Dry matter production, nutritive value and efficiency of nutrient utilization of a complementary forage rotation compared to a grass pasture system

Abstract

In pasture-based dairy farming, new sustainable systems that involve the annual dry matter (DM) production of grazed and conserved forage beyond the potential of grazed pasture alone are being sought. The objective of this experiment conducted in Australia was to compare a complementary forage rotation (CFR) for conservation and grazing, comprising an annual sequence of three crops, namely maize (Zea mays L), forage rape (Brassica napus L) and a legume (Persian clover, Trifolium repesinatum L or maple pea, Pisum sativum L), with a pasture [kikuyu grass (Pennisetum clandestinum) over-sown with short-rotation ryegrass (Lolium multiflorum L)] as a pasture control treatment. The experiment was a complete randomized block design with four replicates (0AE7 ha each). Annual dry-matter (DM) yield over the 3 years averaged >42 t ha )1 year )1 for the CFR treatment and >17 t ha )1 year )1 for the pasture treatment. The high DM yield of the CFR treatment resulted from >27 t ha )1 year )1 from maize harvested for silage and >15 t DM ha )1 year )1 utilized by grazing the forage rape and legumes. Total input of nitrogen (N) and water were similar for both treatments, resulting in higher Nand water-use efficiency for the CFR treatment, which was more than twice that for the pasture treatment. Overall, the nutritive value of the pasture treatment was slightly higher than the mean for that of the CFR treatment. The implications of these results are that a highly productive system based on the CFR treatment in conjunction with the use of pasture is achievable. Such a dairy production system in Australia could increase the total supply of feed resources grown onfarm and the efficiency of use of key resources such as N and water.

Animal behavior and pasture depletion in a pasture-based automatic milking system

“…Daily grazing areas were allocated according to pasture biomass assessment conducted using an electronic rising plate meter (Electronic Plate Counter; Farmworks, Feilding, New Zealand) and weekly calibration equations developed at the same experimental site (Garcia et al, 2008). Target postgrazing pasture biomass was set at 1600 kg DM/ha.…”

Offering a forage crop at pasture did not adversely affect voluntary cow traffic or milking visits in a pasture-based automatic milking system

“…As such, it is possible that feed offered in the paddock, whether it is pasture or a forage crop, is too far removed from the act of milking to be an incentive for volunteering for milking, although the distance at which forage ceases to be an incentive is currently unknown. The absence of any negative effect of soybean on cow traffic indicates that it may be possible to incorporate complementary forage systems (Garcia et al, 2008;Farina et al, 2011) into pasture-based AMS. Forage crops have been used to produce more than twice the annual DM per hectare as that achieved by pasture alone (Garcia et al, 2008), offering farmers the ability to increase the amount of home-grown feed in paddocks close to the dairy (Farina et al, 2011).…”

“…The absence of any negative effect of soybean on cow traffic indicates that it may be possible to incorporate complementary forage systems (Garcia et al, 2008;Farina et al, 2011) into pasture-based AMS. Forage crops have been used to produce more than twice the annual DM per hectare as that achieved by pasture alone (Garcia et al, 2008), offering farmers the ability to increase the amount of home-grown feed in paddocks close to the dairy (Farina et al, 2011). Therefore, although soybean, and potentially other forage crops, may not provide an incentive to encourage voluntary cow traffic, they may still be beneficial through reducing the average walking distance between the dairy and paddocks.…”

“…Pasture compressed height was measured daily by a trained research technician using an electronic rising plate meter (Rising Plate Counter; FarmWorks, Feilding, New Zealand). Pasture biomass was then estimated using calibration equations developed previously on the same site (Garcia et al, 2008) and data were used to calculate area per allocation. Soybean biomass cannot be accurately measured with a plate meter and was estimated daily by taking three 30 × 30 cm quadrant samples of the pre-and post-grazing mass at random sites.…”

Implementing innovative farm management practices on dairy farms:a review of feeding systems

“…Therefore, the amount of home-grown forage produced and consumed is an important factor for productivity improvements in the dairy industry (8,39). As perennial ryegrass is the main source of home-grown forage produced in southwestern Victoria, comparisons of different feeding systems need to be based on profitability gains associated with systems change (40).…”