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1.
The genetic and demographic bottleneck analysis of Indian camel breeds was carried out utilizing 40 microsatellite markers. Allelic polymorphism was observed at 20 loci in the Indian dromedary breeds. A total of 66 alleles were scored. The average number of alleles, expected heterozygosity and polymorphic information content were, respectively, 3.25?±?0.27, 0.56?±?0.04 and 0.49?±?0.04 in Bikaneri; 3.25?±?0.25, 0.53?±?0.03 and 0.46?±?0.03 in Jaisalmeri; 3.0?±?0.21, 0.53?±?0.04 and 0.45?±?0.03 in Kachchhi and 3.1?±?0.19, 0.51?±?0.03 and 0.44?±?0.03 in Mewari breed. Higher genetic variation was observed in most numerous Bikaneri breed. Genetic distances were least between the breed pair Bikaneri and Jaisalmeri which was closely placed with the Kachchhi breed. The Mewari camels had relatively higher genetic distance from the other three Indian dromedary breeds. The bottleneck analysis revealed the presence of genetic bottleneck in all four breeds of Indian dromedary. However, the qualitative graphical method resulted in normal L-shaped distribution of allele frequencies in Jaisalmeri breeds and shifted mode in Bikaneri, Kachchhi and Mewari breeds. The demographic bottleneck analysis revealed minimum reduction (?9.65 %) in the population of camels in Jaisalmeri breeding tract as compared to that of Bikaneri (?14.18 %), Kachchhi (?27.78 %) and Mewari (?32 %) breeding tracts. Conclusively, the genetic bottleneck analysis could explain the demographic bottleneck in the Indian dromedary populations. Therefore, appropriate conservation and improvement efforts are needed in all four dromedary breeds with immediate attention on Mewari and Kachchhi breeds. The present study is the first report in demonstrating the genetic basis of demographic bottleneck in the Indian dromedary populations.  相似文献   

2.
This study aimed to assess and compare the growth performance, feed efficiency, and carcass traits of Pantaneiro sheep and their Texel and Santa Inês crossbreds. Ninety-six lambs, fifty-one males, and forty-five females, with a mean weaning weight of 15.21?±?1.25 kg and 78?±?13 days of age, were slaughtered at a 32-kg body weight. The results showed better production efficiency from males compared with females. Texel-crossed lambs had a better growth performance than the other genotypes. The Texel?×?Pantaneiro lambs were more efficient with a better feedlot performance, higher ribeye muscle area, and better carcass characteristics with an adequate amount of fat cover. Pantaneiro lambs and their crosses with meat breeds could be useful in meat production systems under Savanna environmental conditions.  相似文献   

3.
The characterisation of the small ruminant populations in developing countries will play a major role in the maintenance of the genetic resources as the basis for future improvement in livestock production. The present study aimed at morphological characterisation of the two main breeds of sheep in Ghana by assessing variation within and between breed populations using principal component and discriminant analyses. The two breeds were the Sahel and the Djallonke sheep of both sexes and of two groups namely, young (1 year old, consisting of 74 animals) and mature sheep (≥2 years old, comprising 219 animals). The analysis of variance revealed significant (P?<?0.05) differences in the morphological traits of the Sahel and the Djallonke sheep breeds with higher values recorded for the former. Sexual dimorphism was in favour of male animals in all the morphological traits examined. Mature animals also had comparative advantage over the young. Two principal components were extracted to discern the structure of the two genetic groups. The most discriminating traits between the two sheep breeds were rump height, height at withers, neck girth and pin-bone width. Mahalanobis distance between the two genetic groups was 5.723 (P?<?0.0001). The developed discriminant functions clearly discriminated and classified the Sahel and the Djallonke sheep into their breeds of origin, thus yielding 100, 93.4 and 90.4 % accurate classification for the rams, ewes and the overall sheep population, respectively. The present approach would greatly help in establishing management and conservation policies for the sustainable production of the two Ghanaian sheep breeds.  相似文献   

