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AFBI Evaluates Costs of Finishing Suckler Bred Bulls

09 February 2009

With current high costs and low returns from beef production, suckler producers and beef finishers need to re-evaluate their production systems and examine methods by which output and efficiency can be improved, while at the same time controlling or reducing production costs, reports Agri-Food and Biosciences Institute.

Finishing male cattle from the suckler herd as bulls offers an opportunity to increase returns from beef production relative to steers, bearing in mind the ability of bulls to grow faster, utilise food more efficiently and produce leaner carcasses than steers.

Outline of recent study

A recent study, jointly funded by Agri-Search and DARD, and undertaken at AFBI Hillsborough has evaluated the effect of different feeding systems on performance and meat quality from young bulls slaughtered at weights ranging from 500-800 kg. The study involved 250 young bulls originating from the suckler herd (3/4 or greater continental bred and 350 kg initial live weight) being offered either ad libitum concentrates with 5 kg fresh weight of grass silage daily or a 50:50 ratio of grass silage: concentrate, on a dry matter basis. The grass silage offered was high quality (26 per cent DM and D-value of 740 g per kg).

Effects of slaughter weight on performance

The effect of weight at slaughter on feed intake, animal performance and margin over feed costs are presented in Table 1. Increasing slaughter weight increased food intake but daily live weight gain remained constant at 1.4 kg per day. Consequently at 500 kg live weight, 8.9 kg feed DM was required per kg carcass weight, whereas at 800 kg live weight, 9.6 kg feed DM was required per kg carcass weight. The food conversion ratio, even at the heavier slaughter weight, is excellent for beef cattle, and clearly illustrates that suckler bred continental bulls can be taken to heavy final live weights efficiently.

Table 1: The effect of weight at slaughter on feed intake, animal performance and economics of suckler bull beef production
Parameter Slaughter weight 500kg Slaughter weight 600kg Slaughter weight 700kg Slaughter weight 800kg
Feed intake (350kg to finish)        
concentrate (kg DM) 589 1015 1494 1984
Silage (kg DM) 257 463 722 992
Animal Performance        
Carcass weight 292 349 405 462
Conformation        
per cent E & U 29 66 72 88
per cent R & O 71 34 28 12
Economics of production        
Feed Costs (£ per head)1 156 271 403 539
Margin / feed cost (£ per head)2 -11 30 42 57
1 Feed costs – assuming silage cost £120 per tonne DM and concentrate cost £180 per tonne fresh weight
2 Margin/feed cost = Carcass value (assuming base price of £2.60 per kg carcass weight) minus feed costs minus purchase price (350 kg @ £600)

Increasing slaughter weight from 500 to 800 kg improved carcass conformation by ½ a grade and resulted in a greater proportion of carcasses grading as fat class 3 rather than 2, however there was a tendency for some carcasses grading fat class 4H at the heavier weights. Increasing slaughter weight increased feed costs due to both the longer finishing duration and the poorer feed conversion ratio of the heavier bulls.

However, the heavier bulls produced heavier, better conformed carcasses leading to higher carcass values, resulting in a £68 higher margin/feed cost for bulls slaughtered at 800 kg relative to the 500 kg. It should however be noted that no penalty for heavy carcasses was included in these economics.

Impact of changes in concentrate cost on beef price

Figures 1 and 2, illustrate the impact of concentrate price and beef price on margin over feed costs of suckler bulls finished at a range of live weights. At concentrate prices of £200 per tonne or greater, margin over feed is low or negative, consequently concentrate must be priced below £200 per tonne before finishing suckler bulls could be considered, regardless of slaughter weight.

Figure 1. The impact of concentrate price and slaughter weight on margin over feed costs

Figure 2, clearly highlights that the profitability of finishing suckler bulls is very dependant on beef price. At beef prices below £2.60 per kg carcass, finishing suckler bulls would not be economical at present production costs (silage £120 per tonne DM & concentrate £180 per tonne fresh) and purchase price (£1.71 per kg live weight). Weight at slaughter had no effect on meat quality attributes as measured by lean colour or tenderness.

Figure 2. The impact of beef price and slaughter weight on margin over feed costs

Silage versus concentrates for finishing bulls

The effects of diet type on feed intake, animal performance and margin over feed costs are presented in Table 2. Replacing 50 per cent of the high concentrate diet with high quality grass silage had little impact on live weight gain, carcass conformation or fat classification.

Table 2: The effect of using high quality grass silage on feed intake, animal performance and economics of suckler bull beef production
Parameter 50:50 silage: concentrate Ad lib-concentrate
Feed intake (350kg to finish)1    
Concentrate (kg DM) 938 1640
Silage (kg DM) 943 290
Animal Performance    
Liveweight gain (kg per day) 1.44 1.47
Carcass weight (kg) 385 391
Conformation    
per cent E & U 68 73
per cent R & O 32 27
Economics of production    
Feed Costs (£ per head)1 312 382
Margin / feed cost (£ per head)2 89 35
1 Feeding duration 219 days
2 Feed costs–assuming silage cost £120 per tonne DM and concentrate cost £180 per tonne fresh weight
3 Margin/feed cost = Carcass value (assuming base price of £2.60 per kg carcass weight) minus feed costs minus purchase price (350 kg @ £600)

Feeding ad-libitum concentrates improved kill out percentage and subsequently carcass weight, but only by 7 kg per animal. Replacing 50 per cent of the high concentrate diet with grass silage reduced total concentrate requirement by 702 kg DM, decreased feed cost by £70 per head and increased margin over feed by £54 per head. Consequently, replacing 50 per cent of a high concentrate diet with high quality grass silage is a method which beef finishers could use to reduce production costs and increase margin over feed costs when finishing suckler bred bulls. Diet type had no effect on meat quality attributes as assessed by lean colour or tenderness.

Conclusions

  • Continental bulls are very efficient converters of food to carcass gain, even at live weights up to 800 kg live weight.
  • Finishing bulls to heavy slaughter weights has potential to improve output, providing markets are available – check with your processor before pursuing this option.
  • High quality grass silage can be used to reduce concentrate costs but maintain animal performance relative to a high concentrate diet.

January 2009

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