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dc.contributor.authorWright, Iain Alexanderen
dc.date.accessioned2018-01-31T11:40:40Z
dc.date.available2018-01-31T11:40:40Z
dc.date.issued1982en
dc.identifier.urihttp://hdl.handle.net/1842/27713
dc.description.abstracten
dc.description.abstractSuckler cow management systems generally require cows to be dependent on their body reserves of energy and protein at some stage of the production cycle. In nutritional studies with suckler cows it is therefore important that the rate of use or replenishment of body reserves be considered with contemporary nutrition. This requires the quantification of body reserves and hence a means of measuring body composition in the live animal.en
dc.description.abstractThe methods available for the estimation of in vivo body composition in animals are reviewed and a number of techniques (live weight, skeletal size, total body water as estimated by deuterium oxide dilution, blood and red cell volumes as estimated by Evans Blue dilution, ultrasonic measurement of subcutaneous fat depth and eye-muscle area, and body condition scoring) were examined using 73 non-pregnant, non-lactating cows of five genotypes (Hereford x Friesian, Blue-Grey, Galloway, Luing and British Friesian) ranging in body condition score from 0.75-4.5. Direct measurement of body composition in terms of water, fat, protein and ash were made following slaughter.en
dc.description.abstractLive weight, deuterium oxide dilution, ultrasonic measurement of subcutaneous fat depth and eye-muscle area, and body condition scoring were all considered to be potentially useful predictors of body composition, but a combination of techniques offered a better prediction than did any single index. Using a combination of techniques it was possible to predict body fat and protein with residual standard deviations of 13.1 kg and 3.15 kg respectively.en
dc.description.abstractBody composition changes were also examined, and it was calculated that the composition of empty body-weight change was dependent upon empty body weight, containing more fat and less water, protein and ash at higher empty body weights.en
dc.description.abstractImportant breed differences were found in the partition of fat among the main adipose tissue depots, with the Friesian cows having a greater proportion of fat in the internal depots and a lower proportion in the subcutaneous depot. The implications of breed differences in fat partition are discussed in relation to in vivo body composition measurement.en
dc.description.abstractAn ancillary study was carried out into the effects of body condition on maintenance requirements and on the use of blood metabolites to measure energy status in suckler cows. This indicated that body condition affected maintenance requirements to the extent that at 500 kg live weight, maintenance requirements were 8 MJ ME/day less for each unit increase in condition score. Plasma free fatty acids were shown to be particularly useful in assessing energy status in cows, but 3-hydroxybutyrate concentrations were of little value in non-pregnant, non-lactating animals.en
dc.description.abstractFinally, the conclusions of the two studies are discussed in relation to areas of study likely to prove useful in the development of efficient systems of suckled calf production.en
dc.publisherThe University of Edinburghen
dc.relation.ispartofAnnexe Thesis Digitisation Project 2017 Block 16en
dc.relation.isreferencedbyAlready catalogueden
dc.titleStudies on the body composition of beef cowsen
dc.typeThesis or Dissertationen
dc.type.qualificationlevelen
dc.type.qualificationnamePhD Doctor of Philosophyen


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