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1.
Information is presented on the genetic diversity and relationship among six Indian sheep breeds/populations belonging to the Southern peninsular and Eastern agroecological zones, based on microsatellite markers. Parameters of genetic variation, viz., allele diversity, observed heterozygosity, gene diversity and population inbreeding estimates, were calculated for the six breeds. The allele diversity ranged from 6.40 to 7.92, whereas the gene diversity varied from 0.617 to 0.727. The highest allele and gene diversity was observed for Nellore sheep, while the lowest was exhibited by Garole breed. Within population inbreeding estimate (F IS) revealed a significant deficit of heterozygotes in Deccani, Madgyal, Nellore and Garole, whereas Ganjam and Chhotanagpuri sheep showed an excess of heterozygotes. The contribution of each breed to the total diversity of the breeds was quantified by the Weitzman approach. The marginal loss of diversity incurred with removal of Nellore and Garole breeds was higher (>27%), whereas removal of Deccani breed resulted in lowest loss of diversity (3.84%) from the set. Estimation of the genetic differentiation (F ST) and genetic distance (D A) between the pairs of breeds revealed a close relationship between Deccani and Madgyal sheep (F ST = 0.017; D A = 0.080) and greatest demarcation between Madgyal and Garole breeds (F ST = 0.110; D A = 0.622). The information generated would help in shaping genetic management and conservation programs for the sheep breeds under consideration.  相似文献   

2.
A study was conducted to evaluate growth performances of Washera sheep under smallholder production systems in the Yilmanadensa and Quarit districts of the Amhara National Regional State, Ethiopia. Data were collected and analysed on the growth of 690 lambs owned by 110 households from October 2004 to September 2007. Weight (kilograms) of Washera lambs at birth, 1, 3, 6, 9 and 12 months of age was 2.69 ± 0.02, 7.10 ± 0.16, 12.42 ± 0.11, 16.12 ± 0.91, 20.05 ± 0.55 and 23.47 ± 0.68, respectively. Birth weight was significantly (P < 0.05) affected by district, year of birth, parity of the dam, birth type and sex of lamb and by the interaction effect of parity by birth type and parity by sex of lamb. Weaning weight was also affected by year of birth, type of birth and sex of lamb. Yearling weight was affected by only year of birth and sex of birth. The average daily weight gain (ADG; grams) from birth to 30 days, birth to 90 days, 90 to 180 days and birth to 1 year of age was 143.37 ± 13.46, 107.09 ± 2.67, 39.78 ± 9.73 and 60.13 ± 1.89, respectively. Growth rates from birth to 30 and 90 days of age were significantly (P < 0.05) affected by birth year, birth type and sex. ADG from birth to 1 year of age was affected by lamb sex and district. The indigenous Washera sheep had faster growth rate than those sheep breeds of Ethiopia extensively studied thus far. Integrated efforts combining improved nutrition, health and participatory community-based breeding would help the smallholder farmers to utilise and conserve this immense sheep genetic resource of Ethiopia.  相似文献   

3.
Biochemical polymorphisms and major mtDNA haplotypes in Bergschaf breeds and Waldschaf as contribution to descent of domestic sheep Morphological similarities between domestic sheep and certain subspecies of Ovis ammon L. 1758 are not necessarily proof of the domestication of a specific subspecies, as crossbreeding of foreign wild sheep populations of different genetic origin with domestic sheep could have led to observed similarities. The maternal inherited mitochondrial genome offers the opportunity to trace modern domestic sheep breeds across numerous generations to presumptive wild ancestors regardless of domestication induced morphological changes and crossbreeding, etc. An investigation based on haplotype specific HinfI – mtDNA fragments and protein polymorphisms in different mountain sheep breeds thought to represent maternal descendants of the Torfschaf as well as in the Waldschaf breed, which belongs to the Zaupel group, were used to help clarify if the major European mtDNA haplotype B was associated with the Torfschaf (Ovis aries palustris RÜTIMEYER 1862), the oldest domesticated sheep in Europe. Samples derived from Steinschaf of the Slovenian and Bavarian type, white and brown varieties of Bergschaf, Brillenschafe from Bavaria and Villnösserschafe showed haplotype B. A single investigated ram of the Bergamasker breed was of the same haplotype. mtDNA haplotype A was detected in more than 50% of the Waldschaf animals. This demonstrates that not all sheep breeds derived from Zaupelschaf are descendants of the same wild ancestor. Within haemoglobin (HBB) the variants HBBA and HBBB occur in a well balanced pattern in all breeds investigated, while the frequency of HBBA was high (0.857) in the brown Bergschaf. Steinschafe of Bavarian type were polymorphic at the CA2‐locus and Waldschafe at the GC‐locus. At the transferrin locus, differences in the occurrence and frequency of the different alleles could be demonstrated between populations. Relationships between Torfschaf, Kupferschaf, Steinschaf, Zaupelschaf, Bergamasker and European Mouflon are discussed. It is likely that the domesticated ancestors of most European sheep can be traced from the Torfschaf to an as yet unknown wild sheep (Ovis ammon) subspecies in Asia.  相似文献   

