Indigenous Muscovy ducks in Congo-Brazzaville. 1. A survey of indigenous Muscovy duck management in households in Dolisie City

A cross-sectional study by means of a questionnaire with open-ended questions and multiple-choice questions was used to collect data on the profile of duck keepers, husbandry practices, and performances, opportunities and constraints of Muscovy duck breeding in households (n = 88) in Dolisie city (Congo-Brazzaville). The study confirmed the common observations on traditional poultry keeping such as scavenging during the day and housing overnight. The flock size (7.7 ± 3 ducks per unit) showed no specialization of husbandry (100% of surveyed flocks were kept for simultaneous production of ducklings, meat and eggs) and a high drake-to-duck ratio (1:3). The hatchability was close to 80.5% ± 13%, whereas the average number of eggs was 13.2 ± 5 per clutch. In addition, a high mortality (80%) was observed in ducklings, which was due to poor feeding, lack of veterinary care and housing conditions. Eggs and live ducks were sold by duck farmers in response to the family needs rather than market price. The three most important findings were as follows: (1) duck keepers were mainly men (80% versus 20% of women); (2) there was no evidence of taboo; and (3) the duck as an exotic bird was not proscribed by cultural beliefs, and therefore development of the Muscovy duck in Congo Brazzaville should be unhindered.     

Heritabilities and genetic correlations of body weights and feather length in growing Muscovy selected in Taiwan

1. Heritabilities and genetic correlations in the base population of a closed strain of Muscovy duck, moderately selected for body weight at 10 weeks of age, have been estimated from the data of 9 successive generations for the following traits: male and female body weight at 10 and 18 weeks of age (BW10m, BW18m, BW10f, BW18f) and length of the 8th primary feather at 10 weeks of age (F110m, F110f). 2. Multivariate REML with an animal model was used, pooling data from the 9 generations (3283 and 3289 male and female offspring respectively). The same trait expressed in male and female was considered as 2 different traits. 3. The 8th primary feather was longer in females than in males by 6% to 22% at 10 weeks of age. Body weight was heavier in males than in females by 42% to 58% at 10 weeks of age and by 57% to 75% at 18 weeks of age. 3. The heritability estimates for body weight traits showed moderate values, being a little higher for females than for males at the same age, increasing with age from h2=0.24 at BW10m to h2=0.43 at BW18f. 4. The heritability estimates for feather length showed that a greater response would be obtained in selection for male feather length (h2=0.37) than for female length (h2=0.14). Both have high genetic correlations with body weight so they could be indirectly improved. 5. Heritabilities of the difference in body weights between males and females at 10 weeks (h2=0.07) and 18 weeks of age (h2=0.10) were small, as well as for feather length (h2=0.10). It would probably be difficult to modify sexual dimorphism in body weight through selection. 6. Genetic correlations between BW10m, BW18m and BW10f, BW18f were respectively r(g)=0.77 and r(g)=0.80. They were larger for body weight at the same ages between males and females, r(g)=0.90 (r(g)=0.88 between F110m and F110f). Body weight in males and females at the same age should be better considered as 2 different traits in a selection programme. 7. The cumulated predicted genetic gains expressed per unity of the genetic standard deviation (sigma(g)) over the 8 generations of selection were 1.3 sigma(g) and 1.4 sigma(g) respectively for the BW10m and BW10f. The predicted correlated responses were 1.2 sigma(g) for body weights at 18 weeks of age, 0.9 sigma(g) and 0.7 sigma(g) for F110f and F110m respectively.     

Heritabilities and genetic correlations of laying performance in Muscovy ducks selected in Taiwan

