Ruminal pH and whole-tract digestibility in dairy cows consuming fresh cut herbage plus concentrates and conserved forage fed either separately or as a partial mixed ration
J. S. Greenwood A B , M. J. Auldist A , L. C. Marett A , M. C. Hannah A , J. L. Jacobs A and W. J. Wales A
+ Author Affiliations
- Author Affiliations
A Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Vic. 3821, Australia.
B Corresponding author. Email: Jae.Greenwood@depi.vic.gov.au
Animal Production Science 54(8) 1056-1063 https://doi.org/10.1071/AN12406
Submitted: 29 November 2012 Accepted: 13 September 2013 Published: 26 November 2013
Abstract
The objective of this experiment was to compare ruminal pH and whole-tract digestibility in cows consuming fresh cut herbage plus concentrates and silage or hay fed either separately or as a partial mixed ration (PMR). Fourteen rumen-fistulated Holstein-Friesian cows that had calved in late winter were housed in metabolism stalls for 9-day experiments in spring (97 days in milk (DIM)) and autumn (237 DIM). All cows were offered 8 kg dry matter (DM)/day of fresh cut perennial ryegrass (Lolium perenne L.) herbage, provided in two equal portions after each milking. Seven cows were assigned to each of two diets: (i) Control: 8.8 kg DM/cow.day milled wheat grain in two equal portions at milking, plus 3.2 kg DM/cow.day perennial ryegrass silage, with all cows receiving the silage portion of their diet after their grain but before their fresh herbage at the afternoon milking; and (ii) PMR: 12 kg DM/cow.day of a PMR containing similar ME as the Control supplements, but comprising maize grain, maize silage, wheat grain, lucerne hay (spring) and pasture silage (autumn). Intake and faecal output was measured on 5 days during each experiment, and ruminal pH was measured every 2 h for a 24-h period. Degradability of wheat and maize grain was measured using standard in sacco techniques. In both experiments, cows fed PMR had higher ruminal fluid pH than Control cows for at least part of the day. Apparent whole-tract digestibilities of DM, organic matter, nitrogen, neutral detergent fibre and starch were greater for Control than PMR cows in spring and not different in autumn (except starch). Ruminal pH was increased by feeding a maize-based PMR but this was not associated with increased whole-tract digestibility. We conclude that the ruminal pH in the Control cows was not low enough for long enough to compromise digestion, or that there was compensatory post-ruminal digestion.
Additional keywords: supplements, volatile fatty acids.
References
AFIA (2009) ‘AFIA – laboratory methods manual.’ (Australian Fodder Industry Association: Melbourne)AFRC (1992) Technical Committee on Responses to Nutrients, Report No. 9. Nutritive requirements of ruminant animals: protein. Nutrition Abstracts and Reviews (Series B) 62, 789–835.
Allen MS (1997) Relationship between fermentation acid production in the rumen and the requirement for physically effective fibre. Journal of Dairy Science 80, 1447–1462.
| Relationship between fermentation acid production in the rumen and the requirement for physically effective fibre.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXks1Ogs7g%3D&md5=be38faa10a07e80d79c36b4252021e19CAS | 9241607PubMed |
Auldist MJ, Marett LC, Greenwood JS, Hannah MC, Jacobs JL, Wales WJ (2013) Effects of different strategies for feeding supplements on milk production responses in cows grazing a restricted pasture allowance. Journal of Dairy Science 96, 1218–1231.
| Effects of different strategies for feeding supplements on milk production responses in cows grazing a restricted pasture allowance.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhsl2isrrP&md5=a93fc99406ca51f541df732b7b4ba0b8CAS | 23219117PubMed |
Auldist MJ, Marett LC, Greenwood JS, Wright MM, Hannah MC, Jacobs JL, Wales WJ (2014) Replacing wheat with canola meal in a partial mixed ration increases the milk production of cows grazing at a restricted pasture allowance in spring. Animal Production Science
| Replacing wheat with canola meal in a partial mixed ration increases the milk production of cows grazing at a restricted pasture allowance in spring.Crossref | GoogleScholarGoogle Scholar | in press
Baird DB (1994) The design of experiments with covariates. PhD Thesis, University of Otago, New Zealand.