4.
The current study aimed to investigate the circadian rhythm of blood metabolic parameters associated with summer heat stress (HS) in dairy cows. Ten healthy lactating Holstein Friesian cows were followed during HS for three successive days at six different time points. Blood was sampled from each cow starting from 07:00 am; at 4-h intervals. Ambient air temperature and relative humidity were recorded, and temperature-humidity index (THI) was calculated as well. Respiration rate (RR) and rectal temperature (RT) were recorded for each cow at the time of blood sampling. Concentrations of glucose, non-esterified fatty acids (NEFA), total cholesterol (TC) and urea were measured in each blood sample. The THI values were >68 at all times of the day, and the highest values were recorded at 11:00 am, 03:00 pm and 07:00 pm (80.9, 83.7, and 80.8, respectively). All the cows showed a significantly higher RR and RT coinciding with higher THI values (93 ± 4 and 39.6 ± 0.1; 90.2 ± 3.4, and 40.1 ± 0.1; 87.6 ± 4.1, and 39.8 ± 0.1, respectively, P < 0.05). The concentrations of glucose were the lowest at 11:00 am and 03:00 pm (3.75 ± 0.1 and 3.44 ± 0.1 mmol/L, respectively, P < 0.05). Decreased glucose concentrations coincided with increased NEFA concentrations, (0.43 ± 0.01 and 0.56 ± 0.02 mmol/L, respectively, P < 0.05), and were highly negatively correlated (r = −0.50, P < 0.001). The highest urea and TC concentrations were registered at 11:00 am (6.11 ± 0.15 mmol/L and 109.9 ± 2.2 mg/dl, respectively) whereas the lowest urea and TC values were recorded at 03:00 am (4.97 ± 0.18 mmol/L and 99.5 ± 1.7 mg/dl, respectively, P < 0.05). The results of the present study indicate that there was a circadian variation in glucose, NEFA, urea, and TC resulting in the most unfavorable metabolic condition during the hottest moment of the day in dairy cattle. Earlier work revealed that HS-metabolic changes are reflected in the follicular fluid. The circadian changes observed in the present study associated with HS may imply that also the microenvironment of the oocyte is affected.  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.
(Co)variance components and genetic parameters for various growth traits of Avikalin sheep maintained at Central Sheep and Wool Research Institute, Avikanagar, Rajasthan, India, were estimated by Restricted Maximum Likelihood, fitting six animal models with various combinations of direct and maternal effects. Records of 3,840 animals descended from 257 sires and 1,194 dams were taken for this study over a period of 32 years (1977–2008). Direct heritability estimates (from best model as per likelihood ratio test) for weight at birth, weaning, 6 and 12 months of age, and average daily gain from birth to weaning, weaning to 6 months, and 6 to 12 months were 0.28 ± 0.03, 0.20 ± 0.03, 0.28 ± 0.07, 0.15 ± 0.04, 0.21 ± 0.03, 0.16 and 0.03 ± 0.03, respectively. Maternal heritability for traits declined as animal grows older and it was not at all evident at adult age and for post-weaning daily gain. Maternal permanent environmental effect (c 2) declined significantly with advancement of age of animal. A small effect of c 2 on post-weaning weights was probably a carryover effect of pre-weaning maternal influence. A significant large negative genetic correlation was observed between direct and maternal genetic effects for all the traits, indicating antagonistic pleiotropy, which needs special care while formulating breeding plans. A fair rate of genetic progress seems possible in the flock by selection for all traits, but direct and maternal genetic correlation needs to be taken in to consideration.  相似文献   

