S. N. Nahashon

An initial map of chromosomal segmental copy number variations in the chicken

BackgroundChromosomal segmental copy number variation (CNV) has been recently recognized as a very important source of genetic variability. Some CNV loci involve genes or conserved regulatory elements. Compelling evidence indicates that CNVs impact genome functions. The chicken is a very important farm animal species which has also served as a model for biological and biomedical research for hundreds of years. A map of CNVs in chickens could facilitate the identification of chromosomal regions that segregate for important agricultural and disease phenotypes.ResultsNinety six CNVs were identified in three lines of chickens (Cornish Rock broiler, Leghorn and Rhode Island Red) using whole genome tiling array. These CNVs encompass 16 Mb (1.3%) of the chicken genome. Twenty six CNVs were found in two or more animals. Whereas most small sized CNVs reside in none coding sequences, larger CNV regions involve genes (for example prolactin receptor, aldose reductase and zinc finger proteins). These results suggest that chicken CNVs potentially affect agricultural or disease related traits.ConclusionAn initial map of CNVs for the chicken has been described. Although chicken genome is approximately one third the size of a typical mammalian genome, the pattern of chicken CNVs is similar to that of mammals. The number of CNVs detected per individual was also similar to that found in dogs, mice, rats and macaques. A map of chicken CNVs provides new information on genetic variations for the understanding of important agricultural traits and disease.

Performance of Single Comb White Leghorn fed a diet supplemented with a live microbial during the growth and egg laying phases

360 Dekalb XL Single Comb White Leghorn pullets were fed corn-soya bean meal diets containing either condensed cane molasses solubles (CCMS), which was used as a carrier for Lactobacillus or CCMS-1100 mg viable Lactobacillus (Lacto) kg−1 diet from 7 to 59 weeks of age to determine the long-term effect of feeding Lacto diets on layer performance, anatomical changes of the gastrointestinal (GI) tracts and nutrient retention (fat, nitrogen, calcium, and phosphorus). The pullets were randomly assigned to three dietary treatments consisting of corn-soybean meal (control), control + CCMS and control + CCMS-1100 mg kg−1 Lacto (4.4 × 107 colony forming units (cfu) mg−1 Lacto). The dietary treatments were replicated four times. Condensed cane molasses solubles served as the carrier for the Lacto, and the CCMS and CCMS-Lacto premix were incorporated at 2% of the diet. Between 7 and 19 weeks of age, pullets fed the control + CCMS-Lacto diets had better (P < 0.05) daily feed consumption and body weight gains than pullets fed either control or control + CCMS diets (59 vs. 57 g per pullet, and 272 vs. 261 and 234 g per pullet, respectively). Supplementing pullet diets with CCMS depressed feed conversion (P < 0.05). No differences in shank length were observed among dietary treatments. During the laying phase (20–59 weeks of age), layers fed the control + CCMS-Lacto diets had increased (P < 0.05) daily feed consumption and egg size when compared with layers fed either control or control + CCMS diets (121 vs. 118 and 119 g per layer, and 86.4 vs. 85.4 and 84.6%, respectively). Nitrogen and calcium retentions were better (P < 0.05) for layers fed the control + CCMS-Lacto diet than layers fed either control or control + CCMS diets (44.8 vs. 33.9 and 36.6%, and 54.9 vs. 45.6 and 47.1%, respectively). Fat retention was not different among dietary treatments. Phosphorus retention was better for layers fed either control + CCMS-Lacto or control + CCMS diets than layers fed the control diet. Positive correlations between Lacto diets and nitrogen and calcium retention, and egg mass and between fat, nitrogen, calcium and phosphorus retention and body weight gain, calcium and phosphorus retention and egg mass, respectively, were observed. Intestinal length and dry weight were lower (P < 0.05) in layers fed the CCMS-Lacto diets compared to the control diet at the end of ten 28-day periods. Increased daily feed consumption, egg size, nitrogen, and calcium retentions and decreased intestinal length were observed in layers fed Lactobacillus diet from 7 to 59 weeks of age.

