Evaluation of LYSOFORTE Extend on Rumen Fermentation Parameters, Rumen and Total Tract Digestion, and Fatty Acid Digestion | UNL Beef

Authors: Anna M. Kobza, Graduate Student; Dalton J. Anderson, Research Technician; Jerilyn Hergenreder, Kemin Industries, Des Moines, IA; Jim C. MacDonald, Professor, Animal Science, Lincoln.

Summary with Implications

Supplemental fat fed in finishing diets in recent years has generally increased in price. This digestibility study evaluated LYSOFORTE Extend, a lysophospholipid based nutritional emulsifier, in beef finishing diets containing tallow or corn oil. Five ruminally and duodenally cannulated steers were used in a 5 × 5 Latin Square design. Treatments followed a 2 × 2 +1 factorial: 1) No Oil (negative control), 2) Corn Oil (3.5%), 3) Tallow (3.5%), 4) Corn Oil + LFE (8 g/d), and 5) Tallow + LFE (8 g/d). Cattle fed the negative control diet had greater dry matter intake than cattle consuming diets with supplemental fat but no LYSOFORTE Extend. But, when LYSOFORTE Extend was added to diets with corn oil and tallow, intake did not differ (P = 0.50) from the negative control. There was no difference in total tract dry matter (DM), organic matter (OM) or apparent energy digestibility across any of the 5 dietary treatments (P ≥ 0.23). The impact of LYSOFORTE Extend on rumen fermentation parameters, such as average pH and volatile fatty acid (VFA) concentration were limited. There was no difference in average pH (P ≥ 0.21) across treatments, but a main effect of LYSOFORTE Extend on total VFA concentration (P ≤ 0.05), where diets that included LYSOFORTE Extend had greater total VFA concentration than those without LYSOFORTE Extend. While supplemental fat reduced intake, when fed with LYSOFORTE Extend it appeared to mitigate this effect, which may warrant further research into this response.

Introduction

Fat plays several dietary roles, some of which include, increasing dietary energy density. improving palatability, feed lubrication, and decreasing dust. Supplementing large amounts of fat is known to interact with rumen digestion parameters, resulting in biohydrogenation and limiting digestion in the small intestine. In a survey conducted to assess nutritional recommendations of consulting feedlot nutritionists in 2016, 54.2% of nutritionists’ clients were adding fat in feedlot diets. The percentage of cattle feeders using supplemental fat today is largely driven by cost. The cost of fat has been variable but is generally higher due to increased demand for and production of renewable diesel. Improvements in fat digestion in beef finishing diets would reduce the cost per unit of energy. LYSOFORTE Extend (LFE; Kemin Industries, Inc., Des Moines, IA), is a lysolecithin product that acts as a natural emulsifier that is known to improve fat digestion in nonruminant species but has not been studied in beef finishing diets. Our objective was to evaluate LYSOFORTE Extend in beef finishing diets containing a saturated fat source (tallow) and unsaturated fat source (corn oil) on rumen fermentation parameters, as well as ruminal and total tract digestibility of nutrients.

