A survey of anthelmintic resistance on ten goat farms in the Manawatu region in 1988

A survey of anthelmintic resistance on ten goat farms was carried out. The criterion for resistance was a faecal egg count reduction (FECR) of <90 percent based on arithmetic means of 11 to 19 goats per group. It was found that nine of the ten farms harboured nematodes resistant to oxfendazole when used at 5mg/kg although on two of these, the FECR's were 89.2 percent and 89.8 percent. Post treatment larval cultures indicated Haemonchus, Ostertagia and Trichostrongylus were the resistant genera involved. On none of the ten farms was resistance to oral ivermectin at 0.2mg/kg detected.     

Effects of an induced pause in egg production and supplementation of the diet with iron on egg shell colour,quality and performance of brown egg layers

1. A pause in egg production was induced in brown‐egg laying hens, aged 68 weeks, by feeding them whole oats for 7 d. Subsequently, these hens, together with control groups, were given laying diets with either 400 or 600 mg/kg iron. The 200 mg/kg of supplemental iron was added in the form of either ferrous sulphate or iron proteinate (chelated iron).

2. The feeding of whole oats halted egg production in 5.7 ±0.22 d and the duration of the pause was 8.3 ±0.78 d.

3. The induction of a pause improved the subsequent rate of egg production, egg output, efficiency of food utilisation, albumen quality, egg specific gravity and shell colour. It also increased food intake and body weight gain but neither egg weight nor the rate of mortality were affected.

4. Neither supplementation of the diet with iron nor its source had any significant effect on laying performance, egg quality or shell colour.     

Effect of saturated fat on growth,body fat composition and carcase quality in chicks

1. The effects of feeding two fats with different degrees of saturation on skin tearing, carcase quality and body fat composition were examined in male and female chickens.

2. No differences in growth or efficiency of food utilisation were apparent on feeding the more saturated fat. Skin tearing was slightly reduced and carcase quality slightly improved on feeding the more saturated fat for 28 d.

3. Decreases in linoleic acid content in intra‐abdominal fat were apparent after 14 d feeding the diet containing saturated fat. These decreases were greater after feeding the saturated fat for 28 d.     

Current and future role of artificial insemination in the broiler industry

1. This article addresses the current and future role of artificial insemination (AI) in the broiler industry.

2. The application and success of AI programmes in commercial broiler breeder operations are largely dependent on efficient cage management (nutrition, lighting, environment, health programmes) of both males and females.

3. Artificial insemination will remain a viable alternative for the broiler industry, which competes within the economic constraints of least‐cost production.     

Simple acid-base disorders

The body regulates pH closely to maintain homeostasis. The pH of blood can be represented by the Henderson-Hasselbalch equation: pH = pK + log [HCO3-]/PCO2 Thus, pH is a function of the ratio between bicarbonate ion concentration [HCO3-] and carbon dioxide tension (PCO2). There are four simple acid base disorders: (1) Metabolic acidosis, (2) respiratory acidosis, (3) metabolic alkalosis, and (4) respiratory alkalosis. Metabolic acidosis is the most common disorder encountered in clinical practice. The respiratory contribution to a change in pH can be determined by measuring PCO2 and the metabolic component by measuring the base excess. Unless it is desirable to know the oxygenation status of a patient, venous blood samples will usually be sufficient. Metabolic acidosis can result from an increase of acid in the body or by excess loss of bicarbonate. Measurement of the "anion-gap" [(Na+ + K+) - (Cl- + HCO3-)], may help to diagnose the cause of the metabolic acidosis. Treatment of all acid-base disorders must be aimed at diagnosis and correction of the underlying disease process. Specific treatment may be required when changes in pH are severe (pH less than 7.2 or pH greater than 7.6). Treatment of severe metabolic acidosis requires the use of sodium bicarbonate, but blood pH and gases should be monitored closely to avoid an "overshoot" alkalosis. Changes in pH may be accompanied by alterations in plasma potassium concentrations, and it is recommended that plasma potassium be monitored closely during treatment of acid-base disturbances.     

