Genetic and environment factors influencing first and overall lactation milk yield in Karan Fries cattle

• Published in: Indian journal of animal sciences 2009-07, Vol.79 (7)
• Main Authors: Rashia Banu N, Singh, Avtar, Joshi, B K
• Format: Article
• Language: English
• Subjects: BOVIN; CATTLE; GANADO BOVINO; GENETICA; GENETICS; GENETIQUE; http://www.fao.org/aos/agrovoc#c_1391; http://www.fao.org/aos/agrovoc#c_15998; http://www.fao.org/aos/agrovoc#c_3222; http://www.fao.org/aos/agrovoc#c_4140; LACTACION; LACTATION; MILK YIELD; RENDEMENT LAITIER; RENDIMIENTO LECHERO
• ISSN: 0367-8318

Data on 1369 Karan Fries cattle spread over a period of 33 years (1973-2005) were analyzed to study the effect of genetic and non-genetic factors on first lactation and overall lactation 305-day milk yield. The season of calving had highly significant effect (P0.01) on overall lactation milk yield but not on first lactation milk yield. The least squares means for first and overall lactation 305-day milk yield were 2969±31 kg and 3509±25 kg respectively. The autumn calvers had the highest overall lactation milk yield (3649±48kg) whereas the summer calvers had lowest overall lactation milk yield (3374±41 kg). Period of calving had highly significant (P0.O1) effect on both the milk yield traits. The performance of the herd for first and overall lactation milk yield over the periods did not exhibit any consistent trend. The parities showed highly significant (P0.01) effect on 305-day milk yield. The 305-day milk yield peaked at 4th parity and then declined from the 5th parity onwards. The heritability estimate for first lactation milk yield (0.20±0.06) was slightly lower than for overall lactation milk yield (0.2 1±0.06) was slightly lower than for overall lactation milk yield (0.2 1±0.04). The repeatability of 305-day lactation milk yield estimated by intraclass correlation method was 0.33±0.01.