摘要
<span style="font-family:Verdana;">The present study was designed to investigate the effects of season and lactation number on milk yields in Holstein dairy cows at Kabul Bini Hesar Dairy Farm. For this purpose, data were collected from the dairy farm herd book records during 1392-1393 (2013-2014). Considering the milk yield stages of the cows, the total milk production was highest during the spring season 18</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">454.95 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 33</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">L followed by summer 17</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">060.85 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 34.5</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">L while the lowest milk production obtained in winter 16</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">398.45 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 31.5</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">L. Moreover, the average daily milk production of the cows w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> significantly different (p</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;"><</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">0.05) between the 1st, 2nd and 3</span><span style="font-family:Verdana;">rd</span><span style="font-family:Verdana;"> lactations and the amounts were 12.04 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 0.7, 13.24 </span><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 0.8 and 14.10 </span><span style="font-family:Verdana;">±</span><span><span style="font-family:Verdana;"> 0.6 L/day respectively. Milk yields of individual cows were gradually increased from 1st to 3rd lactation. The highest milk yield was rec</span><span style="font-family:Verdana;">orded in 3rd lactation and </span></span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">lowest was in 1st. From this study it was found that season and lactation number had a significant effect on the milk quantity.</span>
<span style="font-family:Verdana;">The present study was designed to investigate the effects of season and lactation number on milk yields in Holstein dairy cows at Kabul Bini Hesar Dairy Farm. For this purpose, data were collected from the dairy farm herd book records during 1392-1393 (2013-2014). Considering the milk yield stages of the cows, the total milk production was highest during the spring season 18</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">454.95 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 33</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">L followed by summer 17</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">060.85 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 34.5</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">L while the lowest milk production obtained in winter 16</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">398.45 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 31.5</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">L. Moreover, the average daily milk production of the cows w</span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> significantly different (p</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;"><</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">0.05) between the 1st, 2nd and 3</span><span style="font-family:Verdana;">rd</span><span style="font-family:Verdana;"> lactations and the amounts were 12.04 </span><span style="font-family:;" "=""><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 0.7, 13.24 </span><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> 0.8 and 14.10 </span><span style="font-family:Verdana;">±</span><span><span style="font-family:Verdana;"> 0.6 L/day respectively. Milk yields of individual cows were gradually increased from 1st to 3rd lactation. The highest milk yield was rec</span><span style="font-family:Verdana;">orded in 3rd lactation and </span></span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">lowest was in 1st. From this study it was found that season and lactation number had a significant effect on the milk quantity.</span>
作者
Emal Habibi
M. Ibrahim Qasimi
Noorullah Ahmadzai
Nasrin Stanikzai
M. Zaher Sakha
Emal Habibi;M. Ibrahim Qasimi;Noorullah Ahmadzai;Nasrin Stanikzai;M. Zaher Sakha(Department of Animal Production, Faculty of Veterinary Sciences, Kabul University, Kabul, Afghanistan;Department of Preclinic, Faculty of Veterinary Sciences, Kabul University, Kabul, Afghanistan;Department of Food Hygiene and Technology, Faculty of Veterinary Sciences, Kabul University, Kabul, Afghanistan)
