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Complete Rations for Dairy Cattle. II. Sugarcane Bagasse Pellets as Roughage in Blended Rations for Lactating Cows1,2,3
Complete Rations for Dairy Cattle. II. Sugarcane Bagasse Pellets as Roughage in Blended Rations for Lactating Cows I ,2,3 S. P. MARSHALL and H. H. VAN HORN Dairy ScienceDepartment
University of Florida Gainesville 32611 percent was highest on the 30% bagasse ration.
ABSTRACT Three groups of six lactating cows were allotted to complete rations containing either 25% sugarcane bagasse pellets, 25% cottonseed hulls, or 12.5% of each which were fed ad libitum for 10 wk in a continuous trial. Covariance adjusted dry matter intake as percent of body weight, kg milk/day, kg solids corrected milk/day and milk fat percent on the respective rations averaged 3.9, 4.1, 4.0; 21.7, 22.8, 21.7; 22.0, 20.6, 21.1; and 4.1, 3.8 and 3.8. Sugarcane bagasse pellets were a satisfactory roughage substitute for cottonseed hulls. In Experiment II 36 lactating cows were assigned to complete rations containing 20, 25, or 30% sugarcane bagasse pellets fed ad libitum for 15 wk. Within each bagasse percent Coastal bermuda hay (1.36 kg offered~cow daily), sodium bentonite (3.7% of complete ration) or the control ration for that bagasse percent was fed for 5-wk periods (3 × 3 Latin square design). Covariance adjusted means for dry matter intake as percent of body weight, kg milk/day, milk fat percent; kg solids corrected milk/day, solids-not-fat percent, and protein percent were 3.5, 3.6, 3.5; 18.6, 18.5, 18.1: 4.3, 4.7, 4.6; 18.8, 20.1, 19.2: 9.09, 9.15, 9.20; and 3.6, 3.6 and 3.6 for the 20, 25, and 30% bagasse rations. Cows on the 20% bagasse ration produced more solids corrected milk when hay was fed, and solids-not-fat
INTRODUCTION
Received September 11, 1974. 1Florida Agricultural Experiment Station Journal Series No. 5554. 2 Supported in part by a grant from United States Sugar Corporation, Clewiston, FL. 3 Digestive tract examinations were made by F. C. Neal, Veterinary Science Department, University of Florida, and Paul Randet, University of Puerto Rico, Lajas 00667.
Blended complete rations are convenient to feed and permit precise control of the ratio of ingredients and nutrients consumed. Dry matter intakes have been high with blended rations (3, 8, 11, 12), and their ad libitum usage offers an attractive means for maximizing feed intake in high producing cows during the early postpartum period. Although some health problems have been experienced on blended rations low in roughages (6, 9), advantages to be gained in animal response from the increased nutrient intake is an incentive for developing optimum ration formulas. Dry matter intakes on blended rations have been high when cottonseed hulls (11, 17) or ground roughages (5, 16) were employed. Frequently these or other roughages suitable for blending into complete rations are in short supply or expensive where confinement feeding is desirable. Sugarcane is grown almost universally in the warmer areas of the world (7), and the bagasse residue from sugar production is a by-product of little or no economic value. Investigations have been conducted on the use of bagasse in rations (10, 14, 15), and production responses were more favorable when it was fed in ground form at small percents (14, 15). This study investigated (a) the suitability and optimum sugarcane b~gasse pellets as roughage in blended rations of lactating cows, (b) the effect of incorporating sodium bentonite or long hay into the rations, and (c) to determine whether or not bagasse fibers penetrate the reticulorumen wall. EXPERIMENTAL PROCEDURE Experiment I After 2-wk standardization on a complete ration containing 12.5% sugarcane bagasse pel-
896
SUGARCANE BAGASSE PELLETS lets and 12.5% cottonseed hulls fed ad libitum, 18 lactating cows (12 Holsteins and 6 Jerseys) were divided into three comparable groups which were allotted randomly to complete rations containing either 25% sugarcane bagasse pellets, 25% cottonseed hulls, or 12.5% of each of these roughages. Ingredient composition and proximate analysis of these r~tions are in Table 1. The sugarcane bagasse pellets were made by drying sugarcane residue after juice extraction, grinding the dried bagasse in a hammer-type mill with a .79-cm screen, adding 10% blackstrap molasses, and pelleting through a .95-cm dye. The bagasse pellets contained 93.8% dry matter, 3.1% crude protein, 3.3% ash, 34.0% crude fiber, 36.9% cellulose, and 10.5% lignin. Each animal was kept separately in small outside paddocks provided with shade and water~ The complete rations were fed twice daily in amounts estimated to give an 8% daily weigh-back. Animals were milked twice daily, and weights recorded. Aliquots of 1 day's production were taken weekly and tested for milk fat and specific gravity (2). The cows were weighed on 3 successive days at the beginning, end, and at 4-wk intervals during the experiment.
