The effect of some environmental factors that affecting daily milk yield of Iraqi buffaloes in Ninewah
Garabed A. Avadesian1, Alaa S. Al – Haddad2, Odday S. Al – Obaddy2, Nassar N.Al – Anbari1 and Ali S. Sadiq2
This study was carried out on the local buffalo in Ninewah, data were collected from154 buffalo in two herds during the period 1/7/2010 until 18/7/2010 in which milk collected daily in sequence ( 1st day , 5th day , 9th day , 13th day and 17th day ) and recording maximum and minimum temperature .Data were analyzed using general linear model ( GLM) within SAS program to study the fixed effects ( parity , herd , stage of lactation and test day ) , and regression coefficient with heritability . Overall average daily milk yield was 9.69 ± 0.12 kg and it appeared that parity , herd and stage of lactation has a highly significant effects in daily milk yield , while test day recorded no significant effect in the above . Minimum temperatures ranged (23.5 – 27.5 °C) and maximum was (41.8 – 45.6 °C). Regression coefficient for daily milk yield on maximum temperature was -0.259 kg / °C on (P > 0.01) and for minimum was 0.0325 kg / °C and this was non - significant, while the prediction equation (ŷ) was:
Y^ (max) = 21.121 – 0.259 (X1)
Y^ (min) = 8.863 + 0.0325 (X2)
The heritability estimate for daily milk yield was ranged between (0.17 – 0.21) for the test day (recording day) , it was concluded that from this a number of fixed effects , and yield was decreased significantly with rising in ambient temperature and the estimates of heritability for daily milk yield belonged to test day was rather low.