Methane fermentation residue as a protein supplement for beef cattle

Biological Wastes 19 (1987)123-132

Methane Fermentation Residue as a Protein Supplement for Beef Cattle C. R. Jones, D. N. M o w a t , J. G. B u c h a n a n - S m i t h & G. K. M a c l e o d Department of Animal and Poultry Science, University of Guelph. Guelph, Ontario, N1G 2W1 Canada (Received 28 October 1985; accepted I April 1986) A BS TRA C T Methane fermentation residue (MFR) produced from cattle or swine wastes was evaluated as a protein supplement for growing beef cattle. Steers f e d traditional urea or soybean meal supplements had markedly greater weight gains and feed efficieneies than steers supplemented with cattle e~,IFR. Although diets containing M F R were consumed readily, steer performance was reduced due in part to poor nutrient digestibilities of the MFR. No adverse effect on rumen fermentation was noted when feeding cattle or swine MFR. It was concluded that M F R produced from cattle wastes has little if an)" value as a supplemental protein source for growing beef cattle. However, swine M F R would appear to have some potential as a feed source due to its higher crude protein content and improved nutrient digestibilities.

INTRODUCTION The concept of refeeding raw manure to beef cattle has been examined in the past but has met with little success, with the possible exception of laying hen excreta (Anthony, 1971; Bucholtz et al., 1971; Bhattacharya & Taylor, 1975). Recently interest has developed in feeding MFR, a material produced from animal wastes which have undergone anaerobic fermentation to generate methane gas. Fermented effluent from the digestion process is centrifuged to produce a liquid fertilizer and a semisolid residue (MFR). M F R produced from the digestion of cattle and swine wastes has recently been shown to contain 21% dry matter (DM), and 25 123 Biological Wastes 0269-7483/87/$03.50 © Elsevier Applied Science Publishers Ltd, England, 1987. Printed in Great Britain

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C. R. Jones, D. N. Mowat, J. G. Buchanan-Smith, G. K. Macleod

and 38% crude protein (CP), respectively (Buchanan-Smith et al., 1986). Since almost 50% of the crude protein fraction is present as non-protein nitrogen (NPN), the ruminant would appear to be the ideal animal to make use of these potential protein supplements (Harris et al., 1982; Prior & Hashimoto, 1981; Buchanan-Smith et al., 1986). The present study was conducted to evaluate the nutritive value of MFR, produced from a commercial beef feedlot operation and a swine enterprise, as protein supplements for growing beef cattle. METHODS

Feediot trial Eighty late maturing steers averaging 296kg were blocked according to shipment group and randomly assigned to pens of four. Following adjustment, steers were randomly assigned to one of four dietary treatments as outlined in Table 1. MFR~ was formulated to be isonitrogenous and isocaloric with the urea and SBM control diets. M F R 2 was formulated to be isonitrogenous, but with equal ratios of corn silage:high moisture corn as the SBM diet, resulting in a lower estimated energy content. Cattle were fed once daily ad libitum. Steers were implanted with Compudose (Elanco Products Co. London, Canada) and weighed full on two consecutive days at the beginning and end of trial. Individual weights were taken every 28 days and refused feed was weighed back at this time to calculate DM intakes and feed conversion on a pen basis. M F R sampled weekly and corn silage sampled daily were frozen and composited on a weekly basis. All other feed ingredients were sampled on a biweekly basis. Feed samples were analyzed for DM by freeze drying. Crude protein was determined on wet samples by macro-Kjeldhal analysis (AOAC, 1975). Freeze-dried samples were ground through a 1 mm screen and analyzed for ash by heating in a muffle furnace at 600°C for 8 h; acid detergent fibre (ADF) by the method of Goering & Van Soest (1970); neutral detergent fibre (NDF) by the method of Van Soest & Wine (1968); calcium and phosphorus according to the AOAC (1975) procedures. The General Linear Model of the Statistical Analysis System (SAS Institute, 1976) was used to analyze performance data as a complete block design with unequal replication.

