豌豆在仔鸡营养中的作用

给杂种Slougal肉用雏鸡饲喂不含豌豆的或用含13.5％、27.0％和40.5％豌豆的基础日粮,代替25％、50％和75％黄豆粉(SBM)及部分玉米。结果增重分别为400克、394克、387克和376克;饲料转化率分别为1.63、1.71、1.78和2.02;蛋白     

REDUCTIVE DECHLORINATION OF DDT TO DDD BY YEAST

Labeled DDD [ 1,1-dichlor-o-2,2-bis(p-chlorophenyl)-ethane] was formed from C(14)-labeled DDT in the presence of yeast. The formation of DDD from DDE [1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene] was not observed, indicating that a reductive dechlorination of DDT occurs.     

Hypercalcaemia associated with angiostrongylus vasorum in three dogs

Hypercalcaemia was identified in three dogs that presented primarily for evaluation of respiratory disease. Angiostrongylosis was diagnosed in all three cases and both the respiratory signs and the hypercalcaemia resolved with treatment. Infection with Angiostrongylus vasorum is known to lead to formation of pulmonary granulomata. Granulomatous disease in humans may lead to hypercalcaemia secondary to increased unregulated production of 1,25-dihydroxycholecalciferol by activated macrophages in the granulomata. In one of the three dogs, 1,25-dihydroxycholecalciferol was measured and found to be increased, providing supportive evidence for a similar mechanism in dogs. To the authors' knowledge, hypercalcaemia has not previously been reported in association with angiostrongylosis in dogs. Since prolonged untreated hypercalcaemia may lead to permanent impairment of renal function, dogs with angiostrongylosis should be evaluated for the presence of hypercalcaemia.     

Effect of amount and source of supplemental dietary vegetable oil on broiler chickens exposed to aflatoxicosis

1. Addition of sunflower oil (SFO) at 30 or 60 g/kg or three vegetable oils, namely SFO, soybean (SBO) or groundnut (GNO), at 30 g/kg to isocaloric and isonitrogenous broiler chicken diets were evaluated for possible counteractive effects against aflatoxin (AF) (0.3 microg B1/g diet) from 0 to 42 d of age. 2. Body weight, food intake and serum concentration of protein were lower in the AF group than in the control, whereas in the SFO and SBO supplemented groups they were comparable with those of the control. Sunflower oil at both concentrations exerted similar effects on growth. Groundnut oil did not improve growth or food intake in AF-fed birds. 3. The serum concentration of cholesterol and triglycerides decreased with AF feeding and was increased by supplementation of any of the three oils both in the control and in AF-fed groups. 4. Liver and giblet weight and liver fat content were increased by AF; these effects were countered by dietary oil inclusion, except for liver weight at 60 g/kg SFO. Weights of pancreas and gall bladder were increased by AF. Oil supplementation reduced the weight of pancreas in chickens given AF. 5. Humoral immune response was depressed by AF and dietary oil supplementation (particularly SFO or SBO) countered this effect. Other variables, namely, serum gamma glutamyl transferase activity, bone mineralisation, weights of lymphoid organs, kidney and adrenals, ready-to-cook yields and fat content in muscle and skin showed little or no effect of dietary oil supplementation. 6. It is concluded that dietary inclusion of SFO or SBO at 30 g/kg may alleviate the adverse effects of 0.3 microg/g of AF B1 in commercial broiler chickens. Groundnut oil, although showing beneficial effects on some biochemical variables, failed to improve growth performance.     

Effect of phytase supplementation to a low- and a high-phytate diet for growing pigs on the digestibilities of crude protein, amino acids, and energy

Supplementation of microbial phytase usually improves the digestibility and utilization of phosphorus in feedstuffs of plant origin. The effect of phytase supplementation on the digestibilities of AA also has been examined, but the results have been inconsistent. This study was carried out to determine the effect of phytase (Natuphos) supplementation, at a rate of 2,000 phytase units/kg, to two basal diets on the apparent ileal digestibilities (AID) of GE, CP, and AA, and on the apparent total-tract digestibilities (ATTD) of CP and GE. The basal diets contained 18% CP and were formulated (as-fed basis) to contain either a low (0.22%) or high content (0.48%) of phytate P. The high-phytate diet contained 20% rice bran, which is a rich source of phytate and has low intrinsic phytase activity. Eight barrows (average initial BW = 40.6 kg), fitted with a simple T-cannula at the distal ileum, were fed the four diets according to a replicated 4 x 4 Latin square design. The pigs were fed twice daily at 0800 and 2000, equal amounts each meal, at a rate of 2.4 times the daily maintenance requirement for ME. Each experimental period comprised 14 d. Ileal digesta were collected from 0800 to 2000 on d 12, 13, and 14. Feces were collected from 0800 on d 8 until 0800 on d 12. Chromic oxide was used as the digestibility marker. The AID of GE, CP, and AA and the ATTD of CP and GE were less in the high- than in the low-phytate diet (P < 0.01). With the exception of glutamic acid, phytase supplementation did not affect (P > 0.10) the AID of CP and AA. There was no effect (P > 0.05) of phytase on the ATTD of CP and GE. These results show that if a response occurs to phytase supplementation, it is independent of the dietary phytate content.     

