Fat-tailed Breeds Research Articles

Fat-Tailed sheep-An important sheep genetic resource for meat production in tropical countries: An overview

Sheep are a major animal genetic resource for rural farmers of developing countries. Human population growth, increase in purchasing power and awareness among consumers are the major driving forces for raising the demand of sheep products. The contribution of Indian sheep to world meat production is only 5%. It has been foresighted that sheep sector is going to play a key role to uplift the economy of farmers by improving the livelihood of the rural poor, who account sizable of Indian population. Apart from the utility (meat, wool and milk) sheep can also be classified phenotypically by their tail type as fat-tailed and thin-tailed sheep. Compared to thin-tailed, fattailed sheep are well adapted to harsh environments of the tropics and also contribute more meat-(nearly double of thin tailed sheep) to the shepherds. Fat-tailed sheep constitute 25% of the world-sheep population. More than 293 million sheep of about 60 fat-tailed breeds are found in the different parts of world in the Middle East, North and Southern Africa, Iran, Pakistan, Central Asian Republics and China. In India, at-tailed sheep are scanty in number. The propagation of at-tailed ff sheep can increase meat production and provide more income and livelihood to the farmers. In this review, history of fat-tailed sheep along with their breeds, distribution, adaptive qualities, growth, production and reproduction performance, carcass yield and quality are reviewed with an objective to explore the possibility of their propagation for increase in meat production.

Genetic Diversity and Population Structure of Ethiopian Sheep Populations Revealed by High-Density SNP Markers.

Sheep in Ethiopia are adapted to a wide range of environments, including extreme habitats. Elucidating their genetic diversity is critical for improving breeding strategies and mapping quantitative trait loci associated with productivity. To this end, the present study investigated the genetic diversity and population structure of five Ethiopian sheep populations exhibiting distinct phenotypes and sampled from distinct production environments, including arid lowlands and highlands. To investigate the genetic relationships in greater detail and infer population structure of Ethiopian sheep breeds at the continental and global levels, we analyzed genotypic data of selected sheep breeds from the Ovine SNP50K HapMap dataset. All Ethiopian sheep samples were genotyped with Ovine Infinium HD SNP BeadChip (600K). Mean genetic diversity ranged from 0.29 in Arsi-Bale to 0.32 in Menz sheep, while estimates of genetic differentiation among populations ranged from 0.02 to 0.07, indicating low to moderate differentiation. An analysis of molecular variance revealed that 94.62 and 5.38% of the genetic variation was attributable to differences within and among populations, respectively. Our population structure analysis revealed clustering of five Ethiopian sheep populations according to tail phenotype and geographic origin—i.e., short fat-tailed (very cool high-altitude), long fat-tailed (mid to high-altitude), and fat-rumped (arid low-altitude), with clear evidence of admixture between long fat-tailed populations. North African sheep breeds showed higher levels of within-breed diversity, but were less differentiated than breeds from Eastern and Southern Africa. When African breeds were grouped according to geographic origin (North, South, and East), statistically significant differences were detected among groups (regions). A comparison of population structure between Ethiopian and global sheep breeds showed that fat-tailed breeds from Eastern and Southern Africa clustered together, suggesting that these breeds were introduced to the African continent via the Horn and migrated further south.

Genetic parameters for tick count and udder health in commercial and indigenous ewes in South Africa

The genetics of tick infestation in sheep need study, as host resistance often forms part of integrated pest control programs. Repeated udder health scores, site-specific tick count, mating weight and reproduction records (N=879–1204) were recorded annually from 2010 to 2015 on ewes of the indigenous Namaqua Afrikaner (NA) fat-tailed breed, as well as the commercial Dorper and SA Mutton Merino (SAMM) breeds. Udders were scored subjectively on a 1–5 scale (1 – udder intact and 5 – udder damaged severely) and ticks were counted on three locations. The body sites counted were the head and thoracic limb (HTLTC), udder-pelvic limb (UPLTC) and perineum-breech-tail (PBTTC). These counts were also totaled for a total tick count (TTC). Reproduction traits were number of lambs weaned per ewe lambed and total weight of lamb weaned per ewe lambed. Udder health scores of NA ewes were lower than those of Dorpers, which in turn had lower scores than SAMM ewes. NA ewes had lower values for HTLTC, UPLTC and TTC than the commercial breeds, but higher values for PBTTC than Dorpers. Heritability estimates amounted to 0.26±0.04 for HTLTC, 0.53±0.04 for UPLTC, 0.07±0.06 for PBTTC, 0.44±0.06 for TTC and 0.61±0.03 for udder health score. Animal permanent environment also affected PBTTC (0.14±0.07). Significant genetic correlations were found between the HTLTC and UPLTC (0.47±0.10), UPLTC and udder health score (0.52±0.07), HTLTC and UPLTC (0.24±0.11) as well as UPLTC and PBTTC (−0.44±0.11). Heavier ewes had higher UPLTC (0.38±0.09), TTC (0.33±0.09) and impaired udder health (0.21±0.08). Udder health scores and tick counts at all sites were not related to reproduction traits. The indigenous NA breed outperformed the commercial breeds with lower values for HTLTC, UPLTC, TTC and a better udder health score. Mechanisms contributing to the better performance of the NA breed under pastoral conditions and the scope for selection for tick tolerance within breeds should be studied further.