1. Genetic parameters in the base population of a closed experimental strain of Muscovy ducks, selected for body weight at 10 weeks of age, were estimated from data in 8 successive generations, for the following traits: age at first egg (AGE1EGG), total number of eggs laid at 40 and 52 weeks of age (NEGG40 and NEGG52), number of eggs laid during 15 and 22 weeks in the first laying cycle (NEGG15W and NEGG22W), and their Box-Cox transformed data. 2. The method of multi-trait restricted maximum likelihood with an animal model was used to estimate genetic parameters. Only the results obtained with non-transformed data are shown. 3. Heritability estimates for laying performance showed moderate values, increasing little with age: 0.20+/-0.03 (AGE1EGG), 0.23+/-0.03 (NEGG40), 0.27+/-0.03 (NEGG52), 0.20+/-0.03 (NEGG15W), and 0.22+/-0.03 (NEGG22W). 4. Genetic correlations between laying traits were high. Genetic correlation between AGE1EGG and egg number was negative, it was positive between total numbers of eggs at 40 and 52 weeks and egg numbers in the first laying cycle. 5. Body weight at 10 weeks of age exhibited positive genetic correlations (0.46+/-0.06) with age at first egg and negative with egg production traits (-0.28+/-0.06 to -0.41+/-0.06). 6. The cumulated predicted genetic gains, after 7 generations of selection, expressed per genetic standard deviation unit (sigma(g)) were 0.06 sigma(g), 0.07 sigma(g), 0.17 sigma(g), 0.23 sigma(g), and 0.25 sigma(g) for AGE1EGG, NEGG40, NEGG52, NEGG15W, and NEGG22W, respectively. 7. Selecting Muscovy ducks to improve laying in Taiwanese climatic conditions would be possible using the number of eggs laid up to 52 weeks of age as the selection criterion. Because unintended selection effects for laying traits were present, the selection experiment for body weight at 10 weeks of age was not antagonistic with laying traits.     

Study of the live body weight and body characteristics of the African Muscovy duck (<Emphasis Type="Italic">Caraina moschata</Emphasis>)

Three hundred and twenty 1-week old ducklings (160 males and 160 females) were used to evaluate the body weight, body parts and carcass characteristics of the African Muscovy duck. Sexual dimorphism was in favour of the male for all the parameters throughout the experimental period, however the difference was significant (P < 0.05) only after week 2. The 12-week old male weighed 1832.0 ± 180.4 g while the female reached only 68.2% of the male weight. Metatarsus diameter, thoracic perimeter, body length, length of bill, foot and wing in cm were respectively 1.3, 29.5, 57.5, 7.0, 27.1 and 27.8 for the male as compared with 1.2, 25.8, 51.0, 6.3, 23.3 and 26.9 for the female. Body measurements were highly (P < 0.01) correlated with body weight for both sexes, however the highest correlation coefficients were obtained with wing length (0.990 and 0.995) and thoracic perimeter (0.993 and 0.973) for female and male respectively. Live body weight had a linear relationship with both wing length (R² = 0.991 and 0.81) and thoracic perimeter (R² = 0.948 and 0.986) for male and female respectively. The female duck yielded higher percent ready-to-cook carcass (66.3%), breast (13.6%), liver (2.8%), heart (1.5%) and gizzard (3.8%) as compared to the male (65.0%, 12.0%, 2.5%, 1.1% and 3.4% respectively) although the difference was not significant (P > 0.05). The male small intestine (185.1 ± 3.4 cm), colon (14.8 ± 1.0 cm) and caecum (17.9 ± 0.4 cm) were significantly (P < 0.05) longer than that of the female (152.2 ± 1.8, 10.8 ± 0.7 and 14.85 ± 0.6 cm respectively).     

Crossbreeding effects on reproductive traits in two strains of duck (Anas platyrhynchos): Brown Tsaiya and Pekin

1. The reproductive performances of 211 domestic duck females (Anas platyrhynchos) from the pure breeds Brown Tsaiya (Ts) and Pekin (Pk) and their two reciprocal crossbreds were analysed.

2. Differences in the 4 genotypes, additive direct and maternal crossbreeding effects and heterosis were estimated on the following traits: age at first egg, egg production to the ages of 30, 35, 40 and 52 weeks of age, egg weight at 30 weeks of age, and (egg) fertility by artificial insemination with Muscovy drakes’ pooled semen.

3. Egg production up to 52 weeks of age was higher in Ts than in Pk (respectively 214 ± 7 and 150 ± 8 eggs), but not statistically different from that of the reciprocal crossbreds. The ratio of settable eggs to total eggs was nearly 90%, without any difference between genotypes.

