Effective calving transition

Last month’s article focused on transitioning cows from a milking diet onto a winter diet. This month’s article will focus on bringing cows back to the milking platform after the dry period and the best way to support the cow through this phase, for optimal productivity throughout the season.

Physiologically speaking, a springer cow has a lot to do in a short space of time. She needs to adapt from a winter diet to a milking diet (which may be vastly different) and allow parturition of a calf, all while adapting to making milk. If this process fails, she may be a downer cow or she may just function sub-optimally — affecting her season productivity and ability to get back in-calf. Let us look at the diet of a springer cow. A critical component is ensuring she is on a low potassium (K+) and low sodium (Na+) diet, with adequate magnesium for at least 14 days prior to calving and that any dietary changes are completed before this critical period. Looking at the K+ component, this is typically a paddock that does not get effluent and has high pasture covers. Older, long and rank pasture has reduced uptake of potassium and so springer cows may be better on pastures with higher pasture covers, rather than younger shorter grass. It is a good idea to get some pasture analysis done, to ensure they are optimal for the springing cow. Grass can still be risky if it is the predominant diet. Consider reducing the grass component and using other feeds that consider the K+ and protein components — if your herd has a high milk fever risk. For example, maize can reduce the protein and K+ component

Three important points for effective calving transition:

1. Use feeds that are low in potassium (K+) and low in sodium (Na+) for at least 14 days prior to calving. 2. Magnesium should be supplemented for at least 14 days prior to calving. 3. Any dietary changes should be made over a period of days and should be completed before the critical 14 day springer period.

of the diet, which are both useful for milk fever prevention. Cereal forages and silages and silage made from poorer quality grass can also be useful to reduce the K+ component of the diet. A cow needs to be primed with adequate magnesium for at least 14 days prior to calving, to allow her to mobilise calcium effectively at calving. In many situations, farmers will pull out cows from the dry mob and into the springer mob, based on visual assessment of the udder but unless this is done using predicted calving dates as well, some cows will be in the springer mob for less than 14 days. A very strategic approach is needed here, to ensure cows get effective mineralpriming for a minimum of 14 days prior to calving. Maintaining rumen health is a critical component of effectively transitioning a dry cow to a milking cow. Cows must be transitioned from their dry cow diet and onto their springer diet at least 3 weeks before calving and over a period of days, to allow the rumen microbes time to adapt to a new diet. Any sudden dietary change shocks the rumen and compromises the cow’s ability to function. An example of bad transitioning would be having cows on kale one day and then pasture the next and then expecting the cow to calve 10 days later without compromise. If the transitioning process fails, there will be downer cows. Unfortunately this will be the tip of the iceberg in terms of compromised productivity for the season. ProDairy probiotic extract can help support your herd’s rumen health and support transitions to calving.

For more information, contact your Farmlands Technical Field Officer, or the friendly team at your local Farmlands store.

Article supplied by Donaghys