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1.
1. Thirty‐two Khaki Campbell laying ducks were divided into two equal groups and housed either in floor pens or in cages in an environmentally controlled building. The food for two replicate groups of four birds each in each management system was rationed by weight and two other replicate groups were fed ad libitum. Housing and feeding treatment effects were assessed by measuring efficiency of food conversion into eggs and egg production.

2. Housing ducks in cages did not reduce egg production or efficiency of food conversion compared with the more conventional floor‐pen housing system. Egg production and egg size were adversely affected by the restricted feeding programme.

3. Caging in a controlled environment with unrestricted food appears to be a potentially feasible management system for laying ducks, comparable with such systems for laying fowls.  相似文献   


2.
A cross-sectional study was conducted between May 2003 and January 2004 on 130 households and 655 (246 indigenous and 409 crossbred) cattle to determine the prevalence of bovine tuberculosis (bTB) and assess risk factors associated with prevalence in smallholder dairy and traditionally managed herds in the Tanga region of North-eastern Tanzania. Random sampling, single intradermal tuberculin (SIT), comparative intradermal tuberculin (SCIT) tests and a questionnaire were used to gather individual animal and herd level information. From 642 animal tested by SIT, 35 (5.4%) were positive reactors for tuberculosis. Out of those 35 bTB positive reactors, eight (1.25%) proved to be positive reactors for tuberculosis upon further testing by SCIT. Based on the SCIT test, individual animal prevalences of bTB in the smallholder dairy and traditionally managed cattle was 2% and 0%, respectively. The corresponding overall herd prevalence was 5.7% and 0%, respectively. In conclusion, bTB prevalence seems low; however, its potential risk to public health is of concern; underscoring the need for further research, active surveillance to better understand the epidemiology of the disease in different cattle production systems in Tanzania.  相似文献   

3.
Maternal performance of 134 Hereford (H), Brangus (B), and reciprocal crossbred (H x B and B x H) cows from 2 to 7 yr of age was evaluated under semidesert conditions in this study. Calves produced by 2- and 3-yr-old cows were sired by Brangus and Hereford bulls. Calves produced by 4- to 7-yr-old cows were sired by Charolais bulls. Breed of sire and breed of dam of cow affected kilograms of weaning weight, 205-d weight, weaning weight as a percentage of cow weight, and 205-d weight as a percentage of cow weight produced annually. Brangus (either as sire or dam of cow) was superior to Hereford in all cases. Observed maternal heterosis on 2- to 3-yr-old cows was 23.0, 20.1, 30.0, 29.1, 23.9, and 23.0% for calf birth date, weaning percentage, weaning weight per year, 205-d weight per year, weaning weight as a percentage of cow weight per year, and 205-d weight as a percentage of cow weight per year, respectively (P less than .01). Observed maternal heterosis from mature cows was 19.8, 12.8, 21.0, 18.7, 17.4, and 15.4% for calf birth date, weaning percentage, weaning weight per year, 205-d weight per year, weaning weight as a percentage of cow weight per year, and 205-d weight as a percentage of cow weight per year, respectively (P less than .01). Results indicate large heterotic effects on annual cow productivity and an adaptive advantage for cows with Brangus sires and(or) dams under semidesert conditions.  相似文献   

4.
5.
Data on adult body weight of ewes belonging to Nali, Chokla breeds and their crosses (F1) with Rambouillet and Soviet Merino raised under semi-arid conditions in India were analysed. The ewes belonged to 5 distinct age groups ranging from 16.5 to 64 months. Nali and Chokla were significant lighter than all the 4 crossbred groups. There were no significant differences in body weight between crossbred groups except in the case of Soviet Merino x Chokla group which was the lightest and differed significantly from all other groups. Rambouillet crosses were heavier than Merino crosses but the difference was statistically significant only on Rambouillet x Chokla and Merino x Chokla. The improvement in body weight in crossbreds over native sheep ranged between 9.3 and 21.88%. The increase in live weight was significant only up to 49 months.  相似文献   

6.
不同杂交组合半番鸭生产性能的研究   总被引:3,自引:1,他引:3  
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  相似文献   

7.
1. Mule ducks were produced by naturally mating Muscovy drakes and Khaki Campbell ducks. 2. Semen was collected from 6-month-old mule drakes via an artificial vagina. The fluid was clear without any spermatozoa or spermatids. 3. Testes from 27-week-old mule drakes were smaller in size than those of Khaki Campbell drakes but heavier than Muscovy males of the same age. Histological sections of these testes revealed that spermatogenesis was not complete. 4. Testosterone concentration in the mule drakes was higher than in Muscovy males but similar to Khaki Campbell drakes. 5. Mule drakes have strong sexual drives as a result of high concentrations of testosterone, but, because spermatogenesis is incomplete, their semen had no sperm.  相似文献   

8.
9.

