The neglected nutrition component
Minerals are frequently implicated as a cause of poor reproductive performance and poor production in dairy cows. Is this fair? A multitude of anecdotal "claims" for minerals are perpetuated by "snake-oil" sales people that lead to abuse of and unrealistic expectations from the use of minerals.
Commonly deficient essential minerals are readily checked with blood tests in early lactation and just before mating. Beta-hydroxybuterate (BOHB) can also be included with early lactation tests. BOHB is not a mineral, it is a ketone produced in excess amounts when animals are in negative energy balance, and provides an indication of nutritional status.
Trials involving selenium supplementation have improved 3-week submission rates from 78% to 94% and improved the non-return-rate to first mating from 60% to 78%. Copper deficiency has been implicated in infertility and more recently molybdenum toxicity has been shown to affect fertility through the formation and absorption of thiomolybdate complexes. There is no suitable blood test for molybdenum, though levels in pasture can be measured.
Subclinical hypocalcaemia is common in dairy cattle around calving. Prolonged hypocalcaemia causes decreased gut contraction and intermittent appetite depression leading to lower energy intakes and lower milk production. Subclinical milk fever is also a risk factor increasing the incidence of endometritis or "dirty cows".
Subclinical magnesium deficiency is associated with an increased risk of milk fever, reduced appetite, reduced milk-fat production and chronic udder oedema.
All the above tells us that an animal with a mineral deficiency or imbalance is likely to be failing to thrive, have a poor appetite and be losing excessive weight - all of which will indirectly adversely impact on fertility and milk production.
Early lactation blood tests do help:
- Confirm that your current mineral supplementation plan is doing its job
- Determine the mineral status in your herd and the need for supplementation
- Determine if mineral deficiencies are playing a role in problems such as retained foetal membranes, non-cycling cows, excessive weight loss and low milk production
- Allow development of a supplementation plan to meet your requirements
Underfeeding and excessive condition loss between calving and mating-start is one of the primary causes of non-cycling cows, low submission rates and poor six-week in-calf rate. Poor production is also a consequence of mineral deficiency.
Many mineral deficiencies are attributable to a simple lack of feed intake. That is, the feeds offered may contain adequate minerals. The cows just don't eat enough of it!
Blood tests around calving and again pre-mating, together with an overall assessment of cow health, condition, feeding and production, will identify nutritional deficiencies or imbalances before it's too late to do anything about them.
Plan with Totally Vets to monitor your herds' mineral status around calving and before mating before it's too late to reap the real benefits. Pregnancy testing is too late!
