The Impact of Cooling Ponds in North Central Texas on Dairy Farm Performance

Abstract

Theobjectiveofthisstudywastodeterminewhether measurable differences existed between farms with and without cooling ponds. Data from Dairy Herd Im- provement records for 1999 through 2002 were ob- tained on 42 herds located in North Central Texas. Nineteen herds had installed cooling ponds, whereas 23 herds had not. Monthly somatic cell counts for each herd were obtained from the Federal Milk Market Ad- ministrator. Data were analyzed using the PROC MIXED regression model of SAS. Within and across herd groups, milk production from June to October wassignificantlylowercomparedwithmilkproduction for the rest of the year. Although there was numeri- cally higher average milk production per cow per day throughout the year for herds that used cooling ponds, differences between herd groups that used or did not use cooling ponds were significant only for August pro- duction. Herds without a cooling pond had 4.8 kg/d per cow lower production in August than in the cool- season months of November to May (26.4 ± 0.6 vs. 31.2 ± 0.5 kg/d), whereas the difference in August produc- tion was only 2.9 kg/d per cow in herds that used cool- ing ponds (29.0 ± 0.7 vs. 31.9 ± 0.6 kg/d). Differences caused by seasonal use of a cooling pond in culling, days to first service, days open, percentage of estruses observed, and somatic cell counts were not significant. Bulktankmilksamplesculturedfor10differentbacte- ria showed no difference between cooling pond and noncooling pond herds in 2002. Also, there was no difference in incidence of violations from the Texas Department of Health for herds that used or did not use cooling ponds. However, herds with cooling ponds did have a lower percentage of successful breedings, fewer days dry, and a higher percentage of cows in milk compared with dairy herds that used other forms of cooling. Such differences may or may not be attrib-