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Abstract
Eight Holstein cows in early lactation and fitted with ruminal and duodenal cannulas were used in a 4 × 4 Latin square design experiment to determine the influence of forage source on microbial digestion in the rumen and nutrient supply to the intestine and to determine relationships between DMI, ruminal fill, and NDF content of silage. Cows were fed a TMR formulated to contain a 50:50 concentrate:forage ratio. A significant negative correlation was found between dietary NDF concentration (range 32.2 to 37.9%) and DMI (16.7 to 19.6 kg/d). In addition to forage NDF concentration, the lower DMI of cows fed oat or triticale silage (16.7 and 17.2 kg/d, respectively) relative to that of cows fed barley or alfalfa silage (18.6 and 19.6 kg/d, respectively) might reflect a lower true rate of NDF digestion (range 2.39 to 4.09%/h), higher ruminal turnover time (12.9 to 17.1 h), and lower rate of NDF intake (3.31 to 3.96%/h). However, differences in ruminal bacterial yield, ruminal metabolites, and nutrient supply to the intestine associated with different silages had no major effect on dairy cow performance. We concluded that the dairy cow can maintain similar milk yield despite marked differences in the type of end products arising from carbohydrate and protein digestion.
Key words
Abbreviation key:
DNA (diaminopimelic acid), kd (rate of digestion), kdt (rate of digestion (true)), ki (rate of intake), kp (rate of passage)References
- Evaluation of barley silage harvested at boot and soft dough stages.J. Dairy Sci. 1991; 74: 167
- Is cereal silage a viable alternative to alfalfa? Animal perspective.in: Proc. 1991 Western Can. Dairy Sem. Adv. Dairy Technol. Vol. 3, Univ. Alberta, Edmonton, AB, Canada1991: 27
- Determination of ammonia nitrogen.J. Clin. Pathol. (Lond.). 1960; 13: 156
- Protein supplementation of silage-based diets for milk production.in: 54th Ann. Agric. Rep. Res. Inst., An Foras Taluntais, Dublin, Ireland1981: 13
- Synthesis of microbial protein in the rumen. III. The effect of dietary protein.Aust. J. Agric. Res. 1970; 21: 305
- Effects of crude protein and energy levels on milk production in early lactation.Anim. Prod. Res. Rep. An Foras Taluntais, Dublin, Ireland1977 (Page 106)
- Effect of whole crop cereal grain silage substituted for alfalfa silage on performance of lactating dairy cows.J. Dairy Sci. 1993; 76: 3536
- Effect of canola meal treated with acetic acid on rumen degradation and intestinal digestibility in lactating dairy cows.J. Dairy Sci. 1993; 76: 1607
- Factors influencing rumen microbial growth rates and yield: effect of amino acid additions to a purified diet with nitrogen from urea.J. Dairy Sci. 1976; 59: 648
- Measurement of protein degradation in the rumen.Proc. Nutr. Soc. 1977; 36 (Abstr.): 152A
- Nutrient Requirements of Dairy Cattle.6th rev. ed. Natl. Acad. Sci., Washington, DC1989
- The influence of energy-rich supplements on nitrogen kinetics in ruminants.in: Physiology Aspects of Digestion and Metabolism in Ruminants. Proc. 7th Int. Symp. Rumin. Physiol. Acad. Press, Inc., New York, NY1991: 515
- Effect of cereal grain silages versus alfalfa silage on chewing activity and reticular motility in early lactation cows.J. Dairy Sci. 1994; 77: 1315
- Effects of feed intake on particle distribution, passage of digesta, and extent of digestion in the gastrointestinal tract of cattle.J. Anim. Sci. 1991; 69: 3435
- Relationships between reticular contractions and digesta passage in steers consuming alfalfa hay and barley strain combinations ad libitum.J. Anim. Sci. 1993; 71: 3043
- Digesta passage and microbial protein synthesis.in: Milligan L.P. Grovum W.L. Dobson A. Control of Digestion and Metabolism in Ruminants. Prentice-Hall, Englewood Cliffs, NJ1988: 196
- The detergent system of analysis and its application to human foods.in: James W.P.T. Theander O. The Analysis of Dietary Fiber in Food. Marcel Dekker, Inc., New York, NY1981: 123
- Influence of ammoniation of high-moisture barley on digestibility, kinetics and rumen ingesta turnover, and milk production in dairy cows.Can. J. Anim. Sci. 1989; 69: 195
- Evaluation of duodenal cannula for dairy cattle.J. Dairy Sci. 1990; 73: 3146
- Effect of forage amount and particle size in diets of lactating dairy cows on site of digestion and microbial protein synthesis.Can. J. Anim. Sci. 1985; 65: 101
- Fermentation of peptides by Bacteroides rummicola B14.Appl. Environ. Microbiol. 1984; 45: 1566
SAS® User's Guide: Statistics, Version 5 Edition. 1985. SAS Inst., Inc., Cary, NC.
- Effect of ammonia concen tration on ruminal microbial protein production in vitro.Br. J. Nutr. 1974; 32: 199
- A comparison of the responses by lactating cows given grass silage to changes in the degradability of quantity of protein offered in the supplement.Anim. Prod. 1990; 50: 391
- Effects of intake of a mixed diet by steers on digestion events.J. Dairy Sci. 1984; 67: 995
- Prediction of the energy value of cow's milk.J. Dairy Sci. 1965; 48: 1215
- Preharvest factors influencing quality of conserved forage.J. Anim. Sci. 1978; 47: 712
- Impact of dietary fiber and physical form on performance of lactating cows.J. Dairy Sci. 1986; 69: 1035
Article info
Publication history
Accepted:
January 12,
1996
Received:
December 12,
1994
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© 1996 American Dairy Science Association. Published by Elsevier Inc.
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