The objective of this study was to evaluate the protein requirement of Korat chicken (KRC), a slow-growing cross strain between the Thai indigenous fighting cock (Leung Hang Khoa) and the modern genotype females. Four periods were considered: from hatch to 21 days (phase 1), 22 to 42 days (phase 2), 43 to 63 days (phase 3), and 64 to 84 days of age (phase 4). A total of 3120 mixed-sex KRC were randomly allocated to 5 dietary protein levels containing 19, 20, 21, 22, and 23% with 2978 kcal of ME/kg (900 birds in phase 1); 18, 19, 20, 21, and 22% with 3151 kcal of ME/kg (780 birds in phase 2); 16, 17, 18, 19, and 20% with 3200 kcal of ME/kg (720 birds in phase 3); and 15, 16, 17, 18, and 19% with 3200 kcal of ME/kg (720 birds in phase 4) with 6 replicates in a completely randomized design. The results showed that BW, BW gain, average daily gain (ADG), and protein intake (P?<?0.05) were increased with increasing dietary protein (P?<?0.05) in all phases. However, FI, feed cost per kg of BW gain, energy intake, and blood urea nitrogen of chickens were not found to be significantly different among treatments. On the other hand, increasing dietary protein levels depressed the protein efficiency ratio of chickens from hatch to 21 and from 64 to 84 days of age (P <?0.05), and tended to decrease it from 22 to 42 (P?=?0.08) and from 43 to 63 (P =?0.07) days of age as well. According to a broken-line regression analysis, the protein requirements of chickens from hatch to 21 and from 22 to 42 days of age for maximum BW gain were 21.26 and 20.45%, respectively. While the requirements of maximum responses for BW gain and FCR in the period of 43 to 63 days of age were 18.00 and 18.04%, respectively, and in the period of 64 to 84 weeks of age were 17.94 and 18.03%, respectively.

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10.
11.
This study aimed to characterize the local chickens and their production systems and to investigate the opportunities for improvement. The study was carried out in 18 villages in northern Jordan with the participation of 120 households. Data were collected by individual interviews and surveys supported with structured questionnaires. A scoring system was developed to study the effect of different levels of management on chicken performance. The main reasons for keep local chickens were egg production and generation of income. The main features of the production systems were improper housing and inadequate hygiene. Newcastle disease, predators, and parasites were the main causes of flock losses. Purchasing rate was controlled by the chickens’ phenotype, sex and age, and by season of year. The average flock size was 41.6 (±32.9) chickens per household, with a hen:cock ratio of 6.4:1. The average effective population size was 15.35, which indicated a high rate of inbreeding (5.52%). The main selection criterion adopted by farmers was egg production. There were positive significant correlations (p < 0.001) between management level and chickens’ performance. Hatchability, survivability, flock size, number of clutches, egg weight and egg mass were the major parameters that improved significantly with improvement in management level. Local chickens fulfil significant functions in the livelihood of rural smallholders; however, many constraints affected the efficiency of the production systems. Solutions should start with improving the management practices and establishing an effective breeding system.  相似文献   

12.
Occurrence and diversity of Eimeria species in two groups of indigenous South African goats kept under traditional management systems, as well as in a mixed herd of Saanen, indigenous and crossbred goats kept under an intensive management system were examined. Infection rates ranged from 88.7 to 100% in the various groups. Mean OPG of immature goats (< 1 year old) exceeded that of adult goats at all three sites. There was no consistent difference between adult OPG counts at the three sites. Under the intensive system, adult crossbred goats had significantly higher OPG counts than adult Saanen or indigenous goats. Overall, OPG counts of immature goats were significantly higher during the dry season (winter) than during the wet season (summer). Ten Eimeria species were identified, Eimeria arloingi being the most prevalent species at all three sites, followed by Eimeria hirci. Up to seven Eimeria species were recovered from individual specimens.  相似文献   

