Effect of different grazing strategies on dry matter yields and nutritive characteristics of whole crop cereals
J. L. Jacobs A C , J. Hill B and T. Jenkin AA Department of Primary Industries, 78 Henna Street, Warrnambool, Vic. 3280, Australia.
B School of Agriculture and Food Systems, Faculty of Land and Food Resources, University of Melbourne, Parkville, Vic. 3010, Australia.
C Corresponding author. Email: joe.jacobs@dpi.vic.gov.au
Animal Production Science 49(7) 608-618 https://doi.org/10.1071/EA08245
Submitted: 29 September 2008 Accepted: 13 February 2009 Published: 11 June 2009
Abstract
Forage cereals offer the potential to increase the amount of forage grown and consumed on dairy farms in southern Australia. The effect of single or multiple grazing of winter cereal forages by lactating dairy cattle on dry matter (DM) yield and nutritive value at grazing and on subsequent silage production harvested at the soft-dough stage of growth was determined in three studies in south-western Victoria. In the first two studies, a range of forage cereals and an annual ryegrass were grazed either once (G1) during tillering (GS 21–29), followed by locking up for silage, grazed twice (G2) (GS 21–29 and GS 32–34), followed by locking up for silage, or not grazed (NG) and harvested for silage only. In the third study, two forage cereals were either ungrazed (NG) or grazed at either GS 21, GS 24, GS 30 or GS 32 and subsequently locked up and harvested for silage. All silage harvests occurred at GS 84 (soft dough). In all studies, grazing at early tillering resulted in DM yield of less than 1.4 t DM/ha, although crude protein (CP) (30–37% DM) and estimated metabolisable energy (ME) (12.2–14 MJ/kg DM) were high. Deferring grazing until the start of stem elongation resulted in higher DM yields (1.8–4.3 t DM/ha). Silage DM yields were higher (P < 0.05) for G1 and NG treatments than for G2 in all cases apart from McKellar wheat in study 1. At silage harvest, CP and estimated ME contents of cereals were lower than for annual ryegrass. In general, total DM yields across the growing season were higher for the G1 and NG treatments compared with forages that were grazed twice before silage harvest. Deferment of a single grazing from early tillering to stem elongation did not adversely affect total DM production. However, delaying grazing until stem elongation resulted in significant declines in CP concentration and estimated ME. These studies highlight the potential of cereal forages to contribute to DM production on dairy farms in southern Australia. They can provide additional flexibility into forage systems through the provision of forage for a single grazing in early winter and in the production of high DM yield silage harvests. Cereals grazed in early winter have a high estimated ME and CP content, whereas the nutritive characteristics when harvested for silage at soft dough are of only moderate feed value. Consideration is required as to how best to incorporate these into diets of lactating dairy cattle.
Acknowledgements
The authors acknowledge the Victorian Government, Dairy Australia, WestVic Dairy, Gipps Dairy and Murray Dairy for providing financial assistance for the study. We also thank DemoDAIRY for the use of land on their farm to undertake the experiment. The technical support of Stewart Burch, Robyn Bush and Paul Moloney and biometric support from Gavin Kearney are also acknowledged.
Chapman DF,
Kenny SN,
Beca D, Johnson IR
(2008a) Pasture and forage crop systems for non-irrigated dairy farms in southern Australia. 1. Physical production and economic performance. Agricultural Systems 97, 108–125.
| Crossref | GoogleScholarGoogle Scholar |
Chapman DF,
Kenny SN,
Beca D, Johnson IR
(2008b) Pasture and forage crop systems for non-irrigated dairy farms in southern Australia. 2. Inter-annual variation in forage supply, risk and business risk. Agricultural Systems 97, 126–138.
| Crossref | GoogleScholarGoogle Scholar |
Clarke T,
Flinn PC, McGowan AA
(1982) Low cost pepsin–cellulase assays for prediction of digestibility of herbage. Grass and Forage Science 37, 147–150.
| Crossref | GoogleScholarGoogle Scholar |
de Ruiter JM,
Hanson R,
Hay AS,
Armstrong KW, Harrison-Kirk RD
(2002) Whole crop cereals for grazing and silage: balancing quality and quantity. Proceedings of the New Zealand Grassland Conference 64, 181–189.
