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Update on Hill Top Dairy
UPDATE ON HILL TOP DAIRY
The months of July and August have been
hot in much of the U.S. Dairy cows drop in milk production and DMI decreases
in hot weather. I saw a record of the daily high and low temperature for
the month of July. The most severe drop in milk production occurred when
low night time temperatures stayed above 70 degrees F. for three or more
straight nights. Cows need night time temperatures below 69 degrees F.
to help survive high day time temperatures. Many U.S. dairymen have fans and sprinkler
systems in their free stall barns. The combination of sprinkling water
on cows and fans blowing air helps to cool cows. We did see a decrease
in milk production of 10 to 15% or more in groups of cows cooled with
fans and sprinklers. I think we still need more research on individual
cow body temperatures, DMI, and milk production. Then we would know when
to start cooling cows and more about the efficiency of cooling cows. Fans, sprinklers, and electricity necessary
for cooling cows are expensive. However, it is the right thing to do for
animal well being. I hope animal rights groups support small and large
dairymen on this issue. We are building a new fresh cow barn at
Hill Top Dairy. Construction of the barn will be finished by Sept. l.
This will give us 2.5 feet of bunk space for each fresh cow when the barn
is full of cows. We are excited to see how well this new barn functions.
We wrote an article for Hoard Dairyman on bunk space for fresh cows.
The article was accepted last April but still not published. Hoard's Dairyman
has a long list of articles waiting to be published. I will write more
about this issue after the article is published.
Last year (July Newsletter, 2000) I wrote about an intravaginal progesterone insert device for synchronizing estrus in cattle. The common name for this vaginal insert device is CIDR. We thought CIDR would be available commercially in the U.S. in the year 2001. Now we are getting signals that it may be 2002 before they are finally approved in the U.S. CIDR's are approved and marketed in Canada and Mexico. Some embryo transfer veterinarians in the U.S. are using experimental CIDR's. Preliminary reports look promising for improved synchronization of estrus, expression of estrus and improved pregnancy rates. I saw a group of 18 cows that were synchronized with CIDR's during very hot weather in early August. The good expression of estrus in these 18 cows was dramatic!! Part of the reason for the strong expression of estrus is that a small dose of estrogen is injected when the CIDR is removed from the vagina (this addition of estrogen is one reason for the delay in market approval). We still need more fertility data in hot weather following CIDR removal. I think that CIDR's will be another valuable treatment for controlling reproduction in cattle. Are CIDR's available in Japan?
The best news is that the price of milk is now well above the 5 year average. This makes up for record low prices of last year. It is hard to believe that a small decrease in supply of milk causes such a large increase in price. The laws of supply and demand are at work in the U.S. with no control on the supply side of milk production.
News Letter from Dr. Whitmore, September No.6 2001