Resumo: Objetivou-se avaliar os efeitos dos aditivos própolis verde, própolis marrom e monensina sódica sobre o comportamento ingestivo, consumo de matéria seca e fibra em detergente neutro e desempenho produtivo de cordeiros terminados em confinamento. Foram utilizados 32 cordeiros, machos, sem raça definida, com oito animais por tratamento. O confinamento teve duração de 64 dias, no qual utilizou-se dieta com relação volumoso:concentrado de 50:50, a base de feno de capim-Tifton 85 (Cynodon spp.) e concentrado comercial. O delineamento experimental foi o de blocos ao acaso, pelo critério de peso, e os animais distribuídos aleatoriamente entre os tratamentos: (1) controle, dieta sem aditivo; (2) própolis verde, (3) própolis marrom e (4) monensina sódica. Para ruminação e ócio, houve efeito de tratamento, com menor tempo de ruminação e maior de ócio, no tratamento própolis verde. Os cordeiros apresentaram semelhante eficiência de alimentação. Os consumos de matéria seca e fibra em detergente neutro, em porcentagem do peso vivo e em g/kg de peso metabólico, foram maiores para tratamento controle. Os valores de ganho de peso foram superiores para tratamentos controle; entretanto, a conversão e eficiência alimentar foram superiores para própolis marrom e monensina sódica. Tecnicamente, a própolis marrom pode ser utilizada como aditivo alimentar em substituição a monensina sódica em dietas para ovinos confinados. Mais estudos são necessários para identificação dos melhores níveis de inclusão de própolis marrom como aditivo alimentar para ovinos. / Abstract: It was aimed at to evaluate the effects of the additive green propolis, brown propolis and sodic monensin about the ingestive behavior, dry matter and neutral detergent fiber intake and productive performance of lambs finishing in feedlot. It were used 32 lambs, males, without defined breed, with eight animal per treatment. The feedlot had duration of 64 days, in which a diet was used with roughage:concentrate relation of 50:50, with grass-Tifton 85 hay (Cynodon spp.) and commercial concentrate. The experimental design was blocks at random, by the weight, and the animals were distribuited among the treatments: (1) control, diet without additive; (2) green propolis, (3) brown propolis and (4) sodic monensin. For the activities rumination and idle, there was treatment effect, with minor spent time for rumination and major for idle to the green propolis. The lambs presented the same feeding efficiency. The dry matter and neutral detergent fiber intakes, in % BW and BW0.75, differed with major values presented by control diets. The weight gain were highest for the animals fed to control diets, however feeding conversion and efficiency values were superior for the brown propolis and sodic monensin. Technically, the brown propolis can be used like additive in substitution of sodic monensin in the diet of sheep in feedlot. More research is necessary to identification of best level of brown propolis as additive in the diets for sheep. / Orientador: Ciniro Costa. / Coorientador: Maria das Graças Morais / Banca: Heraldo César Gonçalves / Banca: Ricardo Orsi / Banca: Cledson Augusto Garcia / Banca: Francisco Assis Fonseca de Macedo / Doutor

Tydens embrio ontwikkeling groei weefsel deur selvermeedering, maar soos wat soogdiere volwassendheid nader vind groei net plaas deur sel vergroting. Volwassenheid word beskou as wanneer spiergroei ‘n maksimum bereik. Groei sluit die neerlegging van vet in, maar spiermassa is van primêre belang. Die groeikurwe (Fig 1) waarin massatoename teenoor ouderdom vergelyk word, volg ‘n sigmoidale kurwe (Owens et al, 1993). Onder ideale toestande is die groeitempo van lammers relatief konstant van kort na geboorte totdat die helfte van volwassemassa bereik word, waarna dit geleidelik afneem tot volwassenheid (Black, 1983). Die afname in groeitempo begin gewoonlik met die bereiking van puberteit (Owens et al, 1993).