897
Experiment i l
Each of 36 cows (18 Holsteins, 9 Guernseys, and 9 Jerseys) was offered ad libitum a complete ration containing 25% sugarcane bagasse pellets plus 1.36 kg of coastal bermuda grass hay daily during a 14-day standardization after which they were divided into three comparable groups and allotted to complete rations containing either 20, 25, or 30% sugarcane bagasse pellets for 15 wk. Within each bagasse percent either a control ration for that percent, the control ration supplemented with a daily offering of 1.36 kg of coastal bermuda hay, or the control ration with 3.7% of sodium bentonite added were fed for 5-wk periods in a 3 × 3 Latin square design rotation. Ingredient composition and proximate analysis of the blended rations are in Table 2. When sodium bentonite was incorporated into the control rations, proportionate reductions were made in bagasse pellets, citrus pulp, ground corn, and soybean meal to accommodate this inclusion. Conventional Latin square analysis procedures were used for comparing the three treatments within squares. Comparison of bagasse percents (continuous treatments) were made by covariance analysis averaging cow
TABLE 1. Ingredient compositiona and proximate analyses of rations in Experiment I.
Bagasse
Rations Cottonseed hulls
Cottonseed hulls
(%) Sugarcane bagasse pellets Cottonseed hulls Citrus pulp, steamed dried Corn, ground Soybean meal, 49% crude protein Duofosb Urea, 280 Trace mineral salt Dry matter Crude protein Ether extract Crude fiber Ash Nitrogen-free extract
25 . . . 37 26 10 1.1 .5 .4 90.0 12.8 2.5 14.1 3.5 67.1
25 37 26
12.5 12.5 37 26
10
10
•
.
.
1.1
1.1
.5
.5
.4-
.4
(Proximate analysis, %) 88.1 13.0 2.4 15.8 3.7 65.1
89.0 12.9 2.5 15.0 3.6 66.0
a55,000 IU Vitamin A added per kg. bDiammonium phosphate. Journal of Dairy Science Vol. 58, No. 6
898
MARSHALL AND VAN HORN
TABLE 2. Ingredient composition a and proximate analysis of rations in Experiment II. Rations 20
20B
25
25B
30
30B
(%) Bagasse Citrus pulp Corn, ground Soybean meal, 49% crude protein Bentonite Duofosb Urea Salt Deft. phos.c
20 37 31.6
19.3 35.6 30.3
25 37 25.8
24.1 35.6 24.8
30 37 19.9
28.9 35.6 19.1
9.2 ... 1.1 .5 .4 .2
8.9 3.7 1.1 .5 .4 .2
10.0 ... 1.1 .5 .4 .2
9.6 3.7 1.1 .5 .4 .2
10.9 ... 1.1 .5 .4 .2
10.5 3.7 1.1 .5 .4 .2
Dry matter Crude protein Ether extract Crude fiber Ash N-free extract
89.7 12.8 2.6 12.7 4.1 57.5
90.1 12.4 2.5 12.2 7.1 55.9
90.3 12.8 2.3 16.0 4.4 54.7
90.6
(Proximate analysis, %) 90.0 12.8 2.5 14.3 4.3 56.1
90.3 12.4 2.4 13.8 7.5 54.3
12.4 2.2 15.4 7.6 53.0
a55,000 IU Vitamin A added per kg. bDiammonium phosphate. CDefluorinated phosphate. production across the three Latin square periods. Housing, management, milking, milk sampling, and milk analyses were as described in Experiment I with nitrogen analyses also on milk samples. The coastal bermuda grass hay was fed once daily in separate mangers. Post-mortem examinations of the digestive tracts for evidence of damage from fiber penetration was on two cows that had been on a complete ration containing 25% sugarcane bagasse pellets for over 105 days, one that had been receiving corn silage as the roughage, and two that had been grazing oat and rye pasture. Fifteen tissue samples from each cow were taken along the digestive tract from rumen to colon, preserved in formalin solution, and examined for fiber penetration. Tissue slices of samples were stained for lignin with phlorgucinol. The tissues also were observed under low power magnification.
