Growth Performance Of Poultry Research Articles

RETRACTED ARTICLE: Antibiotic growth promoters virginiamycin and bacitracin methylene disalicylate alter the chicken intestinal metabolome

Although dietary antibiotic growth promoters have long been used to increase growth performance in commercial food animal production, the biochemical details associated with these effects remain poorly defined. A metabolomics approach was used to characterize and identify the biochemical compounds present in the intestine of broiler chickens fed a standard, unsupplemented diet or a diet supplemented with the antibiotic growth promoters, virginiamycin or bacitracin methylene disalicylate. Compared with unsupplemented controls, the levels of 218 biochemicals were altered (156 increased, 62 decreased) in chickens given the virginiamycin-supplemented diet, while 119 were altered (96 increased, 23 decreased) with the bacitracin-supplemented diet. When compared between antibiotic-supplemented groups, 79 chemicals were altered (43 increased, 36 decreased) in virginiamycin- vs. bacitracin-supplemented chickens. The changes in the levels of intestinal biochemicals provided a distinctive biochemical signature unique to each antibiotic-supplemented group. These biochemical signatures were characterized by increases in the levels of metabolites of amino acids (e.g. 5-hydroxylysine, 2-aminoadipate, 5-hydroxyindoleaceate, 7-hydroxyindole sulfate), fatty acids (e.g. oleate/vaccenate, eicosapentaenoate, 16-hydroxypalmitate, stearate), nucleosides (e.g. inosine, N6-methyladenosine), and vitamins (e.g. nicotinamide). These results provide the framework for future studies to identify natural chemical compounds to improve poultry growth performance without the use of in-feed antibiotics.

Effects of direct-fed microorganisms and enzyme blend co-administration on intestinal bacteria in broilers fed diets with or without antibiotics.

Direct-fed microorganisms (DFM) and exogenous enzymes have been demonstrated to improve growth performance in poultry and are potentially important alternatives to antibiotic growth promoters (AGP). We investigated the administration of a feed additive composed of a DFM product containing spores of 3 Bacillus amyloliquefaciens strains and an enzyme blend of endo-xylanase, α-amylase, and serine-protease in diets with or without sub-therapeutic antibiotics in broiler chickens over a 42-d growth period. Evaluation of growth performance determined feed efficiency of broiler chickens which were administered the feed additive was comparable to those fed a diet containing AGPs. Characterization of the gastrointestinal microbiota using culture-dependent methods determined administration of the feed additive increased counts of total Lactic Acid Bacteria (LAB) relative to a negative control and reduced Clostridium perfringens to levels similar to antibiotic administration. Additionally, greater counts of total LAB were observed to be significantly associated with reduced feed conversion ratio, whereas greater counts of C. perfringens were observed to be significantly associated with increased feed conversion ratio. Our results suggest the co-administration of DFMs and exogenous enzymes may be an important component of antibiotic free poultry production programs and LAB and C. perfringens may be important targets in the development of alternatives to AGPs in poultry production.

Peroxidized lipids reduce growth performance of poultry and swine: A meta-analysis

Animal performance is affected by feeding peroxidized lipids. Nevertheless, inaccuracies and limitations of common lipid peroxidation analyses are associated with inconsistent results regarding animals consuming diets with peroxidized lipids. A comprehensive meta-analysis was conducted to determine the effects of feeding dietary peroxidized lipids on growth performance and oxidative status in poultry and swine. A total of 29 publications with 42 poultry and 23 swine observations were analyzed. Concentration of dietary thiobarbituric acid reactive substances (TBARS) and peroxide value (PV), along with ADG, ADFI, G:F, and serum or plasma concentrations of vitamin E and TBARS were obtained from publications when reported. The relative impact of feeding peroxidized lipids was calculated as a percentage of ADG, ADFI, and G:F relative to responses from feeding isocaloric diets containing unperoxidized lipids. Data were analyzed for outliers, general distribution, and correlations among variables. Overall, feeding peroxidized lipids to both species resulted in a 5% reduction in ADG, a 3% reduction in ADFI, and G:F was reduced by 2% compared with feeding unperoxidized lipids. The difference in the average magnitude of reduction in ADG, compared with less average magnitude of reduction in ADFI, suggests that factors other than caloric intake (i.e. oxidative stress) contribute to reduced ADG when feeding peroxidized lipids. Both species fed peroxidized lipids had reduced serum or plasma vitamin E content (52%) and increased TBARS concentration (120%) relative to animals fed unperoxidized lipids, suggesting that feeding peroxidized lipids contributes to increased oxidative stress. Dietary PV was negatively correlated with ADG (r=− 0.81, P<0.01) for poultry, whereas for swine, dietary TBARS was negatively correlated with ADG (r=− 0.58, P=0.04), but there were large prediction errors for poultry (MSE=0.87) and swine (MSE=12.79). In conclusion, these results suggest that feeding peroxidized lipids reduce growth performance of poultry and swine, but the magnitude of reduction varies among experiments due to differences in fatty acid profiles among types of lipid sources, time and temperature of peroxidation conditions, and relative growth responses among studies. More accurate peroxidation measurement methods need to be developed to accurately estimate the negative impacts of feeding peroxidized lipids on animal growth performance.

