Examining performance, milk, and meat in ruminants fed with macroalgae and microalgae: A meta-analysis perspective

Area of Science:

• Animal Science
• Nutritional Science
• Marine Biology

Background:

• Algae are increasingly explored as sustainable feed ingredients for ruminants.
• Understanding the impact of different algae types on animal performance is crucial for optimizing livestock production.

Purpose of the Study:

• To consolidate data from multiple studies on algae feeding in ruminants.
• To identify patterns in the effects of algae on milk composition, carcass yield, and growth performance.

Main Methods:

• Meta-analysis of 67 scientific articles.
• Analysis of factors including algae type (macro- and microalgae), species, and animal breed.
• Statistical evaluation of performance metrics like average daily gain, feed conversion ratio, and carcass weight.

Main Results:

• Algae feeding improved average daily gain in Barki sheep, Moghani sheep, and Zaraibi goats.
• Adverse effects on feed conversion ratio were observed in Canadian Arcott and Ile-de-France sheep, particularly in young and castrated animals.
• Algae extract increased hot carcass weight, while raw algae reduced milk fat and protein content in cattle and sheep.
• Conjugated linoleic acid (CLA) and docosahexaenoic acid (DHA) levels increased in meat and milk.

Conclusions:

• Algae inclusion in ruminant diets yields mixed results, with benefits in growth and carcass yield but potential drawbacks in feed efficiency and milk quality.
• Further research is needed to optimize algae supplementation strategies for sustainable ruminant production.
• Algae can enhance beneficial fatty acid profiles (CLA, DHA) in animal products.