Prevalence and Antimicrobial Resistance of Pathogenic Bacteria in Chicken and Guinea Fowl

This study was conducted to compare the presence and antimicrobial susceptibility of Campylobacter, Salmonella spp., and other enteric bacteria between chickens and guinea fowls. Birds were reared on enclosed concrete floor housing covered with pine wood shavings litter material. Chicken (n = 40) and guinea fowl (n = 40) carcasses, drinking water (10 mL; n = 40), and litter (10 g; n = 40) were aseptically collected randomly from a poultry farm and analyzed within 1 h of collection. Individual pens served as experimental units and were replicated twice. Campylobacter spp., Salmonella spp., and other enterobactericeae were isolated and identified using standard selective media and biochemical tests. Isolates were tested for sensitivity to tetracycline, ampicillin, streptomycin, kanamycin, nalidixic acid, gentamicin, erythromycin, ciprofloxacin, cefoxitin, and colistin using the Kirby-Bauer disk diffusion test. Campylobacter spp. and Salmonella spp. were isolated from 28 and 35% of whole carcass rinses of chickens and from 18 and 23% of whole carcass rinses of guinea fowl, respectively. Although only Salmonella spp. were recovered from drinking water, both Salmonella and Campylobacter spp. were recovered from litter material. Campylobacter upsaliensis was recovered only in the guinea fowl, whereas Klebsiella oxytoca and Enterobacter sakazakii were recovered only in chickens. Although no antibiotic resistance was determined in Campylobacter upsaliensis, most Campylobacter, Salmonella, and Escherichia coli isolates from both chickens and guinea fowl were resistant to antibiotics such as ampicillin, kanamycin, erythromycin, and nalidixic acid.

Nutrient retention and production parameters of Single Comb White Leghorn layers fed diets with varying crude protein levels and supplemented with direct-fed microbials

Four hundred and eighty Dekalb XL Single Comb White Leghorn layers (30 weeks of age) were fed five diets for eight 28-day periods in a completely randomized split-plot design to determine the effects of feeding Lactobacillus (Lacto) with varied dietary protein levels on the retentions of fat (ether extract), nitrogen, calcium, and phosphorus, and on layer performance. The five dietary treatments were 13.8%, 14.3% and 15.3% crude protein (CP) diets each supplemented with 1100 mg Lacto per kg (4.4 × 107 colony forming units) and 15.3% CP diet supplemented with and without condensed cane molasses solubles (CCMS) which served as a carrier for the Lacto in a premix. The CCMS-Lacto premix was incorporated at 2% of the diets. Linear contrasts for hen-day egg production and daily feed consumption were not significant with CCMS-Lacto supplementation regardless of the dietary protein levels. Layers fed the 15.3% CP CCMS-Lacto diet laid significantly (P < 0.05) larger size eggs than those on 15.3% CP CCMS diet. Feed conversion, egg mass, egg weights and egg size were higher (P < 0.05) for layers fed the 15.3% CP CCMS-Lacto diet than 14.3 and 13.8% CP CCMS-Lacto diets. Interior egg quality and egg shell thickness were not different with layers fed CCMS-Lacto supplementation diets. Egg yolk color scores were highest (P < 0.05) from layers fed CCMS-Lacto diets with 13.8% CP diet. Fat and phosphorus retentions were higher with CCMS-Lacto supplementation and with change in dietary CP levels from 15.3% to 14.3% in CCMS-Lacto supplemented diets, respectively.

Growth performance and carcass characteristics of guinea fowl broilers fed micronized-dehulled pea (Pisum sativum L.) as a substitute for soybean meal

This study was conducted to evaluate the effect of substitution of soybean meal (SBM) with dehulled-micronized peas (Pisum sativum) in diets of guinea fowl broilers on their growth performance, carcass yields, and fatty acid composition of meat. One hundred forty 1-d-old guinea fowl keets were randomly assigned to 2 dietary treatments, which were fed from hatch to 12 wk. The birds were fed 2 wheat middling-based diets comprising a control diet, which contained SBM (78 g/kg) and a test diet containing dehulled-micronized peas (180 g/kg) as the main protein source. The substitution of SBM with peas had no adverse effect on growth performance, dressing percentage, or breast and thigh muscle relative weights of the guinea broilers. However, a reduction of abdominal fat content (P < 0.05) was observed in birds fed the pea diet compared with the control. Breast and thigh meat of birds fed the pea diet had higher lightness scores (P < 0.05) and water-holding capacity (P < 0.01) than the control. Meat from guinea fowls fed the pea diet had less cholesterol (P < 0.01) and lipids (P < 0.05), and higher concentrations of phospholipids (P < 0.05). Feeding peas increased polyunsaturated fatty acid concentration in breast and thigh muscles, and decreased the saturated fatty acid concentration. Feeding the pea diet also lowered the n-6/n-3 polyunsaturated fatty acid ratio of the guinea broiler muscles. Our results suggest that replacing the conventional SBM as the protein source with dehulled-micronized pea meal in diets of guinea fowls broilers can improve carcass quality and favorable lipid profile without adversely affecting growth performance traits.

