Magra Sheep Research Articles

Studying genetic diversity of magra sheep using pedigree analyses

Studying genetic diversity of magra sheep using pedigree analyses

Seasonal Variability in Transcript Expression of Type I and Type II Keratins in Wool Follicles of Lustrous Fleece-Producing Magra Sheep

ABSTRACT Magra sheep reared around the Bikaner area of Rajasthan, India is famous for producing lustrous fleece as compared to other wool-producing native sheep breeds. Three clips of Magra wool, namely, February, July, and October months of the year are showing variations in luster and gross appearance. Present work has been conducted to unravel seasonal variations, in transcript expression patterns in major type I and type II keratin genes, that occur in wool follicles of lustrous wool-producing Magra sheep. Wool samples randomly collected were graded in high and low luster by Gloss 60° values. Wool follicles of the sheep with low (gloss 60° values; < 2.5) and high (gloss 60° values; > 2.5) luster were used for the analysis of type I and type II keratin transcripts. The results of Quantitative PCR had shown up-regulated expression of keratin genes in high-lustrous sheep as compared to low-lustrous sheep. K32, K40, and K82 transcript expression differed significantly (P ≤ .05) between high- and low-lustrous sheep. Nucleotide sequence analysis of the K40 and K82 genes revealed five and four non-synonymous mutations, respectively. From the present study, it can be speculated that the higher amount of keratin protein may play a crucial role in determining the luster property of the wool.

Evaluation of growth performance and inbreeding effect in Magra sheep

A study was conducted to evaluate the growth performance and effect of inbreeding on the growth performance in Magra sheep. The growth data generated on 5056 Magra sheep over a period of 22 years (1998 to 2019) at Arid Region Campus (ICAR-Central Sheep and Wool Research Institute), Bikaner (Rajasthan) were used in the study. The overall least squares means for body weights at birth, 3, 6, 9 and 12 months of age were 3.11±0.01, 16.09±0.06, 23.21±0.09, 27.98±0.10 and 30.22±0.12 kg respectively. The overall least squares means for average daily gain (ADG) during 0-3 (ADG1), 3-6 (ADG2) and 6-12 (ADG3) months of age were 143.95±0.70, 81.18±0.79 and 30.05±0.54 g, respectively. The results revealed 6.76, 19.71, 17.04, 25.65 and 30.59% improvement in body weights at birth, 3, 6, 9 and 12 months of age, respectively during the last 22 years. On all the growth traits, significant effects of year of birth, sex and dam's weight at lambing were observed. There was non-significant effect of inbreeding on 6MWT, 12MWT, ADG2 and ADG3. Inbreeding classes had variation; however negative effect was not seen. The study concluded that the mating programme of Magra sheep is in the right direction; however, regular monitoring of inbreeding in the flock may be followed and non-genetic factors affecting growth must be monitored so as to attain better growth rates in Magra sheep.

Polymorphism of keratin intermediate filament type- i gene and its association with wool quality traits in Magra sheep

A study was conducted to identify the polymorphism of keratin intermediate filament type-I (KIF-I) gene and its association with wool quality traits in Magra sheep. Blood samples and greasy fleece yield data of 162 adult males and females of Magra sheep (2 to 4 yr old) were collected. Following isolation of genomic DNA, genotyping of KIF-I gene was done by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The PCR-RFLP of KIF-I gene at locus KRT1.2 generated three genotype viz., AA, AB and BB with genotype frequencies of 0.49, 0.43 and 0.08, respectively. The frequencies for A and B allele were 0.71 and 0.29, respectively. Hardy-Weinberg equilibrium indicated that the population was in genetic equilibrium with respect to KIF-I gene. In conclusion, greater frequencies of allele A and genotype AA and AB are suggestive of its importance in quality of wool traits in Magra sheep.

Transcript variability in keratine 33 (K33) gene of magra sheep

In a study, single nucleotide polymorphisms (SNPs) were analysed in open reading frame (ORF) of keratin 33 (K33) gene from lustrous Magra sheep. Blood (120) and wool follicle bulb (20) samples were collected from November 2017 to April 2019. Tajima's D value was -0.212492 and was non-significantly (p>0.05) different from 0, which suggested that the neutral mutation hypothesis can explain the nucleotide polymorphism of K33 in lustrous Magra sheep. Seventeen mis-sense variations were observed in Magra K33 protein, out of which 12 variations were novel and were not reported earlier. In phylogenetic tree analysis, all sheep sequences were clustered nearest to goat and farthest from horse. Changes in amino acids viz., serine (S), threonine (T) and tyrosine (Y) were observed above threshold phosphorylation potential which warrant further investigation for their plausible role in regulation of K33 structure and function in lustrous wool.

