Making the most of grazed grass on beef farms

Grazed grass is the cheapest feedstuff available to Irish farmers. Excellent grass management for beef cattle can significantly improve profitability. Better utilisation of grazed grass coupled with strategic use of concentrate supplementation can maximise animal performance, increase output and result in higher margins.

Feed costs account for 75% of variable costs in Irish beef production. Grass and grass silage are the predominant feed input for beef cattle. Grazed grass is estimated to cost circa €70 per ton of dry matter with grass silage approximately double that. Grazing quality grass and making quality silage are essential to performance and profitability. The economic sustainability of beef production systems depends on optimising the contribution of grazed grass to the lifetime intake of feed and using silage and concentrates as efficiently and strategically as possible. Concentrate feeding at grass will improve margins and profitability when use in a manner that minimises substitution of grass intake but rather increases overall intake.

When cattle are housed for fattening, the cost per kg of live weight gain increases by up to 50% compared to grass-based finishing. With this in mind, finishing cattle at grass rather than indoors is economically attractive, while reducing/ removing the cost of housing accommodation and slurry management.

When considering whether or not to finish cattle at grass a number of factors should be taken into consideration. Firstly, identify cattle that have the ability to be finished at grass, where grass finishing is not achievable, such animals should be grazed throughout the summer and finished during the winter period. This decision may be based on gender, breed type and/or animals present condition. However, regardless of the cattle type being finished, meeting market requirements is critical to obtaining the best price when slaughtering. As conformation and appropriate fat cover are critically important to specific markets, ensure those animals selected for grass-based finishing can achieve such market requirements. Where split finishing applies (a number of animals slaughtered off grass with the remainder being finishing indoors), animals should be allocated into groups according to finishing regimes and ran through specific production systems. While also lowering finishing costs when slaughtering cattle prior to the winter period, benefits of running dual systems on farm include increased cash-flow prior to this expensive winter period. Additional benefits to finishing cattle at grass include avoiding the annual autumn price drop and the hidden benefit of substitution effects in the latter half of the year, whereby the reduction in consumed herbage can result in an increased stocking rate and consequently increased output per hectare from a fixed land area.

Concentrate supplementation at grass

Key challenges when finishing beef cattle at grass is achieving adequate fat cover on carcasses and maintaining optimum live weight gain as feed demand on farm increases and grass quality starts to decline as the grazing season progresses. Therefore, concentrate supplementation can be offered to grazing cattle to overcome potential energy deficits, increasing overall performance and fat deposition. Recent research has shown that even when good quality grass is in abundance, feeding 0.5 kg/100 kg bodyweight results in greater performance and margin, without negative substitution effects (feed 3 kg to a 600 kg steer). As we approach the final shoulder of the grazing season, due to autumn grass having a slightly lower nutritive value, coupled with increasing demand on farm due to animals having higher maintenance and intake potential, feeding rates should be increased on the basis of economic return. 

The use of a specific concentrate suited to grazing conditions is important to complement a solely grass-based diet. Energy rather than protein is the primary limiting factor in autumn grass and supplementation with concentrated energy sources is required (such as the GAIN Turbo Finisher Nut). Grass based diets result in higher energy losses through the production of methane than concentrate based diets, with feed additives such as Carneo Boost included in GAIN Turbo Finisher Nut, some of the energy lost as methane will be used for increased live weight gain.

Grassland management

Achieving success when finishing cattle at grass is highly dependent on good grassland management, with the production and efficient utilisation of high yields of high-nutritive value grass throughout an extended grazing season being essential. In systems where rotational grazing is practised, both grass production and animal performance are likely to be higher than alternative grazing systems, therefore implementing paddock systems is advisable. Useful tips to remember when managing grass include:

• Address soil nutrient and physical status to produce a leafy quality sward
• Walk paddocks weekly to asses grass availability on farm
• Target pre-grazing heights of 8-10 cm (1,200 - 1,600 kg DM/ha)
• Target post-grazing heights of 4-5 cm
• Simply ‘grow grass over 3 weeks and graze in 3 days’.

When feeding cattle at grass save time and labour by using mobile troughs, moving them regularly to limit poaching and contamination of feed with soil. Lightweight troughs that can be easily moved coincide well with paddock systems.

For more information contact your local Glanbia Ireland Representative, branch or glanbiaconnect.com.

Updated: 16 June 2021