BUDGET ANALYSIS OF SHRIMP MATURATION FACILITY

Shrimp maturation and reproduction has long been one of the hurdles that must be surmounted to make shrimp farming commercially feasible. Nauplii are now successfully being produced and the commercial feasibility of their production is investigated in this study. The generalized budget simulation model for aquacultural facilities recently developed at Texas A&M University was used for the analysis. An annual budget was estimated to determine costs, returns and profit. Annual cash flow was generated for a 10-year planning horizon. Opportunity cost, initial investment, costs and break-even quantities and prices were also determined.     

Effect of sorghum grain variety and reconstitution on site and extent of starch and protein digestion in steers

Hetero-yellow (HY), red (RED) and brown (BR, high tannin) sorghums were fed dry-rolled or reconstituted (RED and BR only) to evaluate the effect of variety and reconstitution on the site and extent of starch and protein digestion in steers fitted with ruminal, duodenal and ileal cannulae. Processed grains were incorporated into 88% sorghum (DM basis) diets fed at 2% of body weight in a 5 X 5 Latin square. Ruminal fermentation of organic matter, starch and protein tended to be lower for the dry-rolled RED than for either the dry-rolled HY or BR sorghum. Digestion of organic matter (OM) and starch in the small intestine was very low for dry-rolled sorghums. Total tract starch digestibility was lower for the dry-rolled RED sorghum (86.9%) than the BR (90.8%) and HY (91.4%). Nitrogen (N) digestibility ranged from 53.1% for the dry-rolled BR to 64.5% for the HY. Tannins were extensively (95.2%) degraded in the rumen, which may have enhanced fermentation of the BR sorghum. Reconstitution increased (P less than .05) total-tract starch digestion of the RED and tended to increase starch digestion of the BR as well. Total N flow to the duodenum tended to increase with reconstitution, with most of the increase being due to greater (P less than .05) microbial-N. Reconstitution also increased (P less than .05) total-tract N digestibility of the RED. The response to reconstitution for the RED sorghum appeared to be due primarily to an increase (P less than .10) in the extent of fermentation of organic matter and starch in the rumen. Reconstitution of BR, however, enhanced disappearance of starch from the small intestine. In both cases, most (97.3%) of the digestible starch of the reconstituted sorghums had disappeared before the terminal ileum. In contrast, 14.5% (621 g) of the digestible starch of dry-rolled RED disappeared in the large intestine. Sorghum grain variety and reconstitution appear to alter site and extent of starch and protein digestion, which may result in variable performance of cattle fed sorghum grain diets.     

Development of divergent lines of lean and fat broilers using plasma very low density lipoprotein concentration as selection criterion; results over the fourth generation and lack of effect of dietary fat on performance and carcase fat content

Comparisons were made of the performance and carcase composition of lean and fat broilers from the 4th generation of a breeding experiment which were fed diets containing 25 or 80 g fat/kg. Selection over the 4th generation resulted in continued divergence in the selection trait and the correlated responses of total body lipid and protein contents and the efficiencies of conversion of food and dietary protein. In both lines body weight, efficiency of food utilisation and total body lipid and protein contents were unaffected by dietary fat content. Tissue fatty acid composition was influenced by dietary and genetic factors: dietary fat increased the proportions of linoleic and oleic acids at the expense of palmitic, palmitoleic and stearic acids whilst greater body fatness increased the proportion of palmitoleic at the expense of linoleic acid.     

Cervine T-lymphocyte growth factors and their measurement in tuberculosis

Research into the composition and function of the immune response in domesticated ruminants has tended to focus on the ovine and bovine systems. With the recent domestication of deer, health problems have developed which require a fundamental knowledge of the immune function in exotic ruminants. In this report it is shown that although recombinant human and mouse interleukin-2 (IL-2) were capable of stimulating cervine T-cell proliferation, optimal proliferation was only achieved using recombinant bovine IL-2. While some phylogenetic restriction of IL-2 cross-reactivity was found, in some cases this could be overcome by using high concentrations of recombinant IL-2. Using cervine T-cell blasts it was possible to assay in vitro T-cell growth factor (TCGF) production by lymphocytes isolated from deer naturally exposed to tuberculosis Mycobacterium bovis). Differences were found in the amount of TCGF present in the supernatants of antigen-activated cells isolated from severely diseased animals, those with limited disease and non-diseased animals.     

