Master of Science / Department of Animal Sciences and Industry / K C Olson / Eight native tallgrass pastures infested with sericea lespedeza (initial basal frequency = 2.9 ± 2.74%) were grazed by yearling beef steers (n = 279 / yr; 1.1 ha / steer) from 15 April to 15 July for 2 grazing seasons. Subsequent to steer grazing, mature ewes (n = 813 / yr) were allowed to graze 4 of the 8 pastures (0.15 ha / ewe) from 31 July to 1 October. Remaining pastures were rested until the subsequent April. Animals were allocated randomly to pastures annually; grazing treatments remained fixed for the 2-yr experiment. Four permanent 100-m transects were laid out in a north-south gradient in each pasture. Beginning 1 May, steer diet composition was monitored by collecting 5 fresh fecal pats along each transect at 2-wk intervals until steers were removed on 15 July. Fecal pats were dried and ground individually and then composited by weight within transect. Twenty-five mature ewes from each pasture were randomly selected to monitor diet composition. On 15 August and 15 September, ewes were gathered and restrained; fecal grab samples were then collected from the individuals selected for diet composition analysis. Microhistological analysis was conducted on steer fecal composites and fecal samples from individual ewes, using pure samples of 17 predominant grass, forb, and browse species from the experimental site as reference standards. Fecal and standard samples were prepared for microhistological analysis and viewed using a compound microscope at 100x magnification. Botanical composition of pastures was measured in October and compared with botanical composition of yearling beef steer and mature ewe diets. Diet selection exercised by yearling steer and mature ewes was evaluated using Kulcyznski’s Similarity Index. Proportions of bare soil, litter cover, and total basal vegetation cover did not differ (P ≥ 0.38) between pastures for either steer or sheep diet evaluations. Similarly, basal cover of the 17 plants selected as microhistological standards did not differ (P ≥ 0.07) between pastures for either steer or sheep diet evaluations. The proportions of total graminoids and total forbs and forb-like plants in the diets of grazing steers were not different (P = 0.37) between sampling periods and were interpreted to indicate steer diets were strongly dominated by graminoids (≥ 88.4% of diets). Yearling beef steers consistently exhibited strong preference (i.e., ≤ 6% similarity with pasture composition) for Bouteloua gracilis, Bouteloua dactyloides, Dalea purpurea, and Liatris punctata, whereas they strongly avoided Lespedeza cuneata and Symphyotrichum ericoides. The proportions of total graminoids and total forbs and forb-like plants in the diets of grazing ewes were not different (P = 0.67) between sampling periods and were interpreted to indicate that mature ewes selected consistent proportions of grasses and forbs over time (average = 58 and 42% of diets for grasses and forbs, respectively). Mature ewes consistently exhibited strong preference (i.e., ≤ 10% similarity with pasture composition) for Bouteloua gracilis, Bouteloua dactyloides, Dalea purpurea, Liatris punctata, Vernonia baldwinii, and Ambrosia artemisiifolia. None of the 17 microhistological reference standards were consistently avoided by ewes.

