title: Dietary n-6:n-3 Fatty Acid Ratios Alter Rumen Fermentation Parameters and Microbial Populations in Goats.
abstract: Revealing the ruminal fermentation patterns and microbial populations as affected by dietary n-6:n-3 PUFA ratio would be useful for further clarifying the role of the rumen in the lipid metabolism of ruminants. The objective of the present study was to investigate the effects of dietary n-6:n-3 PUFA ratios on fermentation characteristics, fatty acid (FA) profiles, and microbial populations in the rumen of goats. A total of twenty-one goats were randomly assigned to three dietary treatments with different n-6:n-3 PUFA ratios of 2.27:1 (low ratio, LR), 5.01:1 (medium ratio, MR), and 10.38:1 (high ratio, HR). After 100 days of feeding, all goats were slaughtered. Dietary n-6:n-3 PUFA ratios had no effect (P > 0.05) on rumen pH and NH3N concentration. Goats fed HR diet had lower (P < 0.05) propionate and total volatile fatty acids and higher (P < 0.05) butyrate compared with those fed the MR and LR diets. The proportion of C18:0 decreased (P < 0.05) as dietary n-6:n-3 PUFA ratios increased. The proportions of C18:1 trans-11, C18:2n-6, cis-9 trans-11 CLA, and C20:4n-6 were greater in the HR goats compared with the MR and LR goats. Lowering dietary n-6:n-3 PUFA ratios enhanced (P < 0.05) the proportion of C18:3n-3 and total n-3 PUFA in the rumen fluid of goats. The populations of R. albus and R. flavefaciens decreased (P < 0.05) as the n-6:n-3 PUFA ratios increased in diet. Diet had no effect (P > 0.05) on the ruminal populations of F. succinogenes, total bacteria, methanogens, total protozoa, Entiodinium, and Holotrich. The population of B. fibrisolvens was lower (P < 0.05) in the LR goats compared with the MR and HR goats. It was concluded that HR would increase the concentration of cis-9 trans-11 CLA and C18:1 trans-11 in the rumen. However, LR whould decrease the B. fibrisolvens population, which is involved in the BH process in the rumen. Further research is needed to evaluate the potential role and contribution of rumen microbiome in the metabolism of FA in the rumen.
authors.forename: Mahdi
authors.initials: M
authors.lastname: Ebrahimi
authors.forename: Mohamed Ali
authors.initials: MA
authors.lastname: Rajion
authors.affiliation: Department of Animal Production University of Ilorin , PMB 1515, Ilorin, Nigeria.
authors.forename: Kazeem Dauda
authors.initials: KD
authors.lastname: Adeyemi
authors.forename: Saeid
authors.identifier: http://orcid.org/0000-0001-5191-9330
authors.initials: S
authors.lastname: Jafari
authors.affiliation: Agriculture Biotechnology Research Institute of Iran (ABRII) , East and North-East Branch, P.O.B. 91735 844, Mashhad, Iran.
authors.forename: Mohammad Faseleh
authors.initials: MF
authors.lastname: Jahromi
authors.affiliation: Agriculture Biotechnology Research Institute of Iran (ABRII) , East and North-East Branch, P.O.B. 91735 844, Mashhad, Iran.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Oskoueian
authors.forename: Goh Yong
authors.initials: GY
authors.lastname: Meng
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta , Edmonton, T6G 2P5 Canada.
authors.forename: Morteza Hosseini
authors.initials: MH
authors.lastname: Ghaffari
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000032:analysis / Q000378:metabolism*; D043371:Fatty Acids, Omega-6 / Q000032:analysis / Q000378:metabolism*; D005285:Fermentation; D006041:Goats / Q000378:metabolism* / Q000382:microbiology; D012417:Rumen / Q000378:metabolism / Q000382:microbiology*
chemical_list: D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6
keywords: Boer goat; fatty acid; microbial population; rumen fermentation