The View from Northern Ireland: Management notes from the staff from the College of Agriculture, Food and Rural Enterprise (CAFRE) were published this week for the month of August. Below is its guide to grassland management.
Conventional reseeding with ploughing and all associated cultivations is now a very expensive process. (Approximate cost is £640 per hectare). Minimum tillage which involves spraying off the old sward, subsoiling and power harrowing can successfully establish new grass. Two runs with the power harrow (power harrow at 10 cm and then 5 cm depths gives a firm seed bed), followed by rolling, is the main method of reseeding at Greenmount Campus.
Surface seeding on less dense swards after silage is cut using seed drills or tine/air seeders can be successful and at a much lower cost. It is important to achieve good seed/soil contact. This means some form of light cultivation such as the use of a harrow/tine machine.
Moist conditions after sowing are needed. Spray off the old sward if there is a major perennial weed problem and/or if there are high levels of creeping bent. For the spray to be fully effective you will need some grass cover on the sward. If you are using a glyphosate type spray, you can spray five days before cutting or grazing. The sward can then be cut for silage or grazed off quickly before cultivation; this can gain valuable time. Using a subsoiler on land before surface seeding will improve drainage and aeration of the soil.
For the establishment of reseeds, soil fertility must be good. Aim for a soil pH of 6.0, and phosphate and potash indexes of 2. Therefore, always carry out soil analysis before reseeding.
For advice and Information on reseeding techniques and grass/clover mixes contact your local Beef and Sheep Development Adviser.
Suckled calves – value of creep feeding?
The benefits of creep feeding calves pre-weaning are well recognised. For every four kg of meal fed calves will gain 1.0 kg liveweight. Other major benefits include reduced stress levels at weaning and reduced disease level, particularly pneumonia. All of this makes the calf more saleable and easier managed after weaning.
If possible, trough feeding is preferred over ad-lib feeding as meal input can be controlled based on liveweight and sex of calf. Apart from additional meal costs, ad-lib creep feeding can also cause over-conditioned calves, resulting in poor performance post weaning and during housing.
Using two adjoining fields with a creep gate between them allows calves to be fed creep in one of the fields, preferably with a better grass supply, and still have access back to the cows.
Start meal six weeks before weaning and build up to about 1.0-2.0 kg per head per day at the point of weaning. The amount fed will depend on weight and sex of calf.
Ewe body scoring
As soon as possible after weaning body score the ewe flock and offer grass accordingly. Graze ewes with a body score less than 2.5 on good quality grass swards (2,400 kg dry matter per hectare – 6-7 cm in height). It takes about six weeks to improve ewe body condition by one score. Maintain ewes in good condition, that is, body score better than 2.5, on average quality swards (1,900 -2,000 kg dry matter per hectare – 4 cm) and reassess condition in three weeks time.
Selection of replacement ewe breeding stock
A good measurement of sheep productivity is the weight of lamb weaned per kilogramme of ewe liveweight. The most efficient flocks achieve over 1.0kg of lamb liveweight weaned per kilogramme of ewe liveweight. Improved flock efficiency will help offset rising feed and fertiliser costs, which is a very important consideration. In selecting replacement female stock or rams to breed replacements, the mature size of ewes, as well as lamb output should be a high priority.
Selecting lambs for slaughter
Regularly assess lambs for finish and sell them as they reach market specification; feeding lambs to reach excess carcase weights is not economic. The only exceptions are a few specialist heavier carcase markets.
By Kieran Lavelle of the College of Agriculture, Food and Rural Enterprise in Northern Ireland. He can be contacted via email: [email protected]