Matua prairie grass has a potential to extend the grazing season in Virginia due to its higher early spring and fall production. However, little is known about the compatibility of Matua prairie grass with legumes or the effects of legumes on the yield and quality of Matua prairie grass/legume mixtures. An experiment was conducted in 1998 and 1999 to investigate the botanical composition, yield, and chemical composition of Matua prairie grass grown with legumes. Legume treatments consisting of ladino clover (Trifolium repens), red clover (Trifolium pratense), alfalfa (Medicago sativa), and annual lespedeza (Lespedeza stipulacea) were drilled into a Matua prairie grass stand. Nitrogen was applied once each fall at two treatment levels of 0 or 84 kg/ha. The experiment was arranged in a randomized split block design with four replications. Legume treatments had no effect on percentage Matua prairie grass or total dry matter yield in 1998. However, in 1999 the ladino clover and red clover treatments increased (P<0.05) total dry matter yield, but also resulted in a substantial decrease (P<0.05) in percentage Matua prairie grass. Nitrogen application in the fall of 1998 had a residual effect (P<0.05) on the percentage Matua prairie grass and yield in 1999. The highest response to nitrogen fertilization occurred in the harvest immediately after fertilization, in October of 1999, which resulted in the largest increase (P<0.05) in percentage Matua prairie grass and yield, and the greatest decrease (P<0.05) in percentage legumes. The legume and nitrogen treatments similarly influenced the chemical composition of the Matua prairie grass/legume mixed forage. Ladino clover, red clover, and alfalfa treatments generally improved forage quality as indicated by a decrease (P<0.05) in NDF, ADF, hemicellulose, and cellulose, and an increase (P<0.05) in CP and IVDMD. Nitrogen fertilization did not influence the chemical composition of the forages to the same extent as the legume treatments, as a decrease in fiber components and an increase in CP and IVDMD were observed due to nitrogen. Overall, alfalfa appeared to be most compatible with Matua prairie grass, and the incorporation of alfalfa into a Matua prairie grass stand resulted in some improvements in total dry matter yield and nutritive value of the forage, without the detrimental suppression of Matua prairie grass. / Master of Science

Tyrimai daryti 2008 - 2009 Lazdijų rajone Šventežerio kaime, E. Jastramsko ekologiniame ūkyje. Ūkio plotas 120 ha iš jų – 40 ha nuosavos ir 80 ha nuomojamos žemės. Dirvožemio našumo balas yra nuo 33,5 iki 46. Edmundo Jastramsko ūkis įkurtas 1989 m. pagal valstiečių ūkio įstatymą. Pagrindinė ūkio kryptis yra augalininkystė. Specializuojasi ekologiškų rapsų aliejaus spaudime, bei realizavime. Koncentruojamasi į ekologinės sėklininkystės, aliejinių kultūrų auginimą. Pastaraisiais metais vystoma mėsinė galvijininkystė (20 mėsinių galvijų), todėl ūkyje plėtojama ganyklų, bei kultūrinių pievų pašarų gamyba. Žolynų botaninė sudėtis priklausė nuo jų intensyvumo. Ekstensyviame žolyne didžiausią dalį (82 %) sudarė įvairiažolės. Varpinių žolių sudėtyje dominavo (16,7 %) paprastosios šunažolės, o ankštinių žolių praktiškai nebuvo. Paviršiniu būdu pagerintame žolyne rasta (7 %) ankštinių žolių. Varpinių žolių bendrijoje dominavo (34 %) paprastosios šunažolės, o įvairaižolės užėmė pusę žolyno ploto. Persėtame žolyne ankštinės žolės sudarė (39, 4 %) varpinių žolių sudėtyje daugiausiai (20,1 - 19,56 ir 14,0 %) buvo daugiamečių svidrių, paprastųjų šunažolių ir pievinių miglių, o įvairiažolių praktiškai nerasta. Skirtingo intensyvumo žolynų pašarinė vertė buvo nevienoda: ekstensyvaus žolyno vidutinė pašarinė vertė buvo 5,18, paviršiniu būdu pagerinto žolyno 6, 22 o persėto žolyno 9, 46 balai. Žolynų pašarinė vertė tiesiogiai priklausė nuo žolyno botaninės sudėties. Tarp šių rodiklių... [toliau žr. visą tekstą] / Studies have been made 2008 - 2009 Lazdijai Sventezeris countryside, E. Jastramskas ecological farm. An area of 120 hectares of them - own 40 hectares and 80 hectares of land leased. Soil productivity is the score from 33.5 before the 46 th Edmundas Jastramskas farm was established in 1989 Peasant Agriculture