Effect of supplementation with rumen undegradable protein on milk production and ovarian activity in double purpose cows
2013
Garduza-Arias, G. | Garcia-Bojalil, C.M. | Mendoza, G.D. | Sánchez-Torres, M.T. | Suárez, M.E. | Guzmán, A.
In order to evaluate the effect of ruminal undegradable protein (RUP) supplementation on the productive and reproductive performance of double purpose cows, 20 cows (F1 Holstein×Brahman) at 4 days postpartum (body weight 420±24 kg) were divided in two groups (n=20) to receive 2 kg/animal/day of 30% RUP or 45% RUP supplement for 100 days. Cows were weighed, the body condition score (BCS) was recorded weekly and milk production and composition was evaluated twice a week. Faeces, concentrate and pasture samples were collected to estimate forage intake and digestibility. Assessments of oestrous behaviour were performed by visual observation from Day 14 until Day 105 postpartum and blood samples were collected twice a week to measure progesterone. The results show that the use of 45% RUP did not improve intake, digestibility, milk production and composition, body weight or BCS (P > 0.05), but tended to reduce (P = 0.15) the number of days to first normal luteal activity and increased (P=0.14) the number of animals with luteal activity in the first 105 days postpartum. It is concluded that supplementation with 45% RUP did not improve forage use or milk production, but had a positive effect on the restoration of ovarian activity in double purpose cows in early postpartum.
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