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dc.contributor.authorKingsbury, Larissa
dc.date.accessioned2015-01-21T00:18:43Z
dc.date.available2015-01-21T00:18:43Z
dc.date.issued2014
dc.identifier.urihttps://hdl.handle.net/10182/6417
dc.description.abstractThe effect of pre mowing on pastures of high or low mass was investigated to determine whether herbage quality, intake, milk yield and nitrogen use efficiency (NUE) of dairy cows could be increased. The experiment was carried out using tetraploid perennial ryegrass and white clover pastures in autumn at the Lincoln University Research Dairy Farm. Forty eight lactating, pregnant, spring calving Friesian x Jersey cows were used. A 2 x 2 non-replicated factorial design was used to explore the effect of high (HM, 2800 kg DM/ha) versus low (LM, 2200 kg DM/ha) mass on standing (S) versus pre mown (P) pasture. Pastures prepared by manipulating regrowth interval or mowing had little effect on the chemical composition of the herbage of offer. However pre-mowing 3 hours ahead of grazing increased the proportion of neutral and acid detergent fibre (NDF, ADF) and reduced water soluble carbohydrate (WSC) in the diet. Increasing pasture mass increased the proportion of WSC in the diet. In pre-mown treatments the apparent DMI was reduced by 1.4 kg DM/cow/day and 1.2 kg DM/cow/day for low and high pastures, respectively. The daily milk yield was lower (P < 0.001) in P compared with S treatments and lower (P = 0.003) at HM compared with LM treatments. There was a tendency for lower milk protein yield in the P compared with S treatments (P<0.10). While herbage remained digestible after mowing, the increase in crude fibre in P treatments may have reduced rate of energy availability to rumen microbes resulting in reduced microbial protein synthesis. There were interactions between pasture mass and mowing on grazing behaviour. On S pastures cows spent similar amounts of time grazing during the first 6 hours after feeding while P reduced time grazing at LM compared with HM. The N intake was not significantly affected by pasture mass, this resulted in the NUE values being very similar between treatments. When offered the same allowance of herbage, pre-mowing did not improve dairy cow performance. It is likely that loss of DM occurred following mowing – reducing the availability of the diet allowance on pre-mown treatments. The benefits of pre-mowing may be to increase dry matter intake through shifting cows to a new pasture allocation and enabling a higher allowance to be offered.en
dc.language.isoenen
dc.publisherLincoln Universityen
dc.subjectdefoliationen
dc.subjectdieten
dc.subjecttetraploiden
dc.subjectLolium perenneen
dc.subjectsynchronyen
dc.subjectmanipluationen
dc.subjecturine Nen
dc.subjectutilisationen
dc.titleThe effect of pre-mowing pasture on milk, pasture, and nitrogen partitioning of dairy cows in the autumnen
dc.typeDissertationen
thesis.degree.nameBachelor of Agricultural Science (Honours)en
lu.thesis.supervisorBryant, Racheal
lu.contributor.unitDepartment of Agricultural Sciencesen
dc.subject.anzsrc07 Agricultural and Veterinary Sciencesen
dc.subject.anzsrc070204 Animal Nutritionen
dc.subject.anzsrc0701 Agriculture, Land and Farm Managementen
dc.subject.anzsrc0703 Crop and Pasture Productionen


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