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dc.contributor.authorAnwar, Mursan
dc.date.accessioned2011-01-31T20:56:34Z
dc.date.available2011-01-31T20:56:34Z
dc.date.issued1989
dc.identifier.urihttps://hdl.handle.net/10182/3152
dc.description.abstractExperiments were conducted to investigate the possible differences in dry matter intake, bite weight and bite dimensions between young bulls and steers of similar age and genotype offered pasture over a similar range of sward height. In experiment I (i) and I (ii), 20 cattle of 4 and 5 months old respectively (10 bulls and 10 steers), were divided into 4 groups (2 groups bulls and 2 groups steers). A 0.4 ha paddock with ryegrass (Lolium perenne) and white clover (Trifolium repens L) dominant pasture was used in experiment I and subdivided into 4 plots. The grazing area was reduced daily by 10% per day from day 2 until the end of the experiment (day 12). Each group was randomly assigned to 1 of these 4 plots. In experiment II, 0.8 ha paddock of tall fescue (Festuca arundinacae) dominant pasture was used and divided into 4 plots of each of 0.2 ha. All plots were reduced daily in size by 5% from day 2 until the end of the experiment (day 8). The same animals used in experiment I were reused in experiment II (18 months old) and regrouped same as in experiment I. Each group was randomly assigned to graze 1 of the 4 plots. The age of the animals in this experiment was 18 months old. Daily herbage dry matter intake in experiment I and II was measured by chromic oxide/sesquioxide and agronomic methods. Sward surface height was measured daily as a mean of 40 readings in plots grazed by bulls and steers. Herbage mass (kg DM/ha) was estimated from the relationship between sward surface height and herbage mass within cut quadrats. Mean daily sward surface height, herbage mass, dry matter intake and dry matter digestibility were not significantly different in plots grazed by bulls and steers in either experiments (p>0.05), however they significantly declined (p<0.01) over time. Daily dry matter intake measured by chromic oxide method was more closely related to herbage mass per animal per day rather than to herbage mass per hectare. Mean sward surface height, herbage mass, dry matter intake measured by chromic oxide and agronomic methods and dry matter digestibility of pasture in plots grazed by bulls and steers in experiment I and II are presented in Table .i. [see table in thesis] There was no significant difference between the dry matter intake of bulls and steers in either experiment. Daily dry matter intake measured by chromic oxide method gave apparently more meaningful and consistent estimates than the agronomic method in which dry matter intake per animal was estimated by deducting the estimate of herbage mass available on particular day and area plus estimate of daily herbage mass accumulation in each 2 consecutive days divided by the number of animals. In experiment III the relationships between sward height, bite dimensions and bite weight in bulls and steers were examined. Six cattle (3 bulls and 3 steers; mean liveweight were 259 and 251 kg respectively) from experiment I were used. Eighteen turfs of uniform area were cut from a ryegrass dominant sward in early spring and placed into polystyrene boxes. Sward height was measured prior to grazing and swards trimmed where necessary so that height in the surface horizon was uniform (5, 10 and 15 cm). The turfs were offered over 3 days so each animal had 20 bites of a turf of each height daily with different order. There was no significant difference between bulls and steers in bite size and bite dimensions. Sward height which determined bite depth appeared to be the major determinant of bite weight and consequently of daily intake.en
dc.language.isoenen
dc.publisherLincoln College, University of Canterburyen
dc.rights.urihttps://researcharchive.lincoln.ac.nz/page/rights
dc.subjectbullsen
dc.subjectsteersen
dc.subjectdry matter digestibilityen
dc.subjectdry matter intakeen
dc.subjectturfsen
dc.subjectsward surface heighten
dc.subjectbite weighten
dc.subjectbite dimensionsen
dc.subjectgrazingen
dc.titleA comparison of herbage intake between castrated and uncastrated grazing young cattleen
dc.typeThesisen
thesis.degree.grantorUniversity of Canterburyen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Agricultural Scienceen
lu.thesis.supervisorNicol, A. M.
lu.thesis.supervisorHughes, T. P.
lu.contributor.unitDepartment of Agricultural Sciencesen
dc.rights.accessRightsDigital thesis can be viewed by current staff and students of Lincoln University only. Print copy available for reading in Lincoln University Library. en
dc.subject.anzsrc0702 Animal Productionen


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