Skip to Main content Skip to Navigation
Conference papers

Methionine supplementation impacts casein gene expression and cell death in the mammary tissue of lactating dairy goats fed low and adequate net energy supplies

Abstract : Methionine supplementation is known to modulate milk and protein yields in dairy ruminants. However, the mechanism involved in this phenomenon is still unknown. The cellular and molecular responses in the mammary tissue to methionine (Met) supplementation through HMBi (MetaSmart, Adisseo) at low (LE) and adequate levels (AE) of NEL were investigated according to a 2 × 2 factorial arrangement on 48 multiparous Alpine goats at mid lactation, assigned to a randomized block design in 4 groups during 5 weeks. Each goat was genotyped for CSN1S1 gene to balance each group according to the high or low genotypes for CSN1S1 gene. A fixed amount of hay was distributed per group (1.17 Mcal/kg DM) and a fixed amount of concentrates was distributed individually (1.72 vs. 1.83 Mcal/kg DM in LE and AE, respectively). Metabolizable methionine were 1.95 vs. 2.45% of metabolizable protein in unbalanced (LE and AE) vs. balanced (LEMET and AEMET) diets, respectively. Goats (23) were slaughtered after 5 weeks of treatment. Mammary tissues were collected for the analyses of milk protein mRNA levels by real time RT-PCR and apoptosis by immunohistochemistry using TUNEL assay. A variance analysis was performed with genotype, E, Met and E x Met, E x genotype, Met x genotype interactions as fixed effects and for milk, pre-treatment data yields was used as a covariate. Met supplementation increased milk protein yield (+6.5 g/d; P = 0.03). The treatments did no modify LALBA whereas an interaction E x Met (P = 0.001) were observed for both CSN3 and CSN1S1 mRNA levels showing 2-fold increases with Met supplementation in goats fed AE diet. The supplementation of Met reduced by 51% apoptosis rates in the mammary tissue (P < 0.01). Apoptosis rate was correlated with milk yield (−0.48; P < 0.05). These results suggest that Met increased casein gene expression at AE level and reduced cell death which could partly explain the positive effect of Met supplementation on milk synthesis in the goat mammary tissue.
Complete list of metadata

https://hal.inrae.fr/hal-02969329
Contributor : Emilie Bernard <>
Submitted on : Friday, October 16, 2020 - 3:14:16 PM
Last modification on : Friday, March 19, 2021 - 12:40:02 PM

File

Boutinaud_2020_Adsa.pdf
Publisher files allowed on an open archive

Identifiers

Collections

Citation

Marion Boutinaud, Eric Chanat, Antoine Leduc, Sandra Wiart, Perrine Debournoux, et al.. Methionine supplementation impacts casein gene expression and cell death in the mammary tissue of lactating dairy goats fed low and adequate net energy supplies. 2020 American Dairy Science Association (ADSA) Annual Meeting, Jun 2020, Virtual Meeting, United States. pp.22. ⟨hal-02969329⟩

Share

Metrics

Record views

34

Files downloads

17