Antibody responses to bacterial antigens in the pregnant ewe

The humoral immune response to the novel antigen Brucella abortus (S19) was examined in nonpregnant ewes and in ewes at different stages of pregnancy. Both the primary and secondary responses were monitored, by measuring the levels of total antibody, Immunoglobulin G (IgG), and complement fixing antibody. Results showed that total antibody production was significantly (p<0.01) impaired in late pregnancy and that IgG titres persisted at significantly (p<0.05) higher levels in non-pregnant animals late in the primary response and following the booster inoculation. Complement fixing antibody levels were significantly higher in non-pregnant ewes and animals inoculated post-partum. These results suggest that active immunity can be altered during pregnancy, with qualitative changes in the class and biological activity of antibody.     

Pulmonary vascular pressures of strenuously exercising Thoroughbreds after administration of varying doses of frusemide

The frusemide dose-response for attenuation of exercise-induced pulmonary capillary hypertension was studied in 7 healthy, exercise-conditioned Thoroughbred horses using previously described haemodynamic procedures. Four different doses of frusemide were tested: 250 mg regardless of bodyweight (amounting to 0.56 +/- 0.03 mg/kg bwt), 1.0 mg/kg bwt, 1.5 mg/kg bwt and 2.0 mg/kg bwt. Frusemide was administered i.v., 4 h before exercise. Haemodynamic data were obtained at rest and during treadmill exercise performed at 14.2 m/s on a 3.5% uphill grade; this workload elicited maximal heart rate of horses. Airway endoscopy was performed post exercise to detect exercise-induced pulmonary haemorrhage (EIPH). In standing horses, frusemide administration resulted in a significant (P<0.05) decrease in mean pulmonary arterial, pulmonary capillary and pulmonary artery wedge pressures, but significant differences among the various frusemide doses were not observed. In the control experiments, exercise caused significant increments in the right atrial as well as pulmonary arterial, wedge, and capillary pressures, and all horses experienced EIPH. Following frusemide administration, the exercise-induced rise in right atrial and pulmonary vascular pressures was significantly attenuated, but significant differences between the frusemide doses of 250 mg, 1.0 mg/kg, and 1.5 mg/kg were not discerned and all horses remained positive for EIPH. Although a further significant (P<0.05) attenuation of the exercise-induced rise in pulmonary capillary blood pressure occurred when frusemide dose increased from 250 mg to 2.0 mg/kg bwt, all horses still experienced EIPH. It is concluded that a linear response to increasing frusemide dosage in terms of attenuation of the pulmonary capillary hypertension does not exist in strenuously exercising Thoroughbred horses.     

Plasma lipoprotein concentration as an indicator of fatness in broilers: Development and use of a simple assay for plasma very low density lipoproteins

1. A turbidimetric assay for plasma very low density lipoproteins (VLDL) was developed, based on their selective precipitation with heparin and Mg²⁺.

2. Measurements of plasma VLDL concentration using the turbidimetric method showed a correlation of 0–98 with plasma VLDL plus low density lipoprotein triglyceride concentration estimated chemically.

3. Correlations between plasma VLDL concentration measured turbidimetrically and body fat content were similar to or higher than those obtained previously using a chemical assay. Correlations for broiler grandparent stock fed on a low‐fat diet were 0.70 and 0.65 for males and females respectively.

4. Turbidimetric measurement of plasma VLDL concentration provides a simple, rapid and effective method of estimating fatness in live broilers that could be applied to commercial broiler breeding programmes.     

The response of cage‐reared broiler cockerels to dietary supplements of nitrovin,zinc bacitracin or penicillin used singly or in paired combinations

1. The effect of feeding diets supplemented with procaine penicillin (50 mg/kg), zinc bacitracin (25 mg/kg) or nitrovin (20 mg/kg) singly or in combinations on the performance of broiler cockerels from 1 to 56 d was assessed.

2. The growth of treated birds was significantly better than that of controls fed on a basal diet, but no combination of additives was significantly superior to the additives given singly.

3. Performance up to 56 d of birds fed continuously on a diet supplemented with zinc bacitracin (25 mg/kg) from 1 d old was better than that obtained when the supplement was either introduced or withdrawn at different ages.