Sherief M. Abdel-Raheem

Effects of dietary inclusion of probiotic and synbiotic on growth performance, organ weights, and intestinal histomorphology of broiler chickens

A feeding trial was conducted to investigate the effects of dietary supplementations of synbiotic and probiotic on broiler performance, carcass yield, organs weights, and histomorphological measurements of small intestine. Six hundred 1-d-old broiler chicks were randomly assigned to 1 of 3 dietary treatments for 5 wk. The dietary treatments were 1) control, 2) basal diets supplemented with synbiotic (1 kg of Biomin IMBO/ ton of the starter diets and 0.5 kg/ton of the grower diets), 3) basal diets supplemented with probiotic (1 kg of a homofermentative and a heterofermentative Lacto-bacillus sp./ton of feed). The BW, average daily weight gain, carcass yield percentage, and feed conversion rate were significantly (P < 0.05) increased by the dietary inclusion of the synbiotic compared with the control and probiotic-fed broilers. Moreover, a slight improvement in performance traits was observed in broilers fed the probiotic compared with control birds. The absolute and relative weight of spleen and thymus tended to be greater (P < 0.1) for the probiotic-supplemented group compared with the synbiotic-supplemented group. The relative liver weight was greater (P < 0.05) for probiotic-fed birds compared with synbiotic-fed birds. Additionally, the weight of small intestine was greater for either probiotic- (3.17) or synbiotic-fed birds (3.11) than the controls (2.89). Furthermore, dietary treatments influenced the histomorphological measurements of small intestinal villi. The addition of either probiotic or synbiotic increased (P < 0.05) the villus height:crypt depth ratio and villus height in both duodenum and ileum. The duodenal crypt depth remained unaffected (P > 0.05). However, the ileal crypt depth was decreased by dietary supplementations compared with control. In conclusion, synbiotic or probiotic displayed a greater efficacy as growth promoters for broilers. Furthermore, the dietary supplementations resulted in an increase in the villus height and crypt depth of intestinal mucosa of broilers. The increase in the villus height and villus height:crypt depth ratio was associated with improvement of growth performance for both synbiotic and probiotic. This indicates that the synbiotic and probiotic can be used as a growth promoter in broiler diets and can improve the gut health. These products show promising effects as alternatives for antibiotics as pressure to eliminate growth-promotant antibiotic use increases.

Long-term influence of feeding barley treated with lactic acid and heat on performance and energy balance in dairy cows.

ABSTRACT The study evaluated the long-term influence of feeding ground barley treated with lactic acid (LA) alone or with LA and heat on performance, energy and protein balance in dairy cows. Thirty cows were fed three diets differing in the treatment of barley grain, either unprocessed ground barley (Control), ground barley steeped in 1% LA at room temperature (LA-treated barley) or ground barley steeped in 1% LA with an additional heating at 55°C (LAH-treated barley). Cows were studied from week 3 to 17 post-partum. Dry matter intake (DMI), milk yield and composition and body weight (BW) were measured daily. Estimated energy and protein balances were calculated and blood samples were collected three times during the experiment and analysed for common metabolites of energy and lipid metabolism. Digestibility of different treated barley and other dietary ingredients was investigated in vivo using four wethers. The treatment of barley with LA and LAH increased the digestibility of organic matter (OM) by approximately 5% and the content of metabolisable energy by 0.5–0.6 MJ/kg DM. Data showed no effect of feeding diets containing LA- or LAH-treated barley at 39% of DM on overall DMI, BW, BW change, milk production and composition and on the blood variables studied. Diet influenced the estimated balances of net energy of lactation (p < 0.01) and the content of utilisable protein at the duodenum (p = 0.07) with cows fed the diet with LA-treated barley showing improved balances. In conclusion, feeding diets containing LA- or LAH-treated barley had no influence on performance, milk composition and blood metabolites, but LA treatment without heat seems to improve the energy balance of cows.