THE PROGRESSION OF THE LACTATION PERIOD IN COWS

Аннотация

Research has shown that the milk productivity of local cows depends on the nature of the lactation process. Cows with a uniform course of lactation are characterized by higher milk productivity. Keywords: cow, lactation, yield, milk, productivity The milk productivity of cows is associated with the characteristics of their lactation period. Generally, cows with uniform lactation demonstrate better milk productivity. Our study examined how the course of lactation affects milk yield in cows. Research was conducted on local cows in household farms in the Muynak district of the Republic of Karakalpakstan. In household farms, the milk productivity obtained from livestock is quite low. This is due to the lack of opportunities to provide adequate feed, the absence of processing technologies for available feed, and the lack of understanding of feeding livestock based on a balanced ration. In our research, we studied the milk productivity indicators of cows by feeding them a fully balanced ration (Table 1). Table 1 Milk productivity of local cows at different lactation stages in the experimental herd III and above Indicators X±Sx Cv,% Milk yield, kg 2014,8±182,1 29,9 Fat content in milk, % 3,94±0,043 3,63 112 SCIENCE AND INNOVATION IN THE EDUCATION SYSTEM International scientific-online conference Milk fat yield, kg 79,17±7,35 30,73 Protein content in milk, % 3,56±0,029 2,78 Milk protein yield, kg 718,8±9,34 30,93 4% fat-corrected milk yield, kg 1988,9±185,7 30,57 According to the data in Table 1, a higher level of feeding for local cows created an opportunity to significantly increase their milk productivity during the lactation period. On average, 2014.8 kg of milk with a fat content of 3.94% was obtained from one cow during lactation, and the protein content in the milk was 3.56%. Table 2 presents the monthly milk yield of the cows in the experiment during the lactation period, along with the persistency coefficient of the milking period and the milk yield decline index. Table 2 Changes in cows' monthly milk yield, milking period persistency coefficient, and milk yield decline index Groups I Milking Milking period moths Milk yield decline Milk yield, kg persistency coefficient, index, % % I 156,8 100 54,4 II 224,5 143,2 77,8 III 288,2 128,4 - IV 285,7 99,1 99,13 V 262,2 91,8 90 VI 229,7 87,6 79,7 VII 199,2 86,7 69,1 VIII 168,7 84,6 58,5 IX 128,6 - 44,6 X 70,8 - 24,6 Milk yield for the entire 2014,8 102,6 - milking period, kg 113 SCIENCE AND INNOVATION IN THE EDUCATION SYSTEM International scientific-online conference According to the table data, the monthly milk yield of the cows changed uniformly, which can also be observed from the persistency coefficient of the milking period and the milk yield decline index. Studying the lactation curve is of particular importance when evaluating the uniformity of the milking period in cows (Figure 1). 350 300 288,25 285,75 262,25 250 224,5 229,75 200 199 168,75 150 156,875 128,8 100 70,8 50 0 1 2 3 4 5 6 7 8 9 10 Figure 1. Dynamics of Monthly Milk Yield During Cow Lactation As seen in Figure 1, the highest monthly milk yield in cows was observed in the third month of lactation, and it remained high until the fifth month. Starting from the sixth month, the yield gradually began to decline. These findings indicate that, along with achieving high milk productivity through balanced feeding, the milk yield during lactation in local cows also followed a uniform course.