Life Sciences Commons^™

Comparative Foraging Ecology Of Sheep And Goats In Caatinga Woodland In Northeastern Brazil, Scott L. Kronberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Small-ruminant production is an important part of the agricultural economy of northeastern Brazil. However, mild-to-severe undernutrition of livestock is an annual occurrence. Goats can tolerate the marginal forage conditions better than sheep, but the mechanisms underlying their superior tolerance are not understood.

An analysis of animal liveweights at the end of the year-long study indicated that reproducing mixed-race goats gained nearly twice (P<.05) the weight of reproducing hair-sheep of the Santa Ynez breed, and non-reproducing goats gained about 1.2 times more (P<.05) weight than non-reproducing sheep. Daily weight gains of lambs were less (P<.10) than those of kids for their first 80 days of life.

In the wet season, reproducing sheep and goats gained similar (P>.05) weight, while non-reproducing sheep gained more (P≤.05) than non-reproducing goats. Non-reproducing goats had greater (P<.05) forage organic matter intake (OMI) than the corresponding sheep in the two wet periods. In the late-wet period, non-reproducing goats had greater (P<.05) digestible energy intake (DEI) than corresponding sheep did but had similar (P>.05) digestible protein intake (DPI) as sheep.

In the dry …

Effect Of Fertilization On Woody Plant Chemistry: The Role In Diet Selection By Goats, Amanuel Gobena

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lack of forage quantity and quality limit livestock production during the dry season in northeast Brazil. Coppice produced following cutting of tree species in this area has the potential to increase forage quantity and quality during the dry season, because trees that coppice retain green foliage throughout most of the dry season. However, the palatability of coppice is often low.

From a theoretical standpoint, woody plants with inherently slow growth rate should be less palatable to herbivores than plants with inherently fast growth rates, because plants that grow slowly allocate more carbon to compounds such as tannins and resins that …

Seasonal Feeding Behavior And Forage Selection By Goats In Cleared And Thinned Deciduous Woodlands In Northeast Brazil, Roberto Cesar Magalhaes Mesquita

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The seasonal feeding behavior, forage preferences and body weight responses of goats were studied under three densities of woodland (called caatinga), and under three stocking rates. The experiment was located in the semi-arid tropics of northeastern Brazil at 3 42' South latitude, and 40 21' West longitude at an elevation of 75 meters. Mean annual precipitation of the area is 832 mm.

Removing the shrubs and trees increased yields of herbaceous only on partially-cleared sites. Goats gained body weight (kg BW/ha) during the wet season, with the cleared treatment showing the best body weight response per unit of land. However …

Some Morphological And Chemical Responses Of Blackbrush (Coleogyne Ramosissima) To Goat Browsing: Influences On Dietary Blackbrush Selection By Goats And Cattle, Frederick D. Provenza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Domestic goats were used to modify the growth form of blackbrush, a spinescent shrub occurring in nearly monospecific stands on several million hectares of rangeland in the southwestern United States. The objective of this research was to evaluate goat browsing as a means of improving these rangelands for cattle. Winter goat browsing stimulated spring twig growth from basal and axillary buds which resulted in increased production.

Twig production by heavily browsed plants (>95 percent removal of current season's twigs) was a function of precipitation, soil depth, branch location on the plant, and period of rest after browsing. As precipitation …

Biological Manipulation Of Blackbrush (Coleogyne Ramosissima Torr.) By Browsing With Goats, Frederick D. Provenza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to provide data on responses of Angora goats and blackbrush (Coleogyne ramosissima) to a biological manipulation program. Blackbrush utilization levels averaged 30, 16, and 6 percent (545, 367, and 147 kg per hectare) for the heavily, moderately, and lightly browsed pastures, respectively; removal rates of 77, 38, and 19 percent (1164, 582, and 291 kg per hectare) were projected.

Statistically significant differences in body weight loss (P=0.052) were noted for goats browsing in different replications. Goats lost an average of 14 and 19 percent of body weight in replications one and two, …

Forage Selection And Nutrition Of Sheep And Goats Grazing In The Tunisian Pre-Sahara, Rudolfo Ricardo Griego

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nomadic pastoralism has been the traditional method of utilizing grazing resources in arid and semi-arid regions of Africa. However, increased sedentarization accompanied by growing human and animal populations during the past two decades is thought to be accelerating the desertification process, or desert expansion. The specific interactions of the grazing animal with this process has been speculated upon but not studied in detail. A comparative study was initiated during the spring grazing season of 1974 to determine sheep and goat nutritional and production responses, as well as patterns of vegetative selection and utilization under the pastoral system currently employed in …