P<0.01) throughout lactation with no differences between aborted and non-aborted goats (5.0 vs. 4.8 g/100 g). Percentage protein was higher (P<0.05) in aborted goats compared to non-aborted goats (4.7 vs. 4.5 g/100 g). During the early stage of lactation, milk contained higher (P<0.01) lactose levels which then decreased gradually towards the end of lactation. No difference in this milk component was detected between groups of goats (4.6 vs. 4.5 g/100 g). Both magnesium and manganese in goat milk were higher in aborted than non-aborted goats. It was concluded that some milk components are increased in milk from goats whose lactation initiate with abortion, compared with milk from goats whose lactation derive from normal kidding.