4.
Male lambs of the pure breeds Texel, Flemish milk sheep, and Finnish landrace, and of the crossbrech Texel x Friesian milk sheep, Texel x Finnish landrace, Suffolk x Friesian milk sheep, and Finnish landrace x He de France were fed hay and concentrates, the latter differing only in the content of copper. At high (± 35 ppm) and at moderately low (± 10 ppm) copper levels in the concentrate, breed differences in the accumulation of copper in the liver were studied‐Hepatic Cu‐levels increased significantly in the case of the high Cu‐fed animals, but great differences in the metabolism of excessive amounts of dietary Cu exist between the particular breeds and crossbreds. The Texel breed was most susceptible to an excess of dietary Cu and the Finnish landrace was the least susceptible breed, while the Flemish milk sheep and the crossbreds were intermediate. In blood serum, the enzyme activities of sorbitol dehvdrogenase, lactate dehydroge‐nase, γ‐glutamyl transferase, and glutamic oxaloacetic transaminase were increased to a greater or less extent in the high Cu‐fed animals, but the correlation with hepatic Cu‐content was poor. For the most susceptible breeds, even a level of 10 ppm Cu in a ration with nearly equal amounts of hay and concentrate is insufficiently low for the prevention of Cu‐accumulation in the liver.  相似文献   

5.
A total of 135 unrelated sheep from nine Turkish native sheep breeds (Dagl?c, Kivircik, Imroz, Chios, Morkaraman, Ivesi, Hemsin, Karayaka and Akkaraman) were investigated to determinate the maternal genetic diversity using a sequence of a 531-bp segment of the mtDNA control region. Analysis of the mtDNA control region sequence revealed 63 haplotypes and 53 polymorphic sites. Haplotype diversity, nucleotide diversity and the average number of nucleotide differences were estimated to be 0.9496?±?0.011, 0.01407?±?0.00060 and 7.456, respectively. The sequence analysis also revealed high level of genetic diversity among the native Turkish breeds. These breeds were grouped into three major maternal haplogroups: A, B and C, with one animal belonging from the Akkaraman breed to the rare haplogroup E. Irregular shape of mismatch distribution of haplogroup C could be an indicator that haplogroup C may represent different haplogroups. Contrarily to previous studies carried out on Turkish native breeds, majority of animals grouped in haplogroup A in the present study. This result and the irregular shape of mismatch curve of haplogroup C indicate that genetic structure of Turkish native sheep breeds could be more complicated than it is thought.  相似文献   

6.
3866 sheep from 226 flocks of breeding associations and 1218 sheep from 15 independent sheep owners were tested for the presence of serum antibodies against Maedi-Visna and Border Disease viruses. The flocks were randomly selected based on the relative proportion and the geographical distribution of the 4 predominant Swiss sheep breeds (Braunk?pfiges Fleischschaf, Schwarzbraunes Berg- und Juraschaf, Walliser Schwarznasenschaf, Weisses Alpenschaf). Additionally two smaller breeds were included in the study (Charollais Suisse, Milchschafe). Sera of all sheep older than 1 year were collected together with data characterizing host and management factors. The sera were tested using established ELISAs for detection of antibodies to Maedi-Visna and Bovine Virus Diarrhea/Border Disease viruses. ELISA results of Maedi-Visna serology were confirmed by immunoblotting. 9% of the sheep of breeding associations were antibody-positive for Maedi-Visna virus. The results of the different breeds varied between 0.4% and 36%. A multiple logistic regression procedure identified breed, age, airing in barns, herd size, pasturing on alps and way of keeping the animals during winter as associated factors with individual serostatus. The prevalence of antibodies to Border Disease was 20% in sheep of breeding associations and 65% in those of independent sheep owners.  相似文献   