4. Average egg weight at the age of 30 weeks was 75 ± 0.9 g for Pk, which was higher than the corresponding values for Ts (62 ± 0.8 g), but not significantly different from the crossbreds.

5. An effect of genotype was found on egg fertility: the Pk strain exhibited the lowest value, 71.3 ±3.1% compared with 75.9 ±2.1% for Ts, 80.6 ± 2.6% for Ts × Pk and 74.6 ± 1.9% for Pk × Ts.

6. Crossbreeding genetic variables showed favourable direct genetic effects for egg production and (egg) fertility in Ts, while Pk had favourable direct genetic effects on egg weight. The Pk genotype had a favourable maternal effect on fertility. Direct heterosis was 34% and 10% for egg production up to 30 and 52 weeks of age respectively, 8.8% for egg weight and 5.4% for (egg) fertility.

7. Crossing Ts with Pk seems profitable for the production of mule ducklings.     

不同杂交组合半番鸭生产性能的研究

以法国番鸭为父本 ,分别以樱桃谷鸭、金定鸭及樱桃谷鸭与金定鸭杂交后代为母本 ,组成 3个杂交组合。采用人工授精的方法生产半番鸭 ,观测各杂交组合半番鸭的生长速度、生活力、产肉效率和经济效益。发现番樱半番鸭 1 0周龄体重、料肉比、产肉效率、经济效益等指标明显优于其他 2个组合 ,番樱金半番鸭其次 ,番金半番鸭最差     

白羽番鸭生长曲线拟合比较分析

试验测定不同性别法国白羽番鸭早期体重,用Logistic、Von Bertalanffy和Gompertz 3种非线性生长模型拟合其生长曲线。研究结果表明,白羽番鸭公鸭、母鸭4周龄前生长缓慢,后期公鸭生长快于母鸭;通过比较拟合优度（R2）、残差平方和（E）和进行适合性χ2检验结果发现,Gompertz模型拟合效果最佳。进一步比较不同性别Gompertz模型拟合参数,结果发现公鸭与母鸭相比,有较高的初始体重、极限体重、最大周增重和拐点体重,较低的初始生长速度。公鸭拐点周龄为7.03周,较母鸭的5.37周龄晚;公鸭4周龄前相对生长率小于母鸭,4周龄后则超过母鸭,绝对生长率差异较大。     

Evidence of Muscovy duck parvovirus in Muscovy ducklings in California

Muscovy duck parvovirus (MDPV) has been demonstrated in tissue samples from one- to four-week-old commercially reared Muscovy ducks that were weak, unable to walk and had a high mortality rate. On postmortem examination, the thigh and leg muscles, and the myocardium were found to be pale, and there was a fibrinous exudate on the capsule of the liver, and ascites. The parvovirus was isolated in embryonated Muscovy duck eggs and visualised by negative stain electron microscopy, detected by polymerase chain reaction (PCR) directly from the tissues, and antibodies to it were detected by immunoelectron microscopy, ELISA and immunofluorescence. In addition, the PCR products obtained that represented 1625 bp (74 per cent) of the capsid vP1 gene, including a hypervariable region between Derzsy's disease virus or goose parvovirus and MDPV, were sequenced and shown to be 100 per cent homologous with the MDPV 89384 reference strain, but only 82.3 per cent homologous with Derzsy's disease virus.     

Reproductive season and male effect on quantitative and qualitative traits of individually collected Muscovy duck (Cairina moschata) semen

Males of Muscovy duck (Cairina moschata) are mainly used for mule duck production via artificial insemination of females originated from wild mallard duck (Anas platyrhynchos); therefore, the quantity and quality of drake semen play a crucial role. The assessment results of male reaction to sexual stimulation by dummy female and basic semen characteristic (ejaculate volume, sperm concentration and morphology) of 12 individually kept Muscovy drakes carried out during the entire reproductive season are described. The male and period of the reproductive season effect on scored semen traits are documented. In total, 792 individual semen collections and evaluations were performed. The average of positive reaction in the entire reproductive season varied from 90.6% in December and April to 50.0% in July, while for individual males, it varied between 97.1% and 29.0%. Throughout the season, the ejaculate volumes ranged from 0.05 to 2.45 ml, sperm concentration from 0.15 × 10⁹ ml⁻¹ to 4.44 × 10⁹ ml⁻¹, total number of live spermatozoa from 68.0% to 100% and live normal (properly formed, with any deformations) from 51.0% to 99.0%. Our study indicates the necessity of male breeders pre-selection before the onset of the reproductive season, and the need to leave an appropriate number of males to ensure adequate amount of semen for female insemination, especially when using Muscovy drakes (Cairina moschata) for interspecies crossing with Anas platyrhynchos ducks.     