Digestion trial Six steers averaging 410ks were used in a 3 x 3 double latin square digestion trial to determine digestibilities of cattle and swine MFR. Cattle

Digester residues for cattle feed

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TABLE 1 C o m p o s i t i o n of Diets Fed D u r i n g Feedlot Trial

Items

Ingredients ( % D M ) C o r n silage High moisture corn Urea SBM M F R cattle Mineral 1a Mineral 2 e R u m e n s i n premix I Chemical c o m p o s i t i o n Dry m a t t e r (%) C r u d e protein [ % D M ) T D N estimated (°/oDM) h ADF (%DM) NDF (%DM) OM (%DM) Ca ( % D M ) P (%DM)

Nitrogenous feed source Urea

SBM

MFR t

MER,_

88"8 7.5 0"6

89.3 3"0 -4"6 -1.4 -1.8

61.0 22.5 --14'0 -0.7 1'8

81'0 2.7 --13'8 -0.7 1-8

43.4 a 11.4 b 71 21.5 a 36.3 a 95.2 a 0.38 ° 0.45

38.4 b 11.9 c 71 19.6 b 31.1 h 91.5 b 1.02 b 0.49

35.7 c l 1.6 ~ 66 24.0 c 37.6 c 90-5 b 1.14 b 0.50

-

-

-1.4 -1.8

43.3 a 10.9" 71 21.3 ° 36.0 a 95.5" 0-36 a 0-42

SEM o

0.29 0"09 0.23 0.13 7.36 0.08 0.02

a.b.c M e a n s with different superscripts differ. d 17% potassium sulphate, 4 5 % calcium phosphate, 8 % limestone, 15% trace mineral salt (guaranteed analysis: 9 6 ' 5 % salt, 0.4% zinc, 0.16% iron, 0.12% manganese, 0-033% copper, 0.007% iodine, 0-004% cobalt), 4 % vitamin A D E premix (containing: 4 4 0 0 0 0 0 I U k g -~ vit. A, 1 1 0 0 0 0 I U k g -1 vit. D, 7700 I U k g -1 vit. E), 11% corn, 8 m g k g -1 selenium. 4 0 % potassium sulphate, 16 mg kg-~ selenium, 8 % A D E premix (as a b o v e 1 2 2 % trace mineral salt (as above), 30% corn. .r 9 8 ' 8 % g r o u n d corn, 1"2% Rumensin. g S t a n d a r d error o f mean. h Est. T D N ( M F R ) = [-(100% - 36% a s h ) - 13% lignin] × 6 5 % digestible.

or swine M F R replaced 13°,/o of a diet similar to the SBM diet fed in the feedlot trial. The trial consisted of three 21 day periods. Steers were randomly assigned to one of the three diets, with two steers receiving a similar diet within each period. A 10 day adjustment phase was followed by a 4 day restriction phase where all animals received 90% of the lowest DM intake recorded during the adjustment phase. A 7 day total collection of feces and urine followed, with steers confined to individual digestion crates and fed at the restricted level. Animals were fed twice daily. During the collection phase, rations were

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C. R. Jones, D. N. Mowat, J. G. Buchanan-Smith, G. K. Macleod

sampled and orts collected and weighed at each morning feeding. All feed samples and orts were stored at - 1 0 ° C . A 10% subsample of feces was collected and stored at - 10:C for further analysis. All feed, oft, and fecal samples from each steer were individually pooled and a 10% subsample taken and analyzed for DM, CP and organic matter (OM) as previously outlined. Gross energy was measured using a Parr Adiabatic calorimeter. Urine was collected over 100ml 6N HC1 and a 1% subsample stored at - 10~C. Urine samples were analyzed for CP and DM. All data were subjected to analysis of variance procedures (Steele & Torrie, 1960). Digestibility parameters for cattle and swine M F R were calculated using partial digestion coefficients.

Nylon bag and rumen fluid trial Three mature steers fitted with tureen cannulas were used to determine and compare in situ DM and CP disappearance of both sources of M F R with SBM. Diets were identical to those fed in the digestion trial. The trial was designed as a 3 x 3 latin square with three periods, each lasting 14 days. Steers were allowed 10 days to adjust to their assigned diets and were fed ad libitum throughout the trial. On days 11 and 12 of each period, 8 nylon bags containing the protein supplement corresponding to the diets fed, along with 8 bags containing corn silage, were suspended in the rumen of each steer. One bag each of corn silage and protein supplement were withdrawn at 2, 4, 6, 9, 24 and 48 h. The same process was repeated on days 13 and 14. Bags and their contents were washed, dried at 70°C and DM loss calculated. Remaining residue was ground through a 1 mm screen and analyzed for CP by automated Kjeldahl analysis. Rumen fluid samples were obtained at periodic intervals from 0 to 8 h post feeding. Samples were analyzed for pH, NH 3 and VFA levels. Degradation rates and tureen fluid parameters were analyzed as described by Steele & Torrie (1960) for latin square designs.

