Chia Seed Supplementation Increases Ruminal Propionate Concentration in Alfalfa Hay Based Diets Evaluated in a Dual-Flow Continuous Culture System

Abstract Text: Chia seed (CS) and flaxseed (FS) are rich in omega-3 fatty acids which may provide health benefits when added to animals’ diets. However, data on the effects of CS supplementation on ruminal metabolism is scarce. The objective of this experiment was to determine nutrient digestibility, rumen fermentation characteristics, microbial protein synthesis, and long-chain fatty acids flow of supplemented alfalfa hay (AH) diet with either CS or FS. Diets were randomly assigned to six dual-flow continuous culture fermenters (1,200 to 1,250 mL) in a replicated 3X3 Latin square arrangement with three 10-d experimental periods consisted of 7 days for diet adaptation and 3 days for sample collection. Fermenters were fed a total of 72 g of DM/d equally divided in 4 portions. Diets consisted of (DM basis) 95% AH supplemented with: 5% Megalac (Diet A), 5% FS (Diet B), and 5% CS (Diet C). Liquid and solid dilution rates were adjusted daily to 10%/h and 5%/h, respectively. A sample of 500mL from each fermenter was taken on days 8, 9, and 10. Two subsamples of 10ml were filtered through two layers of cheesecloth, were preserved with 0.2mL of 50% sulfuric acid and centrifuged for ruminal NH₃ and VFA analysis. Statistical analyses were performed using the GLM procedure in SAS. Ruminal metabolism data are presented in the table. Supplementing CS increased the molar proportion of propionate and decreased Acetate:Propionate ratio. There were no differences among treatments for ruminal NH₃ concentration, total VFA concentration, and molar proportions of acetate, butyrate, and branched-chain VFA. Results from this experiment indicate that CS supplementation may change ruminal metabolism by increasing ruminal propionate concentration which may be energetically beneficial for glucose synthesis in ruminants.

Keywords: Dual-flow continuous culture, chia seed, flaxseed

	Megalac	Flaxseed	Chia seed	SEM	P-Value
	Diet Composition %DM
EE	5.6	5.6	5.6
CP	18.5	19.2	19.4
NDF	40.9	41.7	42.5
NH3-N, mg/dL	5.34	5.38	6.34	0.58	0.46
Total VFA, mmol	125.61	119.12	116.41	5.02	0.48
Acetate, %	79.61	79.26	78.66	0.36	0.27
Propionate, %	12.59b	12.71b	13.21a	0.12	<0.05
Butyrate, %	4.84	5.11	5.15	0.16	0.42
Isobutyrate, %	0.65	0.62	0.71	0.06	0.58
Valerate, %	1.43	1.37	1.46	0.05	0.44
Isovalerate, %	0.89	0.86	0.84	0.12	0.94
Acetate:Propionate	6.35a	6.25a	5.95b	0.23	0.05
Total BCVFA, mmol	3.47	3.58	3.85	0.08	0.67

^a,bLSmeans with different subscript within rows are different (P≤ 0.05).