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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Střevní paraziti koz ve vybraném chovu / Gut parasites of goats on a chosen farm

VANĚČKOVÁ, Michala January 2011 (has links)
The master thesis is aimed to evaluate intestinal parasites occurrence in a goat breeding. A herd of goats chosen for this survey was kept by a private enterprise focused on milk production. The practical research was conducted during two years, 2009 and 2010. Samples of feaces were collected during that period and analyzed for parasites occurrence. The analyses proved presence of the following parasites: Trichuris ovis, parasites from the order Strongylida, Fasciola hepatica, Dicrocellium lanceatum and coccidia. Total prevalence was significant; 85% of the samples were found to be positive. Species from the order Strongylida were identified as the most often 41,46 %, which meant 199 cases from the total of 509. During the examined period, the highest prevalence of parasites was detected in summer 2009, the second highest then in spring 2010.
52

Etologické projevy u krav chovaných v systému bez tržní produkce mléka / Ethological manifestation at the beef cows bred in the system without market milk production

VESELÁ, Jana January 2008 (has links)
The aim of the work was evaluate on the dynamic of live performance at the beef cows in the system of breeding cows withour market milk production in the subnountain areas. The chosem method was a direct group observation within ten-minute intervals. The longest duration of pasture was in autumn 59.6 % of the day and the shortest in winter 30.8 % of the day. The activity of lying depended on standing and decreased from spring period 15.3 % of the day on 5.7 % of the day in winter period. The observation flows to the fact, that breeding of the livestock from welfare and adaptability herd of view is suitable in sub-mountain areas.
53

Agronomical and ecological research with special reference to pastures of the Eastern Townships of Quebec.

Frankton, Clarence. January 1940 (has links)
No description available.
54

Funny Channel Signaling in Equine Airway Disease

Hunter, Courtney 04 May 2018 (has links)
Traditional animal models of severe asthma do not recapitulate defining asthma characteristics, including persistent airway hyper-responsiveness, and chronic neutrophilic inflammation. This is problematic because moderating airway hyper-responsiveness decreases asthma frequency and severity, making it a paramount pharmacological goal in asthma research. Employing a spontaneous equine asthma model (equine pasture asthma, EPA), we first confirmed reversible airway obstruction in eight diseased horses during asthma exacerbations in response to ß2renergic agonist stimulation. Next, non-specific airway hyper-responsiveness was confirmed using methacholine bronchoprovocation to identify the provocative concentration causing a 40% increase in baseline lung resistance (PC40RL)- a threshold similarly employed in evaluating human asthmatics unable to mount forced expiration. The PC40RL of ten EPA horses was consistently <1mg/ml of methacholine, which is a cutoff that has been used to diagnose severe human asthma. Like non-asthmatic humans, ten control horses did not respond to methacholine doses up to 16 mg/ml. Finally, persistence of AHR was documented during absence of seasonal aeroallergen triggers in five horses that were evaluated between 3 and 31 months following the initial methacholine bronchoprovocation. This unique ability of EPA horses to model AHR attributes that are not addressed by other animal models points to the suitability of EPA horses to decipher the mechanistic basis of airway hyper-responsiveness. Building on knowledge that 2renergic receptor (AR) signaling is required to develop the asthma phenotype in a murine model, differentially expressed genes from serial lung biopsies of two EPA affected and two controls were filtered to identify genes that interact with the 2-AR. Hyperpolarization Activated Cyclic Nucleotide-Gated Potassium Channel 4 (HCN4) was prioritized because of its interactions with the 2-AR. Relative to control horses, HCN4 was constitutively expressed in airway smooth muscle of EPA horses during remission and increased during seasonal disease exacerbation. Agonism of airway contraction by HCN4 was proven using the specific HCN4 antagonist, ivabradine, which caused dose dependent decreases in carbachol induced contractile responses in both EPA and control bronchi in vitro. These findings highlight utility of EPA as a model of severe asthma and HCN4 as a mediator of airway contraction that warrants further investigation in severe human asthma.
55

