Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 88-90).

Thesis (M.S.)--University of Wisconsin--Madison, 1969. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 252-258).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 558-573).

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 95-98).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xi, 90 p.; also includes graphics (some col.). Includes bibliographical references (p. 88-90). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 110-121). Also available on the World Wide Web.

Thesis (M.A. in applied economics)--Washington State University, August 2007. / Includes bibliographical references.

The literature concerning the nutritional content of white clover as a grazed herbage or conserved crop offered to dairy cattle and aspects of frothy bloat are reviewed. In the first nine week change-over design experiment the effect on milk production and behaviour of spring calving dairy cows grazing white clover/grass swards at contrasting sward heights were examined. Grazing the clover/perennial ryegrass sward to a height of 4 cm increased clover content, but reduced milk production. The 8 cm sward increased milk yields by 15.8%. This was accompanied by an increase in fat and protein yields. Grazing time and biting rate were increased on the 4 cm sward. Cows offered choice between sward types produced intermediate milk production values. A second change-over design experiment conducted over 12 weeks examined milk production and behaviour of spring calving dairy cows in early lactation grazing perennial ryegrass or White clover/perennial ryegrass swards alone or offered a choice between the two sward types or grazed on clover/perennial ryegrass during the day and perennial ryegrass at night. The inclusion of clover in the diet of the dairy cows significantly increased milk production, but reduced fat content. Protein content, fat and protein yields were increased. Cows offered a choice or mixed day and night grazing regime produced similar results, which were intermediate between the clover/ryegrass and perennial ryegrass treatments. Grazing time was increased on clover/perennial ryegrass swards. This experiment also 1 demonstrated the ability of cows to adjust their grazing time to maximise herbage intake. The third experiment compared the value in relation to milk production of three different buffer forages fed to spring calving dairy cows in late lactation grazing either clover/ryegrass or ryegrass swards. The forages were ryegrass and ryegrass/clover silages and ryegrass hay. Milk yield and composition were not affected by forage type, but intakes were higher for grass silage for cows grazing clover/ryegrass swards and visa versa. Hay OM intake was low. The final experiment conducted over the first 15 weeks of the grazing season studied the effect of energy:protein concentration of strawmix supplements on the productivity of spring calving dairy cows grazing a high white clover sward. Milk yields were increased by the provision of a strawmix supplement. The energy:protein ratio had a significant effect on milk composition except fat content. The high energy:high protein supplement tended to precipitate ruminal tympany (bloat), while the low energy:high protein supplement tended to reduce ruminal tympany on this clover based sward. These experiments have given some insight into the use of clover and stimulated questions which require further investigation to enable the farmer to safely incorporate clover into dairy farming systems.

Mastitis is an important disease causing health, productivity and welfare problems in dairy cattle. Over the past 40 years, control programs have successfully revolved around prophylactic and therapeutic antibiotic usage. This has led to a substantial decrease in the prevalence of subclinical mastitis and the suggestion that antibiotic prophylaxis should be reduced. This thesis describes a study that compared the efficacy of a non-antibiotic internal teat sealer containing bismuth subnitrate to antibiotic dry cow therapy (DCT). In cows uninfected at drying off, the teat sealer was significantly better than antibiotic DCT at preventing new dry period intra-mammary infections caused by Escherichia coli, all Enterobacteriaceae species and all major pathogens. Animals that received antibiotic DCT suffered numerically more cases of clinical mastitis during the dry period and next lactation. Significantly fewer Corynebacterium bovis intra-mammary infections (III) were cured in the teat sealer group during the dry period. A novel method of speciation based on endonucleaser estriction analysis of the 16S rRNA gene sequence was successfully developed and utilized to differentiate C. bovis for other Corynebacterium species. A novel lipophilic Corynebacterium species, named "C. langfordif', was identified, typed by 16S rRNA gene sequencing and described. Re-analysis of the study database demonstrated for the first time that quarters infected with C. bovis during the dry period were significantly less likely to acquire a major pathogen BE. It appeared that IMI with C. bovis "protected" quarters from infection with mastitis pathogens. In vitro studies on solid and in liquid media demonstrated that metabolic products of C. bovis could inhibit the growth of some mastitis pathogens. The inhibitory factor was partially and almost completely inactivated by heating to 100°C and treatment with Proteinase K respectively. Production of an inhibitory factor (possibly a bacteriocin) is proposed as one explanation for the protective effect demonstrated in vivo