Alpha-lipoic acid: An inimitable feed supplement for poultry nutrition.

Alpha-lipoic acid (ALA) is a multifunction antioxidant that is produced in small amount by cells as well as its dietary provision facilitates fatty acid mobilization, energy expenditure as well as can scavenge free radicals in poultry birds. It exists in oxidized as well as reduced form, characterized by growth promoting, anti-inflammatory, antioxidative, immunostimulatory, and hypocholesterolemic properties when fed as dietary supplement to farm animals particularly chicken birds. Recently, several studies reported that dietary supplementation of ALA can influence growth performance indicators, immunological, biochemical characteristics, lipid metabolism, and oxidative stress as well as increase antioxidant potential and storability of poultry meat and meat products. Accordingly, this paper adds the reviews and discusses the outcomes of studies documenting the effect of lipoic acid dietary fortification on growth performance, biochemical, and immunological characteristics as well as the effects on lipid peroxidation of fresh meat and meat-based products. Furthermore, this paper also describes the possibilities of utilization of ALA as a feed additive in poultry nutrition to improve the growth performance of poultry as well as meat quality of resultant chicken birds.

Efficacy of feed enzymes in pig and poultry diets containing distillers dried grains with solubles: a review.

Distiller's dried grains with solubles (DDGS), a coproduct of the ethanol industry, are often used as feed material in livestock and poultry nutrition. Results of many experiments have indicated, however, that a high dietary level of DDGS can negatively affect the digestibility of nutrients and the performance of monogastric animals due to their high content of non-starch polysaccharides (NSP). Nevertheless, using high levels of DDGS as a protein source in livestock diets can be still economically justifiable in view of the rising prices of soya bean meal and other protein sources. The aim of some recent experiments with poultry and pigs was to improve the nutritional efficacy of high-NSP diets through the addition of feed enzymes. As presented and discussed in this review article, the efficacy of feed enzymes added to poultry and pig diets containing DDGS is not consistent and depends on many factors. However, NSP-hydrolysing enzymes generally seemed to be more efficient than phytases in terms of the digestibility of nutrients and the growth performance of poultry and pigs fed high-DDGS diets. For this reason, supplementation with NSP-hydrolysing enzymes could be an efficient way to enable the use of increased levels of DDGS in poultry and pig diets.

Seasonal Broiler Growth Performance Prediction Based on Observational Study

For the modern poultry breeding companies, it is worthwhile to predict the poultry growth performance parameters to help future production and management. Most of the existing literature of broiler growth performance is based on well designed experiment. However, for the farmers who carry on the large scale breeding all the year round, it is impractical to adjust all the ambient factors to suitable levels systematically like in the laboratory. In this case, it requires an observational study based on the massive historical data gradually cumulated in production. In this paper, observational study is proposed for seasonal broiler growth performance prediction. Systematic observational study with statistical analysis and data mining technology is adopted including macro analysis, exploratory data analysis, and modeling. Case study using the broiler growth dataset of the most famous poultry raising company in China shows the effectiveness of our approach.

Effects of Thyme Essential Oil on Performance, Some Blood Parameters and Ileal Microflora of Japanese Quail

The ban on the use of antibiotics as growth promoters has stimulated the search for alternative feed supplements in poultry production. The active principles of thyme essential oil act as a digestibility enhancer, balancing the gut microbial ecosystem and stimulating the secretion of endogenous digestive enzymes and thus improving growth performance in poultry (Lovkova et al., 2001; Williams and Losa, 2001). A study was performed to investigate the effects of thyme essential oil (TEO) on performance, carcass characteristics, some blood parameters and ileal microflora of Japanese quail. This study lasted 35 days of age. One hundred and fifty day-old male Japanese quail chicks in a completely randomized design with two treatments (with or without 1 g/kg TEO) and five replicates of 15 birds each were used. All parameters were measured at the end of the experiment. The supplementation of TEO significantly (P<0.05) increased live body weight and relative weights of carcass and breast, lowered serum triglyceride, total cholesterol and glucose and improved ileal microflora. It was concluded that the addition of 1 g/kg TEO might offer some beneficial effects on Japanese quail to increase live body weight and improve some blood parameters and gut miroflora.