RESULTS A N D DISCUSSION Experiment I
Treatment means for the characteristics did Journal of Dairy Science Vol. 58, No. 6
not differ among rations (Table 3). High intakes probably were influenced by rapid passage through the digestive tract by the cottonseed hulls (11) and the ground pelleted form (16) of the sugarcane bagasse, the high proportion of concentrate ingredients in the rations, and ration palatability. There was a trend towards higher milk fat test on the bagasse ration. As compared with that of the standardization period, average milk fat test during the 5th through 10th wk was .5% higher on the 25% bagasse ration but did not change on the others. There were variations among cows within all treatments with one declining in test slightly on the bagasse ration. Two declined 22 and 41% on the ration with cottonseed hulls, and four declined slightly on the ration containing bagasse plus cottonseed hulls. The sugarcane bagasse pellets will absorb six times their weight of water accompanied by an increase in volume. This quality may have slowed passage rate through the digestive tract and influenced ration digestion favorably for maintaining milk fat test. Experiment II
Daily
dry
matter
intake
was
highest
SUGARCANE BAGASSEPELLETS
899
TABLE 3. Treatment means for Experiment Ia.
Treatment Bagasse pellets Cottonseed hulls Bagasse pellets + Cottonseed hulls
Dry matter intake (% BW/day)
Milk (kg/day)
Fat (%)
SCMb (kg/day)
SNFc (%)
change (kg/cow per day)
3.9 4.1
21.7 22.8
4.1 3.8
22.0 20.6
9.1 9.0
+.34
4.0
21.7
3.8
21.1
9.0
+.74
BW
+.50
aWith exception of body weight (BW) changes, values are means adjusted by covariance. bSolids-corrected milk. CSolids-not-fat.
(P < .05) on the rations containing 25% sugarcane bagasse pellets (Table 4). Incorporation of sodium bentonite into or supplementation of the rations with Coastal bermudagrass hay did not affect dry matter intake significantly. Dry matter intakes of hay during supplementation periods averaged .49, .44, and .51 kg daily per cow on the 20, 25, and 30% bagasse rations. Although average intakes were similar, there were wide variations between cows within rations and between weeks within some cows. The lower dry matter intake during the second experiment probably was due to a lower quality of citrus pulp in the ration and to warmer, more humid weather. Citrus pulp in the first experiment was dried at a lower temperature by steam heat while that in the latter was dried at a higher temperature by direct flame process which gave a darker prod-
uct with some charring of small particles. Ammerman (1) noted an adverse effect of high drying temperature on digestibility of citrus pulp, and Powell (13) observed an adverse effect on palatability. Treatment differences in milk fat test were not significant. Average tests for animals on the 20% bagasse ration remained constant during the experiment, b u t those for cows on 25 and 30% bagasse rose as lactation advanced. Since the milk fat tests did not decline, the inclusion of hay or sodium bentonite (4) did not cause changes. Milk yields did not differ significantly among treatments. Solids-corrected milk production was highest ( P < .05) on the 20% bagasse ration during the period hay was fed, indicating a beneficial effect from supplemental hay at the lower bagasse level.
TABLE 4. Treatment means for the main effect in Experiment II.
