Abstract #W127

Section: Ruminant Nutrition (posters)
Session: Ruminant Nutrition: Fat and Lipids
Format: Poster
Day/Time: Wednesday 7:30 AM–9:30 AM
Location: Exhibit Hall A

# W127
Heat treatment from pelleting or extrusion did not impact performance of Saccharomyces cerevisiae fermentation products on volatile fatty acid production in an in vitro rumen model.
C. Reedy^*1, I. Yoon¹, J. Butler¹, T. Werner¹, ¹Diamond V, Cedar Rapids, IA.

The objective of this study was to evaluate the effect of Saccharomyces cerevisiae fermentation products, Diamond V Original XPC (XPC), XPC Ultra (XPC Ultra), and NutriTek (NutriTek) on in vitro volatile fatty acid (VFA) production before and after going through either pelleting or extrusion. XPC Ultra was pelleted at 80°C for 60 s. XPC and NutriTek were extruded at 135°C for 30 s and dried at 145°C for 30 min. Test products were added to each serum bottle relative to their recommended feeding rates - XPC (14 g/d), XPC Ultra (7 g/d), and NutriTek (19 g/d) - along with 0.3 g of cellulose as substrate. Each serum bottle was inoculated with 40 mL of buffered rumen fluid from cows on a diet consisting of 70% forage and 30% concentrate and was incubated for 24 h. Ten replicates were run per treatment. Data was analyzed using the GLM model of JMP. Means were compared using Tukey test and significance was defined as P = 0.05. After incubation, VFA production was measured and reported in Table 1.Results showed that both heat-treated and untreated products significantly increased ruminal VFA production over Control while showing no difference between heat-treated and untreated products. In conclusion, heat-treatment had little effect on the performance of the products tested in an in vitro rumen model, which suggests that Saccharomyces cerevisiae fermentation products could go through pelleting or extrusion and fully express their potentials in processed feeds requiring heat treatment. Table 1 (Abstr. W127). Ruminal VFA production (mM) of untreated and heat-treated products

Product	Treatment	Acetate	Propionate	Butyrate	Total VFA
XPC Ultra	Control	8.55^a	1.91^a	0.77^a	11.28^a
	Untreated	11.26^b	2.91^b	0.94^b	15.20^b
	Pelleted	11.28^b	2.95^b	0.95^b	15.24^b
	SEM	0.13	0.03	0.02	0.18
XPC	Control	11.34^a	2.51^a	1.61^a	15.56^a
	Untreated	12.84^b	3.00^b	1.78^b	17.75^b
	Extruded	12.94^b	3.02^b	1.73^b	17.80^b
	SEM	0.19	0.03	0.02	0.24
NutriTek	Control	10.77^a	2.28^a	1.14^a	14.29^a
	Untreated	14.78^b	3.67^b	1.51^b	20.12^b
	Extruded	14.71^b	3.54^b	1.45^b	19.86^b
	SEM	0.34	0.06	0.02	0.43

^a,bMeans within a column within product without a common letter differ by P = 0.05.

Key Words: Diamond V Original XPC, pelleting, extrusion