Procedure

Five ruminally and duodenally cannulated steers were used in a 5 × 5 Latin Square design with 21-d periods consisting of a 16-day adaptation period followed by a 5-d sample collection period over 105 days. The treatment design was a 2 × 2 + 1 factorial with the 5 following treatments: 1) No Oil: negative control containing 0.0% supplemental fat; 2) Corn Oil: 3.5% supplemental corn oil; 3) Tallow: 3.5% supplemental tallow; 4) Corn Oil +L: 3.5% supplemental corn oil + Lysoforte (8 g/d); 5) Tal+L: 3.5% supplemental tallow + Lysoforte (8 g/d). All diets were steam-flaked corn-based with 15% corn silage, 3.5% soybean meal, and 5% supplement, and formulated to include 30 g/ton DM of monensin (Rumensin, Elanco Animal Health; Table 1). Steers were housed individually in a temperature-controlled room and fed once daily at 0700 h with ad libitum access to feed and water. Acid detergent insoluble ash (ADIA) (2.5%) was used as an internal dietary marker fed to cattle as biolite clay (Performance Plus, Grand Island, NE). Biolite clay fed in this study was 80% ADIA, on average. Ingredient samples were taken during the collection period at the time of mixing, composited by period, freeze- dried and ground through a Wiley Mill using a 1- mm screen. Feed refusals were collected on d 17, 18 and 19, 20 before feeding, dried in a forced air oven, ground through a Wiley Mill using a 1- mm screen, and composited by steer within collection period. Fecal, duodenal, and ruminal samples were collected four times daily during the collection period at 0700, 1100, 1500, 1900 h on d 17, 18, 19 and 20. Fecal and duodenal samples were analyzed for ADIA to determine fecal output and duodenal flow to calculate nutrient digestibility. Feed ingredients, feed refusals, duodenal and fecal samples were analyzed for dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), starch, crude protein (CP), digestible energy (DE), and ether extract (EE). Rumen fluid samples were analyzed for volatile fatty acids through gas chromatography, and whole rumen samples were collected on d 21 of each period. Ruminal pH was continuously monitored using Moonsyst Smart Rumen pH Boluses (Moonsyst, Cork, Ireland).

Table 1. Dietary treatment composition (DM basis) and chemical analysis for finishing steers fed corn oil or tallow with or without LYSOFORTE Extend (LFE).
	Treatment
	No LFE			With LFE
Item	No Oil	Corn Oil	Tallow	Corn Oil + LFE	Tal + LFE
Ingredient, %
Steam Flaked Corn	74	70.5	70.5	70.5	70.5
Corn Silage	15	15	15	15	15
SBM¹	3.5	3.5	3.5	3.5	3.5
Corn Oil	-	3.5	-	3.5	-
Tallow	-	-	3.5	-	3.5
Supplement²	5	5	5	5	5
Biolite Clay	2.5	2.5	2.5	2.5	2.5
Chemical Composition, %
Organic Matter	93.61	93.62	93.62	93.62	93.62
Neutral Detergent Fiber	18.46	18.01	18.01	18.01	18.01
Crude Protein	13.48	13.42	13.15	13.15	13.29
Starch	54.64	52.29	52.29	52.29	52.29
Ether Extract	2.95	6.34	6.34	6.34	6.34
¹Soybean Meal. ²Supplement provides Rumensin (30 g/ton of DM) and along with minerals and vitamins to meet or exceed nutrient requirements, along with urea for rumen degradable protein needs.

Data were analyzed using the MIXED procedure of SAS (SAS Institute, Inc.) with period, treatment, and steer as fixed effects. Contrasts were used to test the main effect of fat source (corn oil vs. tallow), the main effect of LYSOFORTE Extend inclusion (± LFE), the interaction between fat source and LYSOFORTE Extend, and the overall effect of fat inclusion (oil vs. no oil). Ruminal pH and total volatile fatty acid concentration of rumen fluid was analyzed using the MIXED procedure of SAS with treatment, hour, and treatment by hour interaction included in the model, with hour being considered a repeated measure and compound symmetry covariate structure provided the best fit. Probabilities less than or equal to alpha (P ≤ 0.05) were considered significant, with tendencies acknowledged at 0.05 < P ≤ 0.10.

Results

There were no significant interactions between LYSOFORTE Extend and fat source (P = 0.33) on dry matter intake, however, there was a main effect of LYSOFORTE Extend (P = 0.02; Table 2). Cattle fed No Oil had the greatest intake (P = 0.16) but intake decreased when cattle were fed Corn Oil and Tallow. However, when fed either fat source with the addition of LYSOFORTE Extend, intake was increased, where Corn Oil + LFE and Tal + LFE had similar DM intake to No Oil (P = 0.02). Because of this, cattle fed Lysoforte also had greater intake of OM, DE, starch and fat (P ≤ 0.03) compared to those fed supplemental fat without LYSOFORTE Extend, however all diets containing fat had greater fat intake than No Oil (P ≤ 0.01).