Mechanistic modeling of turkey growth response to genotype and nutrition

Along with the fast genetic improvement, nutritional and environmental effects on poultry growth performance have made it necessary to develop growth models that have the flexibility to adapt to different genotypes and growing conditions. A mechanistic simulation model of energy and nutrient utilization in growing turkeys is presented herein. The model consists of simulating the average homeorhetic and homeostatic regulations associated with the utilization of circulating glucose, fatty acid, AA, and acetyl-CoA for protein and lipid retention in carcass, viscera, and feathers in a turkey population. Homeorhesis plays a major role in the control of protein and lipid turnover for the definition of genetic potential and feed intake, whereas homeostasis adjusts growth rate through protein and lipid turnover rates and, therefore, BW gain and feed intake to the growing conditions. Also, homeostasis enables the maintenance of a dynamic balance state during all the growing period through the control of circulating nutrient concentration. The model was developed and calibrated with experimental data that described energy utilization in male and female growing turkeys. Then, the ability of the model to adapt to genotypes and to predict the average response of a turkey population to dietary energy was evaluated. Model calibration showed simulations of energy and nutrient utilization that fitted well with the experimental data because ME was satisfyingly partitioned into heat production and energy retention as protein and lipid, and nutrient intake accurately partitioned BW gain into carcass, viscera, and feathers. The evaluation of the model was also satisfactory because BW gain and feed-to-gain ratio were globally in accordance with the observations in different male and female genotypes, in spite of an overestimation of the feed-to-gain ratio during the first weeks of age. Model evaluation showed that the BW gain and feed intake response of growing turkeys to dietary energy was accurately predicted. The model can therefore be used in different growing conditions as it is capable of simulating the growth of different turkey genotypes fed under changing environmental and nutritional contexts.

Quantification of Karanjin, Tannin and Trypsin Inhibitors in Raw and Detoxified Expeller and Solvent Extracted Karanj (Pongamia glabra) Cake

Despite being a rich source of protein (28-34%), karanj (Pongamia glabra) cake is found to be bitter in taste and toxic in nature owing to the presence of flavonoid (karanjin), tannin and trypsin inhibitor, thereby restricting its safe inclusion in poultry rations. Feeding of karanj cake at higher levels (>10%) adversely affected the growth performance of poultry due to the presence of these toxic factors. Therefore, efforts were made to detoxify karanj cake by various physico-chemical methods such as dry heat, water washing, pressure cooking, alkali and acid treatments and microbiological treatment with Sacchraromyces cerevisiae (strain S-49). The level of residual karanjin in raw and variously processed cake was quantified by high performance liquid chromatography and tannin and trypsin inhibitor was quantified by titrametric and colorimetric methods, respectively. The karanjin, tannin and trypsin inhibitor levels in such solvent and expeller pressed karanj cake were 0.132, 3.766 and 6.550 and 0.324, 3.172 and 8.513%, respectively. Pressure-cooking of solvent extracted karanj cake (SKC) substantially reduced the karanjin content at a cake:water ratio of 1:0.5 with 30-minute cooking. Among chemical methods, 1.5% (w/w) NaOH was very effective in reducing the karanjin content. Ca (OH) 2 treatment was also equally effective in karanjin reduction, but at a higher concentration of 3.0% (w/w). A similar trend was noticed with respect to treatment of expeller pressed karanj cake (EKC). Pressure cooking of EKC was effective in reducing the karanjin level of the cake. Among chemical methods alkali treatment [2% (w/w) NaOH] substantially reduced the karanjin levels of the cake. Other methods such as water washing, dry heat, HCl, glacial acetic acid, urea-ammoniation, combined acid and alkali, and microbiological treatments marginally reduced the karanjin concentration of SKC and EKC. Treatment of both SKC and EKC with 1.5% and 2.0% NaOH (w/w) was the most effective method in reducing the tannin content. Among the various methods of detoxification, dry heat, pressure cooking and microbiological treatment with Saccharomyces cerevisiae were substantially effective in reducing the trypsin inhibitor activity in both SKC and EKC. Based on reduction in karanjin, in addition to tannin and trypsin inhibitor activity, detoxification of SKC with either 1.5% NaOH or 3% Ca (OH) 2 , w/w) and with 2% NaOH were more effective. Despite the effectiveness of pressure cooking in reducing the karanjin content, it could not be recommended for detoxification because of the practical difficulties in adopting the technology as well as for economic considerations.

