Abstract/Summary

Interest in phycological feeding within the context of animal science has recently exploded in popularity due to an increasing awareness of a needed exploitation of aquatic resources to maintain output while increasing sustainability within the livestock sector. Animal-sourced foods, specifically milk and dairy products within Europe, represent a vector for essential nutrition for much of the world and increased or maintenance of quality within product is required for increased public health outcomes derived from consumption. This highlights a gap in research, wherein study of how the feeding of phycological matter affects the resulting quality of milk is needed to maintain or improve public nutrition and increase the sustainability of the European livestock sector in doing so. Four studies demonstrated the effect that differing amounts of diet supplementation (in the use of macroalgae) or protein replacement (in the use of microalgae) has upon the resulting milk quality, yield, pathogen resilience, and haematological indicators of the animal. Study 1 examined the effect of feeding Holstein cows 330 g/d Ascophyllum nodosum on DMI, milk yield and composition, and quantified the effect on animal haematological parameters. Studies 2 and 3 questioned the effect of feeding Icelandic cattle a mixture of Laminara digitata and Ascophyllum nodosum on milk yield and composition, and then performed microbiological analysis to judge product resiliency due to feeding seaweed. Finally, study 4 investigated the effect that replacing diets of Finnish Ayrshire cows with microalgae Spirulina platensis at varying rates had on milk composition along with mineral fate through analysis of biofluids included along with milk faeces and plasma. Overall, the feeding of phycological material to dairy cows at reported rates tends to slightly lower milk protein. There were no indications of abnormal rates of feed refusal, and thus there were no differences in milk yield. Microalgae also did not indicate any effect on milk mineral concentrations. Strikingly though, dairy cattle fed macroalgae had among other mineral concentrations that were raised, but not clinically relevant, vastly increased concentrations of iodine in their milk. This was shown to be dose-dependent, and therefore it would be reasonable to conclude that macroalgal feeding to dairy cattle could increase mineral milk quality in terms of iodine concentration in a controlled manner. High concentrations of iodine within the resulting milk due to phycological feeding was found to indicate possible pathogen resilience qualities that could be exploited for the production of milk within vulnerable context.