A study on ocular ultrasonography in small ruminants

A study was conducted to find normal value of echo-morphometric view of inner ocular structure of healthy eyes of adult females of Magra sheep (n=10) and Marwari goats (n=10) by ultrasonography. In ultrasonogram, eyes appeared as well-defined, ovoid structures with mostly anechoic contents. The cornea, anterior and posterior lens capsule, scleroretinal rim and iris appeared hyper-echoic, whereas aqueous chamber, lens nucleus and vitreous chamber were anechoic. The optic disc was also distinctly seen. Average values of aqueous chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD) and axial globe length (AGL) recorded in the eyes of sheep were 2.95±0.05, 8.41±0.08, 10.10±0.16 and 21.64±0.23 and of goats were3.15±0.05, 9.44±0.07, 10.04±0.14 and 22.71±0.16 mm, respectively. The overall ACD, LT and AGL were significantly (p<0.01) lower in sheep than goats. The normal value of echomorphometric view of inner ocular structure of healthy eye of adult females of sheep and goats obtained can be used to evaluate clinical conditions.

Production performance appraisal of magra sheep in farmers’ flocks of arid region

Magra is one of the important carpet wool breeds of arid region of Rajasthan. Since 2013, a field unit of Magra sheep was established at Arid Research Campus (ICAR-Central Sheep and Wool Research Institute), Bikaner under Network Project on Sheep Improvement to bring genetic improvement of Magra sheep in the farmers’ flocks. A total of 9817 sheep belonging to about 100 farm families were registered in five villages during six years from 2013 to 2018. More than 100 elite rams of Magra breed were supplied from the institute to sheep breeders for genetic improvement of field animals for wool and body weight traits. The overall least squares means for body weight at birth, 3, 6 and 12 months were 2.71±0.00, 15.46±0.03, 21.93±0.06 and 28.42±0.08 kg, respectively. The overall mean first greasy fleece yield (GFY) of first clip at 6 months and adult GFY in single clip were 640.1±3.36 and 625.8±2.07 g. All the fixed effects including sex, village and period had significantly (p<0.01) influenced on the body weight traits. The overall mean body weights (6 months) and wool yield (adult GFY, one clip) were improved by 7.67 and 8.70 per cent, respectively in progeny of field animals by use of elite Magra rams from the institute during 2016 to 2019. The study showed that production of field Magraf locks improved bysupply of elite rams fromthe institute.

Better odds of lamb survival in sheep at dry arid tropical region of India

Lamb survival till first 28 days of life is critical as it increases the chances of economic gain in flock. Objective of the current study was to assess the incidence of neonatal mortality in lambs born in arid region of India and genetic and non-genetic factors affecting it. The present study was conducted using the data on 4,137 Magra and 4,595 Marwari sheep over 17 years (1999 to 2016). Incidence of neonatal mortality was very low in Magra (1.04%) and Marwari (2.48%) sheep, respectively in semi-intensive management system. Year and seasonal variation was observed for neonatal losses. Males had lower odds of survival as compared to females. Odds of survival were low if the lambs were born to dams of low body weight and in their first parity. It was observed that the lamb survival can be improved if due care of the lambs born with low birth weight (&lt;2 kg) is taken. The heritability estimate was moderate in Magra sheep (0.17), indicating further scope for genetic improvement for lamb survival through selection. However, for Marwari sheep, the total heritability was 0.02, thus limiting the scope for selection. Arid region favoured the lamb survival. Hardiness of the Magra and Marwari sheep, their high lamb survival along with standard production potential is indicative of the good genetics of these sheep along with better management practices adopted at arid regional campus, thus reflecting better sheep welfare practices.

Age Specific Role of Myostatin Intron-2 Gene on Body Weight of Magra Sheep

Age Specific Role of Myostatin Intron-2 Gene on Body Weight of Magra Sheep

Sequence analysis of high glycine-tyrosine keratin-associated proteins (kaps) in magra sheep

Keratin associated proteins (KAPs) are structural components of the wool fibre. The present study was aimed to analyse nucleotide sequence diversity in three high glycine-tyrosine KAPs gene (HGT-KAP) viz. KAP6, KAP7 and KAP8 from Magra sheep known for lustrous wool. This study was conducted to analyse single nucleotide polymorphisms (SNPs) in these three gene sequences. In open reading frame (ORF), SNPs were not located in KAP 6, however in KAP 7, 14 SNPs were located which leads to 5 synonymous and 9 non-synonymous mutations. In KAP 8 gene only one SNP was present in ORF which leads to tyrosine to asparagine amino acid change. In phylogenetic analysis, KAP 6 proteins of Magra sheep were clustered with KAP 6 amino acid sequence of cashmere goats. Most of the SNPs identified were located into 5′ and 3′ untranslated regions. Since 5′ and 3′ untranslated regions play crucial roles in post-transcriptional regulation of gene expression, these SNPs might play some role in lustrous phenotype of the wool.

