R. D. Miles

Mannanoligosaccharides in Fish Nutrition: Effects of Dietary Supplementation on Growth and Gastrointestinal Villi Structure in Gulf of Mexico Sturgeon

Abstract Although low levels of dietary mannanoligosaccharide (MOS) supplementation have been shown to increase weight gain, decrease feed conversion, and stimulate intestinal villi growth in domestic mammals and birds, the responses of aquacultural species to MOS have not been studied. We examined the effects of MOS supplementation on the growth of and digestive tract morphology in Gulf sturgeon Acipenser oxyrinchus desotoi. There were no differences in growth performance (as measured by condition factors, specific growth rates for weight and fork length, and feed conversion ratios), gross gastrointestinal morphology (gut length and spiral valve length), or spiral valve villi structure (villus length, width, and density) between fish fed control and MOS-supplemented diets. However, in light of the promising results obtained by similar studies across a wide range of animals, dietary MOS supplementation in other aquacultural species merits further investigation.

Probiotics in Poultry Nutrition—A Review

The commercial use of probiotics in the livestock industry, especially poultry, is relatively new. Only within the last few years have research workers documented the results of incorporating probi...

Stable carbon and nitrogen incorporation in blood and fin tissue of the catfish Pterygoplichthys disjunctivus (Siluriformes, Loricariidae)

AbstractA feeding trial was performed in the laboratory with the catfish species Pterygoplichthys disjunctivus to determine stable carbon (13C) and nitrogen (15 N) turnover rates and discrimination factors in non-lethally sampled tissues (red blood cells, plasma solutes, and fin). A second feeding trial was conducted to determine what P. disjunctivus could assimilate from low-quality wood-detritus—refractory polysaccharides (e.g., cellulose), or soluble wood-degradation products inherent in wood-detritus. This was performed by feeding the fish an artificial wood-detritus diet with fibrous (δ13C = −26.36‰; δ15  N = 2.13‰) and soluble portions (δ13C = −11.82‰; δ15  N = 3.39‰) that had different isotopic signatures and monitoring the dynamics of isotopic incorporation in the different tissues over time. Plasma solutes turned over more quickly than red blood cells for 13C and 15 N. However, in contrast to previous studies of juvenile fishes, C and N incorporation was primarily driven by catabolic tissue turnover as opposed to growth rate. Tissue-diet discrimination factors for 15 N varied from 4.08 to 5.17‰, whereas they were <2‰ for 13C (and less than 0.3‰ for plasma and red blood cells). The results of trial two suggested that P. disjunctivus could not assimilate refractory polysaccharides. Moreover, the δ13C and δ15 N signatures of wild-caught P. disjunctivus from Florida confirmed their detrital trophic standing in Floridian aquatic ecosystems.

Subclinical Infectious Bursal Disease in an Integrated Broiler Production Operation

A field study was designed to determine the prevalence of subclinical infectious bursal disease (IBD) in broiler chickens from a commercial poultry company. Bursae of Fabricius (BF) from two vaccinated and three nonvaccinated broiler flocks were evaluated histologically, and antibody profiles of these broiler and matched parent breeder flocks were established. Lesions of IBD, including lymphoid necrosis, stromal edema, and infiltrates of heterophils and macrophages, were first detected in BF at 24 days of age in both vaccinated and nonvaccinated chickens. At 41 days, all BF had lesions characteristic of IBD, including severe lymphoid depletion, proliferation of epithelial cells, and mild fibroplasia. Although mean maternal antibody levels (measured by enzyme-linked immunosorbent assay) in broilers were apparently protective through day 12, IBD antibodies decreased to nonprotective levels (below 1,000) by day 16 or 20. Titers began to increase by day 28 or 32 because of field exposure. Sentinel birds, placed with broiler flocks, also developed IBD antibody titers. Broiler breeders had low and nonuniform antibody titers. Prevalence of field IBD exposure was high, and existing vaccination programs were not effective.

Estimation of the relative bioavailability of copper sources in chicks fed on conventional dietary amounts

Abstract 1. Tissue accumulation of Cu from dietary additions of 0, 5, 10, or 20 mg/kg Cu as reagent grade Cu acetate and feed grade Cu carbonate was determined in day‐old chicks fed on conventional maize‐soyabean meal starter diets (5.41 mg/kg Cu as‐fed basis) for 3 weeks. 2. Average daily food intake, daily weight gain and food conversion were similar among treatments. 3. There were linear increases in plasma and liver Cu concentrations (P< 0.01) as dietary Cu increased. 4. Bioavailability of Cu as carbonate was 0.66 that of Cu in the acetate based on the multiple regression slope ratio of liver Cu concentration on added dietary Cu. Although responses for the two Cu sources did not differ significantly, the relative bioavailability of the Cu carbonate was similar (0.66 vs 0.68) to that obtained in an earlier study (Ledoux et al., 1991) with greater dietary Cu contents (150, 300 and 450 mg/kg) in which the slopes of the equations representing the two sources differed (P<0.05).

