Probiotics as feed supplements to enhance mink kit growth and survival

摘要

The microflora of the gastrointestinal tract is an important component of the health of animals. The growth and metabolism of both pathogenic and beneficial bacteria that inhabit the gut depends, to a large extent, on the substrate provided by the diet. Probiotics, which are live microbial food supplements consisting of non-pathogenic and non-toxigenic bacteria (or yeasts), have been shown to modify the structure and metabolic activity of the microflora of the large intestine leading to an improvement in the performance of animals. These beneficial organisms retain their viability during storage (including freezing) and during passage through the gastrointestinal tract to the site of action in the large intestine (Macfarlane and Cummings, 1999). However, because probiotic bacteria do not permanently colonize the gut of animals, they must be fed regularly to provide prolonged health benefits. Probiotic preparations usually consist of a combination of beneficial bacteria, such as lactobacilli and bifidobacteria, that facilitate the breakdown of dietary carbohydrates and help maintain and improve the microfloral balance of the gut (Macfarland and Cummings, 1999; Gibson and Fuller, 2000; Rolfe, 2000). Depending upon the species and strain(s) of bacteria, they may also synthetize and excrete water soluble vitamins. Some probiotics are reported to reduce the risk of urogenital tract infections, decrease the incidence and duration of certain types of diarrhea, help maintain mucosal integrity, and/or stimulate the immune system (Macfarlane and Cummings, 1999; Klaenhammer, 2000; Sanders, 2000). The potential benefits provided by probiotics are reported to include improved feed efficiency, increased growth rate, enhanced lactation, and reduced mortality(Fuller, 1998).