Genotype x environment interaction effects on carcass traits in Japanese Black cattle

The importance of genotype x environment (region or management system) interactions for carcass traits in Japanese Black cattle was investigated using both univariate and multivariate animal models. The univariate approach was used mainly to test the significance of interaction effects. The multivariate approach was used to estimate genetic correlations, which indicated the magnitude of genotype x environment (GE) interactions. The more a genetic correlation deviates from 1, the larger the interaction. From the univariate approach, the addition of genotype x environment (region or management system) interaction (co)variance components resulted in an improved fit of the model for all traits in both cases (P < 0.001). However, estimates of genetic correlation between regions obtained from the multivariate approach for hot carcass weight, LM area, rib thickness, s.c. fat thickness, and marbling score were 0.97, 0.95, 0.93, 0.97, and 0.93, respectively. The corresponding estimates between management systems were 0.84, 0.92, 0.84, 0.90, and 0.97, respectively. These results indicate that GE interaction effects on carcass traits of Japanese Black cattle may be biologically unimportant. Therefore, breeding values obtained using the multivariate method would rank sires similarly in all environments. Consequently, carcass traits measured in these two different regions or management systems can be treated as the same traits.     

Diagnosis of zinc phosphide poisoning in chickens using a new analytical approach

Approximately 200 chickens were found dead after the flooring of a slat-and-litter house was breached. No clinical signs of illness were observed in the surviving birds. During necropsy, rolled oats were found in the chickens' crops and gizzards, and the contents had a petroleum-like odor. Histopathologic examination revealed severe pulmonary edema and congestion of the chickens' lungs, hearts, livers, and kidneys. Based on the history and necropsy findings, zinc phosphide exposure was suspected. Diagnosis of zinc phosphide poisoning has previously been based on history of exposure, identification of the bait material in the gastrointestinal tract, and chemical detection of phosphine gas. However, currently available diagnostic methods are nonconfirmatory, and may produce false positive results. The objective of this case report was to determine whether the sudden death described in these chickens was caused by the ingestion of zinc phosphide, by developing a sensitive and highly specific gas chromatography/mass spectrometry (GC/MS) methodology for analysis of the gastrointestinal samples submitted to the laboratory. It was also found that the determination of zinc concentrations in liver or kidney tissue or stomach contents is not a reliable indicator of zinc phosphide poisoning.     

Molecular Variability in Different Indian Isolates of Equine Herpesvirus-1

Three abortigenic Indian isolates of equine herpesvirus-1 (EHV-1) (Tohana, Hisar and Bikaner), along with two exotic abortigenic isolates (AB4 and V592) and another EHV-1 isolate (Jind) obtained from a case of perinatal foal mortality, were studied for variability. For this purpose, PCR and restriction endonuclease (RE) digestion techniques were used simultaneously as a DNA fingerprinting system. Nine different regions of EHV-1 virus were amplified by PCR using primer pairs specific for the regions and the products obtained from these regions were subsequently subjected to various restriction endonucleases to further assess the variability in the number of RE sites as well as in their positions. No difference was observed in all the four abortigenic isolates in terms of the size of different PCR products amplified by all the nine primer pairs, except for primer pairs ‘E’ and ‘C’. PCR products obtained with primer pair E revealed that Tohana and Bikaner isolates were most similar while Hisar isolate was like V592 isolate. However, the PCR product obtained from Jind isolate had a size between the PCR products of Hisar and Tohan/Bikaner isolates. The primer pair ‘C’ used to amplify the region between 1151 to 3679 in ‘Gene 1,2,3’ clearly differentiated the EHV-1 isolate obtained from a case of perinatal foal mortality from isolates obtained from abortion cases. This primer pair needs to be exploited more extensively for use as a potential marker for differentiating the EHV-1 isolates, mainly the abortion cases from perinatal foal mortality ones. Restriction endonuclease studies done with PCR product of all the isolates with various primer pairs did not reveal any changes in the position or number of RE sites present in the products amplified, indicating no variation in different RE sites within the amplified PCR products. However, this study clarified that all the Indian isolates belonged to the IP group of EHV-1.     

