Bijeenkomst: EGF2015
Auteur: Abbink G.W., Reijneveld J.A. and Linders P.B.J.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
In the Netherlands, the amounts per ha of nitrogen (N) and phosphorus (P) applied have been reduced by approximately 40% since 1996, due to legislative restrictions. However, as the reductions in N and P fertiliser application have not resulted in a reduction in the dry matter (DM) yield of grassland, we hypothesise that herbage quality is changing. We used a large database (n>350,000) with results of spring forage analyses from dairy farms in the Netherlands. In the period studied (1996-2013), crude protein (CP), crude ash, P, K, Fe, Zn, Mo, Cu and Co content all decreased. In the same period, an increasing content of energy, water-soluble carbohydrate (WSC) and selenium was found. The decreasing CP levels probably induced the increase in the WSC content of herbage. The increase in Se content can be explained by the increased use of Se containing fertilizers. In conclusion, almost all mineral contents in herbage seem to decrease because of the legislative restriction on N and P input. In order to maintain high animal production levels, farmers need to purchase high-protein feed and minerals for their rations to compensate for the decreasing CP and mineral contents in silage.
nitrogen
Herbage and milk production from a grass-only sward and grass-white clover swards in an intensive grass-based system
Bijeenkomst: EGF2015
Auteur: Egan M.J., Lynch M.B. and Hennessy D.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
White clover (Trifolium repens L.; clover) can increase the sustainability of grass-based dairy systems and has the potential to increase milk production. This experiment compared milk production from a perennial ryegrass (PRG) sward receiving 250 kg N ha‑1 yr‑1 (Gr250), a PRG-clover sward receiving 250 kg N ha‑1 yr‑1 (Cl250) and a PRG-clover sward receiving 150 kg N ha‑1 yr‑1 (Cl150) in a rotationally grazed system in 2013 and 2014. Three groups of cows were allocated to graze each sward in 2013 and 2014 (n=14 and 19, respectively). Clover inclusion into PRG swards had no effect on the total herbage production. There was a treatment×week interaction on sward clover content; Cl150 had greater clover content in the second half of the grazing year. Treatment had an effect on cumulative milk yield (MY) and milk solids (MS) production. The Cl150 had lower cumulative MY compared to Cl250 (6,055 and 6,343 kg milk cow‑1, respectively); there was no significant difference between Cl150 and Gr250 (6,055 and 5,912 kg milk cow‑1, respectively); and Cl250 had greater cumulative MY than Gr250 (6,343 and 5,912 kg milk cow‑1, respectively). The MS yield of the clover treatments were significantly greater than the Gr250 and were similar between both clover treatments.
Productivity and herbage quality in two-species grass-legume mixtures under cutting
Bijeenkomst: EGF2015
Auteur: Elgersma A. and Søegaard K.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Inclusion of legumes in grasslands could enhance N-use efficiency of forage production. Performance of 7 binary grass-legume mixtures was studied to examine companion species with contrasting attributes. Perennial ryegrass (PR) was sown alone and with each of four forage legumes: red clover (RC), birdsfoot trefoil (BT), lucerne (LU) and white clover (WC); WC was sown with each of four companion grasses: PR, hybrid ryegrass (HR), meadow fescue (MF) and timothy (TI). Mixtures were studied in a smallplot (1.5×8 m) cutting trial with 4 replications in Denmark to test the effect of species composition on herbage yield, contents of nitrogen (N) and neutral detergent fibre (NDF), and in vitro organic matter digestibility (IVOMD). Plots were fertilised with 300 kg N ha‑1 from cattle slurry and harvested five times from May to October in year 1 and four times in year 2. With different companion grasses, the WC proportion was similar in mixtures with HR and MF, which had a lower WC content than with PR and TI. Annual herbage yield was highest for PR/RC (15.6 Mg DM ha‑1) which had, on average, the highest legume proportion of DM, the highest N content (33 g N kg‑1 DM) and the highest N yield (505 kg N ha‑1) across both years. The mixture with the lowest values was PR/BT (9.6 Mg DM ha‑1; 25 g N kg‑1 DM; 243 kg N ha1). PR/RC had the lowest concentration of NDF (375 g kg‑1 DM) and pure PR the highest (437 g kg‑1 DM). IVOMD ranged from 730 g kg‑1 organic matter (OM) in PR/LU to 774 g kg‑1 OM in WC/HR. Choice of companion grass had less effects than that of companion legume in the examined mixtures. Red clover contributed most to N yield.
Herbage production in grazed grass-white clover plots: effect of N fertilizer application
Bijeenkomst: EGF2015
Auteur: Enríquez-Hidalgo D., Gilliland T.J. and Hennessy D.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
The objective of the experiment was to evaluate herbage removed (HR) and sward clover content in grass-only (GO) and grass-white clover (GW) swards under frequent tight grazing conditions. A series of grazing plots (8×8 m) were established as a 2-sward (GO and GW) × 5-fertilizer N rate (0, 60, 120, 196, 240 kg N ha‑1) experiment. Measurements were taken from 2010 to 2013. Dairy cows grazed swards 8-10 times yr‑1 to a target post-grazing sward height of 4 cm. GW swards had 14-46% greater (P
Perennial ryegrass variety ranking responses to inclusion of white clover and altered nitrogen fertility
Bijeenkomst: EGF2015
Auteur: McDonagh J., McEvoy M., Gilliland T.J. and O’Donovan M.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Perennial ryegrass (Lolium perenne) is the most widely used ryegrass species for high-output pasture based dairy farms in Europe. Repeated selective breeding has enhanced dry matter (DM) productivity potential, elevated nutritive value and provided a large diversity of varieties adapted to variant growing conditions and farming practices. With renewed interest in white ryegrass-clover swards mixtures, there is a concern that sward interactions between perennial ryegrass varieties and white clover will have a significant effect on the dry matter yield performance of a recommended grass variety. The aim of this study was to establish if perennial ryegrass varieties re-rank in DM yield when sown with/without white clover at two nitrogen applications under intensive grazing. Eight perennial ryegrass varieties were sown with (+C) /without (-C) white clover. Swards received two levels of nitrogen 250 (HN) and 100 (LN) kg N ha‑1. Treatments were HN+C, HN-C, LN+C and LN-C. A significant nitrogen by clover interaction occurred because LN-C gave the lowest yield, but although high nitrogen increased both the with and without clover treatments, the highest yielding treatment was LN+C. Grass variety had a significant effect (P>0.001) on DM yield, but the ranking of the ryegrass varieties was unaffected by the imposed treatments and so represented a robust estimation of the relative DM production potential of each ryegrass variety. The inclusion of clover also did not affect the relative performance of the ryegrass varieties, indicating that any inter-species competitive interactions were not variety specific.