Evaluation of florpyrauxifen-benzyl for use in pastures and hayfields

Greene, Wykle 07 December 2021 (has links)
Weed control is a critical component in pastures and hayfields in order to ensure maximum forage yields. Typically, broadleaf weed control in pastures and hayfields is achieved through the use of synthetic auxin. However, these herbicides also control desirable broadleaf species such as forage legumes, including white clover. Use of herbicides can lead to severe injury and often complete elimination of white clover, making it difficult for producers to maintain legumes in mixed grass-legume swards while controlling weeds. It is often desirable to have legumes present in the sward due to their high nutritive forage value and ability to fix nitrogen compared to grass only swards. Florpyrauxifen-benzyl + 2,4-D is a new herbicide which is reported to control broadleaf weed species, while preserving white clover. Little published research exists on this herbicide, particularly for use in pastures and hayfields. Research evaluating sward composition indicates that florpyrauxifen-benzyl + 2,4-D is effective in controlling broadleaf weed species while also preserving greater amounts of white clover than any other herbicide treatments. Florpyrauxifen-benzyl + 2,4-D also resulted in significantly more forage grass production than the nontreated control. Florpyrauxifen-benzyl + 2,4-D was less effective than other herbicides when applied via fertilizer impregnation. Additional research assessing the spectrum of broadleaf weed control found that florpyrauxifen-benzyl + 2,4-D is a viable herbicide for the control of several broadleaf weed species including bulbous buttercup, Canada thistle, broadleaf plantain, plumeless thistle, and common ragweed. However, florpyrauxifen-benzyl + 2,4-D was less effective than other herbicides for controlling certain weeds, such as horsenettle. White clover was injured from florpyrauxifen-benzyl + 2,4-D, but was able to fully recover in 90 to 120 days. There were no differences in white clover response between the four varieties tested. When evaluating establishment of forage species, florpyrauxifen-benzyl + 2,4-D did not injure or reduce biomass of tall fescue or orchardgrass plantings, indicating a high level of safety. Florpyrauxifen-benzyl + 2,4-D was also safe to both drilled and frost seeded clover when applied prior to and at planting. Greenhouse trials revealed that flowering white clover is more sensitive to herbicides compared to vegetative white clover, and that safety of white clover to florpyrauxifen-benzyl + 2,4-D is dependent upon use rate. Considerations such as weed species present, and the amount of white clover injury that is considered acceptable will dictate the decision to utilize florpyrauxifen-benzyl + 2,4-D in pastures and hayfields. This research demonstrates the effectiveness and overall utility of florpyrauxifen-benzyl + 2,4-D for use in pastures and hayfields due to the effectiveness of weed species as well as the level of safety to white clover. / Doctor of Philosophy / Pastures and hayfields are a critical component in livestock production. Grazing livestock perform best on highly nutritious forages. Legumes such as white clover are highly nutritious in forage systems and offer other benefits such as the ability to fixate nitrogen. Conversely, weed