A meta-analysis of the feed intake and growth performance of broiler chickens challenged by bacteria

Abstract

The aim of this meta-analysis was to determine the effect of a bacterial immune challenge (Clostridium spp., Escherichia coli, and Salmonella spp.) on the ADFI, ADG, and nutrient partitioning (maintenance requirements and feed efficiency) of broiler chickens. The database used for the meta-analysis included 65 articles that were published between 1997 and 2012 concerning a total of 86,300 broilers and containing information on the feed intake, protein intake, methionine intake, and weight gain of broilers that were challenged with Clostridium spp., E. coli, or Salmonella spp. and were fed or not fed feed additives. The results of the ADFI and the ADG of the challenged broilers were transformed into values relative to those obtained in control broilers (ADG and ADFI). The meta-analysis involved 3 sequential analyses: graphical, correlation, and variance-covariance analysis. The results obtained for the birds that were challenged with Clostridium spp., E. coli, or Salmonella spp. indicated that the ADFI was reduced by 16, 7, and 9%, respectively, and the ADG was reduced by 40, 10, and 29%, respectively. When the results for the challenged birds that were treated or nontreated were compared, ADFI reductions of 26.0 and 26.5% and ADG reductions of 2.9 and 21.6% were observed, respectively. Regression analyses of the ADG as a function of the protein or methionine intake of the challenged birds suggested that nutrients were diverted to the immune system. The relationship between the ADG and the ADFI was quadratic in the challenged and nontreated or treated broilers, as well as for each disease. The intercept of the regression-based curves for the data from all of the challenges were different from zero and negative (-2.20, -0.70, and -3.37, respectively), indicating that all of the challenges increased the maintenance requirements. In general, this meta-analysis allowed for the quantification of the effects of bacteriological challenges on the maintenance and feed efficiency of broiler chickens, and the knowledge that was generated in this study is applicable to broiler nutrition and for modeling their nutritional requirements.

Impact of dietary Mannan-oligosaccharide and β-Glucan supplementation on growth, histopathology, E-coli colonization and hepatic transcripts of TNF-α and NF- ϰB of broiler challenged with E. coli O78

“…In the present study, the control infected group with E. coli showed varied clinical signs according to their age, an organ involved, and concurrent disease conditions. Results of Clinical signs in the E. coli infected groups (even in the treated one) similar to results of Remus et al [12] who recorded severe liver damage occurs in cases of E. coli infection. However, dietary supplementation of agrimos ® decreased the clinical signs and PM lesions.…”

“…[33]. Remus et al[12] reported E. coli caused severe liver and epithelial damage. However, agrimos ® supplementation to broilers revealed no pathological changes.…”

Meta-analysis of individual and combined effects of mycotoxins on growing pigs

“…The partition between these two effects was calculated using (1) the adjusted ΔG mean (obtained from previously fitted equations) and (2) the ΔFI mean observed in the database. A similar interpretation has been used in previous studies on health challenges (Pastorelli et al, 2012;Remus et al, 2014).…”

Produção de suínos machos em crescimento: uma meta-análise

“…Os resultados médios obtidos foram ajustados por covariância para o peso vivo dos animais (peso médio nas variáveis de desempenho e peso ao abate nas variáveis de carcaça). Os interceptos das equações que estimavam o consumo diário de lisina total (expresso em g/dia) em função do ganho diário de peso (expresso em g/dia) dos animais foram utilizados empiricamente como indicadores da exigência de mantença dos animais, uma vez que expressam o nível de consumo do nutriente no qual o ganho de peso é nulo (REMUS et al, 2014). Todas as análises foram realizadas através do programa MINITAB 15.…”