Effect of CAST and DGAT1 genetic variants on the qualitative and quantitative characteristics of Italian Mediterranean buffalo meat

In recent years, the interest towards buffalo meat has been increasing due to its nutritional quality: reduced fat and choles terol, and high iron content. This study aimed to characterize the chemical-physical compo sition of Italian Mediterranean buffalo (IMB) meat and to assess the effects of CAST and DGAT1 gene polymorphisms. Calpastatin is involved in the tenderness process, while the DGAT1 is a key gene for fat synthesis, although studies have linked it to meat tenderness. DNA of 56 IMB belonging to one farm was isolated. CAST gene was partially sequenced in 10 IMB randomly chosen. SNP discov ery showed the transition A>G at the intron 12 (nt 338) that represents the first marker reported at CAST in the IMB. Regarding the DGAT1, we considered the SNP C>T at the exon 13 (nt 69). The sample was genotyped by PCR-RFLP for both SNP. Twenty out of 56 IMB were slaughtered and a portion of the L. thoracis et lumborum muscle was analysed for chemical (centes imal composition), physical and technological aspects (pH; colour: L*, a*, b*, Hue and Sat; texture 20% and 80%; tenderness; cooking losses; water holding capacity) at 7 and 14 days to assess the ripening effects. Analyses confirmed the values reported in literature at day-7, while data on tenderness were generally rather high. Instead, analyses at day-14 proved the positive effect of the ripening. Genotype distribution was not homogeneous. Hence, we excluded animals with rare genotypes (5 AA for CAST and 8 TT for DGAT1). Regarding CAST, the interaction between the meat shade (Hue) and the day was significant (p=0.038). Such result was partially unexpected because not directly linked to the meat tenderness, despite this association has been investigated in literature. No genotype effects on meat tenderness was found. This might be due to the different genetic structure of the IMB compared to cattle or, simply, to a random allele association between the exam ined SNP and other causative markers on CAST. The SNP C>T at DGAT1 was associated with a different level of Texture Profile Analysis (TPA 80%). The CC genotype showed greater compression force than the CT (p=0.035). Although the TPA 80% links to the stroma more than to the myofibril compo nent, we can consider it as a good indication for the improvement [Ital J Anim Sci vol.22:s1, 2023] [page 183] Italian Journal of Animal Science 2023; volume 22: supplement 1 of meat tenderness as already reported in literature. In fact, the adipose tissue is defined as a specialised connective tissue Therefore, in this respect; the role of the DGAT1 should be recon sidered for affecting, directly or indirectly, the meat texture. Conversely, the lack of DGAT1 association with fat traits needs further investigation. Acknowledgements Study supported by Genobu project (PON01_00486).