Effect of selection for improved body weight and composition on muscle and meat characteristics in Muscovy duck

1. For 25 years, the Muscovy duck has been selected for greater body weight at slaughter age, higher meat yield and lower fat content. The aim of this study was to analyse the effects of such selection on the biochemical and technological characteristics of duck meat. 2. A line which has been maintained without any selection since 1975 (control line) and a heavy line now commercialised (selected line) were reared under the same conditions. We compared growth performances, dressing and dissection yields and biochemical and technological characteristics of duck meat at 8, 10 and 12 weeks of age. 3. Our results showed that an indirect effect of selection was to increase the duck growth rate. At a given age, muscle weights and yields as well as carcase fat content were higher for selected ducks. In the selected line, muscle fibres were larger and the collagen content in muscles lower. 4. The Sartorius muscle in ducks from the selected line exhibited a higher percentage in numbers of white type IIb fibres to the detriment of red type IIa fibres. Its glycolytic enzyme activity was higher and its oxidative enzyme activity lower. 5. In breast muscle, selection decreased the rate of post-mortem decline in pH value, increased protein and mineral contents and decreased moisture. It did not affect fibre type, colour, haem pigment and lipid contents, collagen solubility or drip loss. 6. In conclusion, the effects of Muscovy duck selection on meat quality were relatively moderate.     

Effects of egg weight on the egg quality,chick quality,and broiler performance at the later stages of production (week 60) in broiler breeders

The objective of the present study was to determine the effect of broiler breeder egg weight on egg quality, chick quality, and broiler performance using Hubbard Classic broiler breeder flock. Hatching eggs from a commercial broiler breeder flock (Hubbard classic strain) were obtained at the age of 60 wk and divided into 3 egg-weight categories, namely small, medium, and large. For this purpose, 930 eggs having weights 63.09 ± 0.21, 68.85 ± 0.23, and 74.81 ± 0.11g were divided into 3 egg categories labeled small, medium, and large respectively. We further divided these eggs into 2 categories, eggs for quality parameters and eggs for incubation and posthatch performance parameters. Eggs from the small egg category had greater proportion of the shell weight and more shell strength. Egg weight did not significantly affect the albumen and yolk weight percentage. Egg weight affected the shape index and specific gravity for which lower values were observed for large eggs. Egg weight positively affected the chick weight, chick yield, and chick length (P < 0.05) of both male and female chicks. Results of the body weight gain showed that effect of egg weight on the posthatch performance of chick diminishes with the age of broilers. Egg weight significantly affected the body weight gain of male and female chicks up to 3 wk of age. Egg weights did not significantly affect the feed intake and mortality of broiler. Different egg-weight categories significantly affected the feed conversion ratio of female chicks at wk 2 and 3 of age and did not affect the feed conversion of male and female chicks at the end of wk 5. In conclusion, egg weight positively affected the chick characteristics (e.g., chick weight, chick length) and did not affect the final live body weight, feed conversion ratio, feed intake, and mortality in broilers.     

蛋重对蛋鸭孵化效果的影响

将三个品种(攸县麻鸭、麻旺鸭和三穗鸭)种鸭蛋按蛋重各分5个组在相同的条件下孵化,研究蛋重对不同品种孵化效果的影响。结果表明,种蛋受精率和入孵蛋孵化率:攸县麻鸭蛋重在65~73 g最高,麻旺鸭蛋重在66~70 g最高,三穗鸭蛋重在66~74 g最高,种蛋过重或过轻均不利于种蛋孵化。胚胎死亡率:攸县麻鸭在蛋重61~65 g最低,三穗鸭在蛋重小于62 g时最低,麻旺鸭在蛋重小于58 g时最低,攸县麻鸭种蛋重量适中有利于胚胎成活,三穗鸭和麻旺鸭种蛋重量较轻时有利于胚胎成活。     