Postpartum Associated Metabolism, Milk Production and Reproductive Efficiency of Barki and Rahmani Subtropical Fat-tailed Breeds

Postpartum Associated Metabolism, Milk Production and Reproductive Efficiency of Barki and Rahmani Subtropical Fat-tailed Breeds

Growth and reproductive traits of purebred and crossbred Romanov lambs in Eastern Anatolia

The performance of purebred Romanov (R) lambs and crossbred lambs of Romanov and Morkaraman (M) breeding were compared under a semi-intensive production system. The M breed is a fat-tailed breed native to Eastern Anatolia, Turkey. Analyses were conducted on data from 168 lambs produced from R and M ewes through laparoscopic artificial insemination (LAI) with the semen of pure R and F1 RxM rams. Pure R, F1 (RxM, ½ R), and ¼ R (RxM x M backcross) lambs were produced. The F1 and ¼ R lambs had heavier (P < 0.05) birth weights than R lambs while F1 and R lambs had heavier (P < 0.05) weaning weights than ¼ R lambs. The three groups of lambs differed (P < 0.05) from each other for age of puberty in males and females where with R lambs were the youngest, F1 lambs were intermediate, and ¼ R lambs were the oldest. The percentage of ewe lambs that exhibited estrus within one year of age was higher (P < 0.01) for R (100%) and F1 (67%) lambs than for ¼ R lambs (43%). In conclusion, improvement in growth and early reproductive traits can be obtained from crossbreeding the fat-tailed Morkaraman breed with the Romanov breed.

Signatures of selection identify loci associated with fat tail in sheep.

Identification of genomic regions that have been targets of selection for phenotypic traits is one of the most challenging applications of dense marker panels in animal genetics. In this study, a genomewide scan using approximately 50,000 SNP was performed in an attempt to identify genomic regions associated with fat deposition in sheep, the importance of this not only being limited to livestock facing future climate changes but also for elucidating the physiology of lipid metabolism. The genotyping results obtained with the Ovine SNP50K BeadChip in 2 fat tail breeds were compared with those obtained in 13 thin tail breeds. Direct sequencing of the annotated genes located in proximity to the markers with opposite allele frequency in thin tail vs. fat tail sheep gave additional SNP of interest. To further confirm the results of the genomewide scan, we genotyped the SNP within these genes in the 2 groups of sheep. A missense mutation in the gene, with different allele frequency in the 2 groups, was detected. The results indicated and as the most probable genes involved in the fat tail phenotype.

Fatty acid composition of the ovine longissimus dorsi muscle: effect of feed restriction in three breeds of different origin.

Muscle fatty acid profile reflects the body condition of animals and has a noticeable effect on meat quality. Herein, longissimus dorsi muscle of three different sheep breeds, Damara (a fat-tailed breed), Dorper and Australian Merino sheep, was analysed for fatty acid composition. The three breeds were subjected to two distinctive feeding levels (ad libitum and restricted feeding) over 42 days. The Damara sheep revealed several differences compared to the other two breeds, namely a higher concentration of polyunsaturated fatty acids, which can be related to being a fat-tailed breed. Even in restricted feeding conditions, this breed revealed the highest levels compared to Merino and Dorper sheep respectively, of linoleic acid (+31% and +28%), linolenic acid (+97% and +51%), eicosapentaenoic acid (EPA) (+65% and +37%), docosapentanenoic acid (DPA) (+31% Merino) and dodosahexanenoic acid (DHA) (+63% and +77%). EPA, DPA and DHA are three omega-3 fatty acids, with described beneficial characteristics. With this work we show other qualities (higher levels of the omega-3 fatty acids, EPA, DPA and DHA) of Damara meat that might present this breed as an interesting alternative for animal production in semi-arid climates.

