Effects of an emulsifier blend supplementation on growth performance, nutrient digestibility, intestinal morphology, and muscle fatty acid profile of broiler chickens fed with different levels of energy and protein.

The effects of emulsifier blend (EB) supplementation of diets with various levels of metabolizable energy (ME) and crude protein (CP) on broiler performance, digestibility, gut morphology, and muscle fatty acid profile were investigated over a 42-d period. Diets were arranged factorially (2 × 2 × 3) and consisted of 2 levels of ME (normal [commercially recommended levels] and low [100 kcal/kg reduction in dietary ME]), 2 levels of CP and limiting amino acids (normal [commercially recommended levels] and low [95% of the normal CP level]), and 3 levels of EB supplementation (0, 1, and 2 g/kg of diet). A total of 1,200 one-day-old male broiler chickens (Ross 308) were randomly assigned to 12 treatment groups (5 pens/treatment with 20 birds/pen). Supplemental EB linearly improved (P < 0.05) final body weight, overall average daily gain, and feed conversion ratio, but the magnitude of the responses was greater in low-ME and low-CP treatments, resulting in significant ME × CP × EB interactions. Similarly, the inclusion of EB in the diet, particularly at 2 g/kg, increased the ileal digestibility of crude protein and crude fat, as well as the AMEn value (P < 0.05), but the response was greater at lower ME concentration, indicating significant ME × EB interactions. Additionally, there were CP × EB interactions (P < 0.05) for duodenal villus height and villus height/crypt depth ratio, indicating that the effect of EB on these responses was more marked at lower dietary CP levels. An increase in dietary EB levels was accompanied by a linear increase in the concentration of total saturated fatty acids and a linear decrease (P < 0.05) in the concentrations of total polyunsaturated fatty acids in both breast and thigh meat. In conclusion, the positive effects of EB supplementation, particularly at a dietary inclusion level of 2 g/kg, were clearly evident in broiler chickens fed with low nutrient diets (-100 Kcal/kg ME and/or -5% CP and limiting amino acids) in terms of growth performance, nutrient digestibility, and gut morphology.

Effects of Scrophularia striata hydroalcoholic extract in comparison to salinomycin on growth performance, intestinal health and immunity in broiler chickens following a mixed-species Eimeria challenge.

Poultry coccidiosis is an important disease affecting performance which is characterized by intestinal epithelium damageand increased mortality and is caused by the protozoa parasites of the genus Eimeria. This study evaluated the growth-promoting (experiment 1), protective, and immunostimulatory effects (experiment 2) of salinomycin and Scrophularia striata hydroalcoholic extract (SSE) against coccidiosis in broilers. Two experiments were conducted with 300 1-day-old broiler chickens, which were randomly assigned to 5 treatments with 6 replicate pens of 10 birds (experiment 1) or 10 replicate cages of 6 birds (experiment 2). In both experiments, treatments were: negative control (NC: untreated, and uninfected); positive control (PC: untreated, infected); or PC supplemented with salinomycin (Sal); 200 mg/kg of SSE (SSE200); or 400 mg/kg of SSE (SSE400). All these groups (except NC) were challenged via oral gavage with of sporulated oocysts of Eimeria species (Eimeria acervulina, Eimeria maxima, and Eimeria tenella) on d 10 (experiment 1) or d 14 (experiment 2). In the first trial, all treatments improved growth and feed conversion compared with the PC group, where the best values were noticed in the NC, SAL, and SSE400 groups throughout the entire experimental period (d 1-42). Further, a lower mortality rate (P < 0.05) was observed in the NC, Sal, and SSE400 groups as compared to that in the PC group. In the second trial, intestinal lesion scores and total oocyst numbers were reduced in the Sal and SSE400 groups compared to the PC group, although all coccidiosis-challenged groups had higher intestinal lesion scores (P < 0.05) compared to NC group. Immune responses revealed that among challenged birds, those fed diets Sal and SSE400 had significantly higher Eimeria-specific cecum IgG and IgM levels, but lower serum IFN-γ concentration than the PC group. Among the experimental treatments, broiler chickens fed diet SSE400 had greater (P < 0.05) Eimeria-specific serum IgG and TGF-ß levels, but lower (P < 0.05) serum IL-6 concentration than those fed the PC diet at d 24. Considering the results, dietary SSE, especially at high levels of inclusion in broiler diet (400 mg/kg), could result in a comparable growth performance and a better immune response, compared to a salinomycin supplement under coccidiosis challenge.

Effect of Scrophularia striata and Ferulago angulata, as alternatives to virginiamycin, on growth performance, intestinal microbial population, immune response, and blood constituents of broiler chickens.

An experiment was conducted to investigate the comparative effect of Scrophularia striata, Ferulago angulata, and virginiamycin (VM) on performance, intestinal microbial population, immune response, and blood constituents of broilers. A total of 300 Ross 308 male broiler chickens were randomly assigned to 5 treatments, with 5 replicates/treatment (10 chickens/pen). Birds were fed either a corn-soybean meal basal diet (control) or the basal diet supplemented with 200 mg/kg VM; 4 g/kg S. striata (SS1); 8 g/kg S. striata (SS2); 4 g/kg F. angulata (FA1); or 8 g/kg F. angulata (FA2). After 6 wk, the BW, ADG, and feed-to-gain ratio (F:G) of the VM, SS1, and FA1 groups were better (P<0.01) compared with the control group. At 42 d, cecal lactobacillus counts were higher (P=0.032) in SS2 and FA2 groups compared with the control and VM groups. In addition, broilers fed any of the diets exhibited lower coliform counts (P<0.05) in the ileum and ceca than those fed the control diet. Total and IgG antibody titers against SRBC for secondary responses, relative spleen weight, and lymphocyte counts were higher (P<0.05) in birds fed the SS2 or FA2 diet compared with the control group. Moreover, feeding the SS2 or FA2 diet decreased (P<0.05) the blood heterophil/lymphocyte ratio and plasma triglyceride level, whereas only the SS2 diet increased (P=0.037) the white blood cell counts compared with the control diet. All diets, except for the VM diet, decreased (P=0.009) the plasma cholesterol level compared to the control treatment. The plasma high-density lipoprotein cholesterol level was also increased (P=0.042) in the SS2 and FA2 groups. In conclusion, dietary S. striata or F. angulata at a level of 4 g/kg diet enhanced growth performance, which was comparable to that of VM used as an antibiotic growth promoter. Furthermore, a high dose of both herbs (8 g/kg diet) could beneficially affect the intestinal health and immune status of broilers.