"Investigation of the effect of organic acid water treatment on colonization of broiler chickens with Campylobacter spp during rearing and thinning."
Colonization of the digestive tract by environmental sources of Campylobacter spp relies upon the passage of the bacteria through the upper digestive tract to the large intestine, caecum and cloaca. Evidence that Campylobacter sp may be sensitive to particular organic acids suggested that the provision of these acids in the drinking water around the time of thinning could help in reducing colonization of the gut at this time. The trial was run in four identical broiler sheds on a single site. The birds in two of the sheds were treated with water containing a blend of organic acids (methionine hydroxyl analogue, formic acid and propionic acid, Activate WD Max®) starting at 22 days until the end of the trial (Day 46). Thinning was carried out at Day 36. The other two sheds acted as control with no dosing in the water. Apart from the organic acid treatment all birds were reared with the same management regime. Campylobacter spp were monitored by taking bootsocks from the litter of all houses before thinning and by sampling the caecal contents of 20 birds per shed at the abattoir at thinning and at final clearance. None of the birds in any of the houses was colonized by Campylobacter spp at thinning (< 10 cfu/g caecal contents) and all bootsocks were negative. At final clearance all 20 samples of caecal contents from each of the two control sheds showed very high numbers of Campylobacter spp (log10 7.6-9.3 cfu/g). There was no significant difference between the two control sheds. Numbers of Campylobacter spp in the caecal samples from the two treated sheds were inversely all below the level of detection (<10 cfu/g). These preliminary results indicate that the use of Activate WD Max® in drinking water around the thinning period can reduce colonization of the broiler large intestine by Campylobacter spp resulting in a lower risk of transfer of the pathogen into the food chain.
"Effect of dietary protein and protease supplementation on performance and gut health of broiler chicks."
Effect of dietary protein level and protease supplementation on performance and gut health was evaluated in two studies. For study 1, 288 broilers were used to examine effect of normal crude protein (CP) vs high CP (22% vs 30%) without or with protease (CIBENZA® DP100, Novus International Inc.) supplementation in a 2 X 2 factorial arrangement. Each test diet was fed to 9 replicate pens of 8 birds from 0 to 28 d. All diets contained 20% rye and 25% wheat, high CP diets had 14% poultry meal, and all birds were given a cocci challenge (10X immunizing dose) on d 7. In the absence of protease, increasing dietary CP increased ileal Clostridium perfringens by 2 logs (2.35 vs 4.34) and with protease supplementation no CP effect was seen (2.09 and 2.30 for normal and high CP), accounting for a significant interaction. Protease was also associated with increased growth efficiency in the gut and reduced systemic inflammation demonstrated by improved crypt villus ratio and lower serum-1 glycoprotein level. For study 2, 3 corn soy DDGS based diets - normal CP, low CP (7% less), and low CP + protease, were fed to birds under two stress conditions normal (21 birds per pen) and stress (8-hr feed outage on d 0 and d 14, 25 birds per pen). Each test diet was fed to 8 replicate pens. Under normal condition, body weight was not affected by dietary CP at d 14 and 27 whereas under stress condition, birds fed normal CP actually weighed less. Under normal condition, broilers on normal CP had better 0-14 d FCR than those on low CP, but under stress condition, no significant difference was observed. Protease improved FCR throughout the trial and the response tended to be greater under stress condition from 0 to 14 d. In summary, undigested protein in the gut either from excessive CP supply or comprised gut function by stress could cause gut dysbacteriosis by promoting Clostridium perfringens growth and reduce performance and protease can alleviate these negative effects through improving protein digestion in young broilers.