Table 2. Nutrient intake, excretion, and total tract digestibility of steers fed corn oil or tallow with or without LYSOFORTE Extend (LFE).
	Treatment						P-Value¹
	No LFE			With LFE			P-Value¹
Item	No Oil	Corn Oil	Tallow	Corn Oil + LFE	Tal + LFE	SEM	Fat	LFE	LFE × Fat	Control vs. Fat
Total Tract
DM
Intake, lb/d	23.02	18.87	19.01	23.39	22	1.19	0.88	0.02	0.33	0.16
Digested, lb/d	17.02	14.2	15.12	17.66	16.98	0.95	0.9	0.02	0.41	0.35
Excreted, lb/d	6	4.67	4.76	5.75	5.03	0.38	0.41	0.1	0.3	0.04
Digestibility, %	74.16	75.07	76.42	75.32	77.21	1.11	0.17	0.65	0.82	0.17
OM
Intake, lb/d	21.56	18.45	18.65	22.04	20.5	1.08	0.55	0.03	0.43	0.2
Digested, lb/d	17.22	14.88	15.01	17.48	16.6	0.95	0.71	0.05	0.6	0.27
Excreted, lb/d	4.34	3.57	3.64	4.56	3.88	0.33	0.36	0.08	0.27	0.27
Digestibility, %	80.14	80.74	80.85	79.24	81.04	1.22	0.45	0.6	0.5	0.81
DE
App. DE Digestibility, %	75.46	77.43	77.85	77	78.61	1.33	0.46	0.91	0.66	0.16
DE, Mcal/d	30.83	28.29	28.81	33.89	32	4.01	0.71	0.03	0.52	0.97
DE, Mcal/lb OM	1.43	1.54	1.54	1.53	1.56	0.13	0.65	0.67	0.65	<0.01
TDN, % of OM	71.87	76.95	76.99	76.9	78.23	1.41	0.64	0.68	0.66	<0.01
Starch
Intake, lb/d	13.78	12.06	11.86	13.05	12.59	0.46	0.48	0.08	0.77	0.02
Digested, lb/d	13.51	11.91	11.62	12.79	12.35	0.42	0.42	0.09	0.84	0.01
Excreted, lb/d	0.265	0.154	0.243	0.265	0.243	0.044	0.58	0.24	0.31	0.56
Digestibility, %	98.17	98.68	98.07	97.79	98.04	0.37	0.64	0.24	0.26	0.94
Fat
Intake, lb/d	0.668	1.26	1.26	1.5	1.39	0.07	0.38	0.01	0.4	<0.01
Digested, lb/d	0.514	1.13	1.11	1.33	1.23	0.07	0.34	0.02	0.53	<0.01
Excreted, lb/d	0.154	0.128	0.146	0.172	0.161	0.022	0.87	0.04	0.29	0.84
Digestibility, %	76.25	89.94	88.67	88.66	88.41	1.3	0.57	0.57	0.7	<0.01
Ash Free NDF
Intake, lb/d	4.32	3.79	3.79	4.08	3.97	0.13	0.69	0.11	0.76	0.02
Digested, lb/d	2.13	1.69	1.87	1.83	1.91	0.13	0.33	0.48	0.67	0.04
Excreted, lb/d	2.19	2.1	1.92	2.25	2.08	0.18	0.35	0.42	0.96	0.64
Digestibility, %	50.37	43.35	49.35	45.21	48.33	3.41	0.21	0.9	0.68	0.34
¹Fat=P-value for main effect of fat supplementation; LFE= P-value for main effect of LYSOFORTE Extend supplementation; LFE × fat = P-value interaction between LYSOFORTE Extend inclusion and fat supplementation; Control vs. Fat= P-value for main effect of fat supplementation compared to the negative control.

