Metabolic profile data from an average of 7100 cows in each of the last five years of the operation of the Dairy Herd Health M Productivity Service have shown that between 22 and 35% of early lactation cows (10-20 days after calving) have satisfactory energy balance. This highlights that better energy status at this stage of lactation is achievable and should be sought on more farms to help reverse the widely reported downward trend in fertility. A substantially greater proportion of mid lactation cows (50-120 days after calving), from the same herds at the same time and of similar milk yield level, showed good energy balance. This illustrates that diet content is not usually the problem but rather that feed intake constraints in early lactation is a more common concern. So emphasis should be placed on all management aspects of nutrition, some of which relate to the dry period. Up to 63% of cows with 7-10 days to go to calving had energy and/or effective rumen degradable protein (ERDP) problems. Small percentages of herds showed milk yield to be inhibited by ERDP or fermentable metabolizable energy (FME). No evidence was apparent linking high blood urea to poor fertility. The proportions of mineral and trace element shortcomings in this large number of cows were relatively much less, implying that attention to improving energy balance represents the most fruitful approach to better fertility on most farms. This should enhance heat detection efficiency and tighter calving to first service control, which have greater influences on herd fertility and milk production than conception rates.
|Number of pages||6|
|Publication status||Published - Feb 2005|