From mid-June to late October, a substantial number of beef cattle will be slaughtered off grass, writes Alan Dillon, Teagasc Cattle Specialist.
Slaughtering off grass has a number of advantages due to its lower cost of production with less meal input, cheaper weight gain off grass and heavier carcasses. Those killed in early summer generally benefit from a price rise also.
For farmers targeting a mid to late summer slaughter, there are a number of factors to take into account.
Dietary requirements for finishing cattle consists of: energy; protein; fibre; minerals and water.
Energy is the main driver of live weight gain in cattle and should be maximised throughout the finishing period. At grass this is achieved by utilising top quality grazed grass of 1200-1600 kg DM/ha throughout the grazing season.
Protein requirements for steers and heifers are relatively low during the finishing period. Around 11-12% will suffice at this stage of the animals’ life as they have already achieved most of their target frame growth and the main aim is to lay down fat cover. Growing bulls will require a higher level of protein in the diet.
Fibre requirements where forage makes up a large proportion of the diet is likely to be adequate.
Minerals will need to be supplemented to animals; a general-purpose mineral will suffice at grass.
Water supply is critical at all times of the year. The supply of clean water to finishing cattle at grass should be monitored especially during periods of hot weather.
Finishing cattle at grass
Aim to graze top-quality swards at all times (1200-1600 kg DM/ha- 8-10 cm). Swards should be grazed to 4 cm or topped after grazing to maintain quality if a large amount of material remains after grazing.
Feeding meal to finishing cattle at grass
Feeding meals at grass in early summer is rarely economical if grass quality and quantity is adequate. If grass supply or quality is below target, then there will be a response to feeding 2-4 kg of ration to finishing stock.
What must be remembered is that this cost of finishing will be higher than grass only. There are certain situations where feeding meal at grass may make economic sense such as where it may help move cattle to slaughter faster which can take advantage of higher prices or improve grade to achieve breed bonus or Quality Assurance payments.
Later on in the summer or early autumn time, grass supply can often run tight. Cattle have a higher grass demand as they grow in size and energy value of grass later into the autumn reduces.
Supplementation at this time of year is recommended to speed up finishing of cattle at a rate of 3-4 kg where grass quality and quality is adequate or 5-6kg where grass quality is poor or supply is low.
A high energy, low protein supplement will suffice at this time of year as protein content in grass will be sufficient for finishing cattle.
Feeding supplements is often worthwhile as it reduces the requirement for more costly silage later. Also, the ‘build up’ period to a concentrate finishing diet can be implemented at pasture prior to indoor finishing.