THE RELATIONSHIP BETWEEN MILK PRODUCTION AND ITS COMPONENT IN HOLSTEIN COWS

This study was carried out at Al-Nasr Dairy Cattle Station pertaining to the Limited, United Company for Animal Services in Swairah (50 km south of Baghdad) during the period from 15 / 1 / 2013 to 1 / 4 / 2013 using ten, first parity Holstein cows. The objectives of this study were to determine the colostrum and milk lactoferrin concentrations, milk and colostrum constituents, milk and colostrum mineral concentrations, somatic cells counts, amino acid concentrations and the relationship between lactoferrin concentrations and the above-mentioned characteristics. The statistical analysis system (SAS) program was used to calculate the linear equations. General linear model (GLM) The average daily and monthly milk yield (1st month yield) were 16.95 +/- 0.84 and 508.50 +/- 25.31 kg, respectively, while being 18.50 +/- 0.84 and 555 +/- 25.39 kg respectively for the 2nd month yield. Higher colostrum lactoferrin concentrations was observed 732.78 +/- 28.03 mg /l at the end of the experiment as compared with its milk concentrations 350.30 +/- 16.34 mg/ l. Greater percentages of fat, protein and lactose were noticed in colostrum in comparison with their percentages in milk, namely 6.81 +/- 0.25, 11.93 +/- 0.43 and 3.71 +/- 0.04 % respectively at the beginning of the experiment, whereas being 3.60, 3.05 and 4.77 % respectively at the end of the experiment. The somatic cells count in colostrum was higher than its counterparts in milk, which were 72.30 +/- 2.32 and became 65.40 +/- 3.01at the end of the experiment. Negative and significant (p<0.05) correlation coefficient was noticed between lactoferrin concentrations and milk yield namely(-0.065). Positive and significant (p<0.05) correlation coefficient was found among lactoferrin concentrations and milk fat(0.84). Positive and significant with the rest of the components. We can conclude that lactoferrin was effected by climate period milk production, as its concentration the first period of milk was higher than the concentration at the end of the period.