3个品种鸭的屠宰性能及肌肉营养成分比较

将番鸭、樱桃谷鸭、高邮鸭饲养到70日龄屠宰。测定屠宰性能,同时取胸肉和腿肉测定营养成分。结果表明:樱桃谷鸭早期生长速度最快;番鸭是3个鸭品种中肉用性能最好的优质肉鸭,樱桃谷鸭的腿肉比例偏小,高邮鸭的胸、腿肌率均未达到优质肉鸭的要求。番鸭鸭肉中水分含量较高,樱桃谷鸭与高邮鸭鸭肉中脂肪含量较高。     

四个肉鸭品种的生产性能比较试验

选择北京鸭、英国樱桃谷鸭，美国枫叶鸭，法国番鸭各100羽（公、母各半）在同一条件下进行对比试验，结果表明，美国枫叶鸭的肉用性能明显优于其它3个品种，饲养47d可齐毛上市，平均体重为3132g，而樱桃谷鸭为2815g，北京鸭为2780g，法国番鸭为1753g，经屠宰测定，枫叶鸭全净膛率达76．40%，均高于樱桃谷鸭（74．18％），北京鸭（74．41％），法国番鸭（72．21％），另外，对供试肉鸭品种的耗料量与体重进行了回归分析。     

北京鸭蛋重与受精率、孵化率、蛋形指数及出雏重的关系

本研究将北京鸭Z1系种蛋分为小蛋组(82～92g)、中蛋组(92～105g)和大蛋组(106～124g),分别研究蛋重与受精率、孵化率、蛋形指数及初出重等性状的关系.结果表明蛋重对受精率的影响差异不显著(P＞0.05),但随着蛋重增大,受精率有增大的趋势;孵化率随蛋重的增加而显著减小(P＜0.05或P＜0.01);蛋重对蛋形指数的影响不显著(P＞0.05);雏鸭出生重受蛋重的正向影响差异极显著(P＜0.01).综合以上结果,本文得出北京鸭Z1系适宜孵化的蛋重范围是82～105g.     

不同限饲水平对产蛋期肉种鸭生产性能的影响

本研究旨在探讨不同限饲水平对产蛋期肉种鸭生产性能和孵化指标的影响。试验选取 ４０周龄父母代 ＳＭ３樱桃谷种鸭 ３２００只（母鸭 ２６００只,公鸭 ６００只）,随机分成 ４组,每组 ５个重复,每个重复 １６０只鸭（母鸭 １３０只,公鸭 ３０只）。以玉米 －豆粕 －小麦型配合饲料（代谢能 １１．５０ＭＪ／ｋｇ,粗蛋白质 １８．００％）为基础饲粮。Ｔ１组日饲喂料量最大,为每只鸭 ２２５ｇ,其他组依次降低 １５ｇ,分别为 ２１０（Ｔ２组）、１９５（Ｔ３组）和 １８０ｇ（Ｔ４组）,试验期 ３５ｄ。结果表明：１）当日饲喂料量由２２５ｇ下降到２１０ｇ时,公、母鸭的体增重均显著下降（Ｐ＜０．０５）,产蛋率略有上升,蛋重略有下降,但二者变化均不显著（Ｐ＞０．０５）,当日饲喂料量继续下降到 １９５和 １８０ｇ时,与日饲喂料量 ２２５ｇ时相比,公、母鸭体增重、产蛋率和蛋重均显著下降（Ｐ＜０．０５）;２）经回归分析,公、母鸭体增重、产蛋率、蛋重与日饲喂料量有显著的直线或二次曲线关系（Ｐ＜０．０５）,产蛋率与蛋重之间也有显著的二次曲线关系（Ｐ＜０．０５）;３）日饲喂料量对种鸭死淘率及种蛋合格率、受精率、健雏率、入孵蛋孵化率和受精蛋孵化率均无显著影响（Ｐ＞０．０５）。结果提示,适当限制饲喂料量可降低体增重,提高产蛋率,但过度限饲会影响生产性能。     

The growth and carcass characteristics of crosses between Aabio and Tegal ducks and Muscovy and Pekin drakes

1. The growth and food utilisation of Pekin, Alabio and crosses between Muscovy or Pekin drakes and Alabio or Tegal ducks were recorded up to 20 weeks of age on a high plane of nutrition. Ducks were killed at 6, 10 and 16 weeks of age for carcass analysis.

