Tag Archives: Latvian sheep

xxx I. Trapina, S. Plavina, N. Krasņevska, J. Paramonovs, D. Kairisa and N. Paramonova
MSTN gene polymorphisms are associated with the feed efficiency of fattened lambs in Latvian sheep breeds
Abstract |

MSTN gene polymorphisms are associated with the feed efficiency of fattened lambs in Latvian sheep breeds

I. Trapina¹*, S. Plavina¹, N. Krasņevska¹, J. Paramonovs¹, D. Kairisa² and N. Paramonova¹

¹Genomics and Bioinformatics, Institute of Biology of the University of Latvia,
Jelgava Str. 3, LV-1004 Riga, Latvia
²Institute of Agrobiotechnology, Faculty of Agriculture, Latvian University of Life Sciences and Technologies, Liela Str. 2, LV-3001 Jelgava, Latvia
*Correspondence: ilva.trapina@lu.lv

Abstract:

The economic benefit for sheep farmers depends on the level of feed efficiency of the lambs raised. Promoting breed selection for feed efficiency could provide sheep farmers with higher quality and more economically profitable lambs. In livestock production, marker-assisted selection employs genetic biomarkers linked to specific traits. Myostatin (MSTN), a vital transforming growth factor-beta superfamily member, is pivotal in regulating myogenesis and negatively impacts mammal muscle growth and development. The study aims to find molecular markers related to feed efficiency parameters in the MSTN gene for Latvian sheep breeds. DNA extraction was made from blood collected from 76 controlled fatten lambs, with 63.16% belonging to the Latvian Dark-head (LT) breed. A complete gene sequencing analysis was conducted to identify variations in loci across different sheep breeds, aiming to discover statistically significant associations between identified polymorphisms and feed efficiency indicators.  Polymorphic variants were identified in 23 loci of the MSTN gene among Latvian lambs, with the discovery of a novel SNP. Notably, SNP rs404916326 T>A exhibited statistically significant associations with indicators such as Residual feed intake, Residual intake, and body weight gain, specifically in the LT breed. Furthermore, SNP rs408469734 G>A showed associations with relative growth rate and Kleiber’s ratio within the lamb group. These findings suggest that SNPs rs404916326 and rs408469734 within the MSTN gene are promising molecular markers for marker-assisted selection strategies in sheep breeding to improve feed efficiency indicators.

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xxx I. Trapina, S. Plavina, N. Krasņevska, J. Paramonovs, D. Kairisa and N. Paramonova
IGF1 and IGF2 gene polymorphisms are associated with the feed efficiency of fattened lambs in Latvian sheep breads
Abstract |
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IGF1 and IGF2 gene polymorphisms are associated with the feed efficiency of fattened lambs in Latvian sheep breads

I. Trapina¹*, S. Plavina¹, N. Krasņevska¹, J. Paramonovs¹, D. Kairisa² and N. Paramonova¹

¹Genomics and Bioinformatics, Institute of Biology of the University of Latvia, Jelgava str. 3, LV-1004, Riga, Latvia
²Institute of Agrobiotechnology, Faculty of Agriculture, Latvian University of Life Sciences and Technologies, Liela Street 2, LV-3001, Jelgava, Latvia
*Correspondence: ilva.trapina@lu.lv

Abstract:

Feed efficiency is an economically important indicator in sheep farming. The most effective technology for selecting the best feed-efficient lambs for breeding is marker association selection of genetic variations in the sheep genome as potential biomarkers. In tissue growth and differentiation, insulin-like growth factors (IGFs) play a major role: IGF1 mediates the effects of growth hormone, and IGF2 is a growth regulator, regulating skeletal muscle growth. The study aims to find possible molecular markers for feed efficiency indicators in IGF1 and IGF2 genes for Latvian sheep breeds. The exonic regions of the IGF1 and IGF2 genes were sequenced for the first time in the genomic DNA of 76 controlled, intensively fattened lambs, to search for possible genetic biomarkers. Seven polymorphic loci in the IGF1 gene and sixteen in the IGF2 gene were detected. Statistically significant associations of the IGF1 SNP rs600896367 were found with residual indicators: Residual feed intake, Residual weight gain (RWG), and Residual intake and body weight gain (RIG), and with feed efficiency and feed conversion ratio in the overall group of samples. Additionally, IGF2 SNPs New_7 and rs429576107 exhibited associations with RWG and RIG specifically in the Latvian dark-head sheep group. On average, effect of the IGF1 SNP on associated feed efficiency residuals is 3.9%, with the most pronounced impact observed in RFI. In contrast, the influence of IGF2 SNPs is comparatively lower. Our results indicate that rs600896367 and New7/rs429576107 are potential molecular markers for marker-assisted selection in sheep breeding for residual feed efficiency indicators.

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611-622 I. Trapina, D. Kairisa and N. Paramonova
Feed efficiency indicators and hormones related to nutrient metabolism in intensive fattened lambs of sire rams of different sheep breeds in Latvia
Abstract |
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Feed efficiency indicators and hormones related to nutrient metabolism in intensive fattened lambs of sire rams of different sheep breeds in Latvia

I. Trapina¹*, D. Kairisa² and N. Paramonova¹

¹University of Latvia, Institute of Biology, Laboratory of Genomics and Bioinformatics, Jelgava street 3, LV-1004 Riga, Latvia
²Latvian University of Life Sciences and Technologies, Faculty of Agriculture, Institute of Agrobiotechnology, Liela street 2, LV-3001 Jelgava, Latvia
*Correspondence: ilva.trapina@lu.lv

Abstract:

The feed efficiency increase of each sheep indicates its profitability. Production costs and the environmental impact of animal husbandry are reduced as feed efficiency improves. The gastrointestinal tract is a source of hormones and is important in regulating feed intake and nutrient utilization. The study analyses the relationship between feed efficiency indicators and hormone levels in Latvian sheep breeds. After control fattening, blood samples were taken from 76 lambs, representatives of six Latvian breeds, for seven hormonal analyzes and seven feed efficiency indicators. Feed efficiency, Feed conversion ratio (FCR), Relative growth rate, Kleiber ratio (KR), Residual feed intake (RFI), Residual weight gain, and Residual intake were calculated from daily weight gain and amount of dry matter. Interbreed differences and relationships between indicators/hormones were identified. The best scores of feed efficiency were found for the lamb rams of the Dorper breed; the Latvian black-head was the second according to these indicators. The mean FRC for lambs was determined to be 5.13 ± 0.13 kg with a range of
2.98–10.15 kg; the mean KR was 18.11 ± 0.39 with a range of 8.78–26.88; the mean RFI was in the range of -0.51 to 0.42 kg. A statistically significant difference was found between the breeds for all feed efficiency indicators. Biochemical parameters (IGF-1, insulin, and glucose) were found to be in correlation with feed efficiency indicators. Our results show that Latvian sheep breeds differ in fattening performance. To improve breeds without crossing them, subsequent genetic analysis of breed differences is necessary.

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