Bargo F, Muller LD, Varga GA, Delahoy JE, Cassidy TW (2002) Ruminal digestion and fermentation of high-producing dairy cows with three different feeding systems combining pasture and total mixed rations. Journal of Dairy Science 85, 2964–2973.
| Ruminal digestion and fermentation of high-producing dairy cows with three different feeding systems combining pasture and total mixed rations.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xptlagt78%3D&md5=cecb2a2df39cef098820e1a6f1cda26cCAS | 12487462PubMed |
Beever DE, Doyle PT (2007) Feed conversion efficiency as a key determinant of dairy herd performance: a review. Australian Journal of Experimental Agriculture 47, 645–657.
| Feed conversion efficiency as a key determinant of dairy herd performance: a review.Crossref | GoogleScholarGoogle Scholar |
Bramley E, Lean IJ, Fulkerson WJ, Stevenson MA, Rabiee AR, Costa ND (2008) The definition of acidosis in dairy herds predominantly fed on pasture and concentrates. Journal of Dairy Science 91, 308–321.
| The definition of acidosis in dairy herds predominantly fed on pasture and concentrates.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhsVGisg%3D%3D&md5=e874b3eaa6612f7138a39fa60819655aCAS | 18096953PubMed |
Dairy Australia (2011) Situation and outlook. Available at http://www.dairyaustralia.com.au [Verified 5 October 2013]
de Veth MJ, Kolver ES (2001) Digestion of ryegrass pasture in response to change in pH in continuous culture. Journal of Dairy Science 84, 1449–1457.
| Digestion of ryegrass pasture in response to change in pH in continuous culture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXktlKgs7Y%3D&md5=9cc5d90e0eaa39f6fb678612f66264abCAS | 11417705PubMed |
Dixon RM, Stockdale CR (1999) Associative effects between forages and grains: consequences for feed utilization. Australian Journal of Agricultural Research 50, 757–773.
| Associative effects between forages and grains: consequences for feed utilization.Crossref | GoogleScholarGoogle Scholar |
Doyle PT, Stockdale CR (2011) Dairy farm management systems: seasonal, pasture-based, dairy cow breeds. In ‘Encyclopedia of dairy sciences. Vol. 2’. 2nd edn. (Eds JW Fuquay, PF Fox, PLH McSweeney) pp. 29–37. (Academic Press: Amsterdam)
Doyle PT, Francis SA, Stockdale CR (2005) Associative effects between feeds when concentrate supplements are fed to grazing dairy cows: a review of likely impacts on metabolisable energy supply. Australian Journal of Agricultural Research 56, 1315–1329.
| Associative effects between feeds when concentrate supplements are fed to grazing dairy cows: a review of likely impacts on metabolisable energy supply.Crossref | GoogleScholarGoogle Scholar |
Earle D (1976) A guide to scoring dairy cow condition. Journal of Agriculture, Victoria 74, 228–231.
Firkins JL (1996) Maximizing microbial synthesis in the rumen. The Journal of Nutrition 126, 1347–1354.
Kellaway R, Harrington T (2004) ‘Feeding concentrates: supplements for dairy cows.’ Rev. edn. (Landlinks Press: Collingwood, Vic.)
Khorasani GR, Okine EK, Kennelly JJ (2001) Effects of substituting barley grain with corn on ruminal fermentation characteristics, milk yield, and milk composition of Holstein cows. Journal of Dairy Science 84, 2760–2769.
| Effects of substituting barley grain with corn on ruminal fermentation characteristics, milk yield, and milk composition of Holstein cows.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xosl2rsQ%3D%3D&md5=06efbbe897b2d3bb36a039d6a1175867CAS | 11814032PubMed |
Kolver ES, de Veth MJ (2002) Prediction of ruminal pH from pasture-based diets. Journal of Dairy Science 85, 1255–1266.
| Prediction of ruminal pH from pasture-based diets.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XktFWjs74%3D&md5=c2a65321fc888a2c1d259de8c27b39a8CAS | 12086063PubMed |
Leddin CM, Stockdale CR, Hill J, Doyle PT (2009) Increasing amounts of crushed wheat fed with pasture hay reduced dietary fiber digestibility in lactating dairy cows. Journal of Dairy Science 92, 2747–2757.
| Increasing amounts of crushed wheat fed with pasture hay reduced dietary fiber digestibility in lactating dairy cows.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXmsFems7w%3D&md5=ac68259eb6b42d8fc52abd8eb3839057CAS | 19448009PubMed |
Mould FL, Ørskov ER, Mann SO (1983) Associative effects of mixed feeds. I. Effects of type and level of supplementation and the influence of the rumen fluid pH on cellulolysis in vivo and dry matter digestion of various roughages. Animal Feed Science and Technology 10, 15–30.
