- Supplements that provide extra energy to the cows’ diet can increase milk production by 1.0 kg milk/kg supplement in the short term, and more than 1 kg milk/kg supplement in the long term, depending on pasture quality and availability.
- Energy supplements typically increase milk protein content and allow cows to gain more, or lose less body condition than unsupplemented animals.
- When high-quality forage is available to appetite, responses to supplementation are minimal. However, when animals are restricted in their intake of good quality fodder, or the pasture is of poor quality, much larger production increases to supplementation are possible.
- Although the cereal grains vary widely in their energy and protein contents, they produce similar responses when fed at low levels (less than 4 kg/cow/day).
- At high levels of grain feeding, the differences between grains become more important. The higher fat and fibre levels in oats may result in greater fat-corrected milk yields and milk fat content.
- Differences in fermentation rates between and within cereal grains may cause differences in substitution rates and milk responses when grains are fed at high levels.
- Fermentation of starch in the rumen probably is preferable to the digestion of starch in the intestines.
- Molasses produces a response about 70% of that of the cereal grains for equal amounts on an as-fed basis.
- A wide range of by-products is suitable for inclusion in dairy feeds. Brewers’ grains, citrus pulp and mill mix are regularly fed in dairies close to food processing centres.
- The whole cottonseed has a good balance of energy, protein and fibre and is widely fed.
- With the exception of oats, there are benefits to be gained from processing cereal grains before feeding.
- Grain processing increases its digestibility and improves starch utilisation.
- The optimal method of processing varies with the grain type.
- Sodium-hydroxide treatment may give production benefits, but problems in handling and storing treated grain can limit its use.
- Ammonia treatment of grain may be a better alternative, but it has yet to be investigated with dairy cows.
- Steam flaking can greatly increase the milk response when feeding sorghum, but it is unlikely to be cost-effective.
- Pellets offer several advantages over concentrate meal, particularly at high levels of feeding when feed-mixing facilities are not available on the farm. In addition, the nutritional specification of the pellets can be adjusted to suit the forages available
