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.     

Effect of mixed feeding schedules with varying dietary protein levels on the growth of sutchi catfish, Pangasius hypophthalmus (Sauvage) with silver carp, Hypophthalmichthys molitrix (Valenciennes) in ponds

A 6‐month feeding trial was conducted in field condition using 10 farm ponds (400–600 m²) to investigate the effect of mixed feeding schedules on the growth of sutchi catfish, Pangasius hypophthalmus with silver carp, Hypophthalmichthys molitrix. Fish were stocked at a ratio of 80:20 (sutchi catfish, 4.9±0.5 g: silver carp, 12.0±0.8 g) at the total rate of 25 000 ha^?1. Two diets of high protein (30%, HP) and low protein (16%, LP) were prepared using locally available feed ingredients. Five different feeding schedules of high‐protein diet continuously (HP), low‐protein diet continuously (LP), 1‐day low–protein/1‐day high‐protein diet (1LP/1HP), 7 days low–protein/7 days high‐protein diet (7LP/7HP) and 14 days low–protein/14 days high‐protein diet (14LP/14HP) were tested. The fish were fed twice daily at the rate of 15%, 10%, 8% and 5% of their body weight for first, second, third month and rest of experimental period respectively. Feeding rate was calculated only on the basis of sutchi catfish weight only and was adjusted every 2 weeks according to weight gain. Fish fed LP and HP on alternate day (1LP/1HP) resulted in significantly (P<0.05) higher growth rate, feed utilization and production among the treatments. However, there were no significant differences (P>0.05) between the growth rates and production of fish fed HP regularly and fish fed 7 days LP followed by 7 days HP (7LP/7HP). Fish maintained on LP grew the least. The feed conversion ratio (FCR) values for sutchi catfish ranged between 2.04 and 2.79 with feeding schedule 1LP/1HP showing the best FCR. The total production of fish (including silver carp) ranged between 8310 and 12 422 kg ha^?1 6 months^?1 with 1LP/1HP feeding schedule resulting in the highest production and net profit. The study demonstrated that feeding fish continuously with HP is less economical. Thus, for profitable sutchi catfish culture with silver carp, farmers can use the mixed feeding schedule of alternate day feeding of LP and HP as a means of reducing feed costs.     

Nitrous oxide emission from an irrigated cotton field under semiarid subtropical conditions

In a 1-year study, quantification of nitrous oxide (N₂O) emission was made from a flood-irrigated cotton field fertilized with urea at 100kg N ha⁻¹ a⁻¹. Measurements were made during the cotton-growing season (May–November) and the fallow period (December–April). Of the total 95 sampling dates, 77 showed positive N₂O fluxes (range, 0.1 to 33.3g N ha⁻¹ d⁻¹), whereas negative fluxes (i.e., N₂O sink activity) were recorded on 18 occasions (range, −0.1 to −2.2g N ha⁻¹ d⁻¹). Nitrous oxide sink activity was more frequently observed during the growing season (15 out of 57 sampling dates) as compared to the fallow period (3 out of 38 sampling dates). During the growing season, contribution of N₂O to the denitrification gaseous N products was much less (average, 4%) as compared to that during the fallow period (average, 21%). Nitrous oxide emission integrated over the 6-month growing period amounted 324g N ha⁻¹, whereas the corresponding figure for the 6-month fallow period was 648g N ha⁻¹. Subtracting the N₂O sink activity (30.3g N ha⁻¹ and 3.8g N ha⁻¹ during the growing season and fallow period, respectively), the net N₂O emission amounted 938g N ha⁻¹ a⁻¹. Results suggested that high soil moisture and temperature prevailing under flood-irrigated cotton in the Central Punjab region of Pakistan though favor high denitrification rates, but are also conducive to N₂O reduction thus leading to relatively low N₂O emission.     

