The Effect of Dietary Fat Composition and Post­Hatching Age On Micro-organisms of the Gastro Intestinal Tract (Git) In Broiler Chicks

Abstract

The effect of dietary fat sources differing in fatty acid composition and post-hatching age on the establishment of gut microflora in young broiler chicks was studied. The dietary treatments were Diet 1 (a commercial broiler diet), containing high levels of polyunsaturated fatty acids (PUFA) and free fatty acids  (FFA); Diet 2,  (a tallow  oil based  diet)    high in saturated fatty acids (SFA) and low levels of (FFA) and Diet 3, (soya bean oil based diet) high in PUFA but with low levels of FFA. One hundred and twenty day-old broiler chicks were randomly distributed to the three dietary treatments and fed the respective diets for 4 weeks. Feed and water were given ad libitum. The levels of Streptococci, Clostridia, Lactobacilli and Coliform species were determined in the duodenum, ileum and caecum on days 1, 7, 14 and 26 post-hatch. The bacterial population was low in all gut segments on   day 1 post-hatch but progressively increased for most of the species to the 14th day post-hatch. However decreasing levels of most species was noted thereafter. Dietary fat composition had an effect on the level and type of microorganisms present in the gut. On day 7 post-hatch the level of Streptococci and Coliform species were highest in chicks fed Diet 3 whereas Lactobacilli species were higher in chicks receiving Diet 1 and Diet 2. The number and type of bacterial species studied varied between the gut segments. Most of the bacterial species studied were highest in the caeca and lowest in the duodenum. The present study has shown that the GIT flora in chicks is low at hatching, but rapid establishment occurs soon after hatching and is to some extent influenced by nutrient composition