under the law. After the restoration of 20.20 hectares of public land parents. The main direction of agricultural crop production. Specializes in organic rapeseed oil extraction and realization. Concentrating on organic seed, oilseed crops. Developed in recent years, beef cattle (20 beef cattle), and the development of the farm pastures, grasslands and fodder production. Herbage botanical composition depended on the intensity. Extensive Grass largest share (82%) were forbs. Composition dominated by grasses (16.7%), orchard grass, and legumes were not practical. Surface-enriched grassland found a way (7%) and legumes. Community dominated by grasses (34%), orchard grass, and took half of miscellaneous grassland area. Newly sown grass legumes were (39, 4%) grass containing the most (20.1 to 19.56 and 14.0%) were perennial ryegrass; orchard grass and meadow grass, but in practice forbs found. Differences in herbage nutritive value of intensity have been uneven: in extensive grassland average nutritive value of 5, 18, the surface by improved grassland 6, 22, and the sward newly sown 9,46 points. Herbage nutritive value depended on the botanical composition of... [to full text]

Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv. / Härtill 7 uppsatser.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Doctor of Philosophy / Department of Animal Sciences and Industry / K C Olson / The objective of this series of studies was to examine select factors that affect behavior of beef cattle grazing native-tallgrass rangelands. Mineral supplements with divergent palatability characteristics were delivered to beef cows grazing native tallgrass range during various seasons of the year in order to measure mineral intake, frequency of supplement use, and duration of supplement use. We concluded that molasses-based mineral supplements influenced the activities of grazing cows more strongly than salt-based mineral supplements. These influences extended to the amount of supplement consumed as well as to the frequency, duration, and timing of use. Diet selection preferences of experienced, multiparous beef cows and naïve, primiparous beef cows grazing dormant, native tallgrass pastures were examined also during a short-term winter grazing bout. Naïve, primiparous cows selected more forbs and fewer grasses than experienced, multiparous cows. Previous research indicated that preference for broadleaf plants generally increased with grazing experience; however, these conclusions were based on research with greater-quality forages than those evaluated in our study. The differences in diet selection patterns between experienced, multiparous cows and naïve, primiparous cows during a short-term winter grazing period could be indicative of differences in long-term foraging strategies. In addition, the botanical composition of diets grazed by lactating beef cows with suckling calves and non-pregnant, non-lactating beef cows grazing either burned or unburned native tallgrass prairie during summer were evaluated. There were no differences in botanical diet composition between lactating cows suckling calves and non-lactating cows. In contrast, total graminoid selection was greater on burned (74.2%) than unburned pastures (71.8%) and total forb selection was greater on unburned (28.2%) than burned pastures (25.8%). We interpreted these data to suggest that forage selection preferences of beef cows can be altered with spring burning of native tallgrass pastures. Effects of large, round hay bale feeding method on intake of smooth bromegrass hay and eating behavior by beef cows were examined on dormant tallgrass prairie pastures during winter. Three large, round hay bale-feeding systems were evaluated: bales fed in a ring feeder, bales unrolled on the ground, and bales chopped with a flail-type hay processor (20-cm particle length) and deposited on the ground. Hay intake, hay refusal, frequency of use, and duration of use were not influenced by hay-feeding method. Foraging behaviors of beef cows in our studies were influenced by supplement type, cow age, and prescribed burning of rangeland. Conversely, foraging behaviors of beef cows were not influenced by lactation or by hay-feeding method.

