The efficiency of a grass-based system is hugely influenced by calving pattern, necessitating excellent reproductive performance in a short-breeding season. Therefore, it is extremely important to navigate our way through the transition period this spring with a freshly calved herd and a firm focus on nutrition.
In the weeks post-calving, cows will produce more milk than their feed intake can provide for, resulting in Body Condition loss due to Negative Energy Balance. A cow typically reaches peak milk output 6-8 weeks post-calving but will only reach peak dry matter intake 10-12 weeks after calving. However, the success of breeding 2024 is mainly dictated by the severity and duration of this period of NEB during the weeks post-calving.
NEB will firstly appear in the form of low milk protein % in the short term and in the more long-term have detrimental consequences on fertility during the breeding season. The overall objective is to have calved down the cow at a BCS of 3.25 and maintain an average herd BCS of 3.0 (range 2.75 – 3.25) at the start of breeding, to achieve optimal fertility.
Keeping body condition loss to less than 0.5 BCS between calving and breeding has proven to significantly increase the likelihood of conception to first service, with cows that lost <0.5 body condition score between calving and breeding typically shown to ovulate 15 days sooner, than cows which lost >1 BCS.
In very practical terms, this means bridging and filling the energy gap between what the cow outputs relative to what is put into her in regard to feed. Forage quality (which is lower in many cases after the difficult 2023 silage season) and getting high quality grass into the diet will be the main dictating factors here.
After this, most of the energy deficit will have to be filled via concentrates in the parlour, with milk output coupled with silage analysis and ability to get to grass, dictating feeding rates this spring.
For more information, contact your local Agritech Sales Advisor.