7.
The aim of this study was to characterise ultrasound measurements of live and carcass traits in intact males, females and castrated Tswana goat kids from birth to 12 months of age raised under semi-intensive system in South-eastern Botswana. Measurements were recorded in 15 castrates, 15 intact males and 15 female Tswana goat kids randomly selected at birth. Ultrasonic fat and muscle depths were measured at the first, third/fourth, sixth/seventh, ninth/tenth and 12th/13th thoracic; first, third and fifth lumbar and first, second/third and fourth/fifth sternal vertebrae, fortnightly for the first 6 months and then monthly for the remaining 6 months. The animals were stunned and humanely slaughtered at 12 months of age, and ultrasound and shatterproof ruler were used to measure fat and muscle depths on the carcasses at similar sites as on live animals. A real-time B-mode ultrasound scanner fitted with LV2-1 probe operating at 7.5 MHz (Explorer V5 Vet Laptop B-Ultrasonic Scanner UMC Technology Development Co., Ltd, China) was used to predict ultrasound measurements on live animals and their carcasses. Data were analysed using general linear model in statistical analysis system. Muscle depth measurements increased significantly (p?<?0.05) with age in all sites of measurements. However, there was no significant difference between the sexes at different sites of muscle depth measurements at the same age. Muscle depth at the sternal vertebrae was significantly deeper (almost 55 mm at 12 months of age) than 16 mm at thoracic and 16 mm at lumbar vertebrae at 12 and 8 months of age, respectively. No subcutaneous fat depth measurements were recorded in the lumbar vertebrae (0.00?±?0.00) and the thoracic (0.00?±?0.00) regions in all sex groups. However, fourth and fifth sternal vertebrae showed considerably deeper amount of subcutaneous fat suitable for taking fat measurements as age increases (2.07?±?0.23 mm females, 1.50?±?0.43 mm intact males and 1.80?±?0.38 mm castrates) at 12 months of age. All correlations between live and carcass ultrasound measurements and also between ultrasound carcass and ruler measurements were very high (r 2?=?0.96 to 1.00) for all the sexes indicating that live ultrasound measurements are suitable for use in this meat breed. More research is needed to evaluate the relationships between live ultrasonic measurements and carcass yield in the different sexes of Tswana goat kids.  相似文献   

8.
The experiment was conducted at Sekota District using 36 intact yearling males of pure Abergelle breed and Abergelle crossbred goats (50%) with a mean live weight of 18.92?±?0.72 kg (mean?±?SE). The objective of the experiment was to evaluate the effect of different levels of concentrate mixture supplementation on feed intake, live weight gain, and economic gain of the breeds. Goats were blocked based on initial body weight and were randomly assigned to the dietary treatments. The experimental design was a 2?×?3 factorial in RCBD (randomized complete block design). The treatments included ad libitum feeding of local grass hay and supplementation with three levels (184, 368, and 552 g/day) of concentrate mixture. The experiment consisted of 90 days of feeding. Daily, total dry matter and CP (crude protein) intakes were affected by diet and genotype (P?<?0.01). Significant decrease (P?<?0.001) in hay intake was observed as the level of the supplement increased. Besides, substitution rate increased with increasing levels of supplementation. Average daily body weight gains were significantly impacted only by diet. Animals fed on 184 significantly lower weights, while nonsignificant difference was observed in live weight gain between 368 and 552 supplemented group. Supplementation of 368 concentrate mix significantly improved (P?<?0.05) feed intake, daily weight gain, and feed conversion efficiency. Supplementation of 368 g/day had showed significantly higher net return for both goat breeds. However, the Abergelle breed was significantly better in net profit and sensitivity than the crossbreed. Both genotypes performed better with the diet containing 368 g/day than that with 184 and 552 g/day of concentrate supplementation.  相似文献   

9.
本研究主要以中环肉羊新品种为例,通过了解、认识及亲自参与培育过程及应用情况研究介绍,掌握其培育方法及相关试验操作,从而提高自己在肉羊养殖中的业务水平和工作能力。结果显示,中环肉羊新品种比一般肉羊生长发育快,繁殖水平高,饲料转化率高,肉品质好,具有良好的应用推广价值。目前,中环肉羊新品种育种核心群已达到1.7万只,培育F1代1.2万只。由此可见,该品种的培育效果显著。通过加速培育进程,以此来提高培育效率。将培育、扩繁更优质的肉羊种质资源,应用推广到当地及周边的市、县,使得农户、专业合作社通过发展肉羊产业实现稳定增收,达到共同富裕的目的。  相似文献   