7.
Anglo-Nubian and Saanen goats were imported into Trinidad and Tobago to form the nucleus of the goat expansion and improvement programme. Thermoregulation and performance of the parent stock and the F1 were evaluated under intensive housing and management. Rectal temperature in the a.m. irrespective of breed or season ranged from 38.5°C to 38.7°C and p.m. ranged from 38.8°C to 39.0°C. After 2 h of exposure outdoors without shade, Saanen parent stock (SAPS) respiration rate (105 br/min) was significantly higher (p < 0.001) than Saanen F1 (SAF1, 76 br/min), Anglo-Nubian parent stock (ANSP, 65 br/min) and Anglo-Nubian F1 (ANF1, 51 br/min). Rectal temperature over the same period showed significant differences (p < 0.042) between SAF1 (39.8°C) and SAPS (39.4°C), and ANF1 (39.4°C); the value for ANSP was 39.7°C. Age at first kidding showed no significant difference (p > 0.05) between breeds or between the parent stock and the F1 generations, ranging from 638 to 686 days. The ANPS were the most prolific of all groups (p < 0.05); the mean for this group was 1.86 ± 0.07 kids/kidding. Saanen F1 was the least prolific among the group, with mean number of kids at 1.23 (±0.11) kids/kidding. Kidding interval showed no significant (p > 0.05) difference between the groups, ranging from 319 to 521 days. It was concluded that the Anglo-Nubian appears to be more suitable than the Saanen for the tropical humid environment in Trinidad as indicated by their thermoregulation, prolificacy and kidding interval.  相似文献   

8.
Mitochondrial DNA diversity and the origin of Chinese indigenous sheep   总被引:1,自引:0,他引:1  
Large-scale mitochondrial DNA (mtDNA) D-loop sequences data from previous studies were investigated to obtain genetic information which contributes to a better understanding of the genetic diversity and history of modern sheep. In this study, we analyzed mtDNA D-loop sequences of 963 individuals from 16 Chinese indigenous breeds that distributed seven geographic regions. Phylogenetic analysis showed that all three previously defined haplogroups A, B, and C were found in all breeds among different regions except in Southwest China mountainous region, which had only the A and B haplogroups. The weak phylogeographic structure was observed among Chinese indigenous sheep breeds distribution regions and this could be attributable to long-term strong gene flow among regions induced by the human migration, commercial trade, and extensive transport of sheep. The estimation of demographic parameters from mismatch analyses showed that haplogroups A and B had at least one demographic expansion of indigenous sheep in China.  相似文献   

9.
In a switch-over experiment, eight male animals, four each of sheep and goats of local breeds with mean body weight of 26. 8 ± 2.0 and 30.0 ± 2.1 kg, were fed Dichanthium annulatum (DA) grass and four browse species viz. Helictris isora, Securengia virosa, Leucaena leucocephala (LL) and Hardwickia binnata (HB) in four feeding trials to assess their supplementary effect on activity of rumen enzymes. The sheep and goats were offered DA grass with individual browse in 75:25 and 50:50 proportions, respectively, for more than 3 months during each feeding trial, and rumen liquor samples were collected twice at 0 and 4 h post feeding after 60 and 90 days of feeding. Glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and glutamate dehydrogenase (GDH) enzymes were determined in the bacteria and protozoa fractions of rumen liquor, while cellulase enzyme activity was measured in mixed rumen liquor. LL and HB had the highest and lowest contents of CP, while fibre contents were lower in early than later browse leaves. Supplementation of browse leaves significantly (P < 0.05) affect the specific activity of GDH enzyme in bacteria fraction of rumen liquor of animal species, while GDH activity was similar in protozoa fraction of rumen liquor of sheep and goats on all DA grass–browse-supplemented diets except DA–HB (42.8 units/mg protein), where activity was significantly (P < 0.05) low. Specific activities of GOT and GPT enzymes in both bacteria and protozoa fractions of rumen liquor differ significantly (P < 0.05) due to supplementation of browse leaves to DA grass. Browse leaves significantly (P < 0.05) affect the cellulase enzyme activity in animal rumen liquor, being highest on DA–LL (193.4) and lowest on DA–HB diet (144.8 μg sugar/mg protein). Goat exhibited higher activities of GOT and GPT than sheep in both bacteria and protozoa fraction of rumen liquor, while cellulase activity was similar between the animal species on the grass–browse leaves diets. Results indicate that browse leaves supplementation affect the enzyme activities of sheep and goats rumen, while the goats rumen liquor had higher activities of GOT, GPT and GDH enzyme than sheep.  相似文献   

