Dairy Notes October 2011
Planning for early grass next spring
Grazing conditions across Northern Ireland have been variable this autumn, although grass growth on most farms has been sufficient. Poor ground conditions in some areas has resulted in excessive poaching and sward damage and the only option on these farms is to bring cows in. For farmers still able to graze it is now time to plan for early grass next spring.
- Paddocks that are most suitable for early grazing next spring should be grazed out to 5cm or less on a rotational basis and closed for the winter period, starting on 15 October (in wetter areas this will be earlier).
- The winter period should be looked on as a 120 day rotation. Paddocks closed first will be the first to be grazed in spring.
- Paddocks should not be grazed again over the winter, even if there is good grass growth at the end of October and into November. Paddocks closed in late November will not have sufficient grass for grazing until the end of March or April next year.
The timing of paddock closure and grazing heights in the autumn will determine the starting date and grass quality for your spring grazing the following year.
Calf rearing
Over the next few months I will highlight some fundamental areas to help improve calf rearing on farm. This month I will focus on colostrum.
How much colostrum does a calf need?
A new born calf has no active immunity and is highly vulnerable to infection. Protection is achieved by ensuring the new born calf consumes approximately 10 percent of its body weight (around 3.5 - 5 litres depending on the calf’s birthweight) of colostrum within the first six hours after birth. Colostrum is produced by the cow before and shortly after the birth of the calf and is rich in nutrients. It also contains immunoglobulins (antibodies) which provide the calf with immunity to infection. The effectiveness of colostrum in providing immunity to the calf is greatly affected by the timing of colostrum intake. The ability of the calf to absorb antibodies decreases rapidly after birth. Keep a supply of frozen colostrum which can be used if none is available to feed to new born calves.
Quality of the colostrum
The percentage of antibodies in colostrum decreases rapidly with each milking. The second milking usually has only 60 - 70 percent of antibodies contained in the first milk. Calves should receive the first milk produced from the dam. The number of pregnancies that the dam has had also affects the quality of colostrum. Older cows have been exposed to a greater number of infections than first calved heifers and so have higher concentrations of antibodies in their colostrum. The quality of colostrum is reduced by the presence of dirt or other debris leading to contamination. Always ensure that the cow’s udder and teats are clean before the first feeding.
Forage Maize harvest
The forage maize growing season of 2011 has been the poorest of the last five years. The majority of forage maize grown under plastic has recovered quite well in terms of yield and maturity. The general advice for these crops is to harvest as normal during late October.
Mark Scott Dairying Technologist, Greenmount Campus, CAFRE makes the following points:
- Crops grown in the open must be inspected at this stage to make an assessment of when best to harvest. Look closely at the cob and where no yellow is visible in grains and the cob is either undeveloped or completely white the best course of action is to harvest this crop now before it starts to die off. This will ensure the quality of leaf material is reasonable.
- Where grains show some yellowing this indicates the development of starch and the crop should be allowed to dry down as normal to concentrate starch levels and improve dry matter.