The influence of gender, age, castration on young sheep slaughter figures kazakh-fat-tailed breed in the conditions of Kazakhstan

The article presents the results of a study of meat efficiency of young Kazakh fat-tailed breed grubosherstnoj. The object of the study were rams, valushki, Mutton studied breed. The obtained data and their analysis shows that intensive cultivation of rams, and valushkov yarochek improved the slaughter qualities, as evidenced by the increase in slaughter yield with age. Rams, and Mutton valushki Kazakh fat-tailed breed grubosherstnoj distinguished by high slaughter qualities. This determines its prospects of breeding for high biological value of meat - lamb.

Chronic heat stress in Iranian fat-tailed ram lambs: clinical and paraclinical parameters

BACKGROUND: The effect of heat stress on physiologicalparameters has been well documented. However, there arereports of a genetic based heat tolerance in some sheep breeds.OBJECTIVES: The aim of the present study was to monitor thephysiological responses of an Iranian fat-tailed breed againstheat stress and an acute stress insult. METHODS:Atotal numberof 15 fall-born ram lambs were selected and subjected to directsummer solar radiation throughout the day (May 2009 toFebruary 2010). Ten lambs were semi-castrated in October to seethe physiologic response of animals to an acute stress. Thegeneral parameter as well as blood chemistry and cortisol wereanalyzed during the study. RESULTS: The results showed that allphysiologic parameters had significant changes; however, theirvalues were in normal range. The fact that the animals in thepresent study experienced their first exposure of heat stress anda significant increase in serum cortisol concentration in semicastratedlambs in October, compared to the respected values inthe hottest months of the experiment, may indicate a geneticbased adaptability of the breed in Iran. CONCLUSIONS: Thepresent study shows the dynamic changes of general andbiochemical parameters in response to chronic heat stress and anacute stress that raises a possible tolerance of the breed againstheat stress.

Transcriptome profile analysis of adipose tissues from fat and short-tailed sheep

Recent studies in domestic animals have used RNA-seq to explore the transcriptome of different tissues in a limited number of individuals. In the present study, de novo transcriptome sequencing was used to compare sheep adipose tissue transcriptome profiles between a fat-tailed breed (Kazak sheep; KS) and a short-tailed (Tibetan sheep; TS). The RNA-seq data from these two groups revealed that 646 genes were differentially expressed between the KS and TS groups, including 280 up-regulated and 366 down-regulated genes. We identified genes relevant to fat metabolism in adipose tissues, including two top genes with the largest fold change (NELL1 and FMO3). Pathway analysis revealed that the differentially expressed genes between the KS and TS breeds belong to fatty acid metabolism relevant pathways (e.g. fat digestion and absorption, glycine, serine, and threonine metabolism) and cell junction-related pathways (e.g. cell adhesion molecules) which contribute to fat deposition. This work highlighted potential genes and gene networks that affect fat deposition and meat quality in sheep.

A study on gastrointestinal tract characteristics of ram lambs at the same weights from six Turkish sheep breeds

A study was conducted, first, to compare the gastrointestinal tract (GIT), reticulo-rumens and intestinal capacities (relative to body weight) of ram lambs from six Turkish sheep breeds: Turkish Merino (TM, Anatolia Merino), Akkaraman (AK), Kıvırcık (KV), Awassi (AW), Karayaka (KY) and Morkaraman (MK), and second, to examine the influence of sheep breed on the pH of the digesta in the various segments (rumen, jejunum and caecum) of the GIT. Six ram lambs from each breed were slaughtered at 40.2 ± 0.80 kg liveweight. Lambs from the AK breed had a heavier GIT weight than the AW, KY or MK breeds. The weight of the full stomach was higher in AK lambs compared with the other lambs, except for KV lambs, while the relative weight of the empty stomachs was heavier in MK ram lambs than in TM, AW and KY lambs. The AK lambs had the highest relative empty intestinal weight. The relative weight of empty intestines was heavier in KV lambs than in KY lambs. The pH of the rumen content was higher in TM and AK lambs compared with KY and MK lambs, while the pH of the caecum content of KV lambs was higher than those of KY and MK lambs. In conclusion, significant differences were found among the six breeds in terms of some variables that were studied, although a higher proportional GIT weight in the fat-tail breeds such as the MK, AK and AW was not reflected in all components or in the pH of the GIT content.Keywords: Native sheep breed, digestive system, rumen, small and large intestine, pH value