| Associative effects of mixed feeds. I. Effects of type and level of supplementation and the influence of the rumen fluid pH on cellulolysis in vivo and dry matter digestion of various roughages.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXhtlOrtrs%3D&md5=f774a7bf959ae2201dea631de1a0e407CAS |
National Health and Medical Research Council (2004) ‘Australian Code of Practice for the Care and Use of Animals for Scientific Purposes.’ 7th edn. (Australian Government: Canberra)
Offner A, Bach A, Sauvant D (2003) Quantitative review of in situ starch degradation in the rumen. Animal Feed Science and Technology 106, 81–93.
| Quantitative review of in situ starch degradation in the rumen.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXjtlSmtrk%3D&md5=9a61263c1e089e60f675bce335c9e2fbCAS |
Ørskov ER, McDonald I (1979) The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage. Journal of Agricultural Science 92, 499–503.
| The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage.Crossref | GoogleScholarGoogle Scholar |
Ørskov ER, Mehrez AZ (1977) Estimation of extent of protein degradation from basal feeds in the rumen of sheep. The Proceedings of the Nutrition Society 36, 78A
Packer EJ, Clayton EH, Cusack PMV (2011) Rumen fermentation and liveweight gain in beef cattle treated with monensin and grazing lush forage. Australian Veterinary Journal 89, 338–345.
Standing Committee on Agriculture (1990) ‘Feeding Standards for Australian Livestock. Ruminants.’ (CSIRO Publishing: Melbourne)
Stockdale CR, Callaghan A, Trigg TE (1987) Feeding high energy supplements to pasture-fed dairy cows, effects of stage of lactation and level of supplement. Australian Journal of Agricultural Research 38, 927–940.
| Feeding high energy supplements to pasture-fed dairy cows, effects of stage of lactation and level of supplement.Crossref | GoogleScholarGoogle Scholar |
Tyrrell HF, Reid JT (1965) Prediction of energy value of cow’s milk. Journal of Dairy Science 48, 1215–1223.
| Prediction of energy value of cow’s milk.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaF28%2FktVOjtA%3D%3D&md5=399307097f4d2c51ce18817f484e4d6dCAS | 5843077PubMed |
Wales WJ, Doyle PT (2003) Effect of grain and straw supplementation on marginal milk production responses and rumen function of cows grazing highly digestible subterranean clover pasture. Australian Journal of Experimental Agriculture 43, 467–474.
| Effect of grain and straw supplementation on marginal milk production responses and rumen function of cows grazing highly digestible subterranean clover pasture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXlslOnsbg%3D&md5=6ee20763f0f483026cea24ac32bb6a3cCAS |
Wales WJ, Dellow DW, Doyle PT, Egan AR (2000) Effects of feeding additional pasture hay in autumn to dairy cows grazing irrigated perennial ryegrass-white clover pasture and supplemented with barley grain. Australian Journal of Experimental Agriculture 40, 1–9.
| Effects of feeding additional pasture hay in autumn to dairy cows grazing irrigated perennial ryegrass-white clover pasture and supplemented with barley grain.Crossref | GoogleScholarGoogle Scholar |
Wales WJ, Kolver ES, Thorne PL, Egan AR (2004) Diurnal variation in ruminal pH on the digestibility of highly digestible perennial ryegrass during continuous culture fermentation. Journal of Dairy Science 87, 1864–1871.
| Diurnal variation in ruminal pH on the digestibility of highly digestible perennial ryegrass during continuous culture fermentation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXltlGnsbw%3D&md5=e98387419d87d7ddded5b37bc57531ecCAS | 15453503PubMed |
Walker GP, Stockdale CR, Wales WJ, Doyle PT, Dellow DW (2001) Effect of level of grain supplementation on milk production responses of dairy cows in mid-late lactation when grazing irrigated pastures high in paspalum (Paspalum dilatatum Poir.). Australian Journal of Experimental Agriculture 41, 1–11.
| Effect of level of grain supplementation on milk production responses of dairy cows in mid-late lactation when grazing irrigated pastures high in paspalum (Paspalum dilatatum Poir.).Crossref | GoogleScholarGoogle Scholar |
