Priorities should be to ensure that body condition score (BCS) targets are met and that the cow is in a positive energy balance before the start of mating.
Achieving a BCS at calving of 5 for mature cows and 5.5 for heifers, is proven to result in better reproductive outcomes. A high energy demand due to increasing milk production post-calving, coupled with the inability of the cow to consume enough feed to keep up with this demand for the first 6-8 weeks of lactation, is a challenge. The cow, therefore, utilises body reserves to supply the energy deficit, with a loss in body condition.
A cow in this situation is said to be in a "negative energy balance" (NEB). A BCS loss of 0.5 to 1 is considered acceptable, however, a loss of no more than 0.5 is preferable. Therefore, it stands to reason, that by ensuring the cow starts lactation at the correct BCS, she will be on a better footing once mating starts.
While it is impossible to prevent NEB in the first 5-6 weeks of the lactation cycle, the length of time and severity of the NEB makes a big difference to the cow's overall seasonal success and taking steps to mitigate this is worthwhile.
A cow in NEB at mating will have negative impacts on the quantity and quality of the ova she produces but also delayed and irregular cycling. The more severe the NEB, the greater the impact on reproductive performance.
It helps to feed a more energy and nutrient-dense feed when intake is limited, to mitigate body condition loss and help achieve a positive energy balance at mating.
Rumen protected fats "bypass" the rumen, are energy dense and are not degraded in the rumen. They bypass the rumen and are digested by enzymes and absorbed by the body in the small intestine, not impacting rumen function.
Supplementing the cow's diet with a dietary bypass fat two to four weeks prior to mating is an effective way of mitigating NEB. They can be used through early lactation, to reduce body condition loss by providing more energy to the cow on a daily basis.
SealesWinslow's by-pass fat solution is Energizer Gold. This product contains 3131 MJ ME/kgDM making it almost three times as energy-dense as 1kg of dry matter of an average pasture. The product can be used at a feed rate of up to 5% of a ration in a SealesWinslow pelletised feed, to supply it through an in-shed feeding system, or up to 500g per cow per day as a straight product when added to a mixed ration on a feed pad.
To learn more about Energizer Gold, and to see if it is the right fit for your farm, speak with your local Farm Source team, or your SealesWinslow TSR.
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1 Influence of negative energy balance on cyclicity and fertility in the high producing dairy cow. Wathes, D.C., et al. 2007, Theriogenology, Vol. 68, pp. 232-241.
2 Dairy NZ. Body condition and nutrition for reproduction. Dairy NZ. [Online] 2022.
Article supplied by SealesWinslow.