2.
Study On Various Seminal Characteristics Affected With Aging Phenomenon In Male Nili-Ravi Buffalo
by Mohsin Raza Naqvi, M | Prof. Dr. Rashid Ahmad Chaudhary | Dr. Nisar | Dr. Tayyab Rahil | Faculty of Veterinary Sciences.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 1991Dissertation note: The main aim of the present study was to observe the reproductive performance of Holstein-Friesian and Jersey cows, imported from USA, being maintained under the sub-tropical environmental conditions of the Punjab, and then to compare it with their respective local-born progenies. The influence of environmental factors on some parameters of reproductive performance had been studied in order to estimate the level of their adoptability towards local climatic conditions. The reproductive records of the normal breeding local-born Holstein-Friesian, imported Holstein-Friesian, local-born Jersey and imported Jersey cows were studied during 1985-1991. The outcome of the present study in respect of the following parameters of reproductive performance are summarized as below.
1) Local-born Holstein-Friesian and local-born Jersey heifers conceived for the first time at the age of 502.93±11.71 and 496.37±6.64 days. This shows that Holstein-Friesian heifers took 7 days more for their first conception, but this difference was found to be non-significant.
2) The average age at first calving for local-born Holstein- Friesian and Jersey heifers was 787.38±13.61 and 771.48±7.88 days respectively, while their respective dams calved in USA for the first time at the age of 822.46±10.63 and 800.51±8.43 days correspondingly. The data indicate that local-born Holstein-Friesian and Jersey heifers calved for the first time 35 and 29 days earlier than their dams.
3) The average number of services required per conception for local-born Holstein-Friesian, imported Holstein-Friesian, local- born Jersey and imported Jersey were 1.76±0.100, 1.87±0.089, 1.83±0.069 and 1.88±0.072 respectively, whereas the difference among the groups was found to be non-significant. Although the number of services required per conception increased with increasing parity but the difference was non-significant.
4) The service period for local-born Holstein-Friesian, imported Holstein-Friesian, local-born Jersey and imported Jersey averaged 161.48±14.45, 132.92±511, 100.99±4.63 and 107.03±2.77 days respectively. The local-born and imported Jersey cows conceived 60 and 26 days earlier after calving than their contemporary local-born and imported Holstein cows. Effect of season of calving on subsequent service period was not significant.
5) The average gestation periods of 278.65±0.78, 279.92±0.63, 279.26±0.51 and 277.49±0.36 days were found in local-born Hol- stein-Friesian, imported Holstein-Friesian, local-born Jersey and imported Jersey cows respectively. The data shows that imported Jersey cows carried their calves 1.16, 2.43 and 1.77 days less than the local-born Holstein-Friesian, imported Holstein-Friesian and local-born Jersey correspondingly. Moreover in all the genetic groups except local-born Holstein-Friesian, cows carrying male calves had longer gestation length than those carrying female calves.
6) The calving interval for local-born Holstein-Friesian, imported Holstein-Friesian, local-born Jersey and imported Jersey averaged 443.77±18.67, 415.66±5.09, 380.93±6.36 and 387.18±3.0 days respectively. The Jerseys showed significantly (P < 0.01) shorter calving interval than the Holsteins. The shortet calving interval in all the groups was seen after Winter calvings. Minimum calvings in each group occurred during Summer. The maximum calvings in local-born Holstein-Friesian and imported Holstein- Friesian cows were during winter; whereas in local-born Jersey and imported Jersey these were observed during Spring and winter in order of merit.
7) The 305-day milk production averaged 3643.29±121.26, 4114.40±115.96, 2194.52±57.25 and 3150.48±46.16 litres for local- born Holstein-Friesian, imported Holstein-Friesian, local-born Jersey and imported Jersey cows respectively. The results indicate that imported Holstein-Friesian and Jersey cows produced -significantly more milk than their respective local-born progenies.
8) The average dry period for local-born Holstein-Friesian, imported Holstein-Friesian, local-born Jersey and imported Jersey cows was 192.71±16.14, 191.07±13.11, 157.91±9.70 and 133.30±5.77 days respectively. The dry period in the local-born Holstein- Friesian and imported Holstein-Friesian was significantly (P < 0.05) higher than the local-born and imported Jersey cows.
The findings of this study regarding most of reproductive traits indicate that both local-born and imported Jersey performed better than Holstein-Friesian cows under sub-tropical climatic conditions of Punjab. However local-born groups produced less 305 days milk than their imported dams. The production potential in the exotic herd can be increased by breeding the cows with semen of genetically superior sires, through intensive management and with more effective disease control programme.
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