Choline, Methionine and Sulphate Interrelationships in Poultry Nutrition1—A Review

This review has dealt with the importance of methionine, choline and sulphate in poultry. The interrelationship between methionine and choline and between the sulphur amino acids and inorganic sulp...

Development of diluents for domestic fowl semen

Semen diluents are presently being used both for short- and long-term storage of domestic fowl semen. They are being developed to improve the reproductive efficiency of males and to lower the cost of artificial insemination. The development of semen diluents began with the use of simple NaCl solutions. Now, more complex diluents containing different osmotic regulators, energy sources, buffers and chelating agents are on the market. The discovery of cryoprotectants, such as glycerol and dimethylsulphoxide, has facilitated the preservation of chicken semen indefinitely at −196°C. The diluents which have been developed for short-term storage of semen are currently being used commercially wherever the technique of artificial insemination is being used seriously, especially in the turkey industry. Even though diluents for long-term semen storage are now available, their commercial application is not yet feasible. This paper reviews the development of the various diluents which has resulted in the ability to preserve domestic fowl semen for short and long periods. Also discussed are some of the research data that have been collected on the viscosity of semen and semen diluents and what effects this has on semen quality.

Processing Yields for Meat of Russian and Siberian Sturgeons Cultured in Florida, USA

ABSTRACT Cultured Russian and Siberian sturgeons were processed and analyzed to estimate meat yields and proximate compositions. Sturgeons were approximately 18 to 24 months in age and weighed 2.3–2.6 kilograms (lower and upper intervals, 95% level of confidence) in total body weight. Dressed fillet yields in sturgeon appear to vary by species. The skinless fillet yields for Russian sturgeon and Siberian sturgeon were 26% and 32%, respectively. The proximate composition of edible portions in Russian and Siberian sturgeons may range from 70–76% moisture, 17–19% protein, 5–10% lipid, and 1–2% ash; some 116–151 calories per 100 grams of fresh, uncooked meat. However, the lipid content in Siberian sturgeon may be higher than in other sturgeon species.

Effects of Dietary Vanadium on Performance and Immune Responses of Commercial Egg-Type Laying Hens

Abstract Davis, E.G., Miles, R.D., Butcher, G.D. and Comer C.W. 2002. Effects of dietary vanadium on performance and immune responses of commercial egg-type laying hens. J. Appl. Anim. Res., 22: 113–124. The influence of dietary supplementation of vanadium (V) on feed consumption, feed conversion, egg production, egg interior quality, egg weight, egg shell weight, cell-mediated and humoral immune responses was investigated in a 6-wk experiment using White Leghorn laying hens. Four dietary treatments consisting of a corn/soybean meal basal control diet supplemented with 0, 10, 20 and 30 ppm V were used. Feed consumption was not significantly different among treatments, but a decline in feed intake resulted as higher levels of supplemental V. were fed. Hen-day egg production declined in the hens fed the two highest supplemental levels of V, but the decline was only significant for hens fed 30 ppm supplemental V. Egg weight and egg shell weight were similar for birds fed all four diets, but on d 24 and 29 of the experiment egg shell weight was significantly lower for hens fed the diet supplemented with 20 ppm V and on d 24 for those fed 30 ppm V. Egg interior quality declined within 48h after the supplemental vanadium diets were fed. After d14 and until the end of the experimental period hens fed the V supplemented diets had poorer interior egg quality compared to the birds fed the control diet. Across all treatments no significant differences were observed for the cell-mediated and humoral immune response.

Protein Intake of Broiler Breeder Replacements and its Effect on Body Composition and Subsequent Performance

Abstract Miles, R.D., Wilson, H.R. and Harms, R.H. 1997. Protein intake of broiler breeder replacements and its effect on body composition and subsequent performance. J. Appl. Anim. Res., 11: 25–36. Eight hundred broiler breeder females and 200 males were housed with 40 females and 10 males per pen during the growing phase and 33 females and 3 males per pen during the laying phase. All birds were fed a 21% crude protein (CP) diet for the first 21 days. On day 22, birds were assigned to four dietary treatments formulated varying corn and soybean meal with (1) 14% CP, (2) 20% CP, (3) 19% CP and (4) 17% CP. Birds on treatment 1 were fed diet 1 continuously through 24 wks of age. Birds on treatments 2,3 and 4 were fed diets 2,3 and 4 respectively, two weeks and then the percent CP level in each diet was decreased one percent after each 2-wk period thereafter. Birds were weighed each week and feed was allocated on a skip-a-day program from 3 through 24 wks and a daily restriction program thereafter to maintain...