High levels of replacements reduce herd milk yields, because first calvers usually produce only 80% of the yield of mature cows.
About 18 to 20% replacement is desirable, to raise the EBI of the herd, and keep it relatively young and healthy.
What can farmers do to reduce replacement costs?
Only about 55% of replacements are from AI, at present.
Aim for an average of 5.5 lactations per cow, compared to the present national national average of four.
Aim for a compact calving season in late January and early February.
For example, at a 20% replacement rate, 20 replacements are needed in order to produce 100,000 gallons of milk in a 1,000-gallon herd requires. However, only 13 replacements are required in a 1,450-gallon herd.
Every farmer may not be able to have a 1,400 to 1,500-gallon herd (or the equivalent in high solids) but farmers should be moving in that direction.
With good dairy cows and good grass this type of production can be got with moderate levels of concentrates per gallon of milk on good grassland. With the help of genomic selection, researchers are forecasting very significant increases in milk production and milk solids per cow.
With environmental controls coming down the line, most farmers will eventually be forced to have higher performing herds which will be more profitable.
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