Farm Ireland
Independent.ie

Sunday 28 May 2017

Low-cost production plans not conducive to compact calving

Dr Dan Ryan

It is that time of year when you need to start focusing on getting cows and heifers in calf for spring calving systems in 2012. For many farmers, the primary concern to-date has been the risk of a superlevy, with some farmers producing up to 100pc above their allocated quota. This is not only a high risk financially, but feed restrictions to reduce milk production have implications in the reproductive health of cows for the coming breeding season.

Many farmers have put cows on once-a-day milking, reduced concentrate supplementation, restricted grass and silage availability. The body condition score (BCS) of these cows has suffered. It is very clear from farm visits and looking at cows grazing that a minimum target BCS of 2.5 is not being achieved.

In a survey of 40 spring calving herds I have recorded that an average of 25pc of the dairy cows from last year will calve after April 1. This begs the question is compact calving a myth? Current milk production systems focus on increased grazing pressure and herd size and the use of grazed grass. The development of the EBI has enabled a cow which survives in this system of production.

However, theory and management practices at farm level are two different issues. In essence, we have engineered a cow which cannot survive successfully in a harsh environment. It's nice to walk out to a paddock in the middle of June to see cows in a BCS of 3 chewing the cud with the sun shining on their backs. Low-cost systems which stress cows prior to breeding are not conducive to reproductive health in the cow.

Current management practices during the dry-cow and early post-calving period will have to improve if we are to achieve compact calving in the future. Cows need to be fit at all stages of the production cycle to enable the links in the chain to stay intact.

Do not forget the maiden heifers. Are they meeting target weights for their genotype? Overcrowding of maiden heifers on slats indoors prevents cycling and any other form of stress will do the same.

If the animals are stressed in terms of energy requirements, it makes sense to feed concentrates to cows and heifers during the critical lead-in period to breeding and until pregnancies are established after 35 days. There is no doubt that grazed grass at 6c/kg DM compared to silage at 16c/kg DM and concentrates at 30c/kg DM puts a focus on grazed grass as the primary input for milk production in a grass-based milk production system. Unfortunately, the fallout from this focus is that cows are losing body condition in the dry period which is not acceptable. This creates metabolic problems around calving and reduces the rate of uterine repair post-calving. This ultimately increases the calving to pregnancy interval.

If your cows are fit when they calve, you want to avoid anything in excess of 0.5 BCS loss in the first 60 days post-calving. Thereafter, cows should be putting on weight.

When cows are at grass, they need both quantity and quality in terms of dry matter intake. The focus at all times has to be a fit cow for that stage of the production cycle. If grazed grass does not meet the requirements for a fit cow, get your nutritionist to balance the diet to meet her requirements.

Set a target of a 90pc submission rate for cows calved longer than 40 days in the first three weeks of the breeding season. In actual fact, most herds only achieve 60pc in this period. This is the main reason why compact calving cannot be achieved on more than 90pc of grass-based spring calving systems in Ireland. Compact calving refers to 90pc of cows calved in a nine-to-10 week period where replacement rate is not above 20pc.

The challenge has to be a 90pc heat detection rate, which is possible if your cows are fit! Heat detection aids such as tail-paint, teaser bulls with chin-ball markers and accelerometers which measure cow activity are aids to heat detection.

Teagasc research data shows a cost in excess of €200 for each heat missed in cost-efficient grass-based milk production. Scanning is an excellent tool for reducing your heat detection rate and the ultimate goal of compact calving.

Dr Dan Ryan is a breeding management consultant. His DVD, Achieving a 365-day calving interval, is available at www.cows365.com

Indo Farming



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