Effect of furazolidone and nitrofurazone on egg production, on plasma luteinising hormone and on prolactin concentrations in turkeys

1. Furazolidone or nitrofurazone were given orally to laying turkeys at doses of 7.5, 15 or 30 mg/kg for 7 d. Plasma concentrations of luteinising hormone (LH), prolactin (PRL) and egg production were measured before, during and after treatment. 2. Both drugs produced dose-dependent decreases in LH concentration which were statistically significant at doses of 15 and 30 mg/kg. Plasma PRL concentration was significantly increased in birds receiving 15 or 30 mg/kg of nitrofurazone, and tended to increase in the other treated groups, but this was not statistically significant. 3. Egg production was lowered in a dose-dependent manner by both drugs. However, nitrofurazone appeared to be more potent in reducing egg production than furazolidone. 4. Birds given 15 mg/kg of either drug were injected intramuscularly with luteinising hormone releasing hormone (LHRH) at a dose of 5 micrograms/kg and blood was collected immediately before and 30 min after LHRH administration. 5. Nitrofurazone significantly reduced the rise in LH induced by LHRH. Seven days after withdrawing the drug, the LHRH-induced LH release was not significantly different when compared to that in the control group or that seen on day 7 of treatment.     

Genetic analysis of post-weaning growth traits of Thalli sheep under tropical conditions

Present investigation was carried out to study the influence of genetic and non-genetic factors affecting post-weaning performance traits in Thalli sheep. Data on post-weaning growth of Thalli sheep maintained at Livestock Experiment Station, Rakh Ghulaman, District Bhakkar-Punjab, Pakistan during 1977–2003 were subjected to genetic analysis. The average values for weight at 180 and 270 days of age, yearling weight and post-weaning average daily gain were 22.37?±?4.21, 25.96?±?4.90 and 28.93?±?5.20 kg and 28?±?0.01 g/day, respectively. Weight at 180, 270 and 365 days of age and post-weaning average daily gain were significantly affected by year of birth, sex, type of birth and weaning weight (covariable) whereas season of birth was a significant source of variation for 180 and 270 days of age. The heritability estimates for 180 and 270 days, yearling weight and post-weaning average daily gain were 0.07?±?0.02, 0.08?±?0.02, 0.07?±?0.02 and 0.07?±?0.02, respectively.     

Modulus of elasticity in scarf-jointed wooden beams: a case study with polyvinyl acetate and isocyanate adhesives

In the present study, elastic properties of scarf-jointed oak (Quercus castaneifolia) timbers with the application of two different types of adhesives (polyvinyl acetate and isocyanate) were evaluated using free flexural vibration of free–free beam method in different flexural directions of vibration, i.e., tangential and redial directions. Samples were taken from trees of Hyrcanian forests in Iran with nominal dimensions of 20 × 20 × 360 mm³. Comparing the results of elastic properties of clear oak wood beams with scarf-jointed samples wood showed that scarf joints with the bonding angles of 70° and 75°, covered by polyvinyl acetate adhesive, did not demonstrate any significant effect on modules of elasticity. Scarf-jointed beams with smaller joint angles (60° and 65°) were considerably weaker or totally unreliable in their moduli of elasticity. It is also shown that the magnitude of effect gets worst by using isocyanate rather than polyvinyl acetate adhesive.     

Biological and biochemical characteristics of male reproductive system,serum metabolites and carcass quality of Japanese quails by the supplementation of Pinus ponderosa leaves and α‐tocopherol acetate