10.
Yunnan as a frontier zone that connects China with South and Southeast Asia, has 11 well‐recognized goat breeds. However, the knowledge about maternal origins, population structure and demographic history of Chinese indigenous goats from Yunnan is limited. In this study, we analysed a 481‐bp fragment of first hypervariable segment (HVSI) of the mitochondrial DNA (mtDNA) control region sequences of 749 individuals from 10 Yunnan indigenous goat breeds, of which 556 sequences were newly determined. There were 110 polymorphic sites that defined 158 haplotypes among all sequences. The haplotype and nucleotide diversity of these breeds ranged from 0.782 ± 0.079 to 0.982 ± 0.015 and from 0.028 ± 0.003 to 0.043 ± 0.005, respectively. Phylogenetic analysis identified two lineages A and B, of which the lineage A had higher frequency (68.1%) and distributed in all Yunnan breeds. We combined previously reported sequences with our sequences belonging to the lineage B and detected two subclades B1 and B2, in which the B1 subclade shared individuals from Eastern Asia, Southeast Asia and Southern Asia. Given higher level of diversity and more unique haplotypes, the B2 subclade probably originated from Southwestern China. The haplotype network, analysis of molecular variance (AMOVA) and a Mantel test revealed no significant phylogeographic structuring among Yunnan goat breeds. This can be explained by high gene flow and genetic admixture among these breeds from different geographic regions in Yunnan. Additionally, both the lineages A and B reflected different demographic histories. This study will provide a scientific basis for the conservation and utilization of Yunnan indigenous goats.  相似文献   

11.
The objective of this study was to determine whether season and total rainfall during the breeding season, sheep parity, and/or litter size affect the interval from the introduction of rams to estrus (IRE) in hair Saint Croix sheep in northeastern Mexico. An analysis was made of 874 services performed during 9 years, introducing the rams into the sheep flock after an isolation period of 60 days during the postpartum period. Estrus was recorded twice daily during 35 days. Year and season influenced significantly on the interval between ram introduction and estrus length (P < 0.01). Winter IRE length (7.9 ± 0.1 days) was shorter than in the other three seasons (11.1 ± 0.2, 11.1 ± 0.1, and 16.2 ± 0.2 days in summer, autumn, and spring, respectively) (P < 0.01). An interaction was observed between rainfall and season, then by rainfall between 0 and 100 mm, IRE was shorter (P < 0.05) in winter (6.8 ± 0.3 days), and by rainfall between 100 and 199 mm, IRE was shorter (P < 0.05) in autumn (10.2 ± 0.5 days); however, when rainfall was beyond 200 mm, IRE length was shorter (P < 0.01) in summer (4.8 ± 0.5 days) than in autumn (14.5 ± 0.3 days). The IRE length was also longer in first lambing ewes (P < 0.05) and was not affected by litter size. In the present study, several factors, including the breeding season, rainfall and parity, directly influenced the interval between the male introduction and the onset of estrus by Saint Croix hair sheep.  相似文献   

