Various factors contribute to the profitability of any New Zealand dairy herd, production, longevity, fertility and cow health could all be considered key factors. Managing a successful transition period is a key element to achieving all these factors.
Poor feeding and management during the transition period can result in a host of problems around calving such as dystocia (difficult calving), retained placenta, milk fever, grass staggers and ketosis. These are metabolic diseases and therefore can be significantly reduced if we can manage a transition system to optimise the cows own ability to metabolise nutrients correctly.
Maximising dry matter intakes post calving must be a key outcome from a transition system. Having a high intake post calving will not only help to minimise negative energy balance, but help both production and fertility. It can take until 10 weeks post calving before cows reach peak intake, meanwhile cows will peak in milk yield at approximately 6 – 8 weeks post calving further increasing negative energy balance and weight loss. Whilst feed quality and management are key components to this, animal health should also be considered a first limiting factor.
For example when a cow experiences a case of milk fever, she is then far more likely to experience ketosis (negative energy balance), displaced abomasum (twisted stomach), retained cleansings and even higher cell counts. The same can also be said for sub-clinical milk fever which by its nature, is very difficult to see and treat but can have a similar effect.
Milk fever is expensive, in both money and time. Clinical milk fever is believed to reduce milk yields by 14%, on a $6/kg MS payout that’s $402 per case of lost milk sales alone. Taking into account other costs such as fertility and cost of treatment milk fever is thought to cost the NZ dairy farmer $8000/100 cows (based on 5% clinical and 33% sub-clinical).
DCAD (dietary cation anion difference) is a nutritional method of stimulating the cows own metabolism of calcium reserves, used all over the world. Low DCAD diets can increase calcium utilisation and reduce milk fever, both clinical and sub clinical. However in New Zealand we often feed high DCAD diets made up of pasture and grass silage, as opposed to low DCAD diets such as maize silage, wholecrop silage, hay and straw. Nutritech International have developed a low DCAD product called Springer Cow Balancer, made up of a blend of anionic salts which reduces dietary DCAD more so than a more traditional approach of feeding some magnesium chloride or sulphate, which in many cases cannot reduce the DCAD enough to have a significant effect. Lower DCAD diets can increase calcium mobilisation and help to reduce milk fever issues.
Assuming the cow has calved successfully, she must now achieve an increase in milk yield without entering a state of ketosis (chronic energy deficiency). The most serious period of negative energy balance is generally experienced 2 – 3 weeks post calving and this is the period farmers should focus specific attention on ‘bridging the energy gap’ to ensure a healthy rise to peak production. JumpStart™ is a liquid source of high energy, calcium and magnesium designed to be either supplied as a drench or poured onto feed in the early part of lactation to help cows pass through the most dangerous period of negative energy balance. Managing these conditions will create a platform for a productive and profitable season.
As featured in Rural Diary, June 2017