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Beef and sheep notes April 2007

Turning Cattle Out - Get the Basics Right

Achieving a high level of performance from grazed grass over the duration of the grazing season is a must on beef farms if production costs are to be kept to a minimum.
At, or just before turnout, is an ideal time to plan how best to manage the various groups of stock during the grazing season.

An Efficient Grazing System must:

  1. Be relatively easy to manage, particularly when it comes to moving stock etc.
  2. Be capable of producing the desired quantity of good quality grass using the minimum amount of fertiliser.
  3. Allow assessment of the supply of grass ahead of stock both accurately and quickly.
  4. Where desirable, encourage the growth of clover within the sward, this should be the aim on the majority of beef farms!
  5. Facilitate the removal of grass surpluses as silage when the need arises.
  6. Be capable of operating at a range of stocking rates to suit different situations.

Rotational Grazing - Main Points:

  • 6 to 8 paddocks/divisions is ideal. Equal size not essential.
  • Keep paddocks as ‘square’ as possible.  This reduces poaching damage during wet weather.
  • Use temporary electric fencing to sub-divide larger fields.
  • During the early part of the season maintain rotational length at approximately 20 to 22 days, increasing to 25 by late July/early-August and 40 for September/October.
  • Assess grass supply ahead of stock.

Assessing Grass Supply - Grazing Days Ahead

Maintaining an adequate supply of high quality grass -  a pre-grazing height of approximately 15 cm (6 inches) is the key to achieving high daily liveweight gains. Use the ‘Grazing Days Ahead’ method to quantify the amount of grass within a rotational system at any one point in time, in terms of the number of days grazing available for a particular batch of stock. This is done by:
  1. Walking across each field/division with a pen and notebook.
  2. Estimate the number of days grazing available in each division at that point in time (disregard any future growth).
  3. Tot up the sum of the grazing days - this gives you the Grazing Days Ahead of stock.

Nitrogen Fertiliser

Fertiliser Nitrogen is now an expensive input and it is imperative that it is used as efficiently as possible.  
Most beef/sheep producers are low or moderately stocked and, hence, during April/May relatively low amounts per application (2.5 bags per ha to 1 bag per acre) or less is required depending on grass supply ahead of the cattle.
Remember, if compound fertiliser is used then a soil analysis must be available to show a requirement for phosphate.
Promoting Clover?
If the aim is to maintain or increase the clover component of the sward, then graze tightly and avoid applying nitrogen.

Keeping lamb thrive on target

Each year there are complaints about poor lamb thrive.  For mid-season twin lambs, the expected average growth rate is 1.8 KG per week to 10 weeks of age; 1.5 KG per week from 11 to 14 weeks and one kg per week from week 15 onwards.
This level of growth will give an average weaning weight of 28 to 30 KG for a flock with a weaning rate of 1.6.
In any flock, there is huge variation in lamb weight from the start, with big single lambs, early born strong twins, small twins, and so on.  Half a kilogram difference in liveweight at birth between a set of twins will have increased to a two KG liveweight difference at weaning.

Grass Quality

Once grass heads out, digestibility goes way down from, for example, a D-Value of 78 in early May to around 60 D-Value by mid-June.  This is a huge drop in grass quality, and just at a time when March-born lambs are switching feeds from milk to grass.
Therefore, much of the slow-up in growth rate that we associate with weaning is due to the deterioration in sward quality.  In dry conditions, grass dry matter will range from 19 to 23 percent.  In wet weather it can range from 12 to 15 percent.  This also has a huge impact on thrive.  Little can be done about the weather, but sward quality can be manipulated by maintaining sward height at 6 to 8 cms in April and May.  
If fields have gone stemmy, top closely to generate new leafy pastures.  Many toppers are not set to cut lower  than 9 cm, and this is of no use for lambs; go as bare as you can using a rotary or disc mower.
If parasite control is adequate, and trace mineral problems are taken care of, then the problem of poor thrive may be under your feet!

Meal Feeding

The target for mid-season lambing flocks is to have 65 percent of lambs sold by 1 September.  From weaning onwards, if thrive drops below one KG per head per week, and lamb sales are below target, consider feeding meals.
The main requirement is for energy - barley, oats or beet pulp work well.  Include a suitable mineral mix.  Where grass is scarce, feed 0.5 KG per head per day.  Where grass is plentiful, feed half this amount.  Assuming it takes 10 kilos of meal to produce 1 KG of carcase, and if creep feed costs £160 per ton and  a lamb price of £2.70 kilo caracase weight then £1.60 expense to produce £2.70 worth of carcase is still good business.

Scouring lambs

An explosion of Nematodirus eggs hatching can occur as temperatures rise in April. The highest risk is where lambs are grazing on pastures that were grazed by lambs last year. Dosing should be targeted at 4 to 6 weeks of age as these could be most vulnerable. No resistance has been identified so there is plenty of choice of anthelmintics.
There is no residual activity against nematodirus infection so the cheaper products for example white or yellow drenches are as effective as the more expensive ones.

Grass Tetany

The risk of tetany increases where animals are under stress as a result of deteriorating weather conditions and a change in diet at this time of year. The most susceptible animals are cows that have calved in the last 2 to 3 weeks, shorn ewes and those suckling multiples are also most at risk.
High magnesium concentrates are the most effective way of getting animals over the high risk period.  Cows require 50 to 60 grams of Cal-mag daily, while ewes require 10 grams every day.  

Meat Plant Focus

Linden Foods launched its new Aberdeen Angus Club on 1 March this year.
According to Frank Foster, Supply Chain Manager with Linden Foods, suckler producers  breeding their angus cattle from three-quarter bred continental cows such as Limousin or Simmental crosses  can achieve around 70 percent U and R Grades and also carcase weights can compare favourably with continental type cattle on a weight for age basis.   
To encourage suckler producers to move to the angus breed, Linden Foods  have decided to pay the same bonuses on  R and 0+ grading cattle as well as paying the same bonus on 3,4L and 4H within each grade
The full protocol with regards to traceability and certification is expected soon.
Your questions and comments are very welcome so that we can address the issues that are important to you. Please email the author directly at gerry.donnelly@dardni.gov.uk