In this study genetic parameters were estimated and the importance of genotype by feeding system interactions investigated for a range of health and fertility traits in dairy cattle. Data were from the Langhill Dairy Cattle Research Centre and two UK recording schemes, one a recording scheme operated by the Scottish Livestock Services Ltd. (SLS) and the other a health and fertility recording and management system, the Dairy Information System (DAISY). Genetic parameters for 305 day yield of milk and its components, health traits (mastitis, somatic cell counts (SCC), lameness and milk fever) and fertility traits (calving interval, days to first service and conception to first service) were estimated using data from DAISY and SLS. Heritabilities and correlations agreed well between the two data sets implying that the nature of the recording scheme had little effect on the parameter estimates obtained. Heritabilities for all health and fertility traits were less than 0.10 with the exception of SCC which had a heritability of 0.15. The genetic correlation between SCC and mastitis was estimated to be 0.65. Genetic correlations of health and fertility traits with production were in all cases unfavourable. Using these estimates, a breeding programme designed to maximise response in production was predicted to increase calving intervals, mastitis and lameness by 0.39, 0.27 and 0.13 genetic standard deviations per unit selection differential. Restricting these traits to zero genetic change was predicted to result in 11% less overall economic response in production than an unrestricted index. Genotype by feeding system interactions were investigated for a wider range of health and fertility traits using data from Langhill. Selection and control line animals housed and managed as one herd were assigned to either a high concentrate or low concentrate feeding system. There were no significant genetic line by feeding system interactions. However, regressions of the traits on pedigree index for fat plus protein yield (PI) were significantly different from zero for six measures of fertility and mastitis. It was concluded that selection for production has led to a deterioration in some health and fertility traits in UK dairy herds. This deterioration could be halted, or the situation improved by direct recording and selection. However, in the absence of a national recording scheme for health and fertility, an alternative would be to use predictor traits, as they are generally easier to measure and record and have higher heritabilities. Results from this study supports the use of SCC as a selection criterion for mastitis (on a small data set), but the regressions on sire predicted transmitting abilities for type were less conclusive. Therefore future research should investigate associations between health, fertility, production, type, SCC and other potential predictor traits more fully and compare the role of direct measurements of these traits or indirect predictions of them in national indices.

Postemergence grass herbicides may decrease the dependence upon the currently available preplant incorporated herbicides for weed control during alfalfa establishment. Sethoxydim, fluazifop, haloxyfop, quizalofop, fenoxaprop, SC 1084 and BAS 517 02H evaluated in eight separate studies effectively controlled both annual grass weeds such as large crabgrass, fall panicum and yellow foxtail and perennial grass weeds such as quackgrass in spring seedings of alfalfa at several stages of maturity. The maximum first harvest alfalfa yields generally were obtained when the annual grass weeds were controlled prior to seven weeks after planting. In quackgrass-infested alfalfa seedings, herbicides were more effective when applied prior to the seven-leaf stage of quackgrass growth. Split and single applications of grass herbicides resulted in similar quackgrass control. Tank mixtures of grass herbicides with 2,4-DB controlled both the annual broadleaf and grass weeds. Preemergence treatments of several herbicides controlled annual grass weeds when applied at three to four times the rate required for postemergence control. Herbicides decreased total forage yields, however removal of the weed component increased alfalfa yields. Greater alfalfa yield increases were obtained at the first harvest when the weed component of the forage ranged from 50 to 90%. The weed component of the forage in addition to the time of the first harvest affected the forage quality. The CP content of the untreated annual weeds and quackgrass (8 to 15%) was lower than alfalfa (18 to 20%). The CP content of the forage increased as the weed component decreased. The ADF content of the first harvest forage varied between the annual grass weeds and alfalfa, however the higher ADF content of quackgrass (40%) compared to alfalfa (33 to 35%) will reduce the digestibility of the forage. The higher NDF content of the untreated annual grass weeds (65 to 75%) compared to alfalfa (48 to 55%) will reduce the voluntary intake of the forage. Reduced heribicide rates resulted in lower weed control but increased the CP content and decreased the ADF and NDF content of the remaining weed component. The lower weed component of the second harvest forage and the higher quality of the weed regrowth after the first harvest generally had little affect on the forage quality of the second harvest.

No description available.

This study was performed in the Poroma community of the Oropeza Province, in the department of Chuquisaca. The Poroma community is characterized by a high poverty level among its members due to a number of different factors. Some of the major factors include: a restricted market, small farms, an absence of support systems, and a lack of support for agricultural development. This lack of support is seen in areas such as: research, roads, electricity, technical assistance, marketing systems, organization, and institutions that support rural development. Numerous studies on the production systems of farmers have described and analyzed the agricultural components but ignored the part livestock plays in the development of a rural production system. Due to this situation, this study has placed priority on the study of the livestock production system in the Poroma community. The objectives of this study are: to characterize and identify the components of the livestock production system; to establish the internal relations of the livestock production system; and to establish the relation between the livestock system and other systems present in the community. In order to accomplish the mentioned objectives, the participative research method was applied. The methods used are: Macro planning (participative prediagnosis) followed by case studies (micro planning). The techniques used to collect data are characterized as participatory. With these, we plan to involve farmers in the study. Some of the most important things are family and community workshops, participant observation, and informal discussions. The study investigated components of the livestock system such as: management, food, health, and production. Animal handling was observed to be completely free, like mating or birth, with men intervening very little in comparison to practices such as castration, branding, and grazing. The predominant race is the Creole. Delivery times are concentrated between the months of June and August (dry season) and November to December (rainy season). The main food source is the mountain where native species are used in regeneration. In general, the animals are browsers and the supplements provided are salt and bran. Only a few families control the health of their animals while the majority of families don’t control their health at all. This means that many problems exist with animal disease. The most common diseases in animals are: cattle: foot and mouth disease, anthrax, and diarrhea; sheep and goats: coenurosis; mules: angina; pigs: external parasites and cysticercosis; and birds: diarrhea. With respect to external parasites, the most severe in all the species are ticks and lice. The infrastructure for the animals in this area is not recommended because it does not offer the health conditions for their rusticity, let alone protect them from inclement weather. The products of the livestock system such as milk, meat, leather, manure, etc. are more commonly used for family consumption than for sale. The revenue earned by community members for this service is regular and is obtained at certain times of the year. Generally, they receive it at the beginning and end of each year as well as at fairs that are held in the area.

Photocopy of typescript. / Digitized by Kansas Correctional Industries

Thesis (Ph.D.)--Murdoch University, 2007. / Thesis submitted to the Division of Health Sciences. Includes bibliographical references (p. 171-192).

Digitized by Kansas State University Libraries

Call number: LD2668 .T4 1957 F37 / Master of Science

No description available.

7 pp. / The objectives of this article are to provide an overview of the major grazing systems that have been used on rangelands in the western U. S. and Canada, to summarize the conditions under which they may be applicable, and to highlight examples from the southwestern U. S. when relevant.