Carcass composition of Namaqua Afrikaner, Dorper and SA Mutton Merino ram lambs reared under extensive conditions

This study evaluated the differences in the muscle-fat-bone yield of Namaqua Afrikaner (NA), Dorper (D) and SA Mutton Merino (SAMM) ram lambs. The breeds constituted an indigenous, hardy and late maturing, fat-tailed breed (NA), an early maturing, commercial meat breed (D) and a late maturing commercial dual-purpose breed (SAMM). Lambs were slaughtered at 35 (± 8) days post weaning. Carcasses were cooled for 24 h, separated into retail cuts (leg, loin, rib, and shoulder), weighed and deboned. Meat and fat were separated after deboning and weighed to calculate the muscle-fat-bone yield per cut. Least-square means were computed for the respective breeds, using slaughter age as covariate. Results for percentage meat indicate that, with exception of the rib, retail cuts from the NA breed contained a lower percentage of meat than D and SAMM breeds, particularly in the valuable loin and leg cuts. The shoulder of the NA had a lower percentage meat than that of the D. The percentage fat in retail cuts did not differ between breeds for any of the cuts. In comparison with both D and SAMM, NA contained a higher percentage bone in all cuts. Dorper and SAMM carcasses did not differ in terms of the percentage of bone, fat or muscle for any of the retail cuts. The lower meat yield, particularly in the more expensive loin and leg of the NA, when compared to the commercial meat breed (D) could make the former less preferred for meat production. However, the NA compared more favourably than the dual-purpose SAMM. Differences in carcass composition could be attributed to the fact that the NA is an unimproved and late maturing sheep breed.

Variation in colostral immunoglobulin G concentration in fat tailed sheep and evaluation of methods for estimation of colostral immunoglobulin content

In ruminants, colostrum is a vital source of immunoglobulins that provide passive immunity for their offspring during the neonatal period. It is suggested that colostral immunoglobulin G (IgG) concentration varies between and within breeds and could also be affected by maternal factors. The aim of this study was to investigate possible effects of litter type and ewe parturition number on colostral IgG concentration in two Iranian fat-tailed breeds of sheep (Shaul and Lori Bakhtyari) as well as usefulness of different methods for estimation of IgG concentrations in colostrum. The colostral IgG concentrations were measured in 38 Shaul and 59 Lori Bakhtyari ewes by single radial immunodiffusion, zinc sulphate turbidity and Biuret methods. Measurement of IgG by single radial immunodiffusion revealed that Lori Bakhtyari ewes had significantly (P &lt;0.05) lower colostral IgG levels (48.82 ± 2.10 mg/ml) than Shaul ewes (62.86 ± 2.48). With regard to the effect of litter type and parturition number, a significant (P &lt;0.05) difference in IgG concentration of colostrum was only observed between the first (65.17 ± 5.74 mg/ml) and third parturition (41.10 ± 4.60 mg/ml) of Lori Bakhtyari ewes. The colostral IgG concentration was not associated with ewe serum IgG concentration (P &gt;0.05). The mortality rate was higher in lambs born to ewes with lower IgG in their colostrum. Single radial immunodiffusion did not correlate either with zinc sulphate turbidity method (r = -0.253,P &gt;0.05) or with Biuret method (r = -0.005,P &gt;0.05). We can conclude that concentration of colostral IgG could be influenced by breed but not by litter type and parturition number.

