Get The Most Out Of Your Home Grown Feed

 

As part of our goal to foster collaboration and share information, we are inviting those involved in the industry to share their knowledge and expertise. In this article, Jen Corkran from Barenbrug Agriseeds explains how pasture selection and management helps farmers maximise milk production through increasing the intake of quality home grown feed.

In New Zealand, home-grown pasture is the cheapest form of feed for livestock. Most animal production systems here are based on ryegrass/white clover pasture, which typically costs just 4-5 cents/kg dry matter (DM). That cost rises slightly with nitrogen use, but is still lower than forage crops (which usually averages 15-25 cents/kg DM). This is also much lower than bought-in supplements, which cost upwards of 30 cents/kg DM.

For milking animals, high daily intakes of high-quality feed drive production. That applies to milking sheep and goats, just as it does to cows.

Pasture grown at home can differ throughout the year, in terms of seasonal growth patterns, potential energy content and quality. In this article, the focus is on both ryegrass/clover pastures, and legumes as a high-quality category.

White clover, red clover, lucerne and other legumes are high in feed quality and well known for driving very good animal production. Given the choice or allocation to do so, grazing animals will always choose a 70% legume diet (Parsons et al., 1994). So having high red and/or white clover content in your pastures will maximise intakes and increase production, as shown in the table below.  Both red and white clover show the same effect as they are highly preferred by animals.

Herbage quality aspects and sheep intake over a five day period (Fraser & Rowarth, 1996):

Herbage quality White clover Leafy ryegrass
Digestibility (%) 83 80.2
Protein (%) 28 20.1
NDF 23.17 62.94
Intake (kg DM/head/day) 1.77 1.03

A key difference between the legumes and ryegrass is the fibre content (NDF). Fibre in forage is made up of cellulose and hemicellulose, held together by lignin, and animals must chew this down to 1-2mm before it can pass through the rumen. In other words, they have to work harder to digest it, and it takes longer. Lower NDF levels on the other hand mean more rapid rumen degradation, thus leading to more space and time for higher intakes, which is where the production gain comes from.

If your system uses cut-and-carry ryegrass-based pasture as part of the feeding regime, you can maximise the quality of this (very cheap) home-grown feed by ensuring pastures have high levels of clover. Red and white clovers are both excellent and they also tend to have consistently high metabolisable energy (ME) of 12+ MJ ME/kg DM.

So what can you do to encourage high clover content in your ryegrass-based pastures?

It starts with understanding the ryegrass plant, and aiming to graze or mow pasture at the 2.5-3 leaf stage as often as possible. The chart below shows what happens to ryegrass physiologically, as it grows.

Grazing or mowing at the 3-leaf stage will maximise yield, quality, utilisation and persistence of pastures, as well as ensuring enough light reaches the base of the sward to give clovers what they need to thrive and persist. Yield, quality, utilisation and persistence are the four pillars of getting the best out of your home-grown feed. These will be delved into further in future articles.

Barenbrug Agriseeds has a pasture systems team focused on helping farmers maximise feed grown at home in a way that works best for the individual farm system. They are always available for farm visits and free advice. If you are interested in knowing more, please contact:

Jen Corkran

Pasture Systems Agronomist

Mob 021 308 167

Email jcorkran@agriseeds.co.nz

www.agriseeds.co.nz

References:

Fraser, T. J., & Rowarth, J. S. (1996). Legumes, herbs or grass for lamb performance? Proceedings of the New Zealand Grassland Association, 58, 49-52.

Parsons, A.J., Newman, J.A., Penning, P.D., Harvey, A., and Orr, R.J. 1994. Diet preference of sheep – effects of recent diet, physiological-state and species abundance. Journal of Animal Ecology 63(2): 465-478.

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