Fat supplements are incorporated into dairy diets to provide energy and enable cows to maintain butterfat levels. Most of those used in the UK are formulated with palm acid oil.
While there is nothing nutritionally wrong with this, palm oil production in general is associated with deforestation and a high carbon footprint.
Fat supplements are incorporated into dairy diets to provide energy and enable cows to maintain butterfat levels. Most of those used in the UK are formulated with palm acid oil.
While there is nothing nutritionally wrong with this, palm oil production in general is associated with deforestation and a high carbon footprint.
Milking was done via a robotic milker, three times a day on average. Concentrates were fed during milking according to yield, at a rate of 0.45kg/litre above 32 litres a day.
The trial took place over an eight-week period, giving the first group of 25 cows the control fat for the first four weeks and then test fat for the final four weeks.
This process was reversed for the second group, feeding the test fat first, followed by the control. Data recording was carried out at week four and week eight.
Results
Positive effects were seen, including significant differences in milk yields and quality, as well as increased feed efficiency, when cows were fed the palm-free supplement (see “Palm-free fat supplement trial results”).
As the researchers had hoped, the carbon footprint was also vastly improved – both in terms of the feed itself and the subsequent milk produced – when the palm-free supplement was fed, he adds.
The test fat showed a 64% reduction in feed carbon footprint compared with the palm fat:
- Control fat = 2,830g carbon dioxide equivalent (CO2e)/kg
- Test fat = 1,028g CO2e/kg.
There was also a reduction in the feed carbon footprint of the milk produced when feeding the palm-free fat totalling 11%:
- Control fat = 287g CO2e/kg of energy corrected milk (ECM)
- Test fat = 255g CO2e/kg ECM.
The feed carbon footprint covers all the carbon emissions associated with growing and harvesting a crop, as well as processing, transportation and so on, explains Prof Garnsworthy.
Conclusions
Compared with the control fat, the palm-free supplement:
- Increased milk yield as well as fat and protein content
- Did not affect dry matter intake
- Increased feed efficiency
- Did not affect methane emissions
- Lowered the carbon footprint of feed.
In addition, a change in the milk fatty acid profile suggested improved rumen fermentation of fibre, and healthier milk.
There was also evidence that the fat and vegetable oils in the test fat could improve cow health and fertility.
The Envirolac supplement is set to be launched commercially later this year.