7 LAPAROSCOPIC INTRAUTERINE AND INTRAPERITONEAL INSEMINATION IN FAT-TAILED EWES

The present study was conducted to evaluate laparoscopic intrauterine and intraperitoneal AI in a fat-tailed sheep breed. Multiparous and nulliparous (n = 72) healthy Shall ewes (Iranian native breed) were assigned into 3 experimental groups to be inseminated with 3 laparoscopically insemination methods, including intrauterine insemination with frozen semen (IUIFZ; n = 34), intraperitoneal insemination with fresh semen (IPIFR; n = 21), and intraperitoneal insemination with frozen semen (IPIFZ; n = 17). To perform the experiment easily and control confounding factors, the experiment was conducted in 5 replicates. In each replicate, similar numbers of ewes belonging to each experimental group were included, synchronized, and inseminated with the fresh or frozen semen collected from the same fertile ram. Estrus was synchronized using CIDR for 14 days. Immediately after CIDR removal, all ewes received 400 IU of pregnant mare serum gonadotropin. Inseminations with 300 million total spermatozoa (≥70% progressive forward motility) were performed 51.1 ± 0.64 h after CIDR removal. Intrauterine insemination was conducted at the tip of the uterine horn, ipsilateral to the ovary having a dominant follicle. In the case that both ovaries had a dominant follicle, half of the straw was deposited in each horn. In 2 other experimental groups (IPIF and IPIR) either fresh or frozen semen was deposited on the surface of ovaries having a dominant follicle. Pregnancy was diagnosed with transrectal ultrasonography on Day 30 after AI. Data were analyzed using logistic regression. The pregnancy rate in the IUIFZ group (51.7%) was significantly higher than in IPIFR and IPIFZ experimental groups (17.6 and 0%, respectively; P &lt; 0.01), and there was significant difference between IPIFR and IPIFZ in pregnancy rate (P &lt; 0.05). In conclusion, the laparoscopic intrauterine insemination method can be applied effectively in Shall fat-tailed sheep. Laparoscopic intraperitoneal inseminations with fresh or with frozen semen are not recommended for AI in fat-tailed sheep.

Comparison of the meat quality and fatty acid composition of traditional fat-tailed (Chall) and tailed (Zel) Iranian sheep breeds

The aim of this study was to compare the meat quality of a traditional fat-tailed breed, Chall, to a tailed Iranian sheep breed, Zel. Lambs were grazed on pasture until weaning, and then were finished until slaughter at 10–12months. Meat quality traits were measured on the longissimus dorsi (LD) muscle. Zel lambs accumulated more intramuscular fat (IMF) (p<0.01) and had lower shear force and drip loss than Chall lambs (p<0.05). The meat color of Zel lambs was higher for both a* (p<0.001) and b* (p<0.01) compared to Chall lambs. Meat from Zel lambs was more tender (p<0.01) and more juicy (p<0.05) than Chall lambs. The PUFA:SFA fatty acid ratio (P:S) was higher (p<0.05) and the n−6:n−3 PUFA ratio was lower in Chall compared to Zel lambs (p<0.05). Overall, these results show that the eating quality of Zel lambs was better, but that this was at the cost of less favorable fatty acid profiles and poorer meat color.

Genomic scan of selective sweeps in thin and fat tail sheep breeds for identifying of candidate regions associated with fat deposition

BackgroundIdentification of genomic regions that have been targets of selection for phenotypic traits is one of the most important and challenging areas of research in animal genetics. However, currently there are relatively few genomic regions identified that have been subject to positive selection. In this study, a genome-wide scan using ~50,000 Single Nucleotide Polymorphisms (SNPs) was performed in an attempt to identify genomic regions associated with fat deposition in fat-tail breeds. This trait and its modification are very important in those countries grazing these breeds.ResultsTwo independent experiments using either Iranian or Ovine HapMap genotyping data contrasted thin and fat tail breeds. Population differentiation using FST in Iranian thin and fat tail breeds revealed seven genomic regions. Almost all of these regions overlapped with QTLs that had previously been identified as affecting fat and carcass yield traits in beef and dairy cattle. Study of selection sweep signatures using FST in thin and fat tail breeds sampled from the Ovine HapMap project confirmed three of these regions located on Chromosomes 5, 7 and X. We found increased homozygosity in these regions in favour of fat tail breeds on chromosome 5 and X and in favour of thin tail breeds on chromosome 7.ConclusionsIn this study, we were able to identify three novel regions associated with fat deposition in thin and fat tail sheep breeds. Two of these were associated with an increase of homozygosity in the fat tail breeds which would be consistent with selection for mutations affecting fat tail size several thousand years after domestication.

