• Asian-Australasian Journal of Animal Sciences
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• v.15 no.3
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• pp.438-444
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• 2002

This study was conducted to investigate the effect of aflatoxin $B_1$ ($AFB_1$) alone or mixed function oxidase (MFO)-activated $AFB_1$ on various functions of mule duck peritoneal macrophages. Duck peritoneal macrophages were incubated with $AFB_1$ 0, 5, 10, 20, 50 and $100 {\mu}g/ml$ for 12 h. The cell viability significantly declined as the concentration of $AFB_1$ increased and more obviously detrimental effects was noticed in MFO-metabolized $AFB_1$ treatments. Either in opsonized or unopsonized Candida albicans, phagocytotic ability of macrophages was decreased with the elevation of the concentration of $AFB_1$. Significantly higher levels of macrophages were damaged in MFO-metabolized $AFB_1$ than $AFB_1$ alone in concentrations above $20{\mu}g/ml$. The cytotoxicity activity was in the range of 41 to 33% after exposure to $AFB_1$ 5 to $100{\mu}g/ml$, and a significant higher TNF-like substance secretion by lipopolysaccharide (LPS) stimulation was obtained. When LPS was present in the medium, the percentage of cytotoxicity was higher than all treatments of $AFB_1$ both with and without MFO-activation in the absence of LPS. The results suggest that MFO-metabolized $AFB_1$ can alter cell viability and morphology of duck macrophages more than $AFB_1$ administered alone. Both with and without MFOactivation, $AFB_1$ has detrimental effects on phagocytotic ability and TNF-like substance secretion, increasing with level of $AFB_1$.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.231-235
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• 2006

The objectives of this study were to investigate the effects of dietary fish oil inclusion on the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents and organoleptic characteristics of breast meat in mule ducks. Three hundred mule ducks at four weeks of age were randomly assigned to three dietary treatments with five replicate pens in each. One replicate pen had ten males and females each with a total of 100 ducks in each treatment. The diet in the three treatments contained 0, 1.5, and 3.0% fish oil, respectively. Body weights at 4, 6, 8, and 10 weeks of age, and feed efficiency at 4 to 6, 6 to 8, and 8 to 10 weeks of age were recorded. At 10 weeks of age, one male and one female from each replicate were sacrificed for oxidative stability of breast meat and the sacrificed males were employed for the analysis of fatty acids in breast meat and skin. Sensory evaluation of breast meat was also performed. A level of 3.0% fish oil in the diet significantly deteriorated feed efficiency and body weight gain. Dietary fish oil inclusion had a trend of increasing abdominal fat deposition and decreasing the flavor of breast meat. The EPA and DHA contents in the breast meat were higher than those in the breast skin irrespective of oil sources. The EPA and DHA contents in breast meat and breast skin was significantly increased in the 3.0% fish oil group. Although EPA and DHA were not efficiently deposited in the duck meat through dietary fish oil inclusion, this method can still provide a partial supplementation of EPA and DHA.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.605-611
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• 2015

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie ($h^2=0.07{\pm}0.03$) and M ($h^2=0.07{\pm}0.01$), moderately low for Dm ($h^2=0.13{\pm}0.02$), of medium values for H ($h^2=0.20{\pm}0.03$) and F ($h^2=0.23{\pm}0.03$). High and favourable genetic correlations existed between F and Dm ($r_g=0.93$), between F and H ($r_g=0.97$) and between Dm and H ($r_g=0.90$). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings' feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.412-417
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• 2006

This study evaluated the effectiveness of different arsenical sources on inducing fatty liver, on changes in lipid metabolism and on liver function in mule ducks. Sixty twelve-week-old mule ducks were selected and randomly divided into five treatments, including the control group and four different arsenical sources; Roxarsone (300 mg/kg), arsanilic acid, $As_2O_5$ or $As_2O_3$, containing 85.2 mg/kg arsenic were included in the basal diet. The ducks were fed the medicated basal diet for 3 weeks followed by a one-week drug withdrawal. The results showed Roxarsone treatment decreased body weight, feed intake, liver weight and abdominal fat weight (p<0.05), while it increased the relative liver weight (p<0.05) during medication period ($3^{rd}$ week). The $As_2O_5$ treatment decreased abdominal fat weight and relative abdominal fat weight when compared to the control (p<0.05). Only Roxarsone among the treatment groups increased feed intake, liver weight and relative liver weight, while the $As_2O_3$ group showed the lightest liver weight and relative liver weight among treatment groups during the withdrawal period ($4^{th}$ week). The Roxarsone group decreased (p<0.05) NADP-malic dehydrogenase (MDH) and acetyl-CoA carboxylase (ACC) activities and increased (p<0.05) cholesterol concentration during the medication period, and elevated the MDH and ACC activities during the withdrawal period. All four arsenical treatment groups showed lymphocytic infiltration in liver tissue, while the Roxarsone and $As_2O_3$ treatments showed an increase in aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities (p<0.05). During the withdrawal period, arsenical treatments resulted in liver vacuoles. However, the arsenicals differed in effectiveness and mechanisms of inducing fat vacuoles.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1639-1645
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• 2002

The purpose of this study was to investigate the effects of aflatoxin $B_1$ ($AFB_1$) on the ultracellular morphology alteration, apoptosis induction and reactive nitrogen and oxygen intermediates production of peritoneal macrophages (DPM) from mule ducks. The ducklings were purchased from a commercial hatchery, and were fed a corn-soybean based diet. As the ducklings were grown up to 3 wk of age, the Sephadex-elicited peritoneal exudative cells (PEC) were used as the source for duck peritoneal macrophages. The ultracellular morphology study showed that significant number of cells shifted from category I (normal cell with ruffled membrane) and II (cell membrane blebbing) to category III (cell membrane blebbing and even rupture) after DPM were incubated with $AFB_1$ ($20{\mu}g/ml$) for 12 to 48 h. When DPM were exposed to $AFB_1$ in vitro, the production of NO, $H_2O_2$ and $O_2{^-}$ in macrophages was reduced after 12-48 h incubation with previous LPS stimulation. There was a DNA laddering pattern observed in DPM incubated with $AFB_1$ 5, 10, 20, 50 or $100{\mu}g/ml$ for 12 h. Evidence also revealed that the percentage of apoptotic cells was increased along with the elevation of $AFB_1$ concentration. The results suggest that $AFB_1$ exposure causes duck macrophages going on apoptotic pathway through evidence of ultracellular morphology alteration and DNA laddering in agarose electrophoresis. The production of reactive nitrogen and oxygen intermediates of duck macrophages also depressed after $AFB_1$ exposure, and this implied that $AFB_1$ could cause deteriorated functions of bacteriocidal and tumoricidal activity in duck macrophages.