The objective of this study was to evaluate production, blood metabolites, and nutrient digestibility of Saanen goats either in the beginning or after 60 days of lactation. Twenty goats averaging 59.59 ± 6.97 kg of body weight were assigned to a completely randomized design. The following forage:concentrate ratios were used: 40:60, 50:50, 60:40, 70:30, or 80:20 and provided 2.95, 2.83, 2.70, 2.58, or 2.46 Mcal ME/kg DM, respectively. Animals were confined in individual stalls with daily measurements of feed intake and milk yield. Body weight of goats fed increasing levels of forage did not change significantly in this trial. However, dry matter intake and apparent digestibilities of some nutrients decreased linearly when forage replaced concentrate in the diet although this decrease was dependent of the lactation stage. Milk yield also was affected by treatments; in fact, milk production was highest in the diet with the greatest energy content. No significant differences were observed among treatments for blood metabolites in early lactation but after 60 days of commence of lactation the incremental levels of forage in the diet reduced blood cholesterol linearly. It can be summarized that the forage:concentrate ratio of 40:60 resulted in better production and apparent nutrient digestibilities in lactating Saanen goats.
blood metabolites; digestibility; energy level