Evaluation of drug-resistant Enterobacteriaceae in retail poultry and beef

There has been increasing concern on the emergence of multidrug-resistant foodborne pathogens from foods of animal origin, including poultry. The current study aimed to evaluate antibiotic-resistant Enterobacteriaceae from raw retail chicken/turkey parts (thigh, wings, breast, and ground) and beef meat (ground and chunks) in Middle Tennessee. Resistance of the collected Enterobacteriaceae to a panel of antibiotics was determined by the Kirby-Bauer disk diffusion test. Retail meats were also assayed for the presence of Salmonella spp. and Escherichia coli O157:H7. Two hundred thirty-seven samples representing 95.2% of the total of 249 samples tested were positive for Enterobacteriaceae. The level of contamination with Enterobacteriaceae in raw meats ranged from 3.26 log10 cfu/g to 4.94 log10 cfu/g with significant differences in counts among meat types (P < 0.05). Contamination was significantly greater (P < 0.05) in ground beef, beef chucks, ground chicken, chicken breast, and turkey wings (4.92, 4.58, 4.94, 4.75, 4.13 log10 cfu/g, respectively) than ground turkey and chicken wings (3.26 and 3.26 log10 cfu/g, respectively). Klebsiella oxytoca, Serratia spp., E. coli, and Haffnia alvei were most prevalent contaminants at 27.4, 14.3, 12.1, and 11.4%, respectively. Resistance of the Enterobacteriaceae to antimicrobials was most frequent with erythromycin, penicillin, and ampicillin at 100, 89, and 65.8%, respectively. Few (2.7%) of the Enterobacteriaceae were resistant to chloramphenicol. Salmonella spp., E. coli O157:H7, Morganella morganii, Yersinia enterocolitica, and Vibrio parahemolyticus exhibited multiple drug resistance. This investigation demonstrates that raw poultry and beef are potential reservoirs of antibiotic-resistant Enterobacteriaceae.

Molecular Mechanisms of Obesity-Induced Osteoporosis and Muscle Atrophy

Obesity and osteoporosis are two alarming health disorders prominent among middle and old age populations, and the numbers of those affected by these two disorders are increasing. It is estimated that more than 600 million adults are obese and over 200 million people have osteoporosis worldwide. Interestingly, both of these abnormalities share some common features including a genetic predisposition, and a common origin: bone marrow mesenchymal stromal cells. Obesity is characterized by the expression of leptin, adiponectin, interleukin 6 (IL-6), interleukin 10 (IL-10), monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), macrophage colony stimulating factor (M-CSF), growth hormone (GH), parathyroid hormone (PTH), angiotensin II (Ang II), 5-hydroxy-tryptamine (5-HT), Advance glycation end products (AGE), and myostatin, which exert their effects by modulating the signaling pathways within bone and muscle. Chemical messengers (e.g., TNF-α, IL-6, AGE, leptins) that are upregulated or downregulated as a result of obesity have been shown to act as negative regulators of osteoblasts, osteocytes and muscles, as well as positive regulators of osteoclasts. These additive effects of obesity ultimately increase the risk for osteoporosis and muscle atrophy. The aim of this review is to identify the potential cellular mechanisms through which obesity may facilitate osteoporosis, muscle atrophy and bone fractures.

Occurrence and Antimicrobial Resistance of Enterococci Isolated from Organic and Conventional Retail Chicken

Antibiotic-resistant bacteria existing in agricultural environments may be transferred to humans through food consumption or more multifaceted environmental paths of exposure. Notably, enterococcal infections are becoming more challenging to treat as their resistance to antibiotics intensifies. In this study, the prevalence and antibiotic resistance profiles of enterococci in organic and conventional chicken from retail stores were analyzed. Of the total 343 retail chicken samples evaluated, 282 (82.2%) were contaminated with Enterococcus spp. The prevalence was higher in organic chicken (62.5%) than conventional chicken (37.5%). Enterococcus isolates were submitted to susceptibility tests against 12 antimicrobial agents. Among the isolates tested, streptomycin had the highest frequencies of resistance (69.1 and 100%) followed by erythromycin (38.5 and 80.0%), penicillin (14.1 and 88.5%), and kanamycin (11.3 and 76.9%) for organic and conventional isolates, respectively. Chloramphenicol had the lowest frequency (0.0 and 6.6%, respectively). The predominant species in raw chicken was E. faecium (27.3%), followed by E. gallinarum (6.0%), E. casseliflavus (2.1%), and E. durans (1.4%). These species were also found to be resistant to three or more antibiotics. The data indicated that antibiotic-resistant enterococci isolates were found in chicken whether it was organic or conventional. However, enterococci isolates that were resistant to antibiotics were less common in organic chicken (31.0%) when compared with those isolated from conventional chicken (43.6%). The results of this study suggest that raw retail organic and conventional chickens could be a source of antibiotic-resistant enterococci.

