Management of the late calving cow
Article by Dr. Dan Ryan published in the Farming Independent Newspaper, March 8th 2011.
Calving programmes are now well under way on most dairy farms. Most farmers will have a high proportion of their first calvers milking at this stage. However, a high proportion of the later lactation cows remain to calve on the dairy farm. On a farm visit recently to a dairy farmer outside Tipperary town, over 30% of the farmer’s cows had slipped from January February calving to March through July calving because he delayed breeding date by two weeks. He considers that there is too much of a risk associated with starting breeding in May. The farmer finds that he runs too many risks in breeding cows while grazing grass as the sole diet in early May and ends up with too many cases of sub-clinical and clinical acidosis.
How do we address this issue of later calving cows on the dairy farm? The long term answer is not induced calving. This is a practice used in New Zealand which forces cows to calve 200 days into pregnancy. Cows produce approximately 90% of previous lactation yields with higher milk solids. However, this practice is now being phased out through legislation on animal welfare grounds.
A combination of factors result in late calving cows. A preventative management health programme (PHMP) needs to be put in place on the farm to prevent environmental stressors depressing the immune system of the cow thereby impairing reproductive performance. In essence, good management practices and stockmanship skills are needed at all stages of the production cycle.
Sadly, with increasing herd sizes, a cow becomes a number and the stockman does not have the time to monitor the well being of his cows. The term animal welfare is frowned upon as being associated with a ‘’green evolution’’. However, this should be the gold standard set for your dairy herd management practices.
The primary focus has to be the requirements of the cow to maintain a healthy immune system. The reproductive system is the first line of attack if you place undue stress on the cow.
We can see the impact of poor dry cow, nutrition, calving difficulty, milk fever, lameness and infectious diseases causing embryonic death, by scanning cows from 14 days post calving. Scanning is not just a tool to identify if the cow is pregnant or not. Scanning cows from 14 days post calving will identify if the health of your dairy herd is meeting the requirements to maximize subsequent reproductive performance. All may seem well on the surface, but the health of the reproductive system is key to long term herd profitability.
What steps can we take to reduce the number of late calvers?
- The late calvers need good dry cow management. This area is neglected on many farms. The cows are either fed silage rejected by the milking cows or poor quality silage contaminated with mould. Mycotoxins are extremely detrimental to reproductive performance.
- Ensure dry cow mineral supplementation meets the requirements of your cows. A mineral milk analysis will enable a dry and milking cow mineral specification for your herd. A silage mineral and feed analysis should also be done to ensure cows do not loose body condition in the dry cow period.
- Avoid calving difficulty. Avoid over conditioned dry cows. They will have a higher incidence of metabolic disease and calving difficulty. The temptation to use beef sires which deliver a valuable calf but increase calving difficulty ,should be avoided.
- Vaccination programmes for the various diseases should be put in place based on your requirements. The late calving cow is frequently forgotten in this programme. Ensure needles are changed frequently between cows and that booster vaccinations are given at the correct time.
- Ensure dry matter intakes at grass in the cow freshly calved up to 40 days do not result in more than 0.5kg body weight loss or half a condition score. Top quality concentrates from a reputable merchant are a must for the freshly calved cow. Cost efficient grass based milk production may not concur but lifetime production of the cow is key to animal welfare and profitability.
- Put a profitable health management programme in place. This should incorporate milk and feed analysis for micro and macro nutrient (mineral and feed quality) plus the presence of disease challenges at four intervals throughout the year. An integral part of this programme should also incorporate scanning of cows. Scanning of the reproductive tract in the window of 14 to 50 days calved will identify if there are underlying herd or individual cow stressors impairing reproductive performance.
Remember ‘’Be kind to the cow and she will be kind to you’’