Effect of natural feed additive APC RZ 2000

Effect of natural feed additive APC RZ 2000 on performance of high yielding Holstein cows

Materials and Methods n n The trial was done between 02. 08. 2004 - 11. 09. 2004 in the Gale Khaje Farm, Iran under the control of the University of Isfihan! Two groups of multiparous early lactation cows were randomly assigned to two treatments, either fed APC (n=106 cows) or served as control (n=109 cows) For control and APC-fed cows, mean lactation number were 2. 9 and 3. 1, DIM were 59. 5± 21 and 65. 3 ± 26 and milk yield at last 3 days before the commencement of the trial were 37. 36 and 38 kg/d, respectively The experiment lasted for 6 wk with 14 d of adaptation and 28 d for data collection

Materials and Methods n n Mean ambient temperature throughout the trial was 36. 7° C, hence cows were experiencing severe heat stress Cows were offered TMR 4 times daily at 0600, 1400, 1800 and 2200 h and milked 3 times at 0500, 1300 and 2100 h by a semi-automated milking system DMI were calculated based on average consumption of each group and difference between feed offered and refused each day Weekly samples of TMR, silage and refusals were obtained and DMI adjusted based on DM changes

Materials and Methods n n n Milk yield of individual cows were recorded automatically and then averaged by group For the analysis of milk composition, all cows were sampled at 1 st week, sampling was continued randomly on 24, 36 and 48 cows of each group at wk 2, 3 and 4 respectively. Milk composition was analyzed with Milko-scan by IR Approximately 4 hours after feeding, 20 cows were randomly milk sampled for 3 consecutive Monday and milk urea nitrogen was analyzed calorimeterically to test the effect of treatment on N balance