Database of expression analysis of samples of the 1st trial (A22) of sheep breeds in Latvia within the framework of the project of the Latvian Council of Science LZP-2021/1-0489 project

Project of The Latvian Council of Science (LCS) - LZP-2021/1-0489 project: “Development of an innovative approach to identify biological determinants involved in the between-animal variation in feed efficiency in sheep farming”.

The aim of the project is to determine whether the feed efficiency status of Latvian meat sheep breeds could be predicted using a panel of genetic and molecular markers previously found to be associated with divergent FE status in a training population of lambs when fed the same diet.

Novelty: to determine the parameters predicting the most productive result of lamb rearing, we set out to develop the cheapest and most effective method for determining markers of feed efficiency - based on molecular and genetic markers obtained from the blood of live lambs.

About the project:

The costs associated with lambing (buying or keeping sheep) and preparing or purchasing feed are the two most significant components of variable costs in sheep raising. Feed costs are high due to poor grain growing conditions in major producing countries, the use of feed grains in ethanol production, and increased competition for land in crop production compared to urban development. Feed efficiency in growing lambs (i.e., the animal’s ability to reach a market or adult body weight (BW) with the least feed intake) is a critical factor in the sheep industry. Improving FE reduces production costs. Improving FE by 5% can bring economic benefits up to four times higher than a 5% increase in average daily gain (ADG).

Traditionally, meat breeding programs have focused on outputs due mainly to the routine availability of phenotypic data on outputs or correlated traits. Currently, no marker has successfully explained enough of the variability in feed efficiency that they were used as part of a routine improvement program. According to our data, no genetic parameters for performance and feed efficiency traits are available for sheep. The physiological determinants of feed efficiency or putative biomarkers used to analyse animal-to-animal variation in live lambs could be a cost-effective and rapid tool for genetic selection or management decisions.

About the data of the project:

LZP-2021/1-0489 project data on lamb samples of the year 2022, or the A22 group, which consists of 76 intensively fattened lambs from six breeds. The blood samples for RNA extraction were taken after intensive fattening at an average body weight of 45 – 50 kg.

Gene expression levels were determined using qPCR methodology using the GAPDH gene as a reference. Three genes were analysed in the project: MTOR (The mechanistic mammalian target of rapamycin), CAST (Calpastatin) and UPC3 (uncoupling protein 3).

The data obtained will be used to determine the changes in expression levels related to gene variations (MTOR: https://doi.org/10.5281/zenodo.8146731; CAST: https://doi.org/10.5281/zenodo.8146372; UPC3: https://doi.org/10.5281/zenodo.8146778);  as well as to analyze the relationship of expression levels with biochemical parameters (https://doi.org/10.5281/zenodo.8143225) and feed efficiency indicators (https://doi.org/10.5281/zenodo.8143244) of lambs.

The data is the joint property of the participants of the LCS project: the University of Latvia and the Latvian University of Life Sciences and Technologies.