Aly,, H., Ibrahim, S., Rabie, Z., Khalifa, Z., Hussien, K. (2002). EFFECTS OF PREVIOUS DAYS OPEN, PREVIOUS DAYS DRY AND CURRENT DAYS OPEN ON MILK PRODUCTION .' IN FRIESIAN COWS.. Journal of Animal and Poultry Production, 27(2), 971-977. doi: 10.21608/jappmu.2002.253346
H. M. Aly,; S. A. Ibrahim; Zenat B. Rabie; Zeianb A. Khalifa; K. Hussien. "EFFECTS OF PREVIOUS DAYS OPEN, PREVIOUS DAYS DRY AND CURRENT DAYS OPEN ON MILK PRODUCTION .' IN FRIESIAN COWS.". Journal of Animal and Poultry Production, 27, 2, 2002, 971-977. doi: 10.21608/jappmu.2002.253346
Aly,, H., Ibrahim, S., Rabie, Z., Khalifa, Z., Hussien, K. (2002). 'EFFECTS OF PREVIOUS DAYS OPEN, PREVIOUS DAYS DRY AND CURRENT DAYS OPEN ON MILK PRODUCTION .' IN FRIESIAN COWS.', Journal of Animal and Poultry Production, 27(2), pp. 971-977. doi: 10.21608/jappmu.2002.253346
Aly,, H., Ibrahim, S., Rabie, Z., Khalifa, Z., Hussien, K. EFFECTS OF PREVIOUS DAYS OPEN, PREVIOUS DAYS DRY AND CURRENT DAYS OPEN ON MILK PRODUCTION .' IN FRIESIAN COWS.. Journal of Animal and Poultry Production, 2002; 27(2): 971-977. doi: 10.21608/jappmu.2002.253346
EFFECTS OF PREVIOUS DAYS OPEN, PREVIOUS DAYS DRY AND CURRENT DAYS OPEN ON MILK PRODUCTION .' IN FRIESIAN COWS.
Animal Production Research Institute, Ministry of Agriculture
Abstract
Effects of previous days open and days dry as well as current days open on milk production during the first and later lactations were determined for 451 Friesian cows belonging to Animal Production Research Institute, Ministry of Agriculture. Two models were used for analysis of variance. Model 1. for first lactations included sire, current days open, age at calving and season of calving. Model 2. for later lactations, . included the previous effects plus previous days open, previous milk yield. The milk
production traits were total milk yield (TMY), milk yield 305-days (MY-305 d), and lactation period (LP), current days open had highly significant effects on all studied traits for both first and later lactations.
Differences due to previous days open were insi~nificant for all traits under investigation. TMY and MY-305d tended to increase with increasing days dry till the forth period (91-120 days) then slightly decreased. Previous milk yield affected significantly (P<0.01) both TMY and MY-305d.