RESULTS A N D DISCUSSION

Feedlot trial Chemical composition of diets fed during the feedlot trial is outlined in Table i. Little variation in dietary composition was evident throughout the trial, however D M content of weekly loads of M F R fluctuated between 13.0% and 19"0% due to production variables and collection procedures. Feedlot performance of steers is presented in Table 2. No difference was

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Digester residues for cattle feed TABLE 2

Performance of Growing Steers Over 84 Days Items

No. steers Initial wt. (kg) Final wt. (kg) A.D.G. (kg) DM intake (kgday- l) DM intake/gain

Nitrogenous feed source

SEM c

Urea

SBM

MFR l

MFR2

20 294 400a 1.26a 7-45 5.94a

20 297 410a 1.344 7'58 5.63~

20 292 371h 0.95b 7.39 7.97b

20 296 367h 0.84b 7'22 8-61b

4.56 6.61 0.04 0.13 0.23

,.b Means with different superscripts differ (P < 0-01). c Standard error of mean. found in weight gain or D M intake:gain between the SBM or urea diets, indicating steers could equally utilize N P N supplied by urea. As well, no difference in performance was found between the two M F R diets. However, animals supplemented with M F R displayed markedly depressed weight gains and required more feed per gain (P < 0.01) than animals fed either urea or SBM. Harris et al. (1982) found a similar reduction in performance of feedlot cattle when substituting a combination of flaked corn, distillers solubles and urea with M F R at a level of 10"6% of the total dietary DM. Reduced performance of cattle has also been demonstrated by Johnson et al. (1981), when supplementing a ration with sewage sludge at a level of 11"6% of the total DM. The study concluded that sludge containing 24.9% CP and 45"0% ash had little value as a feed ingredient for beef cattle. There were no differences in D M intakes amongst the diets, suggesting no palatability problems existed when feeding M F R at levels of 14%. However, D M intakes did increase slightly, with each period of feeding M F R , relative to control diets. Prior and Hashimoto (1981) found that including up to 20% dried M F R in diets had no effect on D M intake in cattle. However, when wet M F R was fed to cattle at the same level, D M intake was depressed significantly. N o additional health problems were evident in steers fed M F R . These findings are supported by Albin and Sherrod (1975) and Johnson et al. (1975) for beef feedlot wastes, and Harris et al. (1982) when feeding M F R to cattle. Calculated magnesium, manganese, zinc, and copper contents were doubled when comparing diets containing M F R with control diets. Individually, mineral levels reported should not be sufficient to depress performance (NRC, 1980), however, combined minerals and their interactions may have some adverse effect on performance. Calcium levels

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C. R. Jones, D. iV. Mowat, J. G. Buchanan-Smith, G. K. Macleod

in the M F R diets were double the requirements of growing beef cattle, but were less than maximum tolerable levels of 2% reported by the National Academy of Science-National Research Council (1984). Calcium:phosphorus ratios were approximately 2-1:1. Calculated magnesium levels present were three times the recommended amounts, however at higher calcium and phosphorous concentrations greater levels of magnesium are required (National Academy of Science-National Research Council, 1980). Large concentrations of magnesium depress copper absorption. This effect is magnified in the presence of elevated iron, as in diets containing M F R (National Academy of Science-National Research Council, 1980). In addition, increased amounts of zinc depress both copper and iron absorption in the lower gut (National Academy of Science-National Research Council, 1980). Thus, diets containing M F R may depress feedlot performance as a result of the interactions between the high mineral levels.

Digestion trial Digestibility parameters of the basal ration and both sources of M F R are presented in Table 3. True crude protein digestibilities of M F R are overestimated in view of the higher CP levels of diets containing MFR. The reduced DM digestibility of the cattle M F R compared to swine is partially due to its increased lignin and A D F content (Buchanan-Smith et al., 1986). Both M F R sources contained considerable amounts of ash (36%) which would depress digestible energy content. Using the DE of 1.27 Mcal kg- 1, an estimated T D N content of 28.8% can be calculated for cattle M F R (Crampton & Harris, 1968). Incorporating this value, a calculated TDN content of 69% and 64% can be realized for feedlot diets MFR~ and MFR z respectively. This slight depression in estimated T D N for MFR~ is not sufficient to account for the large difference in weight gains between animals fed the SBM diet versus M F R 1. TABLE 3 Digestibility Coefficients of M F R Calculated by Partial Digestion Equations Items

DM (%) CP (%) OM (%) GE (%) DE (Mcal k g - t)

Cattle M F R

37-0 32-2 52-1 43"8 1.27

" Basal diet included for comparison.