Master of Science / Department of Agronomy / Walter H. Fick / Patch-burn grazing is a relatively new concept in terms of rangeland management. While numerous benefits have been associated with this system, in the tallgrass prairie of Kansas, cattle production and sustainability of rangeland are critical. In 2006, 253 ha at the KSU Bressner Range Research Unit in Woodson County, Kansas were subjected to spring patch-burn grazing (using one-third portions) and traditional full-burn grazing. Each treatment within the split-block design was replicated four times for 3 years. The objectives were to evaluate whether livestock performance would be compromised under this grazing system, to monitor the health of the rangeland, and to observe the usefulness of this tool as a potential control of the invasive plant sericea lespedeza [Lespedeza cuneata (Dumont) G. Don]. In regards to cattle performance, burn treatments had no significant difference in average daily gain (p≥0.10) in any of the 3 years. On average, cattle utilized 61% of the current year’s forage production in patch-burned portions, which was higher (p≤0.10) than that of unburned (30%) and full-burn (41%) portions. Results of the botanical composition show forb and woody plant composition did not differ between treatments, however differences (p≤0.10) were present in grass composition. Total annual grasses increased 19.1 percentage units under patch-burn and 2.1 units under full-burn, while total perennial grasses decreased 18.4 and 1.1 units, respectively. When evaluated by treatment area (one-third portion), results indicated that the 3-year cycle did allow enough time for recovery. At 2 years after treatment (2-YAT), no significant difference in composition(p≥0.10) was present between initial patch-burn portions and the full-burn pastures. Finally, in only 1 year of the study did cattle statistically consume a greater percentage of sericea lespedeza plants (p≤0.10) in the patch-burned portions (92%) than in full-burned pastures (35%). Biomass utilization did not differ (p≥0.10) between burn treatments. Surprisingly, there was a trend for the number of plants in the sampled areas of the patch-burn portions to decrease throughout the cycle. However, at the conclusion of the 3-year cycle, sericea densities did not differ(p≥0.10) between treatments. Patch-burn grazing shows promise as a potential management tool for Kansas land managers.

Após a estabilização da economia na década de 1990, o cenário que vem se consolidando indica claramente o estabelecimento de mercados livres e competitivos, o que conseqüentemente, exige setores eficientes nas diversas atividades. Nesse contexto, a demanda por tecnologia tende a aumentar e, apesar da intensificação, a utilização de pastagens como principal componente da dieta dos rebanhos de animais ruminantes deverá ter o seu lugar de destaque, por ser esta a forma mais econômica de fornecer alimento aos animais. Desse modo espécies de alto potencial forrageiro como a alfafa (Medicago sativa L.), podem ser opções para melhorar a produtividade de forragem e o desempenho animal, pois associam elevada produção com alto valor nutritivo. De março de 2001 a fevereiro de 2002, foi estudado o efeito do método de pastejo sob o acúmulo de forragem total (AFT), o índice de área foliar (IAF), a interceptação luminosa (IL), e os determinantes morfofisiológicos da persistência de cinco genótipos de alfafa num Kandiudalfic Eutrudox. Um experimento do tipo "mob-grazing" foi realizado em área do Departamento de Zootecnia da ESALQ/USP, em Piracicaba, SP. O delineamento experimental foi o de blocos completos casualizados, com parcelas subdivididas (split-plot), com 10 tratamentos e 6 repetições, totalizando 60 unidades experimentais. Nas parcelas foram alocados o fator de tratamento relativo ao método de pastejo ("lotação contínua", simulada por desfolhas semanais, e "lotação rotacionada" com desfolha a cada 4 semanas na primavera-verão e a cada 6 semanas no outono-inverno). Nas sub-parcelas foram alocados os cinco genótipos de alfafa com diferentes aptidões agronômicas em termos de dormência, adaptação local e tolerância ao pastejo (ABT-805, Alfagraze, Crioula, CUF-101 e Pioneer 5432), submetidos a 295 dias de pastejo e sob irrigação. ABT-805 foi o cultivar mais produtivo sob lotação contínua (26,6 Mg MS ha -1 ano -1 ) e no pastejo rotacionado (18 Mg MS ha -1 ano -1 ) e quem teve o maior IAF médio (2,1) e o máximo valor de IL médio (53%) ao longo do experimento, sob pastejo rotacionado. Alfagraze, apesar de ser um dos menos produtivos no pastejo