10.
Milk yield traits and lactation length of two breeds of cattle raised on natural pasture with little or no supplementation were assessed. A total of 42 573 daily milk records on 98 Friesian-Sanga cows collected over a period of 10 years and 17 790 daily milk records on 72 Sanga cows spanning a 6-year period were used in the study. Traits examined for each breed were daily milk yield, total milk yield, 305-day milk yield, 305-day milk yield/day and lactation length. Friesian-Sanga cows outperformed their Sanga counterparts in all traits studied. Friesian-Sanga cows had an average daily milk yield of 1.35?±?0.00 kg; average total milk yield of 266?±?12 kg; average 305-day milk yield of 339?±?10 kg; average 305-day milk yield/ day of 1.11?±?0.03 kg and mean lactation length of 201.1?±?6.9 days. Average values for Sanga cows were 1.01?±?0.00 kg as daily milk yield; 162?±?12 kg as total milk yield; 244?±?10 kg as 305-day milk yield; 0.80?±?0.03 kg as 305-day milk yield/day. Mean lactation length for Sanga cows was 164.1?±?9.4 days. Season of calving significantly (P?<?0.05) influenced daily milk yield of Friesian-Sanga cows and all traits of Sanga cows with animals calving in the major rainy season surpassing those that calved in the minor and dry seasons. Daily milk yield for both Friesian-Sanga and Sanga cows was significantly (P?<?0.05) influenced by season of lactation. Daily milk yield gradually declined from second parity towards the sixth parity for Friesian-Sanga cows. A gradual increase in daily milk yield from first to third parity was observed in Sanga cows. Year of calving significantly influenced all traits for both breeds. Genetic improvement in milk yield traits and lactation length is achievable for both breeds of cattle as co-efficient of variation of traits were moderate to high.  相似文献   

11.
  1. A study was conducted with breeding ostriches over two consecutive breeding seasons to determine their response to different concentrations of a well-balanced dietary protein.

  2. Five concentrations of protein were fed to both females and males at an intake of 2.5 kg/bird d. The respective diets contained 75, 91, 108, 123 and 140 g protein/kg feed with energy held constant at 9.2 MJ metabolisable energy/kg feed.

  3. Egg production (mean ± SE, 39.1 ± 3.6 eggs/female/season) was unaffected by dietary protein concentration. Similarly, no significant trends were found for the number of unfertilised eggs (9.1 ± 1.8), dead-in-shell chicks (8.2 ± 1.3), the number of chicks hatched (19.5 ± 2.5) and change in the mass of females (?16.3 ± 10.2 kg). Egg weight decreased linearly as dietary protein content increased.

  4. Age of the ostrich female had a highly significant effect on the number of eggs laid, the number of chicks hatched, the number of dead-in-shell and infertile eggs produced per hen, as well as the mass change of female breeding birds, but did not affect the response of any of these variables to dietary protein content.

  5. It was concluded that ostriches do not benefit from dietary protein contents greater than about 75 g/kg when this is fed at a daily total feed intake rate of 2.5 kg/bird during the breeding season.

  相似文献   

12.

Decisions of breeding schemes in many countries in sub-Saharan Africa tend to be either government or project driven, with a focus on upgrading local breeds. However, there is scant information on the individual animal traits that smallholder farmers prefer. The aim of this study was to examine farmers’ preferences of dairy cattle traits using a discrete choice experiment methodology. The study was conducted through visits to 555 randomly selected dairy farms in the sub-humid Eastern coast and temperate Southern highlands of Tanzania. Choices of animal traits were presented to farmers who were asked to evaluate choice alternatives based on attribute levels and finally select the alternative with the highest utility. The choice experiment data were analysed using a conditional logit model. Coefficients for milk yield, fertility, feed requirement, temperament and diseases resistance were overall statistically significant (p?<?0.05). In order of perceived importance, farmers were willing to keep a cow with high milk yield (coefficient?=?1.43?±?0.059), good fertility (0.85?±?0.050), easy temperament (0.76?±?0.066), low feed requirement (??0.56?±?0.092) and enhanced tropical disease resistance (0.48?±?0.048). The purchase price coefficient was negative (??0.001?±?0.0003), indicating that farmers would prefer improved dairy cattle at affordable prices. Farmers’ preferred traits were influenced by agro-ecological zone and type of production system (extensive vs intensive). The study provides an opportunity for breeding programme designers to take farmers’ preferred dairy traits into serious consideration.