species negatively impact forage production by competing for resources with desirable forage species. Additionally, many species of broadleaf weeds are toxic to livestock. Because grasses are the backbone of forage systems, the majority of weed control efforts are aimed at controlling broadleaf weed species. However, beneficial forage legumes such as white clover are susceptible to broadleaf herbicides commonly used. This creates a management dilemma for producers who wish to control troublesome weeds, but also have white clover present in their pastures and hayfields. Florpyrauxifen-benzyl + 2,4-D is a herbicide combination which is new for pastures and hayfields. This herbicide is reported to control broadleaf weeds while also preserving white clover. Research trials were conducted in order to determine if florpyrauxifen-benzyl + 2,4-D could be used in forage systems to control weeds, without killing white clover. Several research trials were established to evaluate florpyrauxifen-benzyl + 2,4-D for broadleaf weed control and white clover safety. Research trials were established to determine the effect of florpyrauxifen-benzyl + 2,4-D on the number and overall amount of forage produced and the proportion of weeds and desirable forages as affected by herbicide treatment. Florpyrauxifen-benzyl + 2,4-D resulted in a 140% increase in forage grass production, and more legume production than any other herbicide treatment, while also decreasing the quantity and amount of broadleaf weed species. Because there is little existing research on what weed species florpyrauxifen-benzyl + 2,4-D controls, research trials were established to determine the spectrum of weed species that florpyrauxifen-benzyl + 2,4-D controls. Greenhouse trials were also established to evaluate the effect of white clover variety on injury from herbicide. Results showed that florpyrauxifen-benzyl + 2,4-D is effective in controlling several weeds such as bulbous buttercup, Canada thistle, broadleaf plantain, plumeless thistle, and common ragweed. Greenhouse trials showed that white clover variety did not influence the level of injury from herbicide applications. Seedling forages are more vulnerable to weed competition and therefore weed control around the time of planting is critical. However, seedlings are typically very sensitive to herbicides, compared to mature plants. Research trials were established to determine the effect of florpyrauxifen-benzyl + 2,4-D on the establishment of forage grasses tall fescue and orchardgrass, as well as white clover. White clover was established using two commonly used methods: drilling and frost-seeding. Results from the field show that florpyrauxifen-benzyl + 2,4-D is safe use around the time of tall fescue and orchardgrass establishment, as well as white clover planting with either method. Greenhouse trials were also established to determine if white clover's growth stage at the time of herbicide application influences the response. Results show that white clover is more sensitive to herbicides applied to flowering white clover compared to vegetative growth and the level of injury is dependent upon herbicide rate. Overall, our results demonstrate the utility of florpyrauxifen-benzyl + 2,4-D for forage production by controlling weed species and being safer to white clover than commonly used herbicides.
56