Total Tract Digestion

There was no interaction of LYSOFORTE Extend and fat source on any total tract digestion parameters when using internal ADIA as a marker (Table 2). However, there was a main effect of fat (P < 0.01) where all cattle consuming diets containing fat, from corn oil or tallow, had greater DE (Mcal/lb. of OM) content and fat digestibility than the negative control.

Ruminal Digestion

For ruminal digestibility (Table 3), there was an interaction of LYSOFORTE Extend and fat source (P < 0.01) on true OM and true starch digestibility. Cattle fed Corn Oil + LFE had greater true OM digestibility compared to Corn Oil (P < 0.01), however Tal + LFE did not have greater true OM digestibility than Tallow. This suggests LYSOFORTE Extend may reduce the negative effects associated with feeding an unsaturated fat like corn oil. True starch digestibility was lowest for cattle fed Corn Oil + LFE compared to all other treatments (P < 0.01).

Duodenal flow of bacterial OM was greater for Corn Oil + LFE (P ≤ 0.01) than all other treatments, which did not differ from each other. There was a main effect (P < 0.01) of LYSOFORTE Extend on bacterial OM flow, where cattle fed Corn Oil + LFE and Tal + LFE had greater bacterial OM flow than those fed Corn Oil and Tallow. Similar to bacterial OM flow, there was also an interaction of LYSOFORTE Extend and fat source (P < 0.01) on bacterial starch flow, where Corn Oil + LFE had greater starch flow compared to all other treatments which were not different from each other. While no interaction was observed for ash free NDF flow, there was a main effect of fat (P < 0.01) and LYSOFORTE Extend (P < 0.03) where ash free NDF flow was decreased when feeding Corn Oil + LFE and Tal + LFE and feeding fat without LYSOFORTE Extend. Additionally, ash free NDF flow was greater when feeding Corn Oil or Corn Oil + LFE than Tallow or Tallow + LFE.

There was an interaction of LYSOFORTE Extend and fat source on duodenal flow of bacterial and apparent feed N (Table 4) (P < 0.01) where bacterial N flow was greater for Corn Oil + LFE than all other treatments. Apparent feed N flow was greater for Tal + LFE and No Oil than Tallow and Corn Oil + LFE (P < 0.01). Microbial efficiency was calculated in two ways: 1) g of microbial crude protein/ g of TDN intake and 2) g of N/kg of OM fermented in the rumen. There was no interaction of LYSOFORTE Extend and fat source on microbial efficiency however, numerically, microbial efficiency calculated as g of N/kg of OM fermented in the rumen was greater for Corn Oil + LFE. This improvement in microbial efficiency coincides with greater bacterial N flow for cattle fed Corn Oil + LFE. Compared to cattle fed Corn Oil, Tallow had reduced microbial efficiency (P = 0.03), but Corn Oil + LFE and Tal + LFE had increased microbial efficiency calculated as g of N/kg of OM fermented compared to Corn Oil and Tallow.