  相似文献   

13.
Meat production is the most important trait in the breeding objectives of sheep production in East Africa. The aim of this study was to investigate breed differences in live weight, conformation, carcass traits and economic values for meat production among Red Maasai and Dorper sheep and their crosses. In total, 88 ram lambs, which were reared at the ILRI experimental station, Kapiti plains Estate in Central Kenya, were used for the study. The lambs were slaughtered at Kenya Meat Commission (KMC) at about 1 year of age. Prior to slaughter, the lambs were weighed, measured and assessed by experienced evaluators, and at the abattoir carcass traits were recorded. Large breed differences were found for most traits. Dorper lambs were heavier at delivery for slaughter and had better carcass grade but lower dressing percentage and fat levels than Red Maasai. Crossbreds were generally better than the parental breeds. Evaluators were willing to pay more for the Dorper lambs for slaughter although carcass weights later were shown not to be higher than for Red Maasai. Evaluators undervalued Red Maasai lambs by 8–13 % compared to Dorper lambs according to the prices quoted per kilogramme live or carcass weight by KMC. Live weight was better than any other live measure in predicting carcass weight. Due to the overall higher ranking of the crossbred lambs for meat production, Dorper may be useful as a terminal sire breed for crossing with Red Maasai ewes.  相似文献   

14.
A static, deterministic computer model, programmed in Microsoft Basic for IBM PC and Apple Macintosh computers, was developed to calculate production efficiency (cost per kg of product) for nine alternative types of crossbreeding system involving four breeds of swine. The model simulates efficiencies for four purebred and 60 alternative two-, three- and four-breed rotation, rotaterminal, backcross and static cross systems. Crossbreeding systems were defined as including all purebred, crossbred and commercial matings necessary to maintain a total of 10,000 farrowings. Driving variables for the model are mean conception rate at first service and for an 8-wk breeding season, litter size born, preweaning survival rate, postweaning average daily gain, feed-to-gain ratio and carcass backfat. Predictions are computed using breed direct genetic and maternal effects for the four breeds, plus individual, maternal and paternal specific heterosis values, input by the user. Inputs required to calculate the number of females farrowing in each sub-system include the proportion of males and females replaced each breeding cycle in purebred and crossbred populations, the proportion of male and female offspring in seedstock herds that become breeding animals, and the number of females per boar. Inputs required to calculate the efficiency of terminal production (cost-to-product ratio) for each sub-system include breeding herd feed intake, gilt development costs, feed costs and labor and overhead costs. Crossbreeding system efficiency is calculated as the weighted average of sub-system cost-to-product ratio values, weighting by the number of females farrowing in each sub-system.  相似文献   

15.
We examined the growth, reproduction, rutting behavior, and health status of sambar deer (Cervus unicolor brookei) in secondary Acacia mangium plantation. The data were collected over 11 years from a breeding herd of 21 stags and 33 hinds in Sabal Forest Reserve, Sarawak, Malaysia. Brody’s growth model of the pooled data is Y t ?=?148.56 (1???0.98e?0.023t ), which estimates that maximum weights of adults are 184 and 115 kg for males and females respectively. Sambar deer are nonseasonal breeders with the breeding peak in February. Although the earliest age at which a female reached sexual maturity was 11 months, the mean age was 23?±?7 months. Mean age of first fawning was 32?±?8 months. Mean gestation period was 259?±?12 days (n?=?82). Stags shed antlers mostly between March and July. Velvet hardens at 103?±?27 days (n?=?23), and velvet harvesting is best at 7–9 weeks when antler length is 25–30 cm. Sambar deer are suitable as a farm species in forest plantations and have a vast potential to uplift rural living standards.  相似文献   