Treatment
Dry matter intake (% bw/day)
20% bagassec 25% bagassec 30% bagassec Control H~ty Bentonite
3.48 3.59d 3.47 3.42 3.54 3.58
BW
Milk (kg/day)
Fat (%)
SCMa (kg/day)
SNFb (%)
Protein (%)
change (kg/cow per day)
18.6 18.5 18.1 18.3
4.31 4.67 4.56 4.46 4.59 4.50
18.8 20.1 19.2 19.2 19.8e 19.0
9.09 9.15 9.20d 9.12 9.18 9.14
3.56 3.60 3.59 3.58 3.57 3.60
.45 .29 .31 .35 .29 .41
18.7
18.1
asolids-corrected milk. b Sotlds-not-fat. cWith exception of body weight (BW) changes, values are covariance adjusted means. d(p < .05) for comparisons of bagasse levels. e(p < .05) for comparisons of control rations and those supplemented with hay or bentonite as determined by Duncan's Multiple Range Test. Journal of Dairy Science VoL 58, No. 6
900
MARSHALL AND VAN HORN
The h i g h e r ( P < .05) solids-not-fat o n t h e 30% bagasse r a t i o n versus 20% is w i t h o u t e x p l a n a t i o n . T h e cows gained w e i g h t on all
rations. No evidence of injury to the digestive tract by roughages was obserCed in cows fed rations c o n t a i n i n g 25% sugarcane bagasse pellets, c o r n silage, or o a t a n d rye pasture. Tissue slices s t a i n e d for lignin w i t h p h l o r g l u c i n o l p r o v e d t o b e a n i n e f f i c i e n t m e t h o d o f s t u d y since large n u m b e r s of slices were r e q u i r e d t o d e t e c t s c a t t e r e d fibers. Visual o b s e r v a t i o n u n d e r low p o w e r m a g n i f i c a t i o n readily revealed p e n e t r a t i o n o f e p i t h e l i u m b y small f e e d particles o n all rations. T h e s e particles were n o t d e t e c t e d in tissue u n d e r l y i n g t h e e p i t h e l i u m . Since n o h e m o r r h a g e or i n f l a m m a t i o n was o b s e r v e d in t h e epithelial tissue, t h e c o n d i t i o n was considered t o b e w i t h o u t p a t h o l o g i c a l i m p l i c a t i o n s . P r e s u m a b l y this o c c u r r e n c e has b e e n c o m m o n in cattle.
5.
6.
7. 8.
9. 10. 11. 12.
ACKNOWLEDGMENT
Sodium bentonite was provided by the A m e r i c a n Colloid C o m p a n y , Skokie, IL.
13. 14.
REFERENCES
1. Ammerman, C. B. 1973. Factors affecting the nutritional value of dried citrus pulp. Anita. Nutr. and Health 28(4):6. 2. Association of Official Agricultural Chemists. 1960. Official methods of analysis, 9th ed. Ass. Agr. Chem., Washington, De. 3. Baxter, H. D., J. R. Owen, M. J. Montgomery, C. H. Gordon, and J. T. Miles. 1972. Comparison of corn silage and concentrates fed separately and mixed as a complete ration. J. Dairy Sci. 55:398. (Abstr.) 4. Bringe, A. N., and L. H. Schultz. 1969. Effects of
Journal of Dairy Science Vol. 58, No. 6
15.
16.
17.
roughage type or added bentonite in maintaining fat test. J. Dairy Sci. 52:465. Brooks, O. L., W. J. Miller, E. R. Beaty, and C. M. Clifton. 1962. Performance of dairy cows fed pelleted and baled Coastal bermudagrass and alfalfa hay. J. Dairy Sci. 45:1188. Emery, R. S., L. D. Brown, and J. W. Thomas. 1964. Comparison of corn cobs and hay in ground, restricted-roughage rations affecting milk composition. J. Dairy Sci. 47:1322. Food and Agricultural Organization of the United Nations. 1972. Production yearbook. 26:149. Harner, J. P., and S. L. Spahr. 1971. Effect of dietary energy concentration and stage of lactation on intake by dairy cows fed mixed rations of concentrations and silage. J. Dairy Sci. 54:782. (Abstr.) Hunt, G. C. 1971. Studies with cottonseed hulls as the roughage in complete dairy rations. Ph.D. Thesis. Miss. State University. Kirk, W. G., F. M. Peacock, and G. K. Davis. 1962. Utilizing bagasse in cattle fattening rations. Fla. Agr. Exp. Sta. Bull. 64. McCoy, G. C., H. S. Thurmon, H. H. Olson, and A. Reed. 1966. Complete feed rations for lactating dairy cows. J. Dairy Sci. 49:1058. Owen, F. G., and R. D. Appleman. 1962. Dehy in corn silage-based complete dairy rations. Feedstuffs 44(5):21. Powell, G. W. 1969. Personal communication. Randel, R. F. 1970. Ad libitum feeding of either a complete ration based on sugarcane bagasse or a conventional concentrate mixture to dairy cows. J. Agr. Univ. Puerto Rico 54:429. Randel, P. F. 1966. Feeding lactating dairy cows concentrate and sugarcane bagasse as compared with a conventional ration. J. Agr. Univ. Puerto Rico 50:255. Rodrigue, C. B., and N. N. Allen. 1960. The effect of fine grinding of hay on ration digestibility, rate of passage, and fat content of milk. Can. J. Anita. Sci. 47:1322. Villavicencio, E., L. L. Rusoff, R. E. Girouard, and W. H. Waters. 1968. Comparison of complete feed rations to a conventional ration for lactating cows. J. Dairy Sci. 51:1633.