Dove H,
Holst PJ,
Stanley DF, Flint PW
(2002) Grazing value of dual purpose winter wheats for young sheep. Animal Production in Australia 24, 53–56.
Earle DF, McGowan AA
(1979) Evaluation and calibration of an automated rising plate meter for estimating dry matter yield of pasture. Australian Journal of Experimental Agriculture and Animal Husbandry 19, 337–343.
| Crossref | GoogleScholarGoogle Scholar |
Francia E,
Pecchioni N,
Li Destri Nicosia O,
Paoletta G,
Taibi L,
Franco V,
Odoardi M,
Stanca AM, Delogu G
(2006) Dual-purpose barley and oat in a Mediterranean environment. Field Crops Research 99, 158–166.
| Crossref | GoogleScholarGoogle Scholar |
Fraser TJ,
Knight TL,
Knowles IM, Hyslop MG
(2004) Twenty five tonnes of high quality forages annually in Canterbury. Proceedings of the New Zealand Grassland Conference 66, 85–91.
Hill J, Leaver JD
(2002) Changes in chemical composition and nutritive value of urea-treated whole-crop wheat during exposure to air. Animal Feed Science and Technology 102, 181–195.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Holliday R
(1956) Fodder production from winter-sown cereals and its effect upon grain yield. Field Crop Abstracts 9, 129–135.
Jacobs JL,
McKenzie FR, Ward GN
(1999) Changes in the botanical composition and nutritive characteristics of pasture, and nutrient selection by dairy cows grazing rainfed pastures in western Victoria. Australian Journal of Experimental Agriculture 39, 419–428.
| Crossref | GoogleScholarGoogle Scholar |
Leaver JD, Hill J
(1995) The performance of dairy cows offered ensiled whole-crop wheat, urea treated whole-crop wheat or sodium hydroxide treated wheat grain and wheat straw in a mixture with grass silage. Animal Science 61, 481–491.
McKenzie FR,
Jacobs JL, Kearney G
(2006) Effect of spring grazing on dryland perennial ryegrass/white clover dairy pastures in south western Victoria. 1. Pasture accumulation rates, dry matter consumed and nutritive characteristics. Australian Journal of Agricultural Research 57, 543–554.
| Crossref | GoogleScholarGoogle Scholar |
Oldham JD
(1984) Protein–energy interrelationships in dairy cows. Journal of Dairy Science 67, 1090–1114.
|
CAS |
PubMed |
Platfoot G, Stevens D
(2002) Whole crop cereal silage – on farm feeding demonstrations. Proceedings of the South Island Dairy Event, Invercargill , 153–164.
Shenk JS, Westerhaus MO
(1991) Population definition, sample selection and calibration procedures for near infrared reflectance spectroscopy. Crop Science 31, 469–474.
van Soest PJ, Wine RH
(1967) Use of detergents in the analysis of fibrous feeds. IV. Determination of plant cell wall constituents. Journal of Official Analytical Chemists 50, 50–55.
|
CAS |
Virgona JM,
Gummer FAJ, Angus JF
(2006) Effects of grazing on wheat growth, yield, development, water use, and nitrogen use. Australian Journal of Agricultural Research 57, 1307–1319.
| Crossref | GoogleScholarGoogle Scholar |
Yemm EW, Willis AJ
(1954) The estimation of carbohydrates in plant extracts by anthrone. Biochemistry 57, 508–514.
|
CAS |
Zadoks JC,
Chang TT, Konzak CF
(1974) A decimal code for the growth stages of cereals. Weed Research 14, 415–421.
| Crossref | GoogleScholarGoogle Scholar |
