MANAGING YOUR LATE CALVING COWS AND COLOSTRUM QUALITY FOR LATE BORN CALVES
Spring calving dairy herds are currently at the peak of their calving programmes. It is a very demanding time in terms of labour requirement. Unfortunately, the scarcity of skilled labour is the primary bottle neck in current dairy herd expansion plans.
The challenges faced centre primarily around early calf rearing. It is essential that cows have a positive experience in both the six weeks prior to calving and the first two weeks post calving. This will have a significant impact on both colostrum quality for the new-born calf, milk yield in the current lactation and probability of re-establishing pregnancy.
Farmers will generally achieve good management practices for the first three weeks of the calving season. It is from here onwards that the challenges of maintaining high standards in dry cow transition management, calf rearing, milking parlour routines and transitioning cows on to grazed grass begins.
With an increased work load, the risk of poor dry cow transition management increases. The cows remaining to calve will consist of a greater proportion of the herd, which were either late calvers or problem breeders from the previous breeding season. These transition cows will form the late calving group this year. They will have the minimum voluntary waiting period prior to the start of this year’s breeding season. It is essential that these cows receive optimal management in the weeks ahead.
Ensure fresh high quality silage is fed daily. There are too many situations where silage is only fed two to three times per week and uneaten silage is left to heat at the feed face. The risk of mycotoxins in stale silage and poor pit management cannot be underestimated. Mycotoxins will reduce feed intake, debilitate cow health and result in persistent womb infections post calving.
Other risk factors in your transition cow group include lameness, poor body condition score, cows carrying twins, insufficient feed space, lying areas for cows and adequate clean water.
Do not assume that a mineral bolus will meet the requirements of your dry cows. Mineral and vitamin supplementation is essential to maintain the immunocompetence of your cows. This cannot be underestimated. Feed a dry cow mineral based on a silage analysis. Ensure these late calvers do not lose body condition during the dry period. Supplement silages with concentrates as needed to maintain body condition score (BCS).
Restricting feed intake to avoid oversized calves and the associated calving difficulty will result in an increased risk of “dirty” cows post calving, which will have poorer survival in this year’s breeding programme. Studies conducted in Teagasc, Grange have shown that starvation of cows in the latter stage of pregnancy will not reduce birth weight by any more than 3kg.
Farmers have in the past two years resorted to the greater use of beef semen from AI or beef stock bulls to enhance sales revenue from beef calves sold in the marts. There is an increased risk of calving difficulty and poorer survival rates of cows in this year’s breeding programme. Fit cows will cope better with calving difficulty and resume normal heat cycles earlier post calving.
With reference to new-born calves, focus on getting sufficient high quality colostrum into the calf within the first 3 hours post calving. It is essential that the same rules apply for male calves, which will be sold through the marts within two weeks of birth. Unfortunately, this is an area of concern, whereby calves bought through the marts have an increased risk of subsequent Ecoli, Crypto and Coccidiosis scours.
Replacement heifer calves which experience these scours have an increased risk of delayed onset of cycles when they are needed for breeding. In addition, there is an increased risk of poorer fertility in these animals.
If there is a risk of Johne’s disease in your herd, ensure that a non-contaminated source of colostrum is banked on your farm to meet the requirements of new-born calves from infected cows. It is essential that calves are born into a clean bedded shed, which is not contaminated with faeces. Faeces is a major source of infection from Johne’s for the new-born calf.
In conclusion, optimal dry cow and fresh cow transition management now for your remaining dry cows will result in higher survival rates in this year’s breeding programme. This will also result in higher quality colostrum thereby reducing the risk of infection from various scours.
Dr. Dan Ryan is a bovine reproductive physiologist and can be contacted at www.reprodoc.ie
Article written by Dr. Dan Ryan for the Farming Independent 21st of February 2017.