Manejo nutricional de vacas primíparas aos 24 meses de idade / Nutritional management of primiparous cows 24 months old

Cadó, Lucas Munareto January 2016 (has links)
O experimento conduzido na Fazenda Rancho Santa Zelina, em Júlio de Castilhos, RS, entre julho de 2014 a setembro de 2015, analisou o desempenho reprodutivo de 42 vacas mestiças Angus primíparas aos 24/25 meses de idade postas no pós-parto em pastagem cultivada de aveia (Avena strigosa Schreb) e azevém (Lolium multiflorum Lam.). Aos 80 dias pós-parto foram distribuídas conforme peso (PC) e escore de condição corporal (ECC) em dois sistemas alimentares: SS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural; CS – mantidas por 23 dias na pastagem cultivada e sete dias em pastagem natural com a suplementação diária de 0,8% do PC de suplemento contendo 14% proteína bruta (PB) e 70% de nutrientes digestíveis totais (NDT). O método de pastoreio foi o contínuo com massa de forragem (MF) média de 1450 kg/ha de matéria seca (MS) em pastagem cultivada e 2150 kg/ha/MS em pastagem natural. O delineamento experimental foi o inteiramente casualizado, com dois sistemas alimentares e vinte e uma vacas por sistema alimentar, sendo cada vaca considerada uma unidade experimental. Para comparar os sistemas alimentares, as variáveis que apresentaram normalidade foram avaliadas utilizando o procedimento MIXED do SAS. A variável taxa de prenhez foi avaliada pelo teste do qui-quadrado. A suplementação não influenciou o peso (PCFT) e condição corporal final (ECCFT) das vacas, porém a variação de peso diária média das vacas do CS foi superior a das em SS durante os sistemas alimentares (0,465 kg e 0,227 kg, respectivamente). Os bezerros do CS nesse período apresentaram maior ganho médio diário, 0,829 kg comparado com aqueles do SS de 0,644 kg e maior peso final (130,86 kg e 117,29 kg, respectivamente). As vacas do CS tiveram a significativa maior taxa de prenhez de 80,95%, enquanto as do SS tiveram 57,14%. Aos 42 dias de acasalamento 80,95% das vacas do CS estavam prenhes, enquanto do SS apenas 28,57% já tinham concebido. Vacas primíparas aos 24 meses de idade e que irão conceber têm maior peso e escore de condição corporal ao início do acasalamento do que as futuras falhadas. / The experiment was conducted at the Farm Rancho Santa Zelina in Julio de Castilhos, RS, from July 2014 to September 2015, examined the reproductive performance of 42 crossbred cows Angus gilts to 24/25 months old put postpartum in cultivated pasture oat (Avena strigosa Schreb) and ryegrass (Lolium multiflorum Lam.). After 80 days postpartum were distributed as weight (BW) and body condition score (BCS) in two food systems:SS – 23 days in a cultivated pasture (Avena strigosa Schreb. e Lolium multiflorum Lam.) and 7 days in a natural grassland; CS – 23 days in the same cultivated pasture and 7 days in a natural grassland receiving 0,8% BW supplement with 14% crude protein (CP) and 70% total digestible nutrients (TDN). The grazing method was continuous with herbage mass (MF) average of 1450 kg/ha of dry matter (DM) in cultivated pasture and 2150 kg/ha/DM in natural pasture. Treatments were arranged in a completely randomized design with two food systems and twenty-one cows for feeding system, where each cow was considered an experimental unit. To compare the food systems, variables with normal distribuition were assessed using the SAS MIXED procedure. The pregnancy rate was evaluated using the chi-square test. Supplementation did not affect cows‟ final body weight (FBW) and final body condition (FBC), but the daily average weight variation of cows in CS was higher than in SS (0.465 kg and 0.227 kg, respectively). The CS calves this period had higher average daily gain, 0.829 kg compared to those of the SS 0.644 kg and higher final weight (130.86 kg and 117.29 kg, respectively). The 80.95% pregnancy rate of the CS cows was higher than the 57.14 % of SS cows. After 42 days of mating, 80.95% of the CS primiparous cows had conceived, against just 28.57% from the SS. Primiparous cows at 24/25 months old and that will get pregnant have higher BW and BCS at beginning of the mating than the open ones.
57

The effect of cattle winter feeding systems on soil nutrients, forage growth, animal performance, and economics

