On-farm production of liquefied catfish protein

A method and the equipment used to process channel catfish (Ictalurus punctatus) offal into a liquid catfish protein (LCP) suitable for use as an animal feedstuff component is described. This process uses the offal following cleaning of the catfish for commercial use, i.e., without additional grinding or chopping. Small amounts of either hydrochloric acid or formic acid can be used to liquefy the catfish offal in 2 h or less. The liquefaction is conducted in a drum fitted with a baffle. The drum is heated to 50°C with water from an overhead manifold while turning on a drum roller. Bones and unliquefied material are removed by screening to yield LCP at pH 4.5.Variations in the processing conditions — grinding, agitation rate, acid employed, and time — did not alter significantly the amount of crude protein or the essential amino acid profile. Acid selection altered the amount of essential free amino acids found, with hydrochloric acid producing the lesser amount. Reducing the agitation rate lowered the amount of essential free amino acids. Comparison of the essential amino acid profile of the LCP with those of catfish, menhaden and herring meals showed lower amounts of these acids but sufficient to warrant use as a feed component.     

Economic Effects of Intensification of Baitfish Production

This study analyzed the economic effects of intensifying baitfish production. An economic engineering approach was utilized to develop enterprise budgets for baiffish production that were used to conduct an economic analysis. All indicators utilized, including net returns, internal rate of return, and payback period, indicated dramatic improvement in the economics of baitfish production with yield increases. There were strong economic incentives to increase yield, and minnow production at industry average yield was only marginally profitable under certain scenarios and unprofitable under others. Yields of 600 kg/ha would generate adequate revenue to compete with other aquaculture alternatives in terms of net returns as well as generate M internal rate of return that would outperform current long-term interest rates.     

Failure to induce stress reactions following vaccination against Marek's disease or Newcastle disease

Chickens aged one or 21 days were given single injections of a vaccine against Marek's disease or Newcastle disease respectively, and monitored over a three week period for any signs of a stressor response. No consistent evidence of such a response was found. Some data on normal ontogenetic changes in various adrenal and plasma variables are also presented.     

Vertical migratory behavior of the infective third-stage larvae of Oesophagostomum dentatum

The vertical migratory behavior of third-stage infective larvae (L3i) of Oesophagostomum dentatum was investigated using upright truncated agarose cones and equivalent conical depressions in agarose. Geotactic response varied with the age of the infective larvae. Four-day-old L3i showed no preference for the sloping surfaces of either indented or upright cones, while the 8-day-old L3i showed a positive geotactic reaction, migrating down the sloping surface of the depressions.     

Epidemiologic study of relationships between consumption of commercial canned food and risk of hyperthyroidism in cats

OBJECTIVE: To determine whether the increasing prevalence of feline hyperthyroidism is the result of aging of the cat population and whether consumption of canned foods at various times throughout life is associated with increased risk of hyperthyroidism. DESIGN: Retrospective and case-control studies. STUDY POPULATION: Medical records of 169,576 cats, including 3,570 cats with hyperthyroidism, evaluated at 9 veterinary school hospitals during a 20-year period, and 109 cats with hyperthyroidism (cases) and 173 cats without hyperthyroidism (controls). PROCEDURE: Age-adjusted hospital prevalence of hyperthyroidism was calculated by use of Veterinary Medical Database records. On the basis of owners' questionnaire responses, logistic regression was used to evaluate associations between consumption of canned food and development of hyperthyroidism. RESULTS: Age-specific hospital prevalence of feline hyperthyroidism increased significantly from 1978 to 1997. Overall, consumption of pop-top canned (vs dry) food at various times throughout life and each additional year of age were associated with greater risk of developing hyperthyroidism. In female cats, increased risk was associated with consumption of food packaged in pop-top cans or in combinations of pop-top and non-pop-top cans. In male cats, increased risk was associated with consumption of food packaged in pop-top cans and age. CONCLUSIONS AND CLINICAL RELEVANCE: These findings suggest that the increasing prevalence of feline hyperthyroidism is not solely the result of aging of the cat population and that canned foods may play a role.     

Effects of phenylbutazone, indomethacin, prostaglandin E2, butyrate, and glutamine on restitution of oxidant-injured right dorsal colon of horses in vitro

OBJECTIVE: To study the effects of phenylbutazone, indomethacin, prostaglandin E2 (PGE2), glutamine, and butyrate on restitution of oxidant-injured right dorsal colon of horses in vitro. SAMPLE POPULATION: Right dorsal colon from 9 adult horses euthanatized for reasons other than gastrointestinal tract disease. PROCEDURES: Mucosal segments from the right dorsal colon were injured via exposure to HOCl and incubated in Ussing chambers in solutions containing phenylbutazone, indomethacin, indomethacin and PGE2, glutamine, and butyrate. Transepithelial resistance and mucosal permeability to mannitol were measured, and all mucosal segments were examined histologically. RESULTS: The HOCl-injured mucosa had lower resistance and higher permeability to mannitol, compared with control tissue. Histologic changes were also evident. Resistance of HOCl-injured mucosa recovered partially during the incubation period, and glutamine improved recovery. Phenylbutazone and indomethacin increased resistance, but these increases were not significant. Butyrate and PGE2 had no effects, compared with nontreated HOCl-injured tissues. Mucosal permeability to mannitol was lower in glutamine-treated tissue, compared with nontreated tissue. Histologic changes reflected the resistance and permeability changes. CONCLUSIONS AND CLINICAL RELEVANCE: According to our findings, phenylbutazone and indomethacin do not seem to interfere with restitution of oxidant-injured mucosa of equine colon in vitro, and glutamine could facilitate mucosal restitution.     

Pharmacodynamics of warfarin in cats

The overall purpose of this study was to evaluate the pharmacodynamic response to warfarin in cats. The specific aim was to determine if a log-linear indirect response model (Nagashima et al., 1969) used to describe the in vivo effect of warfarin in humans could be applied to cats. The pharmacokinetics of racemic warfarin were described using a non-compartmental approach. The relationship between prothrombin complex activity (PCA) and normalized prothrombin time (PTR) was defined for feline plasma under our experimental conditions, and determined to be: %PCA=12.38+648 e-PTR/0.492. These data were then integrated and used to predict the warfarin dose associated with therapeutic anti-coagulation defined as an International Normalized Ratio (INR) of 2.0-3.0. The maximum prothrombinopenic response to warfarin in cats after a single intravenous dose of 0.5 mg/kg occurred at 24-48 h. Pharmacodynamic modeling suggested that each cat had a narrow therapeutic range of the steady-state concentration of total warfarin required to appropriately block prothrombin complex synthesis (median: 265.2-358.7 ng/mL). The median daily dose range predicted to yield therapeutic concentrations of warfarin was 0.061-0.088 mg/kg per day. Wide inter-individual variations in both pharmacokinetics and pharmacodynamic response suggest that a more optimal dosing of warfarin may be possible with the development of individual pharmacokinetic/pharmacodynamic algorithms, analogous to those currently employed in human patients.