Dairy nutrition consultant Hefin Richards of Profeed Nutrition Consultancy is warning vets to be on the lookout for an upsurge in over-conditioned cows as winter progresses through spring.
He says his prediction is based on a number of factors that have come together over the last year to greatly increased the risk of cows being over-conditioned at calving, not only potentially affecting productivity but predisposing to a number of clinical conditions.
A high body condition score at calving significantly increases the risk of subclinical ketosis in early lactation, depressing the immune response and increasing the risk of conditions such as retained foetal membranes, metritis and left displaced abomasum.1,2 Conversely, these obese cows go on to suffer excessive body condition loss due to decreased voluntary feed intake and poor energy metabolism.
The ketosis risk has been increased in part because national milk yields were low last summer and autumn as a result of poor weather conditions, low milk prices, high feed costs and the spread of Schmallenberg virus (SBV).3
Hefin said: "SBV and bad summer weather with associated poor forage quality may have delayed rebreeding, leading to more extended lactations and longer dry periods. These two factors can lead to excessively fat cows at calving."
Through the winter many herds were running average milk yields some way below usual winter levels and currently mid and late lactation cows are substantially under target yields.4 This lower yield means that feed intake is very likely to be in excess of actual energy demands, with subsequent fat deposition.
Increasing awareness of this potential issue gives vets the opportunity to reinforce the need to monitor body condition, adjust feeding, review milk yields and consider drying cows off early, using controlled energy feeding.
Hefin suggests that vets ensure that their clients' dry cow nutrition and management is geared towards maximising feed intake in early lactation to help prevent animals falling into a state of negative energy balance. Ketosis is often missed on farm because the signs are not apparent. Consider routinely monitoring herds for ketosis using either blood monitoring or Elanco's Keto-Test cow-side milk test to identify both at-risk cows and herds. Forming a team involving vets, nutritionists and herd managers and harnessing the different skill sets and knowledge allows strategies to be developed that can improve herd performance.
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