Jungnitsch, Paul F. 26 May 2008
Overwintering of cows is a major cost in a cow-calf production system on the prairies. Winter feeding hay and straw directly on pasture is a potentially more efficient and economical system compared to conventional drylot feeding in a yard. The objectives of the research described in this thesis were to compare winter feeding cattle directly on pasture to traditional drylot over-wintering of cattle and the associated mechanized spreading of manure on pasture. This trial compared the effects of winter feeding systems on pasture nutrient distribution, nutrient recovery in soil and forage, pasture forage response, cattle performance, and economics. <p>The experiment was conducted at Lanigan, SK, on an old russian wildrye grass pasture. Pasture nutrient levels and distribution were measured before and after winter feeding, as well as forage yield, and cattle weight and condition. Nutrient capture and cycling was assessed along with the economics of the different systems. In the pasture fed systems, cattle were fed by either bale processing or bale grazing methods over the winter of 2003-2004. Cattle concentration was 2080 cow-days ha-1, with the cattle in the field for 130 d. In the intensive system used for comparison, cattle were fed in a drylot and 67 tonnes ha-1 of raw manure or 22 tonnes ha-1 of compost was mechanically spread on the pasture in the fall of 2003.<p>Soil inorganic nitrogen (N) levels (0-15 cm) measured in the spring where the cattle were winter fed on pasture were 3 to 4 times the unfertilized, unmanured control treatment, with a mean gain of 117 kg N ha-1. Soil inorganic N was not significantly elevated where manure or compost had been spread by machine. Soil extractable potassium (K) was doubled on the winter feeding sites, with a mean gain of 1209 kg K ha-1. Soil extractable K did not increase where manure or compost had been spread mechanically. Soil distribution patterns of both nutrients were highly uneven following pasture feeding, with levels of inorganic soil N ranging from 12 to 626 kg ha-1 and extractable soil K ranging from 718 to 6326 kg ha-1. Additional nutrients in surface residue from uneaten feed, bedding, and manure were also heavy and variable following pasture feeding. Greater retention of N and K from urine added directly to the soil in the field in the bale grazing and bale processing systems compared to the drylot system is believed to be responsible for high soil available N and K levels compared to manure hauled from the drylot into the field.<p>Soil extractable phosphorus (P) levels (0-15 cm) were measured in the fall of 2005. The compost treatment had the largest increase at 2.6 times the control, an additional 46 kg ha-1. Mean soil P levels did not increase significantly where the cattle were wintered.<p> Over 18 months and 3 harvests, forage dry matter yields where the cattle were fed on pasture were 3 to 5 times the control where the cattle were fed on the pasture, and 1.4 to 1.7 times the control where raw manure or compost was mechanically spread. Also, protein content of the forage was increased to a greater extent in the in-field feeding compared to hauled raw manure or compost, reflecting a greater conservation of N.<p>The gain of N in the forage over 18 months on the winter feeding sites was 200 kg ha-1 of N, almost double what was measured in soil inorganic forms. Fourteen kg ha-1 of P was also recovered. This represented 34% of original feed N and 22% of original feed P that was imported into the field. Recovery of nutrients applied in the raw manure and compost sites was much lower, with only 7% recovery of N and 4% recovery of P in the forage. This was calculated to be 1% of original feed N and 3% of original feed P.<p>The system by which the cattle were overwintered had little influence on cattle weight and condition. All systems performed favorably in maintaining body weight and condition over the winter. Some slight advantages in cattle weight gain and condition were found on the winter feeding systems compared to the in-yard drylot that appeared to be related to slightly increased feed intake.<p>Economic calculations favored winter feeding directly on the pasture by 25% over the drylot systems when the feed value of additional pasture growth over 18 months was included and by 56% when the value of additional soil nutrients was factored in. Feed costs were similar between the systems but pasture feeding had savings in machinery use, fuel consumption and manure handling costs, and gains in pasture productivity.<p>Systems that winter fed cattle directly on pasture provided gains in nutrient cycling efficiencies, pasture growth, and economic savings compared to drylot feeding systems, while maintaining similar cattle growth and condition.
58

The effect of cattle winter feeding systems on soil nutrients, forage growth, animal performance, and economics