University of Florida Gainesville 32611 percent was highest on the 30% bagasse ration.
ABSTRACT Three groups of six lactating cows were allotted to complete rations containing either 25% sugarcane bagasse pellets, 25% cottonseed hulls, or 12.5% of each which were fed ad libitum for 10 wk in a continuous trial. Covariance adjusted dry matter intake as percent of body weight, kg milk/day, kg solids corrected milk/day and milk fat percent on the respective rations averaged 3.9, 4.1, 4.0; 21.7, 22.8, 21.7; 22.0, 20.6, 21.1; and 4.1, 3.8 and 3.8. Sugarcane bagasse pellets were a satisfactory roughage substitute for cottonseed hulls. In Experiment II 36 lactating cows were assigned to complete rations containing 20, 25, or 30% sugarcane bagasse pellets fed ad libitum for 15 wk. Within each bagasse percent Coastal bermuda hay (1.36 kg offered~cow daily), sodium bentonite (3.7% of complete ration) or the control ration for that bagasse percent was fed for 5-wk periods (3 × 3 Latin square design). Covariance adjusted means for dry matter intake as percent of body weight, kg milk/day, milk fat percent; kg solids corrected milk/day, solids-not-fat percent, and protein percent were 3.5, 3.6, 3.5; 18.6, 18.5, 18.1: 4.3, 4.7, 4.6; 18.8, 20.1, 19.2: 9.09, 9.15, 9.20; and 3.6, 3.6 and 3.6 for the 20, 25, and 30% bagasse rations. Cows on the 20% bagasse ration produced more solids corrected milk when hay was fed, and solids-not-fat
INTRODUCTION
Received September 11, 1974. 1Florida Agricultural Experiment Station Journal Series No. 5554. 2 Supported in part by a grant from United States Sugar Corporation, Clewiston, FL. 3 Digestive tract examinations were made by F. C. Neal, Veterinary Science Department, University of Florida, and Paul Randet, University of Puerto Rico, Lajas 00667.
Blended complete rations are convenient to feed and permit precise control of the ratio of ingredients and nutrients consumed. Dry matter intakes have been high with blended rations (3, 8, 11, 12), and their ad libitum usage offers an attractive means for maximizing feed intake in high producing cows during the early postpartum period. Although some health problems have been experienced on blended rations low in roughages (6, 9), advantages to be gained in animal response from the increased nutrient intake is an incentive for developing optimum ration formulas. Dry matter intakes on blended rations have been high when cottonseed hulls (11, 17) or ground roughages (5, 16) were employed. Frequently these or other roughages suitable for blending into complete rations are in short supply or expensive where confinement feeding is desirable. Sugarcane is grown almost universally in the warmer areas of the world (7), and the bagasse residue from sugar production is a by-product of little or no economic value. Investigations have been conducted on the use of bagasse in rations (10, 14, 15), and production responses were more favorable when it was fed in ground form at small percents (14, 15). This study investigated (a) the suitability and optimum sugarcane b~gasse pellets as roughage in blended rations of lactating cows, (b) the effect of incorporating sodium bentonite or long hay into the rations, and (c) to determine whether or not bagasse fibers penetrate the reticulorumen wall. EXPERIMENTAL PROCEDURE Experiment I After 2-wk standardization on a complete ration containing 12.5% sugarcane bagasse pel-
896
SUGARCANE BAGASSE PELLETS lets and 12.5% cottonseed hulls fed ad libitum, 18 lactating cows (12 Holsteins and 6 Jerseys) were divided into three comparable groups which were allotted randomly to complete rations containing either 25% sugarcane bagasse pellets, 25% cottonseed hulls, or 12.5% of each of these roughages. Ingredient composition and proximate analysis of these r~tions are in Table 1. The sugarcane bagasse pellets were made by drying sugarcane residue after juice extraction, grinding the dried bagasse in a hammer-type mill with a .79-cm screen, adding 10% blackstrap molasses, and pelleting through a .95-cm dye. The bagasse pellets contained 93.8% dry matter, 3.1% crude protein, 3.3% ash, 34.0% crude fiber, 36.9% cellulose, and 10.5% lignin. Each animal was kept separately in small outside paddocks provided with shade and water~ The complete rations were fed twice daily in amounts estimated to give an 8% daily weigh-back. Animals were milked twice daily, and weights recorded. Aliquots of 1 day's production were taken weekly and tested for milk fat and specific gravity (2). The cows were weighed on 3 successive days at the beginning, end, and at 4-wk intervals during the experiment.