Persistence of Mycoplasma gallisepticum in chickens after treatment with enrofloxacin without development of resistance

The ability of the avian pathogen Mycoplasma gallisepticum to persist despite fluoroquinolone treatment was investigated in chickens. Groups of specific pathogen free chickens were experimentally infected with M. gallisepticum and treated with enrofloxacin at increasing concentrations up to the therapeutic dose. When M. gallisepticum could no longer be re-isolated from chickens, birds were stressed by inoculation of infectious bronchitis virus or avian pneumovirus. Although M. gallisepticum could not be cultured from tracheal swabs collected on several consecutive sampling days after the end of the enrofloxacin treatments, the infection was not eradicated. Viral infections reactivated the mycoplasma infection. Mycoplasmas were isolated from tracheal rings cultured for several days, suggesting that M. gallisepticum persisted in the trachea despite the enrofloxacin treatment. The minimal inhibitory concentration (MIC) of enrofloxacin for most of the re-isolated mycoplasmas was the same as that of the strain with which the birds were inoculated. Furthermore, no mutation could be detected in the fluoroquinolone target genes. These results suggest that M. gallisepticum can persist in chickens without development of resistance despite several treatments with enrofloxacin.     

Impact of molybdenum on the copper status of red deer (Cervus elaphus)

AIM: To determine the effect of increasing molybdenum (Mo) intakes on serum and liver copper (Cu) concentrations and growth rates of grazing red deer (Cervus elaphus). METHODS: Molybdenum- and Cu-amended fertilisers were applied to six 1.1-ha paddocks in a 3 x 2 design. Three levels of Mo were applied on two paddocks at each level in mid April (designated Day 1); levels were: none (control), 0.5 (medium) and 1.0 (high) kg Mo/ha as sodium molybdate. In late May (Day 39), two levels of Cu (none and 3.0 kg Cu/ha, as copper sulphate) were applied to each of the three levels of Mo-treated paddocks. Pasture Mo, Cu and sulphur (S) concentrations were measured at about fortnightly intervals. In late June (Day 74), ten 6-month-old red deer hinds were placed on the six experimental pastures, and serum and liver Cu concentrations were monitored at about monthly intervals for 102 days. The hinds were weighed on four occasions during the trial. RESULTS: Mean pasture Mo concentrations on Day 56 were 2, 4.6 and 11.3 mg/kg dry matter (DM) for the untreated control, medium and high Mo-treated pastures, respectively. Pasture Cu concentration was 95 mg/kg DM on Day 59, 53 mg/kg DM on Day 90, and 9 mg/kg DM by Day 153. Mean S concentration in pasture was 3.3 (range 3.03-3.45) g/kg DM. Copper application to pasture had no significant effect on serum and liver Cu concentrations in deer so data were pooled within Mo treatment. Mean initial (Day 74) serum Cu concentration was 9.2 micromol/L. In the deer grazing the control Mo pasture, this increased to 10.3 micromol/L on Day 112, before decreasing to 6.4 micromol/L on Day 176. In deer grazing the medium and high Mo-treated pastures, mean serum Cu concentrations were 3.8 and 3.9 micromol/L, respectively, on Day 112, and 2.5 and 3.3 micromol/L, respectively, on Day 176. Mean initial (Day 74) liver Cu concentration was 131 micromol/kg fresh tissue. In the deer grazing the control Mo pasture, this declined to 120 and 52 micromol/kg on Days 112 and Day 176, respectively. In deer grazing the medium and high Mo-treated pastures, liver Cu concentrations decreased to 55 and 52 micromol/kg fresh tissue, respectively, on Day 112, and 21 and 20 micromol/kg fresh tissue, respectively, on Day 176. Mean serum and liver Cu concentrations were not significantly different between deer grazing the medium and high Mo-treated pastures, and were lower (serum p=0.003, liver p<0.001) in those groups than in deer grazing the untreated control pastures. No clinical signs of Cu deficiency associated with lameness were observed. Deer grazing pastures that had Mo concentrations >10 mg/kg DM had lower (p=0.002) growth rates (100 vs 130 g/day) than those on pastures containing <2.4 mg Mo/kg DM. CONCLUSION: Increasing pasture Mo concentrations from 2 mg/kg DM to > or =4.6 mg/kg DM significantly reduced serum and liver Cu concentrations in grazing deer. Reduced growth rate was observed at pasture Mo concentrations >10 mg/kg DM.