Swine M F R

49"1 60"6 58"7 52"4 1-73

Basal diet °

67'6 58"4 68"2 65"6 3.04

Digester residues for cattle feed

129

The low CP digestibility of cattle M F R may be largely due to its high A D F - N content. A D F - N accounts for 20.51% of the total nitrogen content (Buchanan-Smith et al., 1986). Harris et al. (1982) reported that A D F - N accounted for 27% of the CP fraction of cattle MFR. Using an equation developed by Goering et al. (1972), a CP digestibility of 45.1-52-0% can be calculated. Approximately 40% of the crude protein fraction of cattle M F R was shown to be in the form of NPN (Buchanan-Smith et al., 1985), which should be largely digestible. This would suggest that the true protein fraction of the cattle MFR may be largely unavailable. Using the equation developed by Goerling et al. (1972), a CP digestibility of 69'1% can be calculated for swine MFR. An actual value of 60.6% was found in the present study. The improved digestibility found for swine versus cattle MFR is in part a reflection of its lower ADF-N content of 3"8% of the total nitrogen (Buchanan-Smith et al., 19861.

Nylon bag and tureen fluid analysis Dry matter and CP disappearance of supplements and corn silage are presented in Table 4. Dry matter disappearance of SBM was greater (P < 0"05) than for swine M F R which in turn was greater (P < 0.05) than for cattle MFR. In addition, CP disappearance was greater (P < 0.05) for SBM than for either source of MFR. These results suggest that MFR is less readily available for digestion by rumen microbes, explaining in part the poor DM and CP digestibilities obtained in the digestion trial. No differences ( P < 0"05) were detected in corn silage DM or CP disappearance when feeding M F R versus SBM. These results imply that including MFR in diets at levels of 13% has no deleterious effects on digestibility of corn silage. The addition of M F R to the diets had no effect (P > 0-05) on the rate of NH 3 production from 0 to 1 h and 1 to 4 h, respectively, after feeding (Fig. TABLE 4 D M and CP Disappearance ~ of S B M or M F R F r o m Nylon Bags Suspended in the Rumen

Items D M supplement D M silage CP supplement C P silage

Basal

Basal + cattle M F R

84 b 50 96 b 55

41 ¢ 55 30 c 59

" After 48 h, excluding the initial soluble fraction. bx.n M e a n s with different superscripts differ ( P < 0-05). e S t a n d a r d error of 3 means.

Basal + swine M F R 63 d 52 38 c 56

SEM e 0.9 0.9 1.2 0.8

130

C. R. Jones, D. N. Mowat, J. G. Buchanan-Smith, G. K. Macleod 12.5 -

R

lO

U MI E N F L

A Mt M 7.s O N I A s

I

N

D

2.5

mg/lOOml

0

1

2

3

5

4

6

7

8

TIMtE ( H O U R S ) ---

Fig. l.

R

CATTLE MtFR

--

SOYBEAN MtEAL

-e- SWINE MtFR

Rumen fluid ammonia-N concentration.

6"8!

Mt6 . 7 ~ U

"

E N

e.s

F

6.s:

L

U

I

s.4: 6.3 6.2

~

6.1 0

1

2

3

4

5

6

nMtE (HOURS) ---

CATTLE IvlFR

Fig. 2.

--

SOYBEAN MtEAL

Rumen fluid pH.

-e- SWINE MIFR

7

8

Digester residuesfor cattlefeed

131

1). However, actual NH 3 levels were slightly greater but not significant for animals fed swine or cattle M F R at 0, 0.5 and 1 h after feeding. As well, M F R had no effect on the rate of decrease of rumen fluid pH from 0 to 4 h post-feeding (Fig. 2). A slight depression (P < 0"05) in the rate of increase in pH from 4 to 8 h post-feeding was noted when adding swine M F R to the ration. No differences were found in actual pH levels or in any VFA analyzed from 0 to 8 h post-feeding (P > 0.05). Although the addition of M F R to the diet would result in a slight decrease in fermentable energy, the decrease was not sufficient to depress V F A production. This corresponds with similar trends in pH. In summary, this study indicated that M F R produced from cattle wastes was of little, if any, value when fed to growing steers as the only supplemental protein source. Although diets containing M F R were consumed readily, steer performance was markedly reduced due in part to the poor nutrient digestibilities of the MFR. In addition, the high levels of minerals and their interactions may also play a large part in depressing performance. Because of its higher CP content and improved nutrient digestibilities, swine M F R would appear to have greater potential for use as a supplemental protein source for growing beef cattle.

