Effects of different levels of trace minerals premix in finisher diets on performance, immune system and meat lipid oxidation of chicken fed barley- or wheat-based diet

The present study was carried out to examine the effects of a trace mineral premix (MP) reduction or withdrawal from finisher diet (29–42 d) on performance, meat lipid oxidation, and immune system of chicks fed wheat- or barley-based diet. The diets were formulated based on wheat and barley for seven treatments and five replicates of each treatment. At 29 and 36 d, 4 birds from each replicate were injected with sheep red blood cells. The cell-mediated immunity was determined via phytohemagglutinin and dinitrochlorobenzene at 34 and 42 d of age. At 35 and 42 d of age, the oxidative stability was evaluated by thiobarbituric acid reactive substances on the thigh samples that were stored for 180 days at −20˚C. The reduction or withdrawal of MP from diets did not affect the performance or the immune system. Results of TBARS showed that lipid peroxidation of the treatment without MP was significantly higher than of the other treatments when slaughtered at 42 days of age. Finally, the results of this study demonstrated that it is not possible to remove the MP in finisher broilers’ diets without negative effects on meat quality during the time of freezing

The effect of earthworm (Eisenia foetida) meal with vermi-humus on growth performance, hematology, immunity, intestinal microbiota, carcass characteristics, and meat quality of broiler chickens

8 páginas, 8 tablas.The present investigation was aimed to evaluate the effect of varied amount of earthworm meal (EW) and vermihumus (VH) on the growth performance of broiler chickens. Three hundred 1-d-old broiler chickens were assigned to 5 starter treatments with 5 pens per treatment, and 12 broiler chickens per pen in a completely randomized design from d 0–14 of the study. Dietary treatments were [per kilogram dry matter (DM)]: control (0 g EW and 0 g VH/kg of DM), and the diets containing 10 g VH/kg of DM supplemented with 0, 10, 20, or 30 g EW/kg of DM. At the end of the study (d 42), one representative broiler chicken per pen, close to the average body weight, was selected for blood sampling using a sterile needle and heparinized vacuum tube. The outcomes of the study depicted the greater overall feed intake value in broiler chicken fed the control diet than those fed the diets containing VH or EW or both, and it decreased linearly and quadratically (P < 0.05) as the amount of EW supplementation increased. The average weight gain for the chickens was numerically increased as supplementation of EW was increased (linear, =0.3; quadratic P=0.4). On the other hand, overall feed conversation ratio was slightly greater (P=0.02) in broiler chickens fed the control diet, and it decreased linearly (P=0.03) as dietary EW supplementation increased. Additionally, the serum total protein, albumin, Ca, and P concentrations were lower in broiler chickens fed the control diet, and those variables increased linearly (P < 0.05) as dietary EW increased. In like manner, humoral immune response (except heterophil/lymphocyte ratio) and relative weights of immune organs were lower in broiler chickens fed the control diet. Remarkable differences were observed between carcass and ileum characteristics of broiler chickens under treatments. Varied concentrations of EW showed increased total counts of lactic acid bacteria (linear, P < 0.05; quadratic, P=0.3) and reduced population of pathogenic intestinal microbiota (linear, P 0.05). Similarly, the meat quality of broiler chicken was markedly affected linearly (P < 0.05) by the supplementation of increased dietary EW. Briefly, diets containing 30 g EW/kg of DM can positively affect the growth performance of broiler chickens and produce meat with better characteristics.We are grateful to the Islamic Azad University, Sanandaj Branch, Sanandaj, Iran for the financial and technical supports, and financial supports of Amize Tabiat Co (Iran) is also gratefully acknowledged.Peer reviewe

Intestinal microbiota associated with differential feed conversion efficiency in chickens

Analysis of model systems, for example in mice, has shown that the microbiota in the gastrointestinal tract can play an important role in the efficiency of energy extraction from diets. The study reported here aimed to determine whether there are correlations between gastrointestinal tract microbiota population structure and energy use in chickens. Efficiency in converting food into muscle mass has a significant impact on the intensive animal production industries, where feed represents the major portion of production costs. Despite extensive breeding and selection efforts, there are still large differences in the growth performance of animals fed identical diets and reared under the same conditions. Variability in growth performance presents management difficulties and causes economic loss. An understanding of possible microbiota drivers of these differences has potentially important benefits for industry. In this study, differences in cecal and jejunal microbiota between broiler chickens with extreme feed conversion capabilities were analysed in order to identify candidate bacteria that may influence growth performance. The jejunal microbiota was largely dominated by lactobacilli (over 99% of jejunal sequences) and showed no difference between the birds with high and low feed conversion ratios. The cecal microbial community displayed higher diversity, and 24 unclassified bacterial species were found to be significantly (<0.05) differentially abundant between high and low performing birds. Such differentially abundant bacteria represent target populations that could potentially be modified with prebiotics and probiotics in order to improve animal growth performance.Dragana Stanley, Stuart E. Denman, Robert J. Hughes, Mark S. Geier, Tamsyn M. Crowley, Honglei Chen, Volker R. Haring, Robert J. Moor