Keratin Gene Expression Differences in Wool Follicles and Sequence Diversity of High Glycine-Tyrosine Keratin-Associated Proteins (Kaps) in Magra Sheep of India

ABSTRACT Wool fibers consist of proteins with majority belongs to keratin family. Longitudinally arrayed keratin intermediate filaments constitute a matrix surrounded by keratin-associated proteins (KAPs). These KAPs play essential role in providing the physico-mechanical properties of the wool fiber. Real time PCR assay revealed that type 1 hair cortex keratin K33A (K1.2) was significantly (p ≤ 0.05) upregulated in lustrous Magra wool follicles however other keratin and keratin associated protein (KAP) genes were found down regulated. Furthermore, nucleotide sequence analysis revealed 4, 30, and 7 single nucleotide polymorphisms (SNPs) in KAP6, KAP7, and KAP8 genes, respectively. The presence of differing amount of type I and type II keratin and hydrophobic high glycine-tyrosine proteins in wool might be partially responsible for different glass transitions exhibited by wool and consequently imparts different physical properties like wool luster.

Subjective and objective/machine evaluation of wool luster in Magra sheep vis-a-vis wool grading and animal selection

ABSTRACTWool of Magra sheep in India is well-known for its fiber quality and luster. In the present study, subjective and objective luster grading wool clips and its association with fiber diameter was done. It was found that for higher luster grades, their fiber attributes are closer to lower limits of ideal carpet wool, viz. fiber diameter and proportion of medullated fibers to 30 µm with medullation 30%. Canary colored wool’s whiteness index (L*) may be considered as one of the physical properties for identification of wool luster. Subjective grades indicated that visual grading of wool samples was very close to the quality appraisal of attributes.

Genetic polymorphism of KRT 1.2, kap 1.3 and THH gene in magra sheep

Physical traits of wool like fibre diameter, medullation, length and lustre are important in textile industry. Magra sheep has been recognised to possess good quality lustrous wool, which has high demand in the Indian carpet industry. The gene responsible for lustre wool in Magra sheep is not known. The present study was aimed to detect polymorphisms at three loci in candidate genes for wool quality viz., KRT 1.2, KAP 1.3 and THH in Magra sheep. KRT 1.2 and KAP1.3 loci were found polymorphic with three genotypes each viz., MM, MN and NN for the former and XX, XY and YY for the latter. Two genotypes (AAand AB) were observed in THH gene locus with genotype frequency of 0.97 and 0.03, respectively. The predominant genotypes were: MM for KRT 1.2, YY for KAP 1.3 and AA for THH locus. Sequence analysis of THH revealed that some repeats (intron) are missing in Magra sheep as compared to Merino sheep. Phylogenetic analysis with THH sequences of other domestic species revealed separate clustering of THH gene sequences in this study. This could be because of two novel SNPs in Magra sheep which have not been reported in any of the analysed species.

Genetic, phenotypic and environmental trends of growth and wool traits in magra sheep

Genetic, phenotypic and environmental trends of growth and wool traits in magra sheep

Influence of environmental factors on production traits and heritability estimates of magra sheep in Arid region

The aim of the present study was to examine the effect of non-genetic factors on growth and wool traits of 1482 Magra sheep spread over a period of five years (2008–12) maintained at the Arid Region Campus, ICAR-Central Sheep and Wool Research Institute, Bikaner. The least squares means for body weight at birth, 3, 6, 9 and 12 months of age were 3.18±0.02, 16.12±0.14, 23.72±0.20, 28.37±0.21 and 31.88±0.25 kg, respectively. The average daily gain in body weights during 0–3, 3–6 and 6–12 months of ages were 143.45±1.43, 84.23±1.35 and 40.22±1.13 g, respectively. For greasy fleece weight at first, second and third clips, least squares means were 567.18±5.16, 628.08±4.97 and 640.01±5.45 g, respectively. Least squares analysis of variance revealed significant (P<0.01) effect of year of birth and sex on all the traits. The fixed effect of parity had significant (P<0.01) effect only on birth weight. Dam's weight at lambing was a significant (P<0.01) source of variation for all the body weight traits, except average daily gains during 3–6 and 6–12 months of age. Greasy fleece weights at first, second and third clips were affected significantly (P<0.01) by lamb's age at shearing. Heritability estimates for body weight at birth, 3, 6, 9 and 12 months of age and average daily gain during 0–3, 3–6 and 6–12 months of age and greasy fleece weight at first, second and third clips were 0.17±0.06, 0.31±0.08, 0.33±0.09, 0.35±0.10, 0.59±0.14, 0.28±0.08, 0.23±0.07, 0.62±0.14, 0.52±0.11 and 0.32±0.10 and 0.11±0.09, respectively. Heritability estimates for all the growth traits was moderate to high, suggesting further scope for genetic improvement in the flock.