12.
Genetic analysis for growth traits of prolific Garole × Malpura (GM) sheep   总被引:1,自引:1,他引:0  
The FecB gene of Garole sheep was introgressed into non-prolific Malpura sheep to evolve a new prolific sheep strain Garole × Malpura (GM), suitable for semi-arid conditions. The present study was conducted to evaluate the impact of breeding program on production profile of GM sheep and to estimate the genetic parameters for growth traits of GM sheep. Overall prolificacy increased significantly in the new strain as compared to the native Malpura sheep. In the GM flock of F2 and F2 onwards generation 35.31% single, 55.83% twins, 8.16% triplet and 0.70% quadruplets were obtained during lambing. Over the years, prolificacy in the flock has increased significantly. Over all least squares means for birth weight, 3, 6, 9, 12 month weight, pre-weaning gain (ADG1) and post-weaning gain (ADG2) were 1.82 ± 0.03, 9.44 ± 0.18, 14.00 ± 0.24, 16.56 ± 0.33, and 19.32 ± 0.35 kg, and 84.08 ± 1.84 and 35.19 ± 0.99 g, respectively. Majority of the fixed effects had significant influence on the performance traits. The heritability estimates for birth, 3, 6, 9, 12 month weight, ADG1 and ADG2 were 0.30 ± 0.11, 0.22 ± 0.09, 0.23 ± 0.10, 0.27 ± 0.10, 0.30 ± 0.11, 0.17 ± 0.08, and 0.17 ± 0.10, respectively. Modest rate of genetic progress seems possible for these traits under selection. The genetic and phenotypic correlations among different body weights were moderate to high and positive. The genetic correlation of pre and post-weaning daily gains with body weight traits were also high and positive.  相似文献   

13.
An investigation was made into the epidemiology of nematode infections of sheep in two districts of Jimma zone, southwestern Ethiopia. We used two approaches—long-term monitoring of identified sheep for nematode infection and abattoir or market survey for analysis. In the first monitoring regime, we used 80 lambs [40 sheep (20 per sex) from each district (Dedo and Yebu)] averaging 4–5 months of age. Faecal egg counts (FEC), packed cell volume (PCV) and body weight changes were monitored over a period of 1 year. Additionally, faecal samples were collected (on a weekly basis) from sheep brought to abattoir/market for 1 year to monitor faecal egg counts. The nematode parasite burden, as judged by FEC and PCV, was generally low indicating that the climatic conditions are not conducive to the development and survival of nematode eggs and the free-living stages; hence, little transmission occurred. In the experimental flocks, the highest FEC and lower PCV were recorded during the long rainy season (June to September) with peak in August and September. Faecal samples collected from abattoir/market also followed the same trend. Results from experimental sheep indicated that location had a significant (P < 0.01) effect on FEC, PCV and average daily body weight gain. The FEC and PCV for sheep in Yebu (mid-altitude) district were 126 ± 3.33 and 30.6 ± 0.26, whereas the values for Dedo (highland) were 93 ± 4.35 and 32.0 ± 0.21, respectively. The results indicate that the highland areas are comparatively less favourable to the survival and development of nematodes. Female lambs had lower FEC and higher PCV compared to male lambs (P < 0.05). The overall nematode parasite challenge in the area, however, is low. We, therefore, recommend rotational grazing management combined with monitoring parasite load and selective treatment to reduce productivity loses and pasture contamination.  相似文献   

14.
1. To explore the genetic diversity of Chinese indigenous chicken breeds, a 585 bp fragment of the mitochondrial DNA (mtDNA) region was sequenced in 102 birds from the Xichuan black-bone chicken, Yunyang black-bone chicken and Lushi chicken. In addition, 30 mtDNA D-loop sequences of Silkie fowls were downloaded from NCBI. The mtDNA D-loop sequence polymorphism and maternal origin of 4 chicken breeds were analysed in this study.

2. The results showed that a total of 33 mutation sites and 28 haplotypes were detected in the 4 chicken breeds. The haplotype diversity and nucleotide diversity of these 4 native breeds were 0.916 ± 0.014 and 0.012 ± 0.002, respectively. Three clusters were formed in 4 Chinese native chickens and 12 reference breeds. Both the Xichuan black-bone chicken and Yunyang black-bone chicken were grouped into one cluster. Four haplogroups (A, B, C and E) emerged in the median-joining network in these breeds.

