ADSA: Production Management and Extension Section Highlights
The following brief summaries are from several posters or presentations made in production management sections of the 2004 joint meetings of the American Dairy Science Association, American Society of Animal Science and Poultry Science Association. More than 1,000 abstracts were accepted.
Minimum dry period length to maximize performance. -Data analyzed nearly 100,000 DHI records from cows with first calvings from 1997 to 1999. Peak milk yield for lactations 2, 3 and 4 occurred with a dry period of 45 to 60 days.
Following first, second and third lactations, dry periods from 35 to 45 days resulted in a decrease of 280, 172, and 182 kg while dry periods of over 70 days resulted in 250, 622, and 727 kg decrease in milk for lactations 2, 3, and 4, respectively.
Effect of photoperiod on milk production in lactating dairy cows. - Study used 98 multiparous and 60 primiparous cows with either normal lighting or supplemental (17 hr above 15 foot candle). No differences in dry matter intake were reported, but multiparous cows with supplemental lighting produced more milk (49.4 vs. 46.5 kg/d) than normal lighting. There was no difference in milk production for primiparous animals.
Effect of automatic milking systems on milk yield in Italian conditions. - Study used 57 multiparous and 20 primiparous cows. Multiparous cows produced 6.88 kg more milk per day with the automatic milking systems compared to milking parlor, but there was no difference in milk production for primiparous animals. Milking frequency was higher in primiparous compared to multiparous animals with the automatic milking systems.
Evaluation of the association between bulk tank somatic cell count and management practices on U.S. Dairy Operations: Results from the NAHMS Dairy 2002 study. - Data was from 21 states representing 82.8% of the dairy operations and 85.5% of dairy cows. Higher rolling herd average, closed herds and use of shredded newspaper bedding were associated with lower bulk tank somatic cell counts. Forestripping prior to milking was associated with higher bulk tank somatic cell counts and no other milking practices were either positively or negatively associated within the model used. Suggestion was made based on this data that our understanding of the relationship between management practices and bulk tank somatic cell counts is incomplete.
Financial performance of dairies in Florida and Georgia in 2002. - Data is from 27 dairies in Florida, Georgia and Alabama. Average herd size was 1,168 cows and 16,810 pounds of milk sold per cow with over 1 million pounds milk sold per worker. Total revenue was $17.68/cwt with total expenses of $17.88 per cwt. Rate of return on assets was -0.02. Milk price, total income and total expenses increased with production level. Net farm income was highest for medium level of production.
Lisa Holden
Dairy and Animal Science