Jungnitsch, Paul F. 26 May 2008 (has links)
Overwintering of cows is a major cost in a cow-calf production system on the prairies. Winter feeding hay and straw directly on pasture is a potentially more efficient and economical system compared to conventional drylot feeding in a yard. The objectives of the research described in this thesis were to compare winter feeding cattle directly on pasture to traditional drylot over-wintering of cattle and the associated mechanized spreading of manure on pasture. This trial compared the effects of winter feeding systems on pasture nutrient distribution, nutrient recovery in soil and forage, pasture forage response, cattle performance, and economics. <p>The experiment was conducted at Lanigan, SK, on an old russian wildrye grass pasture. Pasture nutrient levels and distribution were measured before and after winter feeding, as well as forage yield, and cattle weight and condition. Nutrient capture and cycling was assessed along with the economics of the different systems. In the pasture fed systems, cattle were fed by either bale processing or bale grazing methods over the winter of 2003-2004. Cattle concentration was 2080 cow-days ha-1, with the cattle in the field for 130 d. In the intensive system used for comparison, cattle were fed in a drylot and 67 tonnes ha-1 of raw manure or 22 tonnes ha-1 of compost was mechanically spread on the pasture in the fall of 2003.<p>Soil inorganic nitrogen (N) levels (0-15 cm) measured in the spring where the cattle were winter fed on pasture were 3 to 4 times the unfertilized, unmanured control treatment, with a mean gain of 117 kg N ha-1. Soil inorganic N was not significantly elevated where manure or compost had been spread by machine. Soil extractable potassium (K) was doubled on the winter feeding sites, with a mean gain of 1209 kg K ha-1. Soil extractable K did not increase where manure or compost had been spread mechanically. Soil distribution patterns of both nutrients were highly uneven following pasture feeding, with levels of inorganic soil N ranging from 12 to 626 kg ha-1 and extractable soil K ranging from 718 to 6326 kg ha-1. Additional nutrients in surface residue from uneaten feed, bedding, and manure were also heavy and variable following pasture feeding. Greater retention of N and K from urine added directly to the soil in the field in the bale grazing and bale processing systems compared to the drylot system is believed to be responsible for high soil available N and K levels compared to manure hauled from the drylot into the field.<p>Soil extractable phosphorus (P) levels (0-15 cm) were measured in the fall of 2005. The compost treatment had the largest increase at 2.6 times the control, an additional 46 kg ha-1. Mean soil P levels did not increase significantly where the cattle were wintered.<p> Over 18 months and 3 harvests, forage dry matter yields where the cattle were fed on pasture were 3 to 5 times the control where the cattle were fed on the pasture, and 1.4 to 1.7 times the control where raw manure or compost was mechanically spread. Also, protein content of the forage was increased to a greater extent in the in-field feeding compared to hauled raw manure or compost, reflecting a greater conservation of N.<p>The gain of N in the forage over 18 months on the winter feeding sites was 200 kg ha-1 of N, almost double what was measured in soil inorganic forms. Fourteen kg ha-1 of P was also recovered. This represented 34% of original feed N and 22% of original feed P that was imported into the field. Recovery of nutrients applied in the raw manure and compost sites was much lower, with only 7% recovery of N and 4% recovery of P in the forage. This was calculated to be 1% of original feed N and 3% of original feed P.<p>The system by which the cattle were overwintered had little influence on cattle weight and condition. All systems performed favorably in maintaining body weight and condition over the winter. Some slight advantages in cattle weight gain and condition were found on the winter feeding systems compared to the in-yard drylot that appeared to be related to slightly increased feed intake.<p>Economic calculations favored winter feeding directly on the pasture by 25% over the drylot systems when the feed value of additional pasture growth over 18 months was included and by 56% when the value of additional soil nutrients was factored in. Feed costs were similar between the systems but pasture feeding had savings in machinery use, fuel consumption and manure handling costs, and gains in pasture productivity.<p>Systems that winter fed cattle directly on pasture provided gains in nutrient cycling efficiencies, pasture growth, and economic savings compared to drylot feeding systems, while maintaining similar cattle growth and condition.
59

Response of five rice varieties to zinc application on a Burdekin soil

Shwe, Nyunt Unknown Date (has links)
The influence of genetic variability on the response of the five rice varieties, Cica, Starbonett, Lemont, Bluebonett X IR 43, and IR43, to applied zince at 0, 10, 20 and 40 kg Zn ha^-1 under varying cellulose and water management conditions was studied in a greenhouse experiment. Typical zinc deficiency symptoms, varying in intensity among varieties, were nted, especially in the zero applied zinc treatments. Zinc deficiency symptoms were characterised by blanching at the base of the emerging leaves and rusty brown discolouration in the older leaves.
60

Response of five rice varieties to zinc application on a Burdekin soil

Shwe, Nyunt Unknown Date (has links)
The influence of genetic variability on the response of the five rice varieties, Cica, Starbonett, Lemont, Bluebonett X IR 43, and IR43, to applied zince at 0, 10, 20 and 40 kg Zn ha^-1 under varying cellulose and water management conditions was studied in a greenhouse experiment. Typical zinc deficiency symptoms, varying in intensity among varieties, were nted, especially in the zero applied zinc treatments. Zinc deficiency symptoms were characterised by blanching at the base of the emerging leaves and rusty brown discolouration in the older leaves.

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