Estimation of (CO) variance components for growth traits in Magra sheep

The objective of the study was to estimate the (co)variance components and genetic parameters for different growth traits of Magra flock maintained at the Arid Region Campus, ICAR-Central Sheep and Wool Research Institute, Bikaner, Rajasthan. The study comprised records of 2309 animals distributed over a period of 12 years (1999–2010). The estimation was done by restricted maximum likelihood procedures, fitting six animal models with various combinations of direct and maternal effects. The direct heritability estimates from the best model, as per likelihood ratio test for body weights at birth, 3, 6, 9 and 12 months of age and average daily gain from birth to 3, 3–6 and 6–12 months of age were 0.37±0.04, 0.25±0.04, 0.24±0.04, 0.36, 0.36±0.06, 0.21±0.04, 0.20±0.04 and 0.16±0.05, respectively. The genetic correlation between direct and maternal genetic effects was found to be moderate to large and negative for all the traits, indicating antagonistic pleiotropy, which must be considered while formulating breeding plans. Moderate to high heritability estimates indicate the presence of genetic variability in the flock that can be utilized for improvement of these traits through selection.

Evaluation of Indian sheep breeds of arid zone under heat stress condition

The present study was conducted to assess the effect of the heat stress on the hematological and physio-biochemical parameters of sheep breeds thriving in hot and arid climatic conditions. Thirty animals (female) of about one and half year of age from each sheep breed (Chokla, Magra and Marwari) were used for the estimation of hematological and physio-biochemical parameters under normal (lower Temperature Humidity Index of 65) and heat stress condition (higher Temperature Humidity Index of 84). T test analysis revealed significantly higher values in the heat stressed condition for SGOT, respiratory rate and pulse rate in afternoon hours; and significantly lower values for Hb%, PCV%, Triglycerides and Cholestrol for all the three breeds. Magra breed of sheep had highest overall adaptability (83.29%) followed by Marwari (80.41%) and Chokla with the least adaptability (79.13). Higher overall adaptability in Magra sheep in this region might be due to the white and lustrous coat of Magra which reflects the sun light more as compared to other sheep breeds. However, the effect was found to be non-significant (P>0.05). Therefore, it is concluded that these sheep breeds are equally adaptable to the hot and arid climatic conditions of this region.

Factors Affecting Weight Gain in Magra Sheep under Arid Condition of Rajasthan

Factors Affecting Weight Gain in Magra Sheep under Arid Condition of Rajasthan

Influence of sheep breeds on the susceptibility to strongyle infection in Rajasthan

A study was conducted to observe the influence of sheep breeds on the susceptibility to natural strongyle infection in Rajasthan. Faecal samples (39,896) from native, crossbred and exotic sheep managed under farm condition in both arid and semi-arid agro-climate of Rajasthan were evaluated for incidence and intensity of strongyle infection (predominated by Haemonchus contortus). In semi-arid region, parasitological profile showed relatively the lowest susceptibility of Garole and its crosses followed by Malpura, Chokla, Kheri and the highest susceptibility in crossbreds. Like-wise in arid region, the lowest susceptibility was expressed by Nali sheep followed by Marwari, Chokla, crossbreds and the highest susceptibility by exotic sheep. During wormy season, at Arid Region Campus, Bikaner, Marwari sheep possessed greater resistance compared to Magra sheep. It was also observed that similar genotype of sheep vary in susceptibility according to agroclimatic conditions and resultant pasture infectivity. The over-dispersion phenomenon in faecal egg counts suggested that inter-individual variation in susceptibility to natural infection was of more importance than inter- breed differences. Further the study suggested that for selection for resistance to GIN infection in Indian sheep under natural condition might be possible.

Body water turnover in Indian desert mammals

Body water turnover estimates suggest that the Marwari goat of the Rajasthan desert is more efficient in water use than Marwari and Magra sheep, the Parbatsar goat or the desert donkey. Young Marwari goats are, likewise, superior to Marwari and Magra lambs and Parbatsar kids in respect of water use efficiency.