13.
Summary Chicken mortality was studied in 24 randomly selected smallholder flocks in one village in Yucatan, Mexico between July and December 1993. Each family received a package of 10 to 12 chicks of 3 weeks of age. Approximately half of the chicks were purebred and the remainder were crosses produced by mating exotic with local breeds. All smallholders were visited twice a week. Feeding and management (except vaccination and medication) were left to smallholders. Data were processed by Chi-square, Mantel-Haenzel test and survival analysis. Before reaching 140 days of age 43·2% of the birds died. The highest mortality was observed during the 113 to 140 days of age period and the lowest was in the period between 22 and 56 days of age. Of all birds, 10·5% died from coccidiosis and 7·6% from Marek’s disease. Of the risk factors investigated only medication and genotype showed significant effects on mortality. The effect of genotype was significant up to 112 days of age (P < 0·05). Crossbred birds lived longer than purebred; independently, medicated birds lived longer than non-medicated birds.
Factores Que Afectan La Mortalidad De Los Pollos Hibridos Y Exoticos (Criados Bajo Sistemas De Traspatio) En Yucatan, Mejico
Resumen Se estudió la mortalidad de pollos alojados en 24 corrales de peque?os propietarios seleccionados al azar en un pueblo de Yucatán, México de julio a diciembre de 1993. Cada propietario recibió un grupo de 10 a 12 pollos de 3 semanas de edad. Aproximadamente la mitad de los pollos eran de raza pura y el resto hibridos provenientes de cruce de una raza exótica con una local. Todos los corrales fueron visitados dos veces por semana. La alimentación y el manejo (excepto vacunas y medicamentos) corrieron a cargo de los propietarios. Los datos se analizaron por el test de Chi-cuadrado, test de Mantel-Haenzel y análisis de supervivencia. Antes de que alcanzaran los 140 días de edad el 43·2% de las aves murieron. La mortalidad más alta se observó entre los días 113 y 140 de vida, y la mortalidad más baja durante el periodo de 22 a 56 días de edad. De todas las aves, el 10·5% murieron de coccidiosis y el 7·6% de la enfermedad de Marek. De los factores de riesgo estudiados, solo la medicación y el genotipo mostraron efectos significativos sobre la mortalidad. El efecto del genotipo fue significativo a partir del día 112 de edad (P < 0·05). Las aves híbridas vivieron más que las razas puras; independientemente, las aves medicadas vivieron más que las no medicadas.

Facteurs Affectant La Mortalite Des Poulets (De Race Ou Croises) Gardes En Systeme Ferme Dans Le Yucatan Au Mexique
Résumé La mortalité des poulets fut étudiée chez 24 petits éleveurs de volaille, choisis arbitrairement dans un village du Yucatan au Mexique entre les mois de Juillet et Décembre 1993. Chaque famille re?ut entre 10 et 12 poussins agés de 3 semaines. Près de la moitié des poussins furent de races pures, les autres étant issus de croisements entre races locales et exotiques. Tous les éleveurs furent visités deux fois par semaine. Les éleveurs décidèrent à propos de la nourriture et de la gestion mais pas de la vaccination ou des médicaments. Les données furent analysées par le test de Mantel-Haenzel, l’analyse de la survie et lex 2. 43,2% des poulets moururent avant d’atteindre l’age de 140 jours. La plus grande mortalité fut observée entre les jours 113 et 140 et la plus faible entre les jours 22 et 56. 10,6% des poulets moururent de coccidiose et 7,6% par la maladie de Marek. Médicaments et génotype furent les 2 paramètres ayant des effets significatifs sur la mortalité. L’effet du génotype fut significatif jusqu’au jour 112 (P < 0,05). Les animaux issus de croissement vécurent plus long-temps que les poulets de race pure, indépendemment les poulets recevant des medicaments vécurent plus longtemps que ceux qui n’en eurent pas.
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14.
采用放射免疫分析法 (RIA)测定了不同日龄 (60 ,10 0 ,2 0 0和 380日龄 )绍兴鸭和卡基 康贝尔鸭 (KhakiCampbellDuck)血清中促性腺激素释放激素 (GnRH)浓度 ,试图通过比较不同品种、性别和日龄鸭之间GnRH浓度的变化 ,探讨GnRH与产蛋性能的关系。结果表明 :绍兴鸭和康贝尔鸭母鸭血清中GnRH浓度呈现类似的年龄性变化 ,60日龄时GnRH浓度较低 ,10 0日龄时最高 ,2 0 0日龄时显著下降 ,380日龄时回升至较高水平。公鸭血清中GnRH浓度的年龄性变化与母鸭相似 ,10 0日龄时最高 ,2 0 0日龄时最低  相似文献   

15.
Thirty-six adult ewes rearing single male lambs were randomly allocated to three paddocks (n = 12) grazing permanent Pyrenean pastures in spring (0.5 ha/lot). Treatments were rationed grazing (Rat-Gr) in which lambs remained indoors and ewes grazed during 8 h/day (08:00–16:00 h) and were supplemented 0.5 kg/day of barley meal; continuously grazing ewes rearing non-supplemented lambs (Gr) and continuously grazing ewes rearing supplemented lambs in creep feeders at pasture (Gr + S). Grazing behaviour was registered at weekly intervals by direct observation during the outdoor time in Rat-Gr and from dawn to dusk in Gr and Gr + S.