Table 3. Nutrient flow and ruminal digestibility of steers fed corn oil or tallow with or without LYSOFORTE Extend (LFE).
	Treatment						P-Value¹
	No LFE			With LFE			P-Value¹
Item	No Oil	Corn Oil	Tallow	Corn Oil + LFE	Tal + LFE	SEM	Fat	LFE	LFE × Fat	Control vs. Fat
Ruminal digestibility, %
Apparent OM	61.53	58.07	64.49	53.91	54.54	3.21	0.29	0.05	0.39	0.31
True OM	82.08^ab	77.11^bc	84.16^a	85.46^a	74.92^c	1.93	0.38	0.82	<0.01	0.46
NDF	53.78	54.11	61.89	44.48	51.84	2.58	0.01	<0.01	0.94	0.81
Ash Free NDF	61.25	61.77	69.61	54.58	64.03	2.5	<0.01	0.03	0.75	0.66
Apparent Starch	87.09	84.55	87.97	82.64	84.02	1.87	0.22	0.14	0.59	0.29
True Starch	94.46^a	95.52^a	93.78^a	90.24^b	95.29^a	0.68	0.03	0.02	<0.01	0.34
Duodenal Flow, lb
Bacterial OM	4.34^b	3.53^b	3.75^b	6.99^a	4.17^b	0.42	0.01	<0.01	<0.01	0.58
Feed OM	3.99^ab	4.28^ab	3.00^b	3.20^b	5.23^a	0.49	0.47	0.27	0.01	0.91
Total OM	8.33	7.83	6.77	10.19	9.39	0.68	0.2	<0.01	0.84	0.79
NDF	2.2	1.91	1.6	2.49	2.11	0.13	0.03	<0.01	0.82	0.29
Ash Free NDF	1.71	1.45	1.18	1.87	1.56	0.11	0.03	<0.01	0.83	0.16
Bacterial Starch	0.767^b	0.542^b	0.765^b	1.24^a	0.593^b	0.088	0.02	0.01	<0.01	0.83
Feed Starch	0.875^ab	1.09^ab	0.589^b	0.858^ab	1.26^a	0.176	0.77	0.23	0.02	0.71
Total Starch	1.64	1.63	1.36	2.1	1.85	0.22	0.24	0.04	0.95	0.7
¹Fat=P-value for main effect of fat supplementation; LFE= P-value for main effect of LYSOFORTE Extend supplementation; LFE × fat = P-value interaction between LYSOFORTE Extend inclusion and fat supplementation; Control vs. Fat= P-value for main effect of fat supplementation compared to the negative control. ^abcMeans with different superscripts differ when the interaction of LFE × fat is significant (P ≤ 0.05).

Table 4. Effect of corn oil or tallow with or without LYSOFORTE Extend (LFE) on N flow and microbial efficiency.
	Treatment						P-Value¹
	No LFE		With LFE				P-Value¹
Item	No Oil	Corn Oil	Tallow	Corn Oil + LFE	Tal + LFE	SEM	Fat	LFE	LFE × Fat	Control vs. Fat
Duodenal Flow , lb/d
Bacterial	0.220^b	0.205^b	0.190^b	0.351^a	0.216^b	0.021	<0.01	<0.01	0.01	0.39
Apparent Feed	0.187^a	0.163^ac	0.126^bc	0.101^c	0.229a	0.017	0.03	0.23	<0.01	0.12
Total	0.406	0.368	0.315	0.452	0.445	0.029	0.31	<0.01	0.47	0.73
Microbial Efficiency²	9	9	8.1	13	8.4	0.97	0.02	0.04	0.08	0.56
Microbial Efficiency³	17	19.4	15.7	31.5	19.7	3.22	0.03	0.03	0.23	0.23
¹Fat=P-value for main effect of fat supplementation; LFE= P-value for main effect of LYSOFORTE Extend supplementation; LFE × fat= P-value interaction between LYSOFORTE Extend inclusion and fat supplementation; Control vs. Fat= P-value for main effect of fat supplementation compared to the negative control. ²Microbial N efficiency, calculated g microbial CP/g TDN intake. ³Microbial N efficiency, g of N/kg of OM fermented in the rumen. ^abcMeans with different superscripts differ when the interaction of LFE × fat is significant (P ≤ 0.05).

Ruminal pH & Volatile Fatty Acids

There was no difference in average pH (Table 5) when measured with an indwelling ruminal pH bolus (P = 0.36). However, maximum pH measured with the pH bolus was greater (P = 0.03) for cattle fed Corn Oil, Tallow, and Tal + LFE than No Oil. Maximum pH however was increased for Corn Oil, Corn Oil + LFE, Tallow and Tal + LFE compared to No Oil (P = 0.01). There was no treatment by hour interaction for volatile fatty acids, so main effects of treatment are presented in Table 6. There was no interaction of LYSOFORTE Extend and fat on the proportion of the volatile fatty acids acetate, propionate and butyrate, nor the acetate: propionate ratio (P ≥ 0.10). However, there was a main effect (P = 0.05) of LYSOFORTE Extend where Corn Oil + LFE and Tal + LFE had greater total VFAs than Corn Oil and Tallow but were not different than Control, suggesting addition of LYSOFORTE Extend may increase total VFA concentrations. This observation also follows the response of fat and LYSOFORTE Extend on DM intake which likely explains the increase in total VFA concentrations.