897
Experiment i l
Each of 36 cows (18 Holsteins, 9 Guernseys, and 9 Jerseys) was offered ad libitum a complete ration containing 25% sugarcane bagasse pellets plus 1.36 kg of coastal bermuda grass hay daily during a 14-day standardization after which they were divided into three comparable groups and allotted to complete rations containing either 20, 25, or 30% sugarcane bagasse pellets for 15 wk. Within each bagasse percent either a control ration for that percent, the control ration supplemented with a daily offering of 1.36 kg of coastal bermuda hay, or the control ration with 3.7% of sodium bentonite added were fed for 5-wk periods in a 3 × 3 Latin square design rotation. Ingredient composition and proximate analysis of the blended rations are in Table 2. When sodium bentonite was incorporated into the control rations, proportionate reductions were made in bagasse pellets, citrus pulp, ground corn, and soybean meal to accommodate this inclusion. Conventional Latin square analysis procedures were used for comparing the three treatments within squares. Comparison of bagasse percents (continuous treatments) were made by covariance analysis averaging cow
TABLE 1. Ingredient compositiona and proximate analyses of rations in Experiment I.
Bagasse
Rations Cottonseed hulls
Cottonseed hulls
(%) Sugarcane bagasse pellets Cottonseed hulls Citrus pulp, steamed dried Corn, ground Soybean meal, 49% crude protein Duofosb Urea, 280 Trace mineral salt Dry matter Crude protein Ether extract Crude fiber Ash Nitrogen-free extract
25 . . . 37 26 10 1.1 .5 .4 90.0 12.8 2.5 14.1 3.5 67.1
25 37 26
12.5 12.5 37 26
10
10
•
.
.
1.1
1.1
.5
.5
.4-
.4
(Proximate analysis, %) 88.1 13.0 2.4 15.8 3.7 65.1
89.0 12.9 2.5 15.0 3.6 66.0
a55,000 IU Vitamin A added per kg. bDiammonium phosphate. Journal of Dairy Science Vol. 58, No. 6
898
MARSHALL AND VAN HORN
TABLE 2. Ingredient composition a and proximate analysis of rations in Experiment II. Rations 20
20B
25
25B
30
30B
(%) Bagasse Citrus pulp Corn, ground Soybean meal, 49% crude protein Bentonite Duofosb Urea Salt Deft. phos.c
20 37 31.6
19.3 35.6 30.3
25 37 25.8
24.1 35.6 24.8
30 37 19.9
28.9 35.6 19.1
9.2 ... 1.1 .5 .4 .2
8.9 3.7 1.1 .5 .4 .2
10.0 ... 1.1 .5 .4 .2
9.6 3.7 1.1 .5 .4 .2
10.9 ... 1.1 .5 .4 .2
10.5 3.7 1.1 .5 .4 .2
Dry matter Crude protein Ether extract Crude fiber Ash N-free extract
89.7 12.8 2.6 12.7 4.1 57.5
90.1 12.4 2.5 12.2 7.1 55.9
90.3 12.8 2.3 16.0 4.4 54.7
90.6
(Proximate analysis, %) 90.0 12.8 2.5 14.3 4.3 56.1
90.3 12.4 2.4 13.8 7.5 54.3
12.4 2.2 15.4 7.6 53.0
a55,000 IU Vitamin A added per kg. bDiammonium phosphate. CDefluorinated phosphate. production across the three Latin square periods. Housing, management, milking, milk sampling, and milk analyses were as described in Experiment I with nitrogen analyses also on milk samples. The coastal bermuda grass hay was fed once daily in separate mangers. Post-mortem examinations of the digestive tracts for evidence of damage from fiber penetration was on two cows that had been on a complete ration containing 25% sugarcane bagasse pellets for over 105 days, one that had been receiving corn silage as the roughage, and two that had been grazing oat and rye pasture. Fifteen tissue samples from each cow were taken along the digestive tract from rumen to colon, preserved in formalin solution, and examined for fiber penetration. Tissue slices of samples were stained for lignin with phlorgucinol. The tissues also were observed under low power magnification.