Effect of extrusion of corn and feed form on feed quality and growth performance of poultry in a tropical environment

Two experiments were conducted to study the effect of corn extrusion and feed form on feed quality and growth performance of broilers. In experiment 1, whole corn was extruded at a water flow rate of 16, 19, and 22 L/h. The experimental design was a completely randomized design with 3 replications for each treatment. The extrusion process significantly decreased (P < 0.01) ether extract, crude fiber, and moisture content of corn. Increased water flow significantly decreased enzyme susceptibility from 56 to 47% (P < 0.01), but increased the bulk density of extrudate from 134 to 224 g/L (P < 0.01). However, there was a trend for lower total energy consumption (P < 0.01) and extruding production rate (P < 0.05) when corn was processed at the water flow of 22 L/h. In Exp. 2, 1,600 broilers (initially BW of 41 g) were used to determine the effect of extrudate and feed form on the growth performance in poultry during a 42-d growth assay. There were 50 chicks per pen and 8 pens per treatment. Treatments were arranged in a 2 x 2 factorial arrangement with the main effect of feed form and the main effect of 25% processed corn inclusion. Treatments were 1) conventional corn mash, 2) conventional corn pelleted feed, 3) +25% extruded corn mash, and 4) +25% extruded corn pelleted feed. Chicks fed pelleted feed, regardless of processing of corn, had a greater BW and feed conversion than those fed mash feed diet (P < 0.001). Extruded corn mash decreased the growth performance. Results suggested that optimal growth rate and feed conversion of birds raised in a tropical environment given extruded corn might be achieved by steam pelleting.

Effects of mushroom and herb polysaccharides, as alternatives for an antibiotic, on growth performance of broilers

1. This in vivo trial was conducted to study the effects of polysaccharide extracts of two mushrooms, Lentinus edodes (LenE) and Tremella fuciformis (TreE), and a herb, Astragalus membranaceus (AstE) on growth performance, and the weights of organs and the gastrointestinal tract (GIT) of broiler chickens. 2. Three extracts (LenE, TreE and AstE) were supplemented at inclusion rates of 0·5, 1, 2, 3 and 4 g/kg from 7 to 14 d of age and compared with an antibiotic treatment group (20 mg/kg, virginiamycin (VRG) as well as a group of non-supplemented birds. 3. Body weight (BW) gain, feed intake and feed conversion ratio (FCR) of the extract-supplemented groups were not significantly different from those of the antibiotic group. Significant effects of type of extract and concentration on growth performance were found from 7 to 28 d of age. Generally, birds fed with LenE showed higher BW gain and lower FCR from 7 to 28 d of age than those fed with TreE and AstE and 2 g/kg LenE was considered the optimal inclusion rate for enhanced broiler growth. However, the extracts had no significant effect on the relative weights of organs and GIT compared with the antibiotic group. 4. The birds fed the extracts showed better growth performance than the non-supplemented birds, but were not significantly different from those fed VRG. Of the three extracts, LenE appeared to be a potential growth promoter. Future studies are needed to investigate whether the extracts can be used as alternatives for antibiotic growth promoters in challenged birds, and to elucidate the mechanisms for potentially enhanced growth performance in poultry.

Use of low doses of clenbuterol to reduce incidence of ascites syndrome in broilers

Beta-adrenergic agonists have been shown to be capable of improving growth performance in poultry when added to the feed at 1.0 ppm. However, no reference has been made concerning the cardiovascular responses when one of these agents is added to the feed at a lower concentration during the whole production cycle. The aim of this paper was to assess the effects on the ascites syndrome of 0.25 ppm clenbuterol in the feed, throughout 52 d, in broiler chicks. Results showed a lack of difference in growth and feed conversion rate between the untreated control groups and the experimental group. There were differences in mortality due to the ascites syndrome, abdominal fat:body weight ratio, and ventricular index. A statistically significant positive correlation was also found between ventricular index and mortality rate (r = 0.98). If adequate withdrawal times are ensured, the use of clenbuterol at 0.25 ppm is suggested to reduce mortality due to the ascites syndrome in broilers.