3. It was concluded that these 4 Chinese chicken breeds had high genetic diversity. The phylogenetic tree and median network profiles showed that Chinese native chickens and its neighbouring countries had at least two maternal origins, one from Yunnan, China and another from Southeast Asia or its surrounding area.  相似文献   


15.
Three hundreds, 21 d-old slow-growing chicks were randomly divided among 5 treatments, of 5 replicates each. Each replicate contained 12 unsexed chicks housed in (1 × 1) a floor pen. A group was kept under thermoneutral condition at 28 ± 4°C and RH was 55 ± 3% during 21–84 d of age (positive control) and fed corn-soybean meal diet. The other four groups were kept for three successive days per week under heat stress (HS) at 38 ± 1.4°C and 49 ± 2% RH from 12.00 to 16.00 pm. Chicks in HS treatments were fed corn-soybean meal diet without (negative control) or with 250 mg AA/kg diet and Bet at 0.5 and 1 g/kg diet. HS decreased productive performance, increased (P < 0.05) meat dry matter, plasma triglyceride and serum calcium whereas decreased (P > 0.05) plasma glucose, serum total protein and water holding capacity (WHC) of meat. AA and 1 g of Bet/kg diet was equally potent for partial relief (P < 0.05) of the negative effect of HS on growth, increased (P < 0.05) feed intake, protein digestibility (P < 0.05), dressing out percentage, liver and giblets, whilst improved (P < 0.05) feed conversion ratio (FCR). Also, a complete recovery from the negative effect (P < 0.05) of HS shown on plasma glucose and partial recovery (P < 0.05) observed in total protein, triglyceride, blood pH, packed cell volume (PCV), hemoglobin (Hgb), rectal temperature (RT) and respiration rate (RR) and improved humoral immune competence to sheep red blood cell (SBRCs) test.  相似文献   

16.
Effect of Foot and Mouth disease (FMD) vaccination was studied on semen quality parameters of 19 Karan Fries (KF) and eight Murrah (MU) breeding bulls during the period 2002 to 2004 at Artificial Breeding Complex, NDRI, Karnal. A total of non-vaccinated 155 KF and 72 MU bulls' ejaculates were taken as control, while 169 KF and 51 MU bulls' ejaculates, collected after vaccination, were used to study the effect of vaccination stress. The results showed that FMD vaccination had no significant (P > 0.05) effect on ejaculate volume and total volume per day of semen in both KF and MU bulls. Volume of semen increased slightly during post-vaccination period in both the breeds. After FMD vaccination, there was significant (P < 0.01) decrease in mass activity (2.27 ± 0.06 vs. 1.67 ± 0.07 and 2.49 ± 0.09. vs. 1.75 ± 0.10, for KF and MU, respectively), initial motility (56.89 ± 0.03% vs. 44.62 ± 0.02% and 62.26 ± 0.04% vs. 47.08 ± 0.05%, for KF and MU, respectively), sperm concentration (754.19 ± 23.96 vs. 554.14 ± 22.95 × 106/ml and 848.61 ± 33.65 vs. 571.57 ± 39.99 × 106/ml, for KF and MU, respectively), and total sperm output per ejaculate (3,685.94 ± 158.40 vs. 2,781.54 ± 151.70 × 106 and 2,218.75 ± 133.14 vs. 1,582.84 ± 158.20 × 106, for KF and MU, respectively). Application of FMD vaccine had significantly (P < 0.05) adverse effect on most of the seminal attributes during post-vaccination in KF and MU buffalo bulls. So, the spermiograms affected following vaccination suggest that in bovines, the semen collection and preservation should be suspended till normal fertility of sperm is restored to avoid the failure of conception from artificial insemination using such semen.  相似文献   

17.
In order to evaluate embryo production in Morada Nova (white variety) ewes superovulated with porcine follicle-stimulating hormone, 20 cycling ewes were used as embryo donors and allocated into two groups according to age: group 1 (ewes aged 1–2 years; n = 9) or group 2 (ewes aged 3–4 years; n = 11). Embryo recovery was performed by laparotomy 5–6 days after oestrus. The evaluation of embryos was made under stereomicroscope according to International Embryo Transfer Society rules. The overall recovery rate was 64.6% (5.0 ±  0.7 structures per ewe) and 86.3% of the recovered structures were fertilized. Group 1 was superior (p < 0.05) to group 2 according to recovered (6.6 ±  0.9 vs 3.6 ±  0.8) and fertilized structures (5.6 ±  1.1 vs. 3.5 ±  0.7) per ewe. In conclusion, the ovarian response and the embryo production in Morada Nova (white variety) sheep subjected to a standard superovulation treatment were considered satisfactory. In addition, the use of multiple ovulation and embryo transfer in younger ewes (≤ 2 years old) of this sheep breed appears to be an efficient tool to accelerate the preservation of the Morada Nova (white variety) breed, since younger ewes are as responsive as older ones.  相似文献   

