Effects of Freely Accessed Whey on Performance and Metabolism of Growing Murciano-Granadina Goats

The objective of the present study was to determine effects of freely accessed whey on feed intake and efficiency, growth performance, and various blood indicators of intermediary metabolism in growing Murciano-Granadina dairy goats. Thirty 5-month-old growing goats (16±1 kg body weight; 15 males and 15 females) were randomly assigned to three treatments (10 goats per each treatment) in a completely randomized design study. The experimental treatments were provisions of 1) only freely accessed water or WA (without whey), 2) only freely accessed whey or WY (without water), and 3) freely accessed whey and water or WW (separately). The experiment lasted for 84 days including 14 days of adaptation and 70 days of sampling and data collection. A same total mixed ration was offered to all goats three times daily at 07:00, 14:00, and 21:00 h. Feed and liquid (whey and water) intakes were recorded daily and body weight (BW), body condition score (BCS), and rectal temperature (RT) were recorded biweekly. Blood was sampled at 0900 h on days 37, 60, and 84 for blood metabolites measurements. Data were analyzed by using the Mixed Model Procedures of SAS program. Results showed that BCS, RT, and daily feed and liquid intakes were not affected by treatments (P 0.05). However, average daily gain (ADG) and feed conversion ratio (FCR) were different among treatments (P 0.05), such that female goats fed WY had lower ADG and higher FCR than other female groups. Blood beta-hydroxy butyric acid concentrations were higher (P 0.05) in goats fed WY than in other goats. Blood insulin and non-esterified fatty acids concentration were lower (P 0.05) in goats on WW than in other goats. Blood total protein, albumin, and urea concentration were similar (P 0.05) among treatments. Findings confirmed that offering water and whey together (WW) had no undesirable impacts on goat growth performance. Thus, based on the results of the present study, freely accessed whey may be offered to growing goats alongside water. Also, male goats can effectively utilize WY (offering only whey without water) without any impacts on growth performance. Offering WY to growing goats increased blood glucose and different lipids and decreased some of the liver enzymes, which possess health and metabolic implications and warrant future investigations.