16.
Kosovo, one of the countries in the Balkan Peninsula, has a long tradition in sheep farming, and sheep breeds share triple purpose breed characteristics: milk, meat and wool. Bardhoka sheep, also with triple productive profile, is an important sheep breed because of its economic value with its milk production. In this study, 24 mandibles of adult Bardhoka sheep (12 male and 12 female) aged between 2 and 5 were used. The sheep were acquired from slaughterhouse around Kosovo, and the mandibles were selected without any deformities from healthy sheep. After cleaning the mandibles, a total of 12 morphometric measurements were taken from each sample using digital calliper. The difference between female and male was statistically significant (p < .05) for measurement 11 (height of mandible level of alveolar edge of 3rd molar tooth). The mean value of measurement 11 in male individuals was 42.26 ± 3.96, and it had a higher value than in female individuals (39.37 ± 2.57). In the literature, knowledge related to mandible morphometry of Bardhoka sheep was insufficient. The aim of this study was to determine mean values from osteometric measurements of Bardhoka sheep mandible and obtain references with the values acquired.  相似文献   

17.
The Namaqua Afrikaner is an endangered sheep breed indigenous to South Africa, primarily used in smallholder farming systems. Genetic characterization is essential for the breed’s conservation and utilization. In this study, a genetic characterization was performed on 144 Namaqua Afrikaner sheep kept at the Karakul Experimental Station (KES), Carnarvon Experimental Station (CES), and a private farm Welgeluk (WGK) using 22 microsatellite markers. The mean number of alleles observed was low (3.7 for KES, 3.9 for CES, and 4.2 for WGK). Expected heterozygosity values across loci ranged between 46 % for WGK, 48 % for KES, and 55 % for CES, indicating low to moderate genetic variation. The analysis of molecular variance revealed that 89.5 % of the genetic variation was due to differences within populations. The population structure confirmed the differentiation of three clusters with high relationships between the CES and WGK populations. In the population structure comparison with Pedi and South African Mutton Merino sheep, limited hybridization between the Namaqua Afrikaner sheep and both of these breeds was observed. The results of this study will serve as a reference for genetic management and conservation of Namaqua Afrikaner sheep.  相似文献   

18.
Atriplex nummularia (oldman saltbush) is widely planted on salt-affected land to provide a vegetative cover, which can be used as an alternative feed resource. The study was conducted to evaluate the replacement of commercial concentrate with oldman saltbush (SB) leaf on the feed intake, live weight gain, and carcass parameters of local sheep. Twenty-five sheep with an age of 6 months and weighting 14.60?±?2.47 kg were used in randomized complete block design and distributed into five equal groups, with five animals each. The selected sheep were fed with the dietary treatments for 2 weeks for adaptation and continued until the end of the study, which lasted for 90 days. In the control treatment (SB-0), sheep were fed 100% concentrate mix, while in SB-5, SB-10, SB-15, and SB-20, 5, 10, 15, and 20% of the concentrate mix was replaced by SB, respectively. Wheat straw and water were given at ad libitum throughout the experiment period. Data on feed intake and live weight gain were recorded daily and weekly, respectively, for 90 days. Three animals from each treatment were slaughtered for carcass analysis. Atriplex nummularia leaf (Oldman saltbush) contained 92.02% dry matter (DM), 21.99% crude protein (CP), 24.77% ash, 58.27% neutral detergent fiber (NDF), and 26.56% acid detergent fiber (ADF). Dry matter intake, live weight gain, and carcass parameter were not statistically different among the treatments. Result indicated that concentrate feed can be replaced with Atriplex nummularia leaf up to 20% in sheep diet without negative effect on growth performance and carcass characteristics.  相似文献   

19.
A total of 344 pure animals, representing seven American and South European breeds (White Chiapas Blanca, Brown Chiapas Café, Black Chiapas Negra, Churra Badana, Churra da Terra Quente, Chilean Latxa, and Spanish Merino), were randomly sampled and wool evaluated for isoalcohol scouring yield, length, and proportion for each type of fiber (long-thick, short-thin, and kemp), average of fiber diameter, and F30 (percentage of fibers with a diameter of >30 μm). The objective of this study was to characterize these breeds according to their wool traits. A low percentage of the phenotypic variability in the analyzed animals was due to differences among breeds, and that the largest part of that variability is due to differences within breeds. The obtained topology in the principal coordinates analysis showed the grouping of the three Chiapas breeds clearly separated, but the similarity with their original breed was only evident for Brown Chiapas Café. The three Chiapas sheep breeds must be regarded as clearly sympatric populations.  相似文献   

20.
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