Please read the abstract in the section 00front of this document / Thesis (PhD Agric (Animal Science))--University of Pretoria, 2006. / Animal and Wildlife Sciences / unrestricted

The study aims to determine the contribution made by available ram growth- and breed standard parameters on the sale price of auctioned rams in Namibia. These findings serve as an indication of the importance ram buyers place on individual parameters in selecting rams for breeding purposes. It furthermore tries to establish whether scientific measurement for the estimation of ram breeding values takes precedence over subjective appraisal. The analysis of the 100 day and 270 day growth performance of the progeny of selected Veldram tested rams were used to evaluate the accuracy of the estimation of ram breeding values and may serve to validate the proper execution of these Veldram tests.

There have been alarming declines in the number of California bighorn sheep in the Similkameen region of British Columbia since the latter part of the nineteenth century. Present conflict for food supply with domestic stock makes further herd reduction imminent. This study was initiated to gather sound ecological data on which to base management and conservation practises for the California bighorn sheep in British Columbia and to determine population status of the Ashnola herd. The Ashnola herd was studied in the field from May 1960 through June 1961. The study area is described on the basis of broad soil and vegetation patterns. Line point transects were employed to determine botanical composition of important winter ranges. The sheep population is analysed from age and sex ratios and age structure data. Age structure was determined by collecting remains, in the field, of sheep which died of natural causes. Natality and mortality rates from the above sources indicate that the herd is relatively stable. Census data substantiates this observation. Factors limiting population increase are evaluated with emphasis on competition for food. Predation, accidents and hunting are not considered to be presently limiting herd increase. Incidence of parasitism in the herd was investigated by post mortem examination and fecal analysis. No deaths directly attributable to parasitism were noted during the study. Grazing by cattle appears to be the primary land use presently threatening the welfare of the herd. Bighorn sheep-cattle competition involves spring and fall utilization by cattle of sheep winter ranges. Direct and indirect observation of animal distribution, food habit analysis and exclosure plot technique have been employed to evaluate the competitive interaction. Although competition was slight in 1960, food shortage resulting from cattle grazing and occasional severe snow conditions is suggested as the factor limiting herd increase. Aspects of herd biology and behavior such as rutting, lambing, migration and social organization are also described. Management considerations and recommendations are briefly discussed. / Science, Faculty of / Zoology, Department of / Graduate

Stone sheep (Ovis dalli stonei) and a representative, undisturbed habitat for this species were studied in the northern Rocky Mountain Foothills from May 1969 through May 1971. A highly descriptive and holistic approach was taken in this introductory study, with physiography, soils, climate, and vegetation and the native sheep all being assessed. The study was concerned primarily with the alpine sheep habitat with emphasis on the critical winter range. Vegetation in this northern environment, reflecting physiographic, climatic and edaphic diversity, presents a complex, heterogeneous pattern locally to a degree seldom observed in more southern latitudes. Local variations in climate, on different slopes and aspects, have produced striking floristic differences within short distances. Moreover, soils developed over different bedrock formations and distrubed little by glaciation contributed considerably to diversity in the alpine habitat. Extremely acid soils characterized by impeded drainage and low temperatures limited forage production over much of the habitat. However, soils developed over calcareous parent materials on southern exposures had the favourable characteristics of moderately coarse texture, good drainage and an adequate nutrient status. These soils supported relatively productive plant communities and high quality forage for the sheep. The vegetation was also characterized by stability especially in the alpine zone; this zone is largely free of a fire history and is characterized by climax or long-term disclimax communities. Apparent deteriorating climate over long periods may be very significant, however, because in all likelihood they reduce favourable sheep habitat. Stone sheep were almost entirely dependent on the herbaceous alpine vegetation for their nutritional requirements. Even though plant succession proceeds slowly at these latitudes, seral grasslands tended to be invaded quite rapidly by shrubs which reduced the herbaceous cover and caused drifting snow to accumulate in winter. Grasses and sedges made up 95.6 percent of the winter diet and 78.5 percent of the fall diet of sheep collected in the Nevis Creek study area. Vegetative diversity contributed largely to a balanced habitat for the sheep and the fortuitous combinations of factors of climate, soils and vegetation provided critical winter range on largely snow-free slopes with southern exposures. Three plant communities provided winter forage but one, the Elymus - Agropyron community, provided almost 60 percent of the forage utilized by wintering sheep. About 80 percent of the standing crop in this community, which made up only about 20 percent of the winter range and four percent of the total productive habitat by area, was utilized by the sheep. Although productivity was typically low in this alpine ecosystem, forage quality was relatively high and was maintained in the cured stage by hard fall frosts and the persistent winter cold. Counts conducted in summer and winter over an extensive portion of the northern foothills and Rocky Mountains showed stone sheep populations averaged 35 percent mature ewes, 28 percent mature rams, 15 percent yearlings and 22 percent lambs (n=981). Early summer counts for two seasons in the study area showed an average ratio of 74 lambs per 100 ewes two years of age or older indicating a high birth rate and low mortality in the first few weeks of life. The lambs experienced almost 50 percent mortality by the end of their first year; however, most of it occurred early in the first winter. Classified counts of the ram segment of the population indicate a period of low mortality during adult life to age 8 or 10 years. Of course, intraspecific competition and malnutrition during severe winter conditions, disease and parasites, injury, predation and hunting all contributed to mortality to some degree. Stone sheep populations reflect the stability of their relatively undisturbed alpine habitat. Actinomycosis and lungworm were common in sheep at Nevis Creek but there is no record of large-scale enzootic die-offs in this or other stone sheep populations such as occur in bighorn populations due to lungworm-pneumonia disease. Stone sheep habitat, once remote, is rapidly becoming more accessible and subject to man's influence with development of the north. Interference in this northern environment by man must consider its sensitivity to abuse and its slow recovery. Any change or destruction of this northern sheep habitat, particularly the important and restricted elements such as the Elymus - Agropyron plant community on the Nevis Creek winter range, would unquestionably seriously reduce the sheep populations dependent upon it. / Land and Food Systems, Faculty of / Graduate