The aim of the current study was to evaluate the effect of dietary supplementation of Pinus ponderosa leaves ( pine leaves) and α‐tocopherol acetate (vitamin E) powder on male reproductive system, serum metabolites and carcass characteristics of Japanese quails. A total of 360‐day‐old male quails were purchased from the open market and kept at poultry shed for ninety‐four days. After ten days of adaptation, all quails were randomly assigned into 4 groups, control (IC); supplemented with α‐tocopherol acetate (IE) at the rate of 150 mg/L; Pinus ponderosa leaves (IP) at the rate of 150 mg/L; and 70 mg α‐tocopherol acetate and 70 mg Pinus ponderosa leaves (IEP). Pinus ponderosa leaves and α‐tocopherol acetate supplementation had not significantly (p > .05) effected on final body weight gain, feed intake and feed conversion ratio of quails. The high‐density lipoprotein cholesterol (HDLC) and total cholesterol (TC) were significantly (p > .05) affected by IE and IP groups as compared to IC and IEP groups. Triglyceride (TG), glutathione peroxidase (GPx) and superoxide dismutase (SOD) significantly (p < .05) increased in all treatment groups except for the IC group. Aspartate transaminase (AST) significantly (p > .05) decreased in treatment groups as compared to control group. Overall, the mineral levels significantly (p < .05) increased in treatment groups as compared to control. Cloacal gland index values, the quantity of foam production and testis weight were significantly (p < .05) increased in treatment groups. It was concluded that the supplementation of Pinus ponderosa leaves and α‐tocopherol acetate improved the testis weight, foam production, serum antioxidant enzymes and mineral level especially zinc in Japanese quail considered an indicative characteristic of higher sperm production rate and improved sexual activity. Further, higher gametogenesis rate, sperm production or reproductive behaviour including different hormonal level will be analysed in future study.     

Effect of phosphate‐based seed priming on strigolactone production and Striga hermonthica infection in cereals

Strigolactones, plant‐secreted underground signalling molecules, play an important role in agricultural ecosystems, because they mediate the interaction of crops with symbiotic AM fungi and parasitic weeds like Striga hermonthica. Cereal host plants secret these signalling molecules particularly under nutrient‐deficient conditions and especially when phosphate (P) is limiting. The objective of the present study was to see the potential of P seed priming for S. hermonthica management in cereals in relation to strigolactone production. It has been demonstrated that P fertiliser application down‐regulates the production of these signalling molecules in the rhizosphere, which results in lower S. hermonthica infection of cereals. The laboratory study showed maximum production of strigolactones from dry and water‐soaked seeds, while seed soaking in P solution reduced their production. Similarly, maximum S. hermonthica infection was observed under control treatments with dry sowing or water soaking, while P seed soaking decreased S. hermonthica germination, emergence and dry biomass in all cereal crops. Our study shows that P seed priming resulted in lower exudation of strigolactones, which induced less S. hermonthica seeds germination and hence may lead to lower S. hermonthica infection. P‐based seed priming could prove to be an effective and affordable strategy to reduce S. hermonthica infection in cereals. Further research for practical field application is needed.     

The effect of dietary supplementation with the natural carotenoids curcumin and lutein on pigmentation,oxidative stability and quality of meat from broiler chickens affected by a coccidiosis challenge

1. An experiment was performed to evaluate the effectiveness of the antioxidants curcumin (CRM) and lutein (LTN) on the quality of meat from coccidiosis-infected broilers. A total of 200 one-day-old Arbor Acre chicks were randomly assigned to a treatment group with 5 replicates. The treatments included a basal diet without carotenoid supplementation (control), with 300 mg/kg CRM, with 300 mg/kg LTN or with a combination (C + L) of 150 mg/kg CRM and 150 mg/kg LTN. All chickens were challenged with Eimeria maxima at 21 d old.

2. The results revealed that the coccidiosis reduced redness of meat, while supplementation with carotenoids improved the fresh meat’s redness (a*) and yellowness (b*) and contributed to colour stability maintenance after storage (1 month at ?18°C and 3 d at 4°C).

3. Coccidiosis did not produce lipid and protein oxidation in fresh meat, but after storage for one month, the malondialdehyde levels and carbonyl contents were lower in the CRM and C + L birds and the sulfhydryl contents were higher in C + L birds.

