SHADEMAN SAFARI MONJEGHTAPEH1, MOHAMMAD MEHDI MOEINI2, ALIREZA ABDOLMOHAMADI2
1Kermanshah Azad University, Veterinary, Iran
2Kermanshah Razi University, Animal Science, Iran
In this study 400 local cows were used during cattle breeding programme for productive parameters. The mating design produced the three cow genotype: Holstein-local F1 (H1L1: 1/2 Holstein-1/2local), and backcrosses (H3L1: 3/4 Holstein-1/4 local and H7L1: 7/8 Holstein-1/8 local). First, Holstein sire (AI) was put to local mothers and in the first and 2nd generation, Holstein sire (AI) was used. Dairy recording included milk and fat yield, fat percentage, birth weight, conception rate, calf mortality and calving difficulty. Milking was performed manually twice a day. Best prediction was used to determine actual production (milk and fat) for 305-day lactation and ten records monthly. Records were available from a total of 400, 218 and 127 local, F1 and F2 generation, respectively. Least squares mean were calculated and data were analysed using the GLM procedure (SAS institute, 2000) at level of (p < 0.01). Least squares mean for milk and fat yield ( Local, F1 and F2 generation) were: 1827se12.2, 4264se18.54, 4571se24.88 (milk yield) and 73.16se0.42, 162.18se0.63, 164.64se0.81 (fat yield) respectively. Fat percentage for Local, F1 and F2 generation were: 4se0.03, 3.8se0.05 and 3.6se0.06 and Birth weights were: 20se0.1, 30se0.15 and 33se0.22 respectively. Results on F1 and F2 crosses in this study confirmed their consistently better ranking for milk production compared with local cattle (p < 0.01), but it was not observed significant difference between F1 and F2 generation for milk production. Local dairy cattle were superior for fat percentage compared with F1 (p > 0.01) and F2 (p < 0.01) generation and produced less fat yield apparently. Local breed had less birth weight compared with F1 and F2 generation (p < 0.01). Conception rate for L x H, F1 x H and F2 x H crosses were: 55, 56.89 and 53.55 percent and calf mortality were: 3.5, 2.68 and 3.08 percent respectively. L x H, F1 and F2 crosses had not significant differences (p > 0.01) for conception rate and calf mortality. Calving difficulty scores were 4.5, 3.1 and 2.8 for L x H, F1 and F2 crosses. L x H group had more calving difficulty (most problems) than F1 and F2 crosses (p < 0.01). These results indicate to make heavy use of Holstein sire and the inadequacy of the local cattle as dairy animals.
Keywords: Birth weight, crossbreeding, Holstein, milk and fat production