Table 5. Ruminal pH characteristics for steers fed corn oil or tallow with or without LYSOFORTE Extend (LFE).
	Treatment						P-Value¹
	No LFE		With LFE				P-Value¹
Item	No Oil	Corn Oil	Tallow	Corn Oil + LFE	Tal + LFE	SEM	Fat	LFE	LFE × Fat	Control vs. Fat
Minimum pH	5.47	6.04	5.83	5.71	5.89	0.2	0.96	0.55	0.38	0.17
Maximum pH	5.83^c	6.21^a	6.06^ab	5.91^bc	6.09^ab	0.07	0.71	0.05	0.03	0.01
Average pH²	5.66	6.13	5.97	5.82	6.04	0.19	0.9	0.56	0.36	0.21
¹Fat=P-value for main effect of fat supplementation; LFE= P-value for main effect of LYSOFORTE Extend supplementation; LFE × fat = P-value interaction between LYSOFORTE Extend inclusion and fat supplementation; Control vs. Fat= P-value for main effect of fat supplementation compared to the negative control. ²Average pH measured by indwelling ruminal pH bolus. ^abcMeans with different superscripts differ when the interaction of LFE × fat is significant (P ≤ 0.05).

Table 6. Ruminal VFA concentration for steers fed corn oil or tallow with or without LYSOFORTE Extend (LFE).
	Treatment						P-Value¹
	No LFE		With LFE				P-Value¹
Item	No Oil	Corn Oil	Tallow	Corn Oil + LFE	Tal + LFE	SEM	Fat	LFE	LFE × Fat	Control vs. Fat
Total VFA, mM	214.16	150	154.8	173.7	219.5	19.85	0.23	0.05	0.32	0.1
Acetate, %	56.49	57.57	51.93	53.93	51.34	1.35	0.01	0.14	0.28	0.09
Propionate, %	33.4	29.4	37.94	33.51	36.21	2.05	0.02	0.57	0.18	0.71
Butyrate, %	7.03	8.14	6.44	8.59	8.07	1.24	0.39	0.42	0.64	0.58
A:P²	1.81	2.02	1.41	1.67	1.52	0.13	0.01	0.39	0.1	0.3
¹Fat=P-value for main effect of fat supplementation; LFE= P-value for main effect of LYSOFORTE Extend supplementation; LFE × fat = P-value interaction between LYSOFORTE Extend inclusion and fat supplementation; Control vs. Fat= P-value for main effect of fat supplementation compared to the negative control. ²Acetate to Propionate ratio.

Conclusions

Feeding supplemental fat with LYSOFORTE Extend in finishing diets increased DM intake, as well as OM, DE and fat intake, which could have potential benefits on cattle performance. However, further research on a pen scale is required to validate this hypothesis. Overall, total tract digestion was unaffected, but ruminal digestion varied. Feeding LYSOFORTE Extend with corn oil improved ruminal OM digestion, bacterial OM flow, and microbial efficiency compared to corn oil alone, suggesting LYSOFORTE Extend may mitigate the negative effects of unsaturated fat sources. Rumen pH was largely unaffected by fat source or LYSOFORTE Extend, but cattle consuming fat did have greater maximum pH than the negative control diet. Lastly, total VFA concentrations were greater for diets containing fat plus LYSOFORTE Extend, which is likely driven by the intake response. These findings suggest LYSOFORTE Extend may help offset the negative effects of unsaturated fats on ruminal digestion, though more research is needed to confirm this.

Acknowledgment

Funding for this study was provided by Kemin Industries. Products used in this study were provided by Elanco Animal Health.