Four main experiments were carried out to study the nutrient requirements and management of sheep raised in confinement. Experiment I was designed to study the reproductive performance and protein utilization of ewe lambs bred to lamb at approximately 14 to 16 months of age. Rapeseed meal was compared to soybean meal as a source of supplemental protein during the second half of gestation. Ewe weight gains and lamb birth weights were not affected by either the level or the source of protein. Neither dry matter nor protein digestibility were influenced by the stage of gestation of the ewe. No consistent results were obtained with regard to nitrogen retention of the ewes during the last half of gestation. The results suggest that 11% crude protein (CP) in the dry matter supplying approximately 68 g digestible crude protein (DCP) may be adequate for this class of ewes. The results also indicated that a level of 22% rapeseed meal may be included in the diet of gestating ewes without producing goitrogenic or other adverse effects. Experiment II was conducted to assess the performance of ewe lambs during lactation when fed rapeseed meal or soybean meal together with low quality roughage. Weight changes of the ewes and the average daily gain of the lambs over the eight week lactation period were not affected by the level or the source of protein. The results suggest that 10% CP in the dry matter supplying approximately 92 g DCP may be adequate for the class of ewe studied. A level of 25% rapeseed meal may be included in the diet of lactating ewes. In Experiment III wheat and barley were compared as energy sources in all-concentrate rations for lambs weaned at eight weeks of age. The cereal grains were fed in the whole, rolled, and pelleted forms together with a pelleted protein supplement. Digestiblity trials were also conducted to measure the digestibility of energy and protein as influenced by grain, process and level of intake. There was no difference in growth rate of lambs fed wheat or barley. Whole grains resulted in a faster rate of gain than the pelleted form. Digestibility of energy was not influenced by the method of processing. Protein digestibility was similar for the whole and rolled grains with a tendency for pelleting to depress digestibility of this nutrient. Increasing feed intake from maintenance to appetite resulted in a slight depression in nutrient digestibility. The results of this study suggest that processing of cereal grains for lambs is unnecessary from the standpoint of digestibility and would appear to be detrimental in terms of growth rate and feed conversion efficiency. Experiment IV was designed to study the influence of level of protein supplementation of whole barley based rations for early weaned lambs. A series of digestibility studies were conducted to measure the digestibility of dry matter and protein during three periods of growth. Results of this study demonstrated that 16% CP in the ration of lambs from 20 - 29 kg liveweight was sufficient to produce the most economical gain during this period of growth. In the period from 29 - 36 kg the lambs receiving 14% CP in the ration gained faster and had the best feed conversion efficiency. During the final finishing period the results suggest that one could continue to feed a 14% CP ration. The digestibility of dry matter and crude protein were not influenced by stage of growth of the animal. / Land and Food Systems, Faculty of / Graduate