18.
The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n = 30), cattle (n = 36), sheep (n = 44), dog (n = 35), and poultry (n = 21) and cdt genes prevalence of the isolates were investigated. To determine the genetic diversity of these strains, random amplified polymorphic DNA–polymerase chain reaction (PCR) using a random primer (M13) was performed. The numbers of genotypes determined in human, cattle, sheep, dog, and poultry isolates were 19, 18, 17, 18, and 6, respectively. To find out the prevalence of cdt genes in C. jejuni isolates simultaneously, a multiplex PCR was performed. The prevalence of the separate cdt genes was found to vary from 69% to 100% for cdtA, 92% to 100% for cdtB, and 39% to 98% for cdtC. These rates without host discriminating were 95%, 98%, and 93% for cdtA, cdtB, and cdtC, respectively. The prevalence of all three cdt genes in strains originating from human, cattle, sheep, dog, and poultry were 87%, 67%, 84%, 89%, and 39%, respectively. These results showed the relatively high genetic heterogeneity and variation of cdt genes among C. jejuni isolates from various sources except for poultry isolates. This study gives baseline data on molecular characterization of C. jejuni strains from different sources.  相似文献   

19.

Ethiopia is home to a diverse gene pool of indigenous sheep populations. Therefore, a better understanding of genetic variation holds the key to future utilization through conservation. Three of these breeds, Afar, Blackhead Somali, and Hararghe Highland, are found in eastern Ethiopia where they contribute significantly to the livelihood of most pastoralist, agro-pastoralist, and smallholder farmers. These indigenous sheep are recognized on the basis of morphotype and their genetic distinction remains unknown. Here, to assess genetic variation, and matrilineal genetic origin and relationship of fat-rumed sheep found in eastern Ethiopia, 300 individuals from the three breeds were genotyped for 22 microsatellite markers and sequenced for the mitochondrial DNA displacement loop (mtDNA d-loop) region. The overall HO and HE were 0.57 and 0.75, respectively. Differentiation statistics revealed that a high proportion (97%) of the total genetic variation was explained by differences between individuals within populations. Genotype assignment independent of the population of origin showed K?=?2 to be the optimum number of genetic backgrounds present in the dataset. This result was further confirmed by mtDNA D-loop sequences comparison in which the matrilineal genetic origin of eastern Ethiopia sheep is from two haplotype groups (types A and B) among the five haplotypes globally observed. Taken together, our findings suggest that the sheep populations from three breeds originated from two ancestral genetic backgrounds that may have diverged prior to their introduction to Ethiopia. However, to obtain a complete picture of the evolutionary dynamics of Ethiopian indigenous sheep, more samples and populations from within and outside of the country will need to be analyzed.

  相似文献   

20.
Effects of supplementing sheep consuming wheat straw with local agro-industrial by-products on feed intake, growth, digestibility and nitrogen utilization were determined. Thirty 1-year-old local wethers, with a mean (±SD) live weight of 19.8 (±1.06) kg, were assigned to five treatments: wheat straw + atella (T1), wheat straw + atella + poultry litter (T2), wheat straw + atella + coffee pulp (T3), wheat straw + atella + coffee pulp + poultry litter (T4), hay + concentrate (T5). A 7-day digestibility experiment and a 112-day growth trial were conducted. Total dry matter (DM) and organic matter (OM) intake as well as body weight gain was similar for all treatments. The highest (P < 0.05) nitrogen (N) intake was in sheep fed T1 and T4 diets, while the lowest was in those fed T2 and T5 diets. Sheep fed T1 and T2 diets had greater (P < 0.05) DM and OM digestibility than those fed T4 and T5 diets. The highest (P < 0.05) digestibility of N was for the T2, T4, and T5 diets, while the lowest was for the T1 diet. The highest N retention was in T4 diet, whereas the lowest was in T3 diet. In conclusion, in urban and peri-urban areas where atella, poultry litter, or coffee pulp are available, smallholder farmers could feed the mixtures as a supplement to straw with a good performance without using concentrate feeds.  相似文献   

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