A. J. King

The effect of northern fowl mite (Ornithonyssus sylviarum) infestation on hen physiology, physical condition, and egg quality

The northern fowl mite (NFM),Ornithonyssus sylviarum, is the most common ectoparasite of laying hens in North America. Infestation can cause a reduction in egg production, egg weights, and feed conversion efficiency. However, there is a lack of information on the effects of NFM on hen physiology, physical condition, and egg quality. Singly caged beak-trimmed White Leghorn hens (N=32) were infested with mites at 25 wk of age. The condition of each hen was assessed at wk 0 (infestation) and wk 5 and 7 post-infestation to determine comb temperatures and feather, skin, and comb condition. Heterophil-lymphocyte (H/L) ratios and body weight (BW) were evaluated at wk 0 and wk 1, 3, 5, and 7 post-infestation. Egg weight, egg specific gravity, yolk color, Haugh unit (HU), and eggshell thickness were determined prior to infestation (wk -1) and at 1, 3, 5, and 7 wk post-infestation. The H/L ratio (P<0.0001), HU (P<0.0001), and egg specific gravity (P=0.001) were lowest, and the egg yolk color was lightest (P=0.087) at wk 5, the peak of infestation. At wk 5 and 7, more than 65% of the hens had red skin and more than 75% had scabs on the vent; in addition more than 84% had grey-black vent feathers. There were no effects of infestation on comb color, comb temperature, feather cover, BW, or eggshell thickness. It was concluded that infestation with NFM has negative effects on interior egg quality and hen integument. A decrease in H/L ratio was also observed at the peak of infestation. However, the effects of NFM on the immune system are unclear, and H/L ratio might not be a good stress measure in hens highly infested with NFM.

Manganese Amendment and Pleurotus ostreatus Treatment to Convert Tomato Pomace for Inclusion in Poultry Feed

If freshly dried tomato pomace could be fed to poultry, its naturally occurring alpha-tocopherol would retard lipid oxidation during further processing, long-term frozen storage, and heating of poultry meat; however, the high fiber content in this agricultural by-product adversely affects its use. Experiments were conducted to investigate the chemical composition and in vitro true digestibility of amended (without and with 487 micromol of manganese/g) tomato pomace substrate after treatment with the white-rot fungus Pleurotus ostreatus. In treated pomace without manganese, protein content was improved by 3.1%, cellulose and hemicellulose decreased over time, but lignin degradation was not detected. In addition, treated pomace without manganese showed a significant reduction of in vitro true digestibility. Manganese in pomace inhibited fungal growth and did not enhance lignin degradation. Under the conditions of the experiment, P. ostreatus improved the nutritional composition of tomato pomace; however, it did not reduce lignin. It is possible that manganese amendment at the level used affected gaseous conditions (O(2) consumption and CO(2) evolution rates), important factors that must be considered when attempting to enhance accelerated lignin degradation by P. ostreatus.

The effects of an alternative diet regimen with natural methionine ingredients on white striping breast myopathy in broiler chickens

&NA; Conventional broiler diets include synthetic methionine to optimize fast muscle growth. Recently, a conventional synthetic methionine‐rich diet was compared to alternative diet regimens providing natural sources of methionine. Broilers fed diets with natural methionine sources grew at a slightly slower rate. From this study, we hypothesized that the difference in a growth rate would be reflected in features of the breast muscle from broilers fed the alternative diet. We hypothesized that white striping of pectoralis major muscle would be reduced in slower growing broilers fed the alternative diet regimen with natural methionine. We also hypothesized that there would be associated differences in gene expression for cell differentiation and pathology markers. Broilers fed a conventional corn/soy diet regimen with synthetic methionine were compared to those fed roasted cowpea and sunflower seed meal (60% corn/soy, 20% sunflower seed meal, and 20% roasted cowpea) and no synthetic methionine. Overall broiler growth, muscle gene expression, and muscle collagen content data were compared. Expression analyses of combinations of MYOD1, PPARG, COL1A2, TRIM63, SOD1, PTGS2, and CD36 genes were used to examine differentiation and inflammation in the pectoralis muscles. The group fed an alternative diet gained less weight than those fed the control diet in the starter and grower phases but not in the finisher phase. Ultimately, the conventional diet resulted in a greater final weight for the broilers. However, mean white striping scores for the pectoralis major muscles were greater in the conventional control diet regimen. Gene expression results indicated greater expression of PPARG, PTGS2, and CD36 in the muscle of broilers fed the control diet. These data associate white striping with fat deposition and inflammation. Thus, whether due to differences in feed intake, growth rate, or actual compositional differences, the alternative diet with natural methionine sources seemed to curtail amounts of white striping in broiler muscle. More studies are necessary to further discern the effect of growth rate and natural methionine sources on white striping.

Removal of Excess Cellulose and Associated Polysaccharides in Fruit and Vegetable By-Products – Implication for Use in Feed for Monogastric Farm Animals

© 2013 King, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Removal of Excess Cellulose and Associated Polysaccharides in Fruit and Vegetable By-Products – Implication for Use in Feed for Monogastric Farm Animals