RESULTS A N D DISCUSSION Experiment I
Treatment means for the characteristics did Journal of Dairy Science Vol. 58, No. 6
not differ among rations (Table 3). High intakes probably were influenced by rapid passage through the digestive tract by the cottonseed hulls (11) and the ground pelleted form (16) of the sugarcane bagasse, the high proportion of concentrate ingredients in the rations, and ration palatability. There was a trend towards higher milk fat test on the bagasse ration. As compared with that of the standardization period, average milk fat test during the 5th through 10th wk was .5% higher on the 25% bagasse ration but did not change on the others. There were variations among cows within all treatments with one declining in test slightly on the bagasse ration. Two declined 22 and 41% on the ration with cottonseed hulls, and four declined slightly on the ration containing bagasse plus cottonseed hulls. The sugarcane bagasse pellets will absorb six times their weight of water accompanied by an increase in volume. This quality may have slowed passage rate through the digestive tract and influenced ration digestion favorably for maintaining milk fat test. Experiment II
Daily
dry
matter
intake
was
highest
SUGARCANE BAGASSEPELLETS
899
TABLE 3. Treatment means for Experiment Ia.
Treatment Bagasse pellets Cottonseed hulls Bagasse pellets + Cottonseed hulls
Dry matter intake (% BW/day)
Milk (kg/day)
Fat (%)
SCMb (kg/day)
SNFc (%)
change (kg/cow per day)
3.9 4.1
21.7 22.8
4.1 3.8
22.0 20.6
9.1 9.0
+.34
4.0
21.7
3.8
21.1
9.0
+.74
BW
+.50
aWith exception of body weight (BW) changes, values are means adjusted by covariance. bSolids-corrected milk. CSolids-not-fat.
(P < .05) on the rations containing 25% sugarcane bagasse pellets (Table 4). Incorporation of sodium bentonite into or supplementation of the rations with Coastal bermudagrass hay did not affect dry matter intake significantly. Dry matter intakes of hay during supplementation periods averaged .49, .44, and .51 kg daily per cow on the 20, 25, and 30% bagasse rations. Although average intakes were similar, there were wide variations between cows within rations and between weeks within some cows. The lower dry matter intake during the second experiment probably was due to a lower quality of citrus pulp in the ration and to warmer, more humid weather. Citrus pulp in the first experiment was dried at a lower temperature by steam heat while that in the latter was dried at a higher temperature by direct flame process which gave a darker prod-
uct with some charring of small particles. Ammerman (1) noted an adverse effect of high drying temperature on digestibility of citrus pulp, and Powell (13) observed an adverse effect on palatability. Treatment differences in milk fat test were not significant. Average tests for animals on the 20% bagasse ration remained constant during the experiment, b u t those for cows on 25 and 30% bagasse rose as lactation advanced. Since the milk fat tests did not decline, the inclusion of hay or sodium bentonite (4) did not cause changes. Milk yields did not differ significantly among treatments. Solids-corrected milk production was highest ( P < .05) on the 20% bagasse ration during the period hay was fed, indicating a beneficial effect from supplemental hay at the lower bagasse level.
TABLE 4. Treatment means for the main effect in Experiment II.
Treatment
Dry matter intake (% bw/day)
20% bagassec 25% bagassec 30% bagassec Control H~ty Bentonite
3.48 3.59d 3.47 3.42 3.54 3.58
BW
Milk (kg/day)
Fat (%)
SCMa (kg/day)
SNFb (%)
Protein (%)
change (kg/cow per day)
18.6 18.5 18.1 18.3
4.31 4.67 4.56 4.46 4.59 4.50
18.8 20.1 19.2 19.2 19.8e 19.0
9.09 9.15 9.20d 9.12 9.18 9.14
3.56 3.60 3.59 3.58 3.57 3.60
.45 .29 .31 .35 .29 .41
18.7
18.1
asolids-corrected milk. b Sotlds-not-fat. cWith exception of body weight (BW) changes, values are covariance adjusted means. d(p < .05) for comparisons of bagasse levels. e(p < .05) for comparisons of control rations and those supplemented with hay or bentonite as determined by Duncan's Multiple Range Test. Journal of Dairy Science VoL 58, No. 6
900
MARSHALL AND VAN HORN
The h i g h e r ( P < .05) solids-not-fat o n t h e 30% bagasse r a t i o n versus 20% is w i t h o u t e x p l a n a t i o n . T h e cows gained w e i g h t on all
rations. No evidence of injury to the digestive tract by roughages was obserCed in cows fed rations c o n t a i n i n g 25% sugarcane bagasse pellets, c o r n silage, or o a t a n d rye pasture. Tissue slices s t a i n e d for lignin w i t h p h l o r g l u c i n o l p r o v e d t o b e a n i n e f f i c i e n t m e t h o d o f s t u d y since large n u m b e r s of slices were r e q u i r e d t o d e t e c t s c a t t e r e d fibers. Visual o b s e r v a t i o n u n d e r low p o w e r m a g n i f i c a t i o n readily revealed p e n e t r a t i o n o f e p i t h e l i u m b y small f e e d particles o n all rations. T h e s e particles were n o t d e t e c t e d in tissue u n d e r l y i n g t h e e p i t h e l i u m . Since n o h e m o r r h a g e or i n f l a m m a t i o n was o b s e r v e d in t h e epithelial tissue, t h e c o n d i t i o n was considered t o b e w i t h o u t p a t h o l o g i c a l i m p l i c a t i o n s . P r e s u m a b l y this o c c u r r e n c e has b e e n c o m m o n in cattle.