Bilirubin excretion and bile flow in fed and fasted Brazilian squirrel monkeys (Saimiri sciureus)

Fasted Brazilian squirrel monkeys (BrSMs) exhibited slightly higher serum bilirubin levels (0.30±0.05 mg/dl) than others in the fed state (0.13±0.01). The mean liver weight was 50% lower following a 22 h fast. The rate of bile flow was unaffected by fasting and averaged 13.8 l/min/kg and 47.5 l/min/100g liver in six BrSMs. No significant difference in mean bilirubin excretion/min was observed on a body weight basis following fasting. When the mean rate of bilirubin excretion was calculated as a function of liver weight, a two-fold higher rate was present in fasted monkeys, but only at the p=0.06 level of statistical significance. From data collected in this and earlier studies, it would appear that BrSMs represent the best animals studied to date to serve as experimental controls in comparative studies with Bovilian squirrel monkeys which exhibit a Gilbert-like syndrome.     

Inflammation-related changes in cyclic AMP and cyclic GMP in bovine mastitis

Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) cocentrations in milk and plasma samples from healthy and mastitic cows were determined by radioi-immunoassay and compared with prostaglandins (PGE2, PGF2 and thromboxane B2 [TXB2]), phospholipids and other relevant parameters in milk and blood. The concentrations of cAMP were about five times higher in plasma (p<0.01) than in milk, whereas the cGMP concentration in milk was three times higher (p<0.01) than that in plasma in both healthy and diseased animals. In mastitic milk, the cAMP and cGMP concentrations were 19% and 65% and in blood plasma 13% and 84% higher respectively than in healthy animals. In milk, cyclic nucleotide concentrations correlated with the markedly elevated cell count and also with the prostaglandin concentration and pH. In blood, cAMP correlated positively with phospholipids and cGMP with reduced glutathione (GSH). These changes are considered to be important in the disease process and, in particular, the increase in cGMP deserves further study.     

The problem of the pathomorphological diagnosis "death by drowning"--case histories

The paper describes pathomorphological findings in two dogs and one cat with the intention to clarify whether these animals died by drowning. The investigations are supplemented by experimental results of water instillation into the lung to induce signs of emphysema aquosum post mortem. Additionally, histopathology of the skin lesions due to water exposition after death are demonstrated by systematic investigations of four different localizations for 10 days. Critical evaluation of the results and literature references in human forensic pathology indicate that post mortem findings as described in this paper, especially those of the so called "drowning lung" can be attributed to death by drowning.     

Organochlorine insecticide problems in livestock

1. Antidotal therapy for acute OC intoxications is symptomatic and supportive. Use sedatives to control convulsions and AC to adsorb any pesticide remaining in the gut, and wash topical exposures. 2. Published kinetics should be applied to field situations with caution. In general, residues decline relatively quickly immediately following the last exposure; thereafter, the rate slows considerably. The elimination-rate constant and, hence, the half-life of any given OC is dependent on many variables that usually are not known under field conditions. This fact may result in serious errors if literature values are relied on too heavily in predicting the outcome of "natural" contamination. As a rule of thumb, elimination data derived from animals experimentally fed to plateau concentrations may be regarded as fairly conservative for such purposes, if the contaminated animals are maintained in a normal fashion. Probably the least risky method of predicting return to marketability is using frequent samples, taken at regular intervals (for example, 1 to 2 weeks) during the first month after last exposure, to adjust literature values. 3. Residues from larger dosages and shorter exposures tend to be smaller in proportion to dose and are eliminated more quickly than those resulting from longer exposures and smaller doses. 4. Activated charcoal is of universal benefit only if given immediately after exposure. 5. Pharmaceutical modifiers of xenobiotic metabolism such as phenobarbital are of very limited value. The particular type and amount of residual OC and the potential economic benefit of therapy should be considered thoroughly before undertaking such therapy. In most cases, the expense won't be justified. 6. Mineral oil increases the fecal excretion of some OC. Fecal excretion, however, is so small in relation to total body burdens that even a several-fold increase may not be useful economically except when residue concentrations are low to start with. 7. Nutritional strategies have the advantage of being very cheap. Practitioners should remember, however, that tissue concentrations actually may increase as body fat decreases. The costs of maintaining animals for an extra 6 to 10 months should be considered before undertaking such an effort.(ABSTRACT TRUNCATED AT 400 WORDS)