Genetic analysis of growth traits in Iranian Makuie sheep breed

The Makuie sheep is a fat-tailed sheep breed which can be found in the Azerbaijan province of Iran. In 1986, a Makuie sheep breeding station was established in the city of Maku in order to breed, protect and purify this breed. The genetic parameters for birth weight, weaning weight (3 months), 6-month, 9-month and yearling weight, and average daily gain from birth to weaning traits were estimated based on 25 years of data using DFREML software. Six different models were applied and a likelihood ratio test (LRT) was used to select the appropriate model. Bivariate analysis was used to define the genetic correlation between studied traits. Based on the LRT, model II was selected as an appropriate model for all studied traits. Direct heritability estimates of birth, weaning, 6-month, 9-month and yearling weights and average daily gain from birth to weaning were 0.36, 0.41, 0.48, 0.42, 0.36 and 0.37, respectively. Estimates of direct genetic correlation between birth and weaning weights, birth and 6-month weights, birth and 9-month weights, as well as between birth and yearling weights were 0.57, 0.49, 0.46 and 0.32, respectively. The results suggest there is a substantial additive genetic variability for studied traits in the Makuie sheep breed population, and the direct additive effect and maternal permanent environment variance are the main source of phenotypic variance.

Fattening performance of purebred and crossbred lambs from fat-tailed Kurdi ewes mated to four Iranian native ram breeds

A crossbreeding experiment was carried out to determine the sire breed effects on fattening performance of fat-tailed lambs. Rams from four Iranian fat-tailed sheep breeds, namely Kurdi (K), Afshari (A), Chaal (C) and Sanjabi (S) were mated to Kurdi ewes producing 454 progeny of four genotype groups (KK, AK, CK and SK). A total of 80 lambs comprising ten female and ten male lambs from each genotype group were used in a fattening experiment during a period of 88 days. Genotype of the lamb had significant effect on average dry matter intake (ADMI) (P < 0.05). SK lambs had the lowest ADMI. Average daily gain (ADG) and food conversion ratio (FCR) were not influenced by genotype of the lamb. Sex of the lamb had significant effect on both ADG and FCR (P < 0.01). Slaughter weight (SLW), hot carcass weight (HCW), cold carcass weight (CCW) and daily carcass gain (DCG) were not affected by lamb's genotype. However, genotype had significant effect on dressing percentage, carcass loss percentage (P < 0.01), carcass length (CL), leg circumference (LC), carcass compactness (CC) (P < 0.01) and carcass density (CD) (P < 0.05). Carcass width (CW) and leg length (LL) were not affected by lamb's genotype. Sex of the lamb had significant effects on CL, CW, LC, CC, CD (P < 0.01) and LL (P < 0.05). The results indicated the existence of sire breed difference for daily dry matter intake and carcass conformation in the fat-tailed sheep.

South African sheep breeds: Population genetic structure and conservation implications

This paper details the population genetic structure of South African indigenous, locally developed and introduced breeds using microsatellite markers, and the conservation implications of these results. Blood samples from 622 sheep, comprising 20 breeds, were collected from different regions in South Africa. All animals were genotyped at 12 microsatellite loci. Average unbiased heterozygosity (Hz) was lowest in the fat-rumped breeds (0.466); compared to higher average Hz values of 0.555 and 0.598 in the composite and indigenous fat-tailed breeds; and still higher values of 0.659 and 0.662 in Karakul and the wool breeds respectively. Analysis of patterns of differentiation showed that the average Fst value between fat-rumped and the fat-tailed indigenous breeds was 0.180, with an average Fst=0.184 between indigenous fat-tailed and wool types, and a higher average Fst value of 0.260 between fat-rumped and wool type breeds. Fst values within breeds were generally lower. Results from both Bayesian analysis (STRUCTURE) and a neighbor-joining tree based on standard genetic distance confirmed the known patterns of relationships among these groups and (in some instances) breeds. The results of this study also suggest that the indigenous breeds studied have some uniqueness, which may well translate to local adaptation over time. These results thus provide additional support for programs aimed at the conservation of indigenous and locally developed breeds, in line with international programs that emphasize the conservation of indigenous animal genetic resources.

A review of morphological characteristics relating to the production and reproduction of fat-tailed sheep breeds

The purpose of this study is to survey the literature pertinent to some morphological traits which are related with the production and reproduction of fat-tailed sheep breeds. The fat-tailed breeds were identified according to Food and Agriculture Organization databases. Articles referring to all these sheep breeds were evaluated. The morphology of udders and their measurable variables were collected and described. The particularities of pelt and fleece features which are important from an economic point of view were summarized. Linear, planar, and spatial parameters of body, slaughter, and carcass factors were compared at various ages of breeding. Testicular dimensions and semen characteristics were recorded. Their relationships with productive and reproductive performance were discussed. The pattern of ovarian follicle development and the involution of the genital tract were assessed from the anatomical point of view in normal and untreated animals. The data presented here provide useful baseline information on the normal morphological aspects which are important in the animal production of these breeds.