Sward height of Rat-Gr became higher than the rest (P < 0.05), resulting in a greater dry matter and a lower crude protein content of this pasture (P < 0.05). Ewe live-weight, body condition score and lumbar fat thickness were similar across treatments (P > 0.05), while milk yield was higher in Gr + S (P < 0.05). Lambs from Rat-Gr and Gr + S presented a higher average daily gain than Gr treatment (P < 0.05). Grazing behaviour records showed that all treatments spent grazing similar percentages of daylight time at pasture (average 52%; P > 0.05). Ewes biting rate was greater in Gr (P < 0.05) and it was higher after noon in all treatments (P < 0.001). Gr and Gr + S showed an extended peak of grazing (min/h) in the evening. Lambs followed the grazing pattern of dams since 3 weeks old. It was concluded that in contrast with the traditional indoor system of managing production of light lambs both spring continuous grazing systems allowed producing Ternasco lambs (18–24 kg LW, younger than 90 days old). Lambs supplemented suckling their mothers and grazing until slaughter showed similar performance to those obtained in indoor system. Dietary supplementation of lambs at pasture did not impair ewes milk yield and grazing time but reduced their biting rate and the offspring grazing time.  相似文献   


16.
Data from 82 kiddings from mixed-breed (native x dairy goats) goats reared on rangeland (n = 47) or confinement (n = 35) were used to determine the influence of various factors on length of labour, standing of newborn kids and time to first suckling in pluriparous goats. Both groups were mated at the same time to bucks of the same genotype in February. During the kidding time in July, the goats were monitored for 24 h in order to register parturition traits and kid birth weight and body measurements. For all goats, blood samples were collected at parturition in order to establish the nutritional state of goats. Grazing goats had lower body weight and body condition score (P < 0.01) than pen-fed goats, as well as lower values for some blood metabolites indicative of low body energy reserves. For both grazing and pen-fed goats, the majority of kiddings (>93%) occurred during daylight hours. No kiddings were registered from 2300 to 0500 hours. No effects of height at withers, thoracic circumference and sex of kids at birth were found to influence length of labour. Labour was shorter (P < 0.01) for pen-fed does than grazing goats (10.6 ± 1.18 min vs. 15.4 ± 1.2 min; mean ± SD). The length of parturition was considerably longer (P < 0.05) for twin-bearing does than for single-bearing does (16.6 ± 1.76 min vs. 11.2 ± 0.81 min, respectively). The interval between parturition and standing of kids was shorter (P < 0.05) for kids from litters weighing >3.3 kg (entire litter) than kids from litters with <3.3 kg (22.7 ± 1.82 min vs. 31.1 ± 2.76 min). Time to first suckling was longer (P < 0.05) for kids delivered from pen-fed does than kids from grazing does (57.8 ± 7.57 min vs. 42.9 ± 3.05 min). These results confirm that, independently of type of production system (intensive or extensive), kiddings of does are concentrated during daylight hours. These results also indicate that conformation of kids does not alter duration of labour, and that nutritional stress of goats during gestation (extensive conditions) does not interfere with the neonate’s level of alertness and arousal.  相似文献   

17.
The performance of indigenous Begait cattle (498 cows, 284 calves, and 48 heifers) in northern Ethiopia was studied. System of herd management significantly (P?<?0.01) influenced all production traits. Calves in medium-input herds (MIHM) grew faster than those in low-input herds (LIHM), by 232 g/d from birth to 9 months (Gain1) and by 385 g/d from 9 to 12 months (Gain2). Cow’s dry period, calving interval (CI), and age at first calving (AFC) were 234, 222, and 343 days shorter for MIHM than for LIHM. Compared with LIHM, cows from MIHM had 74% higher daily milk yield (DMY) and 91% higher lactation milk yield (LMY). Calves born at wet season grew faster by 14 and 10% than those calves born in the dry season at Gain1 and Gain2. The subsequent CI of cows calved in the wet season had 77 days shorter, 0.45 kg DMY, and 93 kg LMY increment. The differences between production systems can be attributed to differences in management skills and access to better quality feeds. Technical intervention is needed to ensure provision of balanced rations to exploit the potential productivity of Begait cattle.  相似文献   