5.
6.
7. 8.
9. 10. 11. 12.
ACKNOWLEDGMENT
Sodium bentonite was provided by the A m e r i c a n Colloid C o m p a n y , Skokie, IL.
13. 14.
REFERENCES
1. Ammerman, C. B. 1973. Factors affecting the nutritional value of dried citrus pulp. Anita. Nutr. and Health 28(4):6. 2. Association of Official Agricultural Chemists. 1960. Official methods of analysis, 9th ed. Ass. Agr. Chem., Washington, De. 3. Baxter, H. D., J. R. Owen, M. J. Montgomery, C. H. Gordon, and J. T. Miles. 1972. Comparison of corn silage and concentrates fed separately and mixed as a complete ration. J. Dairy Sci. 55:398. (Abstr.) 4. Bringe, A. N., and L. H. Schultz. 1969. Effects of
Journal of Dairy Science Vol. 58, No. 6
15.
16.
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roughage type or added bentonite in maintaining fat test. J. Dairy Sci. 52:465. Brooks, O. L., W. J. Miller, E. R. Beaty, and C. M. Clifton. 1962. Performance of dairy cows fed pelleted and baled Coastal bermudagrass and alfalfa hay. J. Dairy Sci. 45:1188. Emery, R. S., L. D. Brown, and J. W. Thomas. 1964. Comparison of corn cobs and hay in ground, restricted-roughage rations affecting milk composition. J. Dairy Sci. 47:1322. Food and Agricultural Organization of the United Nations. 1972. Production yearbook. 26:149. Harner, J. P., and S. L. Spahr. 1971. Effect of dietary energy concentration and stage of lactation on intake by dairy cows fed mixed rations of concentrations and silage. J. Dairy Sci. 54:782. (Abstr.) Hunt, G. C. 1971. Studies with cottonseed hulls as the roughage in complete dairy rations. Ph.D. Thesis. Miss. State University. Kirk, W. G., F. M. Peacock, and G. K. Davis. 1962. Utilizing bagasse in cattle fattening rations. Fla. Agr. Exp. Sta. Bull. 64. McCoy, G. C., H. S. Thurmon, H. H. Olson, and A. Reed. 1966. Complete feed rations for lactating dairy cows. J. Dairy Sci. 49:1058. Owen, F. G., and R. D. Appleman. 1962. Dehy in corn silage-based complete dairy rations. Feedstuffs 44(5):21. Powell, G. W. 1969. Personal communication. Randel, R. F. 1970. Ad libitum feeding of either a complete ration based on sugarcane bagasse or a conventional concentrate mixture to dairy cows. J. Agr. Univ. Puerto Rico 54:429. Randel, P. F. 1966. Feeding lactating dairy cows concentrate and sugarcane bagasse as compared with a conventional ration. J. Agr. Univ. Puerto Rico 50:255. Rodrigue, C. B., and N. N. Allen. 1960. The effect of fine grinding of hay on ration digestibility, rate of passage, and fat content of milk. Can. J. Anita. Sci. 47:1322. Villavicencio, E., L. L. Rusoff, R. E. Girouard, and W. H. Waters. 1968. Comparison of complete feed rations to a conventional ration for lactating cows. J. Dairy Sci. 51:1633.