At this time of the year, many beef farmers will be considering feeding meal to cattle at grass, especially in cases where cattle are approaching slaughter weights.
The feed quality of grass can decline in autumn, and with reports of reduced live weight gain from cattle at grass this summer, getting cattle ‘factory fit’ before winter housing will be a challenge on many farms this year.
Feeding concentrates (meal) to cattle at grass can be challenging from a logistics point of view, and as farmers will know, heavy cattle rushing to a feed trough poses health and safety risks for the farmer.
Also, heavy land types may make meal feeding unworkable at grass but where ground conditions are drier, it may be more feasible.
Where meal feeding is possible at grass, Teagasc research affirms it can significantly improve the performance of cattle at grass – especially at this time of year.
In a recent post on the Teagasc website, Martina Harrington, manager of the future beef programme, outlined variables for farmers to consider when opting to feed cattle at grass.
She said: “While every effort should be made to maximise the proportion of autumn grazed grass in the animal’s diet, the strategic use of expensive concentrate supplementation at pasture to enhance the energy density of the diet might be considered, especially if winter silage stocks are low.”
The Teagasc advisor noted that if pasture supply is low or of poorer quality, “a worthwhile growth response to concentrate may be expected.
“However, if pasture quality is good and supply is not limited then the economic response to concentrates might be questionable.”
Two scenarios are outlined in the tables below. The first table outlines Teagasc data from animals that are reaching a finishing weight / fat cover and are nearing slaughter.
These animals are within 60kg of their target finishing weight. The second table details Teagasc data for beef X dairy cattle.
The table below details the effect of feeding strategy on finishing performance:
Suckler steers (95 days) Suckler steers (95 days) Suckler steers (95 days) Suckler steers (75 days) Suckler steers (75 days) Suckler steers (75 days) Finishing strategy Grass only Grass + 5kg of concentrates Difference Grass only Grass + 5kg of concentrates Difference Daily live weight gain (kg) 0.34 1.04 0.7 0.81 1.14 0.33 Slaughter weight (kg) 547 596 49 604 667 63 Carcass weight (kg) 291 323 32 334 379 45 Kill-out proportion (g/kg) 532 541 9 554 568 14 Carcass conformation 6.3 7.6 1.3 7.5 8.8 1.3 Carcass fat score 6.2 7.4 1.2 7.5 8.3 0.8
Studies at Teagasc Grange have shown that with adequate grass in autumn, feeding 0.5-0.75kg of concentrates/100kg of live weight resulted in carcass growth responses between 30-110g/kg concentrate fed.
“Feeding a moderate level of concentrate (0.5 kg/100 kg live weight) is likely to give good growth results,” according to the Teagasc advisor.
The table below details the effect of feeding strategy on finishing performance for dairy-beef cattle:
Finishing strategy Grass only Grass + 1.5kg of concentrates Grass + 3kg of concentrates Difference 0kg vs. 1.5kg Difference 1.5kg vs. 3kg Daily live weight gain (kg) 0.80 0.88 0.91 0.08 0.03 Slaughter weight (kg) 459 469 471 10 2 Carcass weight (kg) 226 233 236 7 3 Kill-out proportion (g/kg) 488 498 500 10 2 Carcass conformation 5.2 5.4 5.2 0.2 0 Carcass fat score 5.1 5.6 5.8 0.5 0.2
Explaining the data, Harrington said: “Table 1 shows that for suckler steers, feeding 5kg of concentrate daily, over 95 days, resulted in a significant increase in daily live weight gain (from 0.34kg to 1.04kg) and carcass weight (from 291kg to 323kg).
“That’s an extra 32kg of carcass for 476kg of meal. When meal is costed at €320/t and a kilogram of beef carcass at €5.15, that’s an extra €165/animal at a cost of €152, in simple sums.”
She added: “In the first example, concentrate feeding increased kill-out percentage by almost 1 percentage unit and improved both conformation (1.3 units: from O+ to R-) and fat score (1.2 units: 2+ to 3-) The results are similar for the second suckler trial.”
In the beef x dairy steer category, it was noted that there was “only a small carcass weight response to the initial 1.5kg of concentrates, but not to the next increment”.
The Teagasc advisor explained: “Feeding 168kg of concentrates/head resulted in an additional 7kg of carcass (1.5kg vs none) and feeding an additional 168kg concentrates (1.5 kg vs. 3kg) only resulted in an additional 3kg of carcass.
“In this case, both pasture quality (DMD 720g/kg) and quantity (pre-grazing herbage mass of 1,800 kg DM/ha) were adequate to meet the animals’ needs.”
For forward stores that won’t finish until next February, “it may be better not to supplement them, as data shows that when comparing autumn supplemented and un-supplemented animals that go indoors for finishing, any advantage attained by the supplemented animals is subsequently lost indoors, and both groups end up similarly with compensatory growth”, according to the Teagasc advisor.