Advances in Soybean and Soybean By-Products in Monogastric Nutrition and Health

Soybean (Glycine max) is a leguminous oilseed and one of the world’s largest and most efficient sources of plant protein. United States holds the largest share of soybean production (32%) followed by Brazil (28%), Argentina (21%), China (7%) and India (4%). Although there are variations based on geographical location, the average crude protein (CP) content of soybean is 38% with a rich and balanced amino acid profile. It is therefore a rich source of protein for humans and food animals besides being a rich source of vegetable oil. Soybean meal is the simplest form of soybean protein and a by-product of the oil milling which by National Research Council standards contains 44-48% CP. It contains higher energy [2,460 metabolizable energy (ME) kcal/kg] and protein than other plant protein sources and has an excellent balance of highly digestible amino acids with the exception of methionine which tends to be low. Soybean meal is however rich in the amino acids lysine, tryptophan, threonine, isoleucine, and valine which are deficient in cereal grains such as corn and sorghum most utilized in poultry and swine diets. These are essential amino acids for monogastric animals such as poultry and swine. Soybeans and soybean meal are also a source of isoflavones which are known to improve growth, promote tissue growth in pigs, and prevent diseases. However, soybean meal possesses anti-nutritional properties which must be overcome to increase its nutritional value. These include antitrypsin inhibitors, oligosaccharides, such as rafinose and stachyose, which are poorly utilized by most food animals. Phytic acid and antigenic factors found in certain soybean proteins cause inflammatory response in the gastrointestinal tract of monogastric animals. Soybeans also contain lectins, compounds that bind with intestinal cells and interfere with nutrient absorption and other compounds such as saponins, lipoxidase, phytoestrogens and goitrogens whose anti-nutritional effects are not known. Soybeans and soybean meal may also be contaminated in the field as a result of using contaminated irrigation water or application of contaminated manure to the growing crop. Since many animal producers use soybean meal as a major constituent of animal feeds, contamination of these feeds with zoonotic foodborne pathogens such as salmonella has increasingly become a global concern. When properly processed for specific purposes, the soybean and soybean by-products can be utilized by all classes of animals ranging from companion animals, monogastric food

Gompertz-Laird model prediction of optimum utilization of crude protein and metabolizable energy by French guinea fowl broilers.

This study was conducted to assess the influence of dietary CP and ME on growth parameters of the French guinea fowl, a meat-type variety. In a 2 x 3 x 3 factorial arrangement, 297 one-day-old French guinea keets (162 females and 135 males) were randomly assigned to experimental diets comprising 3,050, 3,100, and 3,150 kcal of ME/kg, each containing 21, 23, and 25% CP from hatch to 4 wk of age (WOA), and 3,100, 3150, and 3,200 kcal of ME/kg, each containing 19, 21, and 23% CP at 5 to 8 WOA. Using BW and G:F data from hatch to 8 WOA, the Gompertz-Laird growth model was employed to estimate growth patterns of the French guinea fowl. Mean differences in exponential growth rate, age of maximum growth, and asymptotic BW among dietary CP and ME levels were not significant. However, instantaneous growth rate and weight at inflection point were significantly higher (P < 0.05) in birds on the 25% CP diet than those on the 21% CP diet at hatch to 4 WOA (1.12 kg/wk and 0.79 kg vs. 1.04 kg/wk and 0.74 kg, respectively). The exponential growth rate was also higher (P < 0.05) in birds fed the 3,050 kcal of ME/kg diet with either 23 or 25% CP than those fed diets containing 3,050 kcal of ME/kg and 21% CP. Mean G:F was higher (P < 0.05) in birds fed diets containing 3,050 kcal of ME/kg and either 21 or 23% CP than those in other dietary treatments. Therefore, based on the Gompertz-Laird growth model estimates, feeding 21 and 23% CP and 3,100 kcal of ME/kg at hatch to 4 WOA and 19 and 21% CP with 3,150 kcal of ME/kg at 5 to 8 WOA can be recommended as adequate for growth for the French guinea fowl broilers.