Sire selection care - farmers weekly

29 OCTOBER 1999 ------------------------- SIRE SELECTION CARE WHEN increasing genetic potential using North American or Dutch sires, chances are fertility of those cows will be poorer,

admitted Steven Washburn of North Carolina State University in the US. He said that this made it important to select sires carefully, looking at sire and daughter reproductive performance to

avoid the worst bulls. "Producers should also improve daughter management. But that does not mean feeding them a total mixed ration all year in a confined system," he added.

According to his research, fertility results achieved by confined cows were no better than cows grazing pasture year-round and supplemented with hay and grain during grass shortages. Of the

Holsteins fed a mixed ration 53% were pregnant in 75 days, and pasture-fed cows had a 63% pregnancy rate by 75 days. Jerseys in the study had much higher pregnancy rates – 76% by 75 days on

a mixed ration and 80% when pasture fed. Mixed ration fed cows produced 15% higher yields.