Association of adiponectin and adiponectin receptor genes with sow productivity estimated breeding values.

Our objectives were to estimate frequencies of previously identified single nucleotide polymorphisms (SNPs) in adiponectin (ADIPOQ) and its receptors (ADIPOR1 and ADIPOR2) in a population of Duroc, Landrace and Yorkshire pigs and evaluate the effect of these alleles on sow productivity estimated breeding values (EBVs). Eight SNPs were genotyped on 446 pigs in the ADIPOQ (c.178G>A, c.*300A>G, c.*1094_1095insC and c.*1779A>C), ADIPOR1 (c.*129A>C) and ADIPOR2 (c.*112G>A, c.*295G>C and c.*1455G>A) genes. Association analyses were performed with sow productivity EBVs based on litter records collected in Canadian breeding farms. There were significant associations between ADIPOQ c.178G>A and c.*1094_1095insC SNPs and studied traits. However, none of these associations remained significant after applying a Bonferroni correction. The ADIPOR2 c.*112G>A SNP was associated with the total number of piglets born (TNB, P < 0.001) and litter weight at weaning (LWW, P < 0.001) EBVs. Associations were also observed between the ADIPOR2 [A;C;G] haplotype and TNB and LWW (P < 0.001). Our results demonstrate that a selection in favor of the c.*112G allele or against the [A;C;G] haplotype may have the potential to increase LWW EBVs. However, the c.*112G allele is also associated with lower TNB EBVs. Some of the alleles of the genes studied showed substantial variability and in general, the results corroborated previously reported findings for an independent sow population. However, careful cost-benefits analyses should be performed before using these markers in selection program as an improvement in TNB may translate into lighter LWW, with its associated negative impact on production traits such as growth performances.

Effect of Slat and Gap Width of Slatted Concrete Flooring on Sow Gait Using Kinematics Analysis.

The housing of gestating sows in groups requires sound information about the adapted design of the pen floor. Slatted concrete floors are commonly used for effective drainage of manure but can cause feet injuries and lameness. In the present study, kinematics were used to characterize the gait of 12 gilts and 12 lame sows walking in a corridor on slatted concrete floors with different combinations of slat (85, 105 or 125 mm) and gap (19, 22 or 25 mm) widths. The nine experimental floors were tested with slats in the perpendicular and parallel orientation to the direction of animal walk, according to a duplicated lattice design. Gait parameters were quantified using spatial, temporal and angular kinematics for front and rear limbs. Some parameters were significantly affected by the treatments (p < 0.05), but the effects differed between gilts and lame sows and between slat orientations. Gap width had a significant effect on parameters such as back angle, stride length, foot height, and carpal and tarsal joint angle amplitudes. Slat width significantly affected parameters such as foot height, and carpal and tarsal joint angle amplitudes. Comparisons of the different combinations of slat and gap widths revealed that slats with a width of 105-125 mm and gap width of 19-22 mm had the least effect on the gait characteristics of the gilts and sows.

Identification of single nucleotide polymorphisms in carnosine-related genes and effects of genotypes on pork meat quality attributes.

Carnosine has pH-buffering and antioxidant properties that may bring advantages in terms of meat quality attributes. This study aimed at identifying polymorphisms in carnosine-related genes (CARNS1, SLC6A6, SLC15A3, SLC15A4) that might associate with muscle carnosine content and meat quality traits in pigs (Duroc, Landrace, Yorkshire). Twenty seven SNPs were identified and association analyses performed for SLC15A3 c.*35C>T and c.*52C>T (3' UTR region), and SLC15A4 c.658A>G (Ile220Val) and c.818G>A (Ser273Asn) SNPs. Associations were observed for SNP c.658A>G with carnosine content, color b* and L*, drip and cooking losses, pH24h and glycolytic potential values (P≤0.05). The same associations were observed for SNP c.818G>A, but they were not significant after FDR correction. Results suggest that specific SLC15A4 gene variants might increase muscle carnosine content and improve meat quality. With a minor allele frequency of 0.17 for SNP c.658A>G in Yorkshire pigs, selection in favor of the c.658A allele may be considered as a mean to improve pork quality attributes.

Cross-species hybridizations on a multi-species cDNA microarray to identify evolutionarily conserved genes expressed in oocytes.

BACKGROUND: Comparative genomic analysis using cDNA microarray is a new approach and a useful tool to identify important genetic sequences or genes that are conserved throughout evolution. Identification of these conserved sequences will help elucidate important molecular mechanisms or pathways common to many species. For example, the stockpiled transcripts in the oocyte necessary for successful fertilization and early embryonic development still remain relatively unknown. The objective of this study was to identify genes expressed in oocytes and conserved in three evolutionarily distant species. RESULTS: In this study we report the construction of a multi-species cDNA microarray containing 3,456 transcripts from three distinct oocyte-libraries from bovine, mouse and Xenopus laevis. Following the cross-species hybridizations, data analysis revealed that 1,541 positive hybridization signals were generated by oocytes of all three species, and 268 of these are preferentially expressed in the oocyte. Data reproducibility analyses comparing same-species to cross-species hybridization indicates that cross-species hybridizations are highly reproducible, thus increasing the confidence level in their specificity. A validation by RT-PCR using gene- and species-specific primers confirmed that cross-species hybridization allows the production of specific and reliable data. Finally, a second validation step through gene-specific microarray hybridizations further supported the validity of our cross-species microarray results. Results from these cross-species hybridizations on our multi-species cDNA microarray revealed that SMFN (Small fragment nuclease), Spin (Spindlin), and PRMT1 (Protein arginine methyltransferase 1) are transcripts present in oocytes and conserved in three evolutionarily distant species. CONCLUSION: Cross-species hybridization using a multi-species cDNA microarray is a powerful tool for the discovery of genes involved in evolutionarily conserved molecular mechanisms. The present study identified conserved genes in the oocytes of three distant species that will help understand the unique role of maternal transcripts in early embryonic development.