禽蛋新产品的开发

禽蛋除直接食用和加工成各种蛋食品外，还有许多新用途。利用蛋生产高附加值的食品，药品和生物制品已经成为新兴加工业。     

The effects of artificially-induced fly-strike on food intake and liveweight gain in sheep

A single, artificially-induced fly-strike with Lucilia sericata larvae was associated with a rapid (decline in food intake in sheep, with a consequent reduction in liveweight. Loss of weight ranged from 0.5 to 5.5 kg over four to six days and recovery to pre-infestation liveweight took three to 36 days. Pair-fed, uninfested partners of these sheep also showed a reduction in liveweight, whereas uninfested sheep in some experiments fed ad libitum showed either little change or a gain in liveweight over the same period. In general, maggot infested sheep took less time to regain weight than did their pair-fed partners although the weight lost as a proportion of initial weight was similar in both groups. Loss of appetite alone would appear to account for these events.     

Small intestinal carcinoma in cattle

The pathology of carcinoma of the small intestine in six adult cattle is described. The lesions were similar to those of carcinoma of the small intestine of sheep although a slightly less fibrous stroma and a greater tendency to metastasise was observed. Initial findings suggest the disease resembles small-intestinal carcinoma of sheep and cola-rectal carcinomas of man in having a higher prevalence in New Zealand than most other countries. This highlights the need to investigate common environmental factors which may be responsible for the induction and promotion of these tumours in both grazing ruminants and man.     

Relative efficacy of organophosphorus insecticides against susceptible and resistant strains of the strike blowfly Lucilia cuprina (Calliphoridae) in New Zealand sheep

Four groups of five Romney lambs were treated by plunge dipping with one of four registered organophosphorus flystrike preventatives. Untreated lambs acted as controls. The sheep were challenged at weekly intervals with larval implants of organophosphate-susceptible and -resistant strains of Lucilia cuprina. All four treatments provided 19-21 weeks protection against susceptible larvae but chlorfenvinphos provided the longest protection (16-17 weeks), followed by propetamphos (15-16 weeks), dichlofenthion (10-13 weeks) and diazinon (9-13 weeks), against the resistant strain.     

Lymphoid leukaemia in a cow

An 18-month old Friesian heifer which had lost condition and had diarrhoea for several weeks was diagnosed by haematological and pathological examinations as having lymphocytic leukaemia. True lymphatic leukaemia has not previously been described in cattle and does not readily fit into presently accepted classifications of bovine leukosis.     

Actinobacillosis in an alpaca (Lama pacos)

The death of a 6-week-old alpaca being treated for acute polyarthritis is described. Post-mortem and histological findings included fibrinous mural endocarditis, lung abscessation, acute passive congestion of the liver, embolic suppurative nephritis and chronic nonsuppurative polyarthritis. Actinobacillus suis was isolated from the heart lesion and in pharyngeal swabs from four of six clinically normal alpacas in the same flock.     

Some currently available insecticides and their comparative efficacy on louse-infested, long-woolled sheep

The comparative efficacy of 13 of the sheep dips currently registered in New Zealand was investigated using sheep infested with the louse Bovicola ovis and carrying wool which was about 10 cm long at the shoulder. With the exception of one synthetic pyrethroid pour-on formulation, all products were able to effect a significant reduction in louse populations, relative to untreated controls, for 37 days after treatment. Only four products proved capable of eradicating lice and preventing their re-establishment up to 37 days after treatment. Variations in manufacturers' recommendations relating to the length of wool at dipping, and mode of application of dips are discussed in relation to the results.     

An evaluation of two cypermethrin-based pour-on formulations on sheep infested with the biting louse, Bovicola ovis

Two synthetic pyrethroid (cypermethrin) based pour-on insecticide formulations, with high cis/trans isomer ratios (80:20) but differing in their respective active ingredient concentrations and solvent component(s), were applied to sheep infested with the biting-louse, Bovicola ovis. All treated sheep were penned with louse-infested sheep 9,12 and 15 weeks after the insecticide was applied. The 2% cypermethrin formulation achieved a higher level of control than the 1.25% cypermethrin formulation at each challenge interval when applied 12 weeks after shearing. The 2% cypermethrin formulation provided 97-100% control of lice from 4 to 16 weeks after application on sheep shorn 6 or 12 weeks prior to treatment. The 1.25% cypermethrin formulation provided 85% control of lice 4 weeks after application on sheep shorn 12 weeks prior to treatment, the level of control increasing to a maximum of 100% by week 9, and declining thereafter. The 2% cypermethrin formulation may provide a better level of control in long-woolled sheep than 1.25% cypermethrin, by compensating for the diluent effect of lipid.