Browsing by Author "Waghorn, Garry Campbell"

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    The nutritive characteristics of maize silage and maize silage/grass rations for cattle : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University, 1973
    (Massey University, 1973) Waghorn, Garry Campbell
    An experiment was conducted to investigate some of the nutritional properties of maize silage, when fed to rising two year old monozygous twin Jersey and Jersey cross cattle, housed indoors. In a preliminary experiment, silages made from maize harvested with two types of harvester were evaluated in terms of digestibility, rate of passage, and the extent of kernel loss in the faeces. Fine chop (conventional) silage (mean particle size 1.24 cm) and coarse chop silage (2.20 cm) were each fed to six animals at restricted levels of intake. The mean retention times of the fine (44.6 hours) and coarse (49.0 hours) chop silages were significantly different (P<0.01) but differences between DM digestibilities (62.7 and 65.1% respectively) were not significant. Undigested faecal kernel loss from both silages was negligible. Intakes of the fine chop silage were slightly higher than those of the coarse chop, but this may have been due to its higher dry matter content. In the main experiment maize silage and grass (ryegrass/clover (MP), and Tama (Ta) in separate trials), in the ratios of 100:0 (t1), 80:20 (t2), 45:55 (t3) and 0:100 (t4), were fed ad lib to four groups of four cattle. The experimental layout was a balanced incomplete block design, and the main parameters measured were digestibility and voluntary intake. Digestibilities rose as the proportion of grass in the rations increased. Approximate OM digestibilities for t2, t3 and t4 were 68.0, 73.0 and 82.0% respectively, however silage (t1) digestibilities were low, and declined from 65.4 to 57.2% over the duration of the experiment (8 weeks). In most instances, comparisons between t3 (or t4) and t1 were highly significant (P