Farm Ireland
Independent.ie

Thursday 21 September 2017

Farmers must control post-calving condition loss

Dr Dan Ryan

The recent dry spell was the longest period of decent weather experienced in the past six months.

Most farmers have emptied slurry tanks, with many of those with heavier soils taking advantage of umbilical spreading systems in order to avoid the risk of soil compaction.

Lactating cows are currently grazing grass reserves which have built up over the winter period.

However, soil temperatures are still close to 3°C in the first week of March.

Grass growth rates are poor, with grass covers disappearing rapidly on most farms.

It is indeed essential to graze cows on high quality grass, but to remember that this will only meet a proportion of their total dry matter intake requirements.

Our farm visits show that more than half the cows calved so far have body condition scores (BCS) of 2.5 or less.

These cows cannot afford to lose BCS post calving. Unfortunately, these same cows are presenting with the poorest repair of the reproductive tract when scanned between 14 and 44 days post calving.

Also Read


Cows will be in a negative energy balance in the first six weeks post calving. You can expect cows to lose 0.5 BCS in this period.

Your goal is to prevent any greater BCS loss. Farmers may consider the price of dairy rations too expensive for the return in milk sales.

focus

However, your primary focus now has to be the health of the herd. The type of ration fed should bear in mind the need to achieve a minimum BCS of 2.5 after the first six weeks in lactation.

Health problems resulting from multiple births, retained afterbirth, milk fever, Ketosis, soil contaminated silages, inadequate dry cow mineral balance, mastitis and lameness will all impair repair in the critical three-week period post calving.

The reproductive tract of the cow is the primary driver of profit in your business. Neglecting its care is akin to running your tractor without oil. All of the health stressors above impact negatively on the cow 'engine'.

Cows will be slow to resume normal heat cycles and will have more irregular cycles with persistent infections when the 'engine' is placed under stress.

Healthy cows will resume heat cycles from two weeks post calving but 90pc of these first heats are not shown.

Recent research, both here in Ireland and abroad, has shown a clear relationship between early heats post calving and the probability of pregnancy by 210 days in milk.

This research shows that it pays to look after the cow during the transition period.

The longer it takes cows to resume heat cycles post calving, the greater risk of empty cows at the end of the breeding season.

What can I do to avoid this outcome? Talk to your nutritionist or agricultural consultant. Get them to assess the BCS of your cows. Do not forget the dry cows as there are still up to 35pc of cows to calve on most farms.

Focus on having a BCS of 3.0 at calving and 2.5 six weeks post calving. Money spent now on these targets will leave greater profit in the business at the end of the year.

neglected

With improved weather conditions and silage supplies as a limited resource, there is an onus on farmers to focus on tasks outstanding on the farm.

In this situation, the dry cows are usually neglected, which creates the unhealthy 'late-calver syndrome'.

The late calvers will have less opportunity to establish pregnancy and stay in the herd. It is essential that these cows come through the transition phase as healthy cows.

In conclusion, do not stress your fresh cows by practices such as 'golf ball' grazing.

Focus on healthy cows coming through the transition phase to maximise profitability of the business.

Treat your late calvers with extra care as they will have a narrower window of opportunity to establish pregnancy.

Dr Dan Ryan is a bovine reproductive physiologist and can be contacted at www.cowsdna.com

Irish Independent