ACKNOWLEDGEMENTS The authors would like to express their appreciation to Canviro Consultants Ltd, R. Bechtel and the late M. Selves for supplying M F R for this study and to the capable staff at the Elora Beef Research Centre for their assistance in conducting animal trials. This study was supported financially by the Natural Sciences and Engineering Research Council of Canada and by the Ontario Ministry of Agriculture and Food.

REFERENCES Albin, R. C. & Sherrod, L. B. (1975). Nutritional value of cattle feedlot waste for growing-finishing beef cattle. Symposium on Managing Livestock Wastes, Washington DC, USA, pp. 211-17. Anthony, W. B. (1971). Cattle manure as feed for cattle, Li~'estock Waste Management and Pollution Abatement, Ohio, American Society of Agricultural Engineers, St Joseph, MI, p. 293. A.O.A.C. (1975). Official methods of analysis, 12th edn, Association of Official Analytical Chemists, Washington, DC, USA. Bhattacharya, A. N. & Taylor, J. C. (1975). Recycling animal waste as a feedstuff: A review. J. Anita. Sci., 41, 1438-57. Buchanan-Smith, J. G., Lee, S., Mowat, D. N. & Macleod, G. K. (1986). Nutrient

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C. R. Jones, D. N. Mowat, J. G. Buchanan-Smith, G. K. Macleod

composition of methane fermentation residue. Can. J. Anim..Sci. Submitted for publication. Bucholtz, H. F., Henderson, H. E., Thomas, J. W. & Zindel, H. C. (1971). Dried animal waste as a protein supplement for ruminants. Livestock Waste Management and Pollution Abatement, Ohio, American Society of Agricultural Engineers, St Joseph, MI, p. 308. Crampton, E. W. & Harris, L. E. (1968). Applied animal nutrition, 2nd edn, Freeman Publishing Co., San Francisco, USA, p. 476. Goering, H. K. & Van Soest, P. J. (1970). Forage fibre analysis (Apparatus, reagents, procedures, and some applications). Agriculture handbook 379. ARS, USDA, Washington, DC, USA. Goering, H. K., Gorden, C. H., Hemkin, R. W., Waldo, D. R., Van Soest, P. J. & Smith, L. W. (1972). Analytical estimates of nitrogen digestibility in heat damaged forages. J. Dairy Sci., 55, 1275-80. Harris, J. M., Shirley, R. L. & Palmer, A. Z. (1982). Nutritive value of methane fermentation residue in diets fed to feedlot steers. J. Anim. Sci., 55, 1293-302. Johnson, R. R., Panciera, R., Jordan, H. & Shuyler, L. R. (1975). Nutritional, pathological and parisitological effects of feeding feedlot waste to beef cattle. Syrnp. on Managing Livestock Wastes, pp. 203-5. National Academy of Science-National Research Council. (1984). Nutrient requirements of domestic animals no. 4. Nutrient Requirements of Beef Cattle, 6th ed. NAS-NRC, Washington, DC, USA. National Academy of Science-National Research Council. (1980). Mineral tolerance of domestic animals, NAS-NRC, Washington, DC, USA. Prior, R. L. & Hashimoto, A. G. (198t). Potential for fermented cattle residue as a feed ingredient for livestock. In: Fuel gas production from biomass, Vol. III, CRC Press, Florida, USA, pp. 215-37. SAS Institute (1976). SAS user's guide. SAS Institute, Inc., Cary, N.C., USA. Steele, R. G. D. & Torrie, J. H. (1960). Principles and procedures of statistics. McGraw-Hill Book Co., New York. Van Soest, P. J. & Jones, L. H. P. (1968). Effect of silica in forages upon digestibility. J. Dairy Sci., 51, 1644-8. Van Soest, P. J. & Wine, R. H. (1968). Use of detergents in the analysis of fibrous feeds. IV. Determination of cell wall constituents. J. Assoc. Off. Anal. Chem., 50, 50-5.