Dairy goats and sheep represent today an important fraction of the animal production chain in many south European and Middle Eastern regions, with high value milk mainly destined for the domestic cheese industry.
According to the FAO, goat livestock worldwide has increased by about 50 percent in the last 20 years, reaching over 800 million heads in 2005. Dairy goat production has intensified, and farmers are now facing the same kind of problems commonly experienced by dairy cow farmers such as acidosis.
The same can be said of sheep (total world sheep population in 2005 was over 1 billion), with producers more and more concerned about increasing value of their forages while preserving milk quality and hygiene, as well as animal health and longevity, to ensure optimal revenue.
Nevertheless, until now, most of the ruminant research and field trials have been performed in bovines, with less data available on "small ruminants". As a result, no solution is currently available to answer to the growing needs of dairy small ruminant farmers in a natural way.
This article presents recent evidences of the action of probiotic yeast in dairy goats and ewes, showing benefits to both performance and health of dairy small ruminants.
In dairy goats, the effects of ruminant-specific yeast strain Sacharromyces cerevisiae I-1077 (Levucell SC, Lallemand, France) was assessed in around 10 independent trials, involving over 1,000 goats in total. These trials covered different production systems, different environments and various diets and breeds, from western France to southern Italy.
Even though the impact of SC I-1077 supplementation on milk yield varies between trials, the overall tendency is consistent. On average, milk yield is significantly increased by 9 percent (ranging from +4 to +15 percent), with up to 260g/head/day extra milk produced.
Most importantly, this increase does not lead to a decrease in milk quality: fat and protein contents remain unchanged, resulting in an overall increase of total fat and protein yield when Levucell SC I-1077 is supplemented. This extra milk yield has no negative impact on either body score condition or plasma metabolites contents, as shown by Stella et al. (2007). The same conclusions were drawn from dairy ewe trials.
As shown by the increase in feed efficacy, the effect of yeast on milk yield in both species is most probably linked to better feed utilisation due to the metabolic activity of the yeast in the rumen and its interactions with the rumen microflora.
SC I-1077 has been shown to improve fibre digestion and nitrogen metabolism, and its mode of action is now well described. Feed utilisation and feed intake are optimised by rumen activity of the specific yeast strain, resulting in higher fat, protein, and finally milk yield, without affecting the lactating animal body condition score.
Other parameters can also play a part in animal response to the live yeast additive: animal characteristics, environment and the diet. This can explain why the observed increase in milk production varied between trials, especially in the case of dairy goats.
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Article made possible through the contribution of Lallemand Animal Nutrition.