2. The weight of Alabio ducks at 12 weeks of age was increased by 40 and 48% by crossing with Muscovy and Pekin respectively. Pekin crosses grew faster to 8 or 12 weeks of age than Muscovy crosses but after 17 weeks of age there was no significant difference in weight. Food utilisation for Muscovy crosses was generally better at all ages.

3. Both at a given age and per unit of carcass weight, Muscovy crosses contained less fat and as a consequence more protein and ash, and a higher proportion of breast meat than Pekin crosses. Proportion of fat in Muscovy × Tegal ducks increased only slightly with carcass weight, while it decreased in Muscovy × Alabio ducks.     

An Assessment of the Productivity for Meat and the Carcase Yield of Camels (Camelus dromedarius) and of the Consumption of Camel Meat in the Eastern Region of Ethiopia

A survey on camel meat productivity and consumption was conducted in Jijiga and Harar towns in 1999. Almost all the camels slaughtered were adults, predominantly males. Measurements of height, hump girth and thoracic girth were used to estimate the live weight. All the measurements were significantly greater in the male than in the female camels. Average live and carcass weights were 400 and 211 kg, respectively. Males were significantly heavier (p < 0.05) and had better dressing percentages than females. The carcasses contained averages of 76% meat, 12% fat and 20% bone for both males and females. The difference between the males and females was not significant for the ratio of meat and bones, except for fat, which was higher in the males. Camel meat is regarded as a high-quality food with medicinal value and as a least-cost source of meat. Camel meat is preferred to that of any other livestock by some people, particularly by the Somalis in Jijiga town. It is also more available, especially during the dry season when beef is in short supply. Hence, camel meat is a socially acceptable, economically viable and environmentally adaptable alternative source of meat, consumption of which should be encouraged.     

半番鸭及其亲本生长曲线拟合与杂种优势分析

实验测定了樱桃谷鸭、白羽番鸭、苏牧麻鸭、白羽番鸭♂×樱桃谷鸭♀(樱番鸭)、白羽番鸭♂×苏牧麻鸭♀(苏番鸭)早期体重数据,发现樱番鸭杂种优势率为12.8%,苏番鸭为22.04%。用Logistic、Von Bertalanffy和Gompertz3种非线性生长模型拟合其生长曲线,通过比较拟合优度、复相关指数和进行适合性χ2检验,发现Gompertz模型拟合效果最好。比较5组鸭Gompertz模型拟合参数,结果表明:在亲本鸭组中白羽番鸭初始重较樱桃谷鸭和苏牧麻鸭高,初始生长速度、最大周增重较这2个亲本组低,拐点时间也比其晚。2个杂交组最大周增重、成熟速度、极限体重、拐点体重、初始重和拐点时间都有很大提高,存在明显的杂种优势。     

Requirements of Muscovy ducks (Cairina moschata domestica) for crude protein and energy levels of fattening diets

Groups of male and female Cairina ducks subjected to equal starter feeding (1st to 3rd weeks) were used from the 4th week of live (fattening period) to test feed mixes of varying energy and crude protein levels (480 energetic feed equivalents/heu[EFH] - 140 g crude protein[CP]; 480 EFh - 180/g CP; 555 EFh - 140 g CP; 555 EFh - 180 g CP; 625 EEh - 140 g CP; 625 EFh - 180 g CP - all figures referred to 1 kg of feed). The different energy levels remained without influence of the live weight development. High-energy feed caused, however, higher expenditures of energetic feed equivalents per kg of gain and resulted in carcases with higher fat proportion. At all the 3 energy levels under study, high-protein feeding proved superior to low-protein rations with regard to live weight gains and meat yield. For the time being, 500 EFh and 180 g CP per kg of organic matter are recommended as indicators for Cairina duck fattening rations.