Supplementation of Cattle Fed Tropical Grasses with Microalgae

Costa, D.F.A., Quigley, S.P., Isherwood, P., McLennan, S.R. and Poppi, D.P. - Journal of Animal Science

Type: Research Paper
Knowledge level: Advanced

Farm Table says:

Great paper showing the potential of microalgae as a high-protein supplementary feed for beef cattle grazing on low-quality tropical grasses.

Increases microbial protein production and average daily gain

What is the problem?

Beef cattle production in tropical Australia is affected by declining pasture quality during the dry season, causing low average daily gain or body weight loss in growing cattle. As a result, there is a need to identify and examine alternative, low-cost crude protein supplements. This study conducted three experiments to evaluate the use of microalgae as supplementary feed for beef cattle consuming tropical grasses of low crude protein.

What did the research involve?

Three experiments were undertaken:

  1. in the first experiment, in vitro protein degradability and the chemical composition of 9 algae species and 4 protein supplements were determined
  2. in the second experiment, microbial protein production and rumen function were determined in Bos indicus steers that were fed speargrass hay alone or supplemented with 1 of 3 microalgae species: Spirulina platensis, Chlorella pyrenoidosa, Dunaliella salina; or cottonseed meal
  3. in the third experiment, dry matter intake and average daily gain were determined in B. indicus steers fed speargrass hay alone or supplemented with increasing amounts of NPN (urea combined with ammonia sulfate), cottonseed meal, or S. platensis

What were the key findings?

  1. in the first experiment, the crude protein content of S. platensis and C. pyrenoidosa (675 and 580g/kg DM) was highest among the algae species and higher than the protein supplements examined
  2. in the second experiment, S. platensis supplementation increased speargrass hay intake and MCP production efficiency. Steers did not tend to accept Dunaliella salina
  3. in the third experiment, average daily gain increased with supplementary protein intake from both S. platensis and NPN

Final comment

This paper shows that microalgae, particularly S. platensis and C. pyrenoidosa, could be used as a protein supplement for beef cattle. Algae can be purchased and transported on farm, or produced on-farm if a production and harvesting system is implemented.

2016 - Australia - Costa, D.F.A., Quigley, S.P., Isherwood, P., McLennan, S.R. and Poppi, D.P. - Journal of Animal Science
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