Cross compatibility between Abelmoschus esculentus and A. moschatus

Interspecific cross compatibility between cultivated and wild okra (Abelmoschus esculentus and A. moschatus) and pollen tube growth behaviour in the crosses among a local cultivar of A. esculentus, A. moschatus and their F₁s were studied. Fruit set was observed in all the crosses except one and seed setting was absent in two of the crosses which set fruit. All seed produced were shrivelled but F₁ plants were obtained from two crosses where cultivated okra was used as the seed parent. The F₁ plants were perennial in nature with very low pollen viability and seed set. A high percentage of pollen germination and profuse pollen tube penetration in the style were observed in the cross A. esculentus × A. moschatus but low pollen tube penetration with abnormal pollen tubes was observed in the reciprocal cross. The number of pollen tubes was very low but they appeared to be normal in the backcross A. esculentus × F₁, but were generally abnormal in the reciprocal cross. Both pre- and postzygotic barriers seemed to occur in crosses between the two species. The present studies indicate that these barriers can be overcome and desirable characters from A. moschatus transferred to cultivated okra using conventional hybridisation techniques. This revised version was published online in July 2006 with corrections to the Cover Date.     

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.     

Root traits of different crops under rainfed conditions in the High Barind Tract of Bangladesh

Root traits of six different crops grown on residual soil moisture in the post–rainy season in the High Barind Tract (HBT) of Bangladesh were investigated to better understand their adaptation to this moisture‐limited environment. Deep‐rooting chickpea is the currently favored rainfed crop grown after rainy‐season rice in the HBT, but it is necessary to identify alternative crops to chickpea in order to avoid buildup of pests and diseases. Averaged over 2 y, barley (1.72 Mg ha^–1) produced significantly more grain than chickpea (1.4 Mg ha^–1) which, in turn, yielded better than linseed (1.0 Mg ha^–1), wheat (0.93 Mg ha^–1), and mustard (0.77 Mg ha^–1). Lentil did not produce any grain at all. Grain yield for all crops increased as total root length increased above a threshold value of 0.05 to 0.1 km m^–2. In general, grain yield increased as the proportion of total root produced below 60 cm depth increased, although barley also had thin roots that could more effectively extract soil moisture. Expression of root traits varied considerably between seasons, which was attributable to the different rainfall patterns and bulk‐density characteristics of the soil profile in the 2 years of the study. Although favorable root traits, particularly rooting ability below 60 cm, are a prerequisite for acceptable yield levels of crops grown on residual soil moisture in the HBT, it is recognized that farmers' choice of a post‐rice crop will depend on its economic return or food‐security value.     

Growth Response of Nile Tilapia Oreochromis niloticus to Dietary L-Ascorbic Acid, L-Ascorbyl-2-Sulfate, and L-Ascorbyl-2-Polyphosphate

Abstract.— Purified diets were formulated and fed to seven groups of Nile tilapia Oreochromis niloricus fingerlings for 12 weeks. Six of the formulated diets contained 5 or 50 mg/kg of ascorbic acid equivalent supplied either by L-ascorbic acid (AA), L-ascorbyl-2-sulfate (AS) or L-ascorbyl-2-polyphosphate (APP). The seventh basal diet was ascorbate-free and served as the control. The study indicated that APP or AS was more effectively utilized as a source of vitamin C than equimolar AA in promoting growth, improving food conversion, and preventing scurvy in Nile tilapia. Fish fed the ascorbate-free diet and the diet containing 5 mg AA/kg exhibited external signs of scurvy at 10 weeks. Diets containing 5 mg/kg of ascorbic acid from AS or APP provided some growth with no overt signs of scurvy indicating that this concentration of AS and APP might be near the minimum requirements for the species. The best growth, food conversion ratio, survival rate, and ascorbic acid content in liver were obtained with the diet containing 50 mg ascorbate equivalent/kg diet from APP followed by the diet containing 50 mg ascorbate equivalent/kg diet from AS. Fish fed diets with 50 mg ascorbic acidkg diet from AS and APP gained 27.9% and 36.2% more weight, respectively, than fish fed diets with 50 mg ascorbic acidkg diet from AA. These results indicated nearly equal ascorbic acid activity from AS and APP.