Diet selection and eating behaviour of lactating goats subjected to time restricted feeding in choice and single feeding system

This study was carried out to investigate diet selection and eating behaviour of lactating German FawnxHair Crossbred goats in different feeding methods and levels. Twenty German FawnxHair first backcross does (B₁) were allocated into 4 treatment groups (2 feeding methods single (TMR) and choice feedingx2 feeding levels ad libitum and restricted) with 5 replicates. Restricted feeding was applied only 4h feed allocation during day. Barley, corn, soybean meal, corn gluten meal, wheat bran and alfalfa hay were feed ingredients for single and choice feeding. Eating patterns, milk yield and composition were determined for 8 weeks. The following results were obtained: (1) the meal criteria for goats restricted single and choice-fed, ad libitum single and choice-fed were determined as 1.00 and 0.63, 12.88 and 10.23min, respectively. (2) Ad libitum feeding increased meal size, meal length, intermeal interval, total eating duration and decreased eating rate and meal number, compared to restricted feeding (P <0.01). Choice feeding decreased meal size (P <0.05), meal length (P <0.01) and increased eating rate and meal number (P <0.01), compared to single feeding. Restricted fed goats decreased intermeal interval in single feeding compared to choice feeding (P <0.01), but increased meal number in choice feeding (P <0.01). (3) Ad libitum choice-fed does made a diet containing 12.79% corn, 35.41% barley, 13.21% wheat bran, 5.35% soybean meal, 1.28% corn gluten meal and 29.80% alfalfa meal while restricted choice-fed does made a diet having more corn (27.69%), corn gluten meal (5.62%) and wheat bran (16.17%) and less barley (14.37%) and soybean meal (4.51%). (4) Choice feeding decreased RUP intake (P <0.05) without affecting milk protein, irrespective to feeding levels, while having a tendency to increase in milk yield (14.2%) and 4% FCM (8.8%). (5) Restricted feeding decreased DM, ME, ADF and NDF intakes (P <0.05) with concomitant decreases in 4% FCM, total milk solid, ash and fat compositions (P <0.05), irrespective to feeding methods. (6) Choice-fed goats changed their preferences for a possible synchronized nutrient intake during a daytime, as sorted barley, soybean meal and alfalfa hay from early morning to late afternoon. It could be concluded that choice-fed goats have the ability to make their diet to meet nutrient requirements and had a tendency to increase in milk yield. Restriction in feeding time resulted in lower feed intake and milk yield, although the animal changed their feed preference in favour of high quality ingredients and eating pattern with lower meal criterion and intermeal interval.