4. The sodium dodecyl sulphate–polyacrylamide gel electrophoresis banding pattern showed equivalent myosin chain fragmentations in all treatment groups, whereas lower intensity actin bands were observed in the control group (CONT). Moreover, myofibril protein denaturation (differential scanning calorimetry) profiles showed a reduction in the CONT myosin and actin peaks. Coccidiosis reduced the meat’s water holding capacity in non-supplemented chicken meat and was improved by natural carotenoid.

5. These results emphasise that coccidiosis did not decrease the eating quality of fresh meat, that natural carotenoids are efficient antioxidants and that CRM (300 mg/kg) fed individually or combined with LTN was the most effective supplemented antioxidant compound.     

Factors affecting calf mortality in Iranian Holstein dairy herds

The objective of this study was to document mortality reasons and risk factors for mortality in dairy calves in the northeast of Iran. This was a prospective cohort study of calves born on ten commercial dairy herds from 21 March 2009 to 20 March 2010. A total of 4097 live calves were followed for 90 days after birth. For each calf details of sex, parity of the dam, type of parturition and season of birth were recorded. The interval (in days) from the date of birth to the date of death and the reason for death was recorded for those calves that died before 90 days of age. A Cox proportional hazards model, including a frailty term to account for unmeasured herd-level effects was developed to quantify the effect of factors associated with time to death. Two hundred and sixty-six (6.5%, 95% CI: 5.8-7.3%) of the 4097 live-born calves died or were euthanised before 90 days of age. The most important reasons for death were digestive tract disorders (58% of all deaths, 95% CI: 52-64%) followed by respiratory diseases (13% of all deaths, 95% CI: 9-17%). Calves exposed to dystocia at birth had 2.09 (95% CI: 1.49-2.92) times the daily hazard of death compared with calves born from a normal calving. The daily hazard of death for calves born in the summer was 1.93 (95% CI: 1.41-2.64) times greater than the hazard for those calves born in the autumn. Inclusion of the herd-level frailty term had a significant effect on hazard estimates indicating that the study herds were heterogeneous in the distribution of unmeasured herd-level factors influencing calf survival. Our results show that diarrhoea is the most important cause of calf mortality in dairy herds in this area of Iran and that environmental and management factors affect calf mortality rate.     

Effects of atropine and pralidoxime pretreatment on serum and cardiac oxidative stress parameters in acute dichlorvos toxicity in rats

Recent several studies have reported that oxidative stress could be an important component of the mechanism of cardiotoxicity due to organophosphate-induced toxicity. The aim of this study is to evaluate the oxidative and antioxidative parameters in cardiac toxicity of organophosphate poisoning, and determine the effects of atropine and pralidoxime on this parameters. The experimental groups were randomly divided into five groups as control (corn oil), dichlorvos (30 mg/kg), atropine (10 mg/kg), pralidoxime (40 mg/kg), and atropine (10 mg/kg) + pralidoxime (40 mg/kg) groups. Serum cholinesterase levels were suppressed with dichlorvos, and these reductions were inhibited with atropine and/or pralidoxime pretreatment. Serum, but not cardiac, total free sulfhydryl groups and paraoxonase activities were significantly increased in the pralidoxime group when compared to the control group. Serum arylesterase activities were elevated in the dichlorvos, atropine, pralidoxime, and atropine + pralidoxime groups when compared to the control group (P < 0.05). Total oxidant status, oxidative stress index, malondialdehyde and catalase activities in serum and cardiac tissues were not markedly different between the groups. No significant changes were also observed with cardiac myeloperoxidase and serum ceruloplasmin activities. In conclusion, these results showed that acute dichlorvos administration did not cause marked cardiac damage, and oxidative stress probably does not play a major role in dichlorvos-induced poisoning. On the other hand, especially pralidoxime treatment markedly increased the serum total free sulfhydryl groups, paraoxonase and arylesterase activities. However, the underlying mechanisms for these changes are not exactly known.