Effect of Feeding Dolichousnea longissima (Ach.) Articus as Supplement during Winter on Milk Yield and its Composition in Yaks

Abstract

The study was conducted to determine nutrient contents of Dolichousnea longissima (Ach.) Articus –Methuselah Beard and to assess the effect of feeding it on production of milk and its composition in milking yak cows. The study was undertaken in Haa Dzongkhag during the winter months of December, 2016 to February, 2017. A total of 14 milking cows were selected for this study. D. longissima was collected in and around yak rearing area of Chelela place. All the cows are reared under existing rearing system and feeding practices in the day out and night in system. The experimental animals were divided into two groups and assigned to two treatments, namely feeding and control groups in a Completely Randomized Design (CRD). The treatment group was fed with 3 kg of D. longissima over 42 days including an adjustment period of 14 days in addition to grazing while the control group did not receive the supplement. The milk yield for all the cows was measured daily for 7 days prior to the start of actual feeding trial and for 28 days post the adjustment period. Composite milk samples with 3 replicates were taken on alternative days, stored and transported in cool box and analyzed after
2 hours of sample collection for milk composition. There was no significant difference (p ≥ 1.00) in milk yield between the control group (0.45 ± 0.12 l) and feeding group (0.45 ± 0.08 l) respectively. The fat content of milk also did not differ significantly (p ≥ 0.05) between the groups. While statistically insignificant, the SNF and protein content were slightly higher in the control. Significantly higher (p ≤ 0.0 lactose content was recorded in the control group (5.57 ± 0.06%) than the treated group (5.40 ± 0.17%). There was no significant change in body condition score over the experimental period. This study found that feeding of D. longissima had no effect on milk yield and composition.
However, feeding D. longissima could have supplied additional energy and protein to maintain the body condition of animals during harsh climate.