BS in Dairy Science
Dairy Science Department
The objective of this study was to determine whether the Jersey Breed is economically more feasible than the Holstein Breed on Rancho Teresita Dairy in Tulare. Beginning In March of 2011 the dairy purchased 380 milking Jersey cows. The dairy decided to purchase Jerseys because in 2008 the ethanol mandate started, causing the feed prices to climb. This study evaluated reproduction, calving ease, production, and feed efficiency. Jersey heifers are bred for the first time at 12 months and Holstein cows are bred for the first time at 14 months. The Jersey cows have a higher overall conception rate (CR) of 32% vs. 29% CR of a Holstein cow. Because the Jersey breed has an easier time getting pregnant we see that they also have a higher pregnancy rate of 25% over the Holstein cows at 20%. Jersey cows are bred back after calving around 66 days and Holstein cows at about 69 days. Production has a direct relationship with reproduction. Holstein cows produce an average of 76.91 lbs./day vs. Jerseys with lower number of 59.27 lbs./day. The composition of the milk varies between breeds. Holstein milk has 3.57% fat, 3.03% protein, and 8.78% solids-not-fat. Jerseys on the other hand have 4.98% fat, 3.66% protein, and 9.42% solids-not-fat. Although Holstein cows produce a greater volume, Jersey’s have a much better composition. Energy Corrected Milk (ECM) allows for the Jersey milk to be on equal grounds as the Holstein milk. After energy correcting the milk the Holstein herd had an average ECM of 77.24 lbs. and the Jersey herd had an average ECM of 72.31 lbs. Lastly the feed efficiency (FE) was calculated, the average FE for Jersey cows is 1.61 and for Holstein cows is 1.38. The evaluation was helpful for the dairy by comparing the efficiency of the two breeds.