The feeding of 1 mcg. diethylstilbestrol (DES) per g. dry matter of feed to mature intact and castrated or ovariectomized male and female Wistar strain rats indicated that hormone treatment tends to reduce the water requirements of rats. Implantation of 3 mg., 6 mg., and 9 mg. DES in growing wether lambs did not affect the relationship of total water intake to dry matter intake, gross energy intake, apparent digestible energy, nitrogen intake, apparent digestible nitrogen and nitrogen retention. Feeding of rations of differing protein level, gross energy content, and protein to calorie ratios, did not alter the ratios of total water intake to dry matter intake, apparent digestible energy, nitrogen intake, apparent digestible nitrogen and nitrogen retention in growing wether lambs. / Land and Food Systems, Faculty of / Graduate

The feeding of three different rations varying mainly in crude fat and crude fiber level at a high level of intake to pregnant and non-pregnant ewes had a number of effects on blood glucose, lactic acid, acetone plus acetoacetate, and total volatile fatty acid concentrations during the last three months of gestation for the pregnant animals (February, March, and April). There was no significant effect due to time on blood glucose level or on the level of blood ketone bodies, during the latter stages of pregnancy, for animals consuming high, medium or low roughage rations. The intramuscular injection of 1 mg./kg. body weight of growth hormone into pregnant sheep for 7 days during the last month of pregnancy, caused no significant effects on blood glucose, lactic acid, acetone plus acetoacetate, or total volatile fatty acids concentrations. / Land and Food Systems, Faculty of / Graduate

Changes in serum protein-bound iodine (PBI) levels were estimated in pregnant and non-pregnant mature ewes during the months from August to March. The PBI levels in ewes appeared to be elevated by low temperature (P < 0.001) and depressed by high temperature. The estrous cycle affected the PBI levels in ewes. The peak of PBI level was within 48 hours of estrus period. Breed differences played an important part on PBI levels; the Dorset breed generally had a higher PBI level than the Suffolk crossbred animal. The PBI levels in pregnant ewes became significantly higher (P < 0.05) than in the control after the third week of pregnancy. This increase in PBI level was followed by a significant increase (P < 0.05) in body weight gain at the seventh week of pregnancy. Toward the end of pregnancy (last seven weeks) the ewes with twin lambs had a significantly higher PBI level than the ewes with single lambs. The higher PBI levels remain elevated after parturition until the end of the lactation period. The PBI levels of lambs implanted with 3 and 6 mg diethystilbestroi (DES) were determined. Female lambs had a higher PBI level than mature ewes. Ten days after DES implantation, a significant (P < 0.001) increase in PBI levels was observed. This was followed by an increase in body weight gain over the control of 35% and 37% for 3 and 6 mg DES implants respectively during the remaining part of the experiment. There was a difference in the response to DES treatment between sexes. The wethers grew faster than the female lambs; this difference in growth rate can be reduced by treating the ewes with a larger dose of DES. Iodinated casein (protamone trade name, 1% thyroid activity) fed at 0, 0.25, 0.5 and 1 gm and also in combination with 1.75 mg DES were fed daily to growing lambs. The results showed that Protamone feeding to lambs as well as in combination with DES, caused a significant increase in PBI levels over the controls (P < 0.001). Blood glucose measurements showed a parallel with PBI in fluctuation. The blood sugar levels of lambs were found to be higher than those of mature ewes. DES and Protamone feeding caused an increase rate of gain over the control (DES 13.2 lb; 0.25 gm Protamone 8.7 lb)and improved feed efficiency (DES 1:3.4; Protamone 1:3.9 and control 1:5.6). / Land and Food Systems, Faculty of / Graduate