According to United Feeds’ nutritionist Andrew Fyffe, effective dry cow management has a crucial bearing on two fundamental aspects of dairying performance: the ability of the cow to have a successful lactation after calving and her subsequent fertility performance.
Body Condition Score is the key driver in both cases. From a management point of view, the priorities must be to monitor condition scores throughout the year and to have the proper nutritional planning in place in order to tweak the amount of condition that a cow is carrying, as required.
“Cows should be dried off with a BCS of between 2.75 and 3.0 and maintained at this level of condition up to calving. Fat cover can be tweaked to some extent during the far-off dry period however, the issue should be really addressed during late lactation”.
Commenting specifically on the impact of metabolic disorders at calving, including: milk fever; ketosis and displaced abomasums, the United Feeds’ nutritionist said:
Research has shown that over fat cows at calving will have a reduced appetite. They are more prone to ketosis and fatty liver disease. Overly thin cows will produce less milk after calving. They will also be more difficult to get back in calf. More information on this can be found in our United Feeds’ Pre-calver management programme.
“All of these conditions will have a direct impact on subsequent fertility”.
Milk Fever can be best avoided by feeding fibrous silages during the dry period, which are low in potash. Feeding low DCAD rations during the dry period is critically important in this regard and adding an anionic salt, such as magnesium chloride, to these diets will help reduce DCAD values.
Turning to the rations fed to lactating cows, Andrew said that a 16% crude protein level in the diet is optimal in early lactation, when it comes to driving both milk output and fertility and United Feeds have long term experience on the benefits from this approach.
“High levels of dietary protein can lead to the build-up of excessive ammonia in the blood. In turn, this can lead to increased embryo mortality. Cows fed with lower protein diets have a flatter lactation curve thereby reducing the time in negative energy. However, they will still produce the same amount of milk expected from them across the entire lactation.”
But what about concentrate feeding rates in early lactation? Our Advisory team have been on dairy farms over recent weeks where the practice of delaying the period up to which feeding rates are maximised has been extended.
Andrew commented: “These steps are being taken in the belief that they will act to retain cows’ body condition score in the run-up to the breeding season. This approach comes with risks though.
“In the first instance, the modern Holstein cow is genetically programmed to milk off her back, if she is not receiving sufficient feed to meet her production potential. Slowly building up concentrate feed rates in the weeks after calving might deliver some benefits if the forages on offer are of a very high quality. However, the reality is that many second cut silages now being fed on farms across Northern Ireland are pretty mediocre forages.
Given this reality, I would strongly urge dairy farmers to have their fresh cows on peak concentrate intakes 21 days after calving. Pushing this back to 28 days will only accentuate body condition loss, a development that will have a very negative impact on their subsequent fertility-related performance.”
Andrew confirmed that the cow’s immune system has a key role to play in determining her fertility levels.
“Trace element nutrition plays a crucial role in boosting the cow’s immune system, our HerdCare package makes copper, zinc and manganese available in a totally organic (BIOPLEX) form. HerdCare also contains optimum levels of selenium, in the form of SEL-PLEX, and Vitamin E which is further boosted by the inclusion of Proviox. Research has shown BIOPLEX and SEL-PLEX can significantly reduce retained cleansing and metritis (Cerri et al 2006), while services to conception have seen a reduction of 10% (M.Agovino, 2011).
United Feeds’ team of trained Ruminant Nutrition Advisors are available to assess the situation on your farm and put together a proposal for boosting herd fertility.