18.
Calf mortality rate and causes of death were studied in peri-urban livestock production systems in Bamako, Mali, for calves born and dying from November 2002 to March 2004. Causes of death for 93 deceased calves were diagnosed from clinical autopsies, reported history of death and parasitic information. Calves originated from traditional, modernized and station management systems. Overall mortality rate was 17% during the first year of life (N = 756 live-births). Mortality rate was significantly lower for traditionally (10%) compared to modernized (19%) or to station managed calves (25%). Total perinatal loss (abortions + stillbirths + perinatal mortality) was 5% (N = 784 gestations). The most important death categories were digestive tract disorders (28%), perinatal mortality (16%) and accidents (14%). Vector-borne and infectious diseases were of low importance. Digestive tract disorders and perinatal mortality were the most important categories of death in modernized management while accidents and starvation were the most important causes of death in traditional management. Digestive tract disorders were more common in modernized than in traditional management (p = 0.02), revealing a serious problem with hygiene in stationary enclosures. With better calf management in regard to hygiene, surveillance and control of milk off-take, overall calf survival may be increased and peri-urban livestock production made more profitable.  相似文献   

19.
为探讨不同褪黑素水平对禽类机体免疫系统的调节作用,通过控制不同光照条件,分3组(短光照组、长光照组和对照组)饲养鸡45只、鸭45只、鹌鹑45只,采用荧光双色染色法和流式细胞仪分别检测鸡、鸭、鹌鹑外周血中CD3^+、CD4^+、CD8^+T淋巴细胞及其亚群和Bu-la^+B淋巴细胞数量变化。结果,短光照组由于体内褪黑素水平较高,外周血中CD3^+CD4^+T细胞、CD3^+CD8^+T细胞、Bu-la^+B细胞及白细胞总数都有不同程度升高,且与对照组相比差异显著;长光照组由于体内褪黑素分泌较少,外周血中CD3^+CD4^+T细胞、CD3^+CD8^+T细胞、Bu-la^+B细胞及白细胞总数都有不同程度降低,且与对照组相比差异显著。结果表明,内源性褪黑素对鸡、鸭、鹌鹑外周血中淋巴细胞及其亚群的数量变化有显著影响。  相似文献   

20.
Data were collected over four consecutive years from four, rotationally grazed, grassland management systems each with 15 spring-calving beef suckler cows and their progeny to 13 months of age. The Systems were high stocking rate (SR), high fertiliser nitrogen (N), 2 silage harvests — HH2; high SR, low N, 2 silage harvests — HL2; low SR, low N, 2 silage harvests — LL2, and low SR, low N, 1 silage harvest — LL1. High and low SR were 0.49 and 0.59 ha cow− 1 unit, respectively, and high and low N amounted to an annual input of 239 and 57 kg ha− 1 on the grazing areas, respectively. Where applicable, the four Systems received 114 and 80 kg of N ha− 1 for the first and second silage harvests, respectively. Equal areas of Systems HH2, HL2 and LL2 were conserved as silage (0.29 and 0.21 ha for first (24 May) and second (4 August) harvests, respectively cow− 1 unit) each year. Silage from System LL1 (0.37 ha cow− 1 unit) was conserved 14 days after the other first harvests. Following the final harvesting for silage within any System these areas of grassland were then grazed. During the winter all animals were housed and cows were offered grass silage and calves were offered silage plus 1 kg of concentrate per head daily. Good cow and calf performance at pasture were obtained at both high SR and high N or low SR and low N. At the high SR, increasing the level of fertiliser N application increased cow liveweight gain at pasture by 24 kg, improved body condition score (BCS) gain at pasture by 0.36 units and prolonged the grazing season by 7 days. Similarly, at the low level of fertiliser N, reducing the SR, increased cow liveweight gain at pasture by 21 kg, improved BCS gain at pasture by 0.23 units and prolonged the grazing season by 7 days. At the low SR all the winter silage requirements could be provided in one as opposed to two harvests thereby reducing the conservation area. However, delayed harvesting of silage resulted in lower silage digestibility and reduced calf performance in winter. The results indicate the specifications for a planned lower N grassland system, particularly where qualification for EU environmental schemes is dependent on moderate stocking densities.  相似文献   

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