PREPARING FOR DRY COW MANAGEMENT AND RISK OF NEOSPORA
We are currently experiencing the best grazing conditions in living memory for grass-based milk production. This has tempted farmers to extend lactations and produce high value milk with elevated solids in late lactation. However, this has created a superlevy situation for all Co-Ops in the country.
This scenario has created significant body condition score loss in cows on many farms. Farmers are not willing to supplement cows with concentrates where needed on the basis of a superlevy fine.
Indeed, autumn calvers are facing a more bleak situation. Here, cows are in negative energy balance and concentrate supplementation is being restricted in order to graze out paddocks of grass generated with excellent grass growth rates this autumn. However, the sugar content of this grass and consequent feed value for the early lactation cow is poor.
Many farmers are currently scanning their spring calving dairy herds to identify empty cows, late calvers, those cows carrying twins and accurate pregnancy ageing to generate predicted calving dates. We are currently advising farmers to remove empty cows from the dairy herd where a superlevy is imminent. Many farms are overstocked and there is no economic justification to recycling empty cows if winter housing capacity is already over stretched.
Stock bulls have been left run with the dairy herd until September this year. Farmers have to now decide to sell the associated May and June calvers now or hope a better market in a post quota regime. If a superlevy fine is imminent, we should dry off these late calvers and sell now if housing capacity is a limiting resource.
First and second calvers are at greater risk of poor body condition score (BCS) at this time of year. Pregnancy scan results will identify those cows pregnant over 150 days which should be dried off now if BCS is below target.
The primary objective now for next year’s breeding programme is to get cows to a target BCS, eight weeks before calving and to maintain BCS until cows calve. It is worth noting that up to 80pc of herd health and future reproductive performance is dictated by transition management.
Drying off cows can be a very stressful experience for cows. Some farmers operate a sharp and short dry off regime while others introduce once a day milking for a period prior to drying off. Cows are at greatest risk of abortion to either neospora or samonella at this time. Samonella vaccination is warranted as a routine management practice on most farms. Vaccination against neospora is not possible in this country. It is now the greatest cause of abortion in the UK. Unfortunately, it is a disease occurring with greater incidence in this country. We have encountered a greater risk of the disease when cows have been dried off and faced with a restricted diet.
Neospora attacks the heart valves of the foetus resulting in either abortion or mummification of the foetus. Dogs and foxes are the intermediate host. If canines gain access to the afterbirth from a neospora positive cow, they become infected and start to shed neospora in their faeces. Faecal contamination of feed fed to cows will result in spread of the disease.
If neospora abortions occur on your farm, it is important to scan the remainder of the herd to identify cows, which have mummified calves retained in the womb.
Management of the disease involves a number pf practices. Do not allow dogs or foxes access to the afterbirth. Prevent dogs and foxes gaining access to feed faces and areas where feed is stored as faecal contamination will result in a rapid spread of the disease. Cows which have aborted with the disease are carriers and may abort a subsequent pregnancy. They also harbour a greater risk of disease transmission through their afterbirth. Infected cows will also transmit the disease to their progeny, which reach full-term. If infected cows are retained on the farm where economics will not facilitate a high replacement rate, it is essential they are bred using a beef sire. Female progeny from this cross should not be sold for breeding in the suckler herd.
Neospora positive cows can be identified accurately from a blood sample taken in late pregnancy. Follow this procedure if abortions have occurred on your farm and associated with neospora.
Dr. Dan Ryan is a cow fertility expert and can be contacted at www.cowsDNA.com