rotacionado (13,3 Mg MS ha -1 ano -1 ) foi semelhante em produção com o ABT-805, no pastejo com lotação contínua (26,3 Mg MS ha -1 ano -1 ), com um IL médio de 47% e valores médios de IAF de 1,1 e 1,8 para o pastejo com lotação contínua e rotacionado, respectivamente. Pioneer 5432, situou-se numa condição intermediária, com um IL médio de 49%, produção total de forragem de 24,3 e 15,3 Mg MS ha -1 ano -1 e valores médios de IAF (0.98 e 1,76) para a lotação contínua e rotacionada, respectivamente. O cultivar com melhor persistência, sob lotação contínua foi o Alfagraze com 26% de sobrevivência, enquanto sob lotação rotacionada foi o ABT-805 com 44,9%. Dos cultivares dormentes não adaptados ao pastejo, CUF-101 foi o que revelou menor persistência. Duzentos e dez dias após o inicio do pastejo, sob lotação contínua, havia somente 9,6% de alfafa na massa de forragem pré-pastejo, indicando nessa data o que aconteceria com o estande de plantas ao final do experimento. Trezentos e vinte e cinco dias após o início do pastejo, Alfagraze, ABT-805 e Pioneer 5432 apresentaram valores médios de teores e estoques de CNE em raízes e coroas, em torno de 221 e 112,9 g kg -1 MO e de 406 e 210,7 g m -2 , respectivamente. Sob lotação contínua, os estoques de CNE sofreram drástica redução nas raízes (79,8%) e coroas (84,7%) de alfafa, e em torno de 46 e 59%, respectivamente quando foi sob lotação rotacionada. Cultivares tolerantes ao pastejo tiveram valores médios de teores e estoques de nitrogênio total, nas raízes e coroas, em torno de 168,9 e 231,2 g kg -1 MO e de 331,6 e 326,9 g m -2 , respectivamente. ABT-805 e Alfagraze parecem ser produtivas e moderadamente adaptadas ao pastejo nas latitudes tropicais do Brasil Central, mas o seu uso bem sucedido dependerá das condições climáticas e do método do manejo do pastejo. / With the stabilization of the Brazilian economy in the 1990s, the establishment of competitive free markets has pushed most activities toward the need for professionalization and increased efficiency. The demand for technology is growing and despite the ever rising intensification in the livestock industry, it is likely that grazed forages will continue to be main component of ruminant diets and key to the system as a whole, as it represents a low-cost feeding alternative. The adoption and the efficient utilization of forage species with both high yield potential and high nutritive value, such as alfalfa (Medicago sativa L.) may enhance animal performance and productivity. From March 2001 through February 2002, the impact of grazing method was studied on plots of five alfalfa genotypes on a Kandiudalfic Eutrudox in Piracicaba, SP. Responses measured included total and seasonal herbage accumulation, leaf area index (LAI), light interception by the canopy (LI), plant survival, weed encroachment, stand counts and reserve status (concentrations and pools of total non-structural carbohydrates, TNC, and nitrogen, N) in plant roots and crowns. An irrigated mob-grazing study was conducted in a randomized complete block design with six replications and a split-plot arrangement. Treatments included all possible combinations among two grazing methods as whole plot factor (continuous stocking, simulated by weekly grazing of plots year-round; and rotational stocking, simulated by grazing plots every four weeks during the "wet/wam" season and every six weeks during the "dry/cool" season; plots were grazed down to 7 cm each time) and five alfalfa genotypes (sub-plot factors), represented by commercial cultivars with varying agronomic characteristics regarding dormancy class, origin, and grazing tolerance (ABT-805, Alfagraze, Crioula, CUF-101, and Pioneer 5432). Plots were grazed for 295 days. ABT-805 was the highest yielding genotype both under continuous (26.6 Mg DM ha -1 yr -1 ) and rotational (18 Mg DM ha -1 yr -1 ) stocking. It also had the highest mean LAI (2.1) and mean LI (53%) throughout the experikental period under rotational stocking. Alfagraze, although among the lowest yielding genotypes under rotational stocking (13.3 Mg DM ha -1 yr -1 ) sustained similar total forage accumulation to that of ABT-805 under continuous stocking (26.3 Mg DM ha -1 yr -1 ), with a mean 47% LI and mean LAI between 1.1 and 1.8 for continuous and rotational stocking, respectively. Pioneer 5432 responded with a mean 49% LI, total seasonal herbage accumulation of 24.3 and 15.3 Mg DM ha -1 yr -1 and mean LAI of 0.98 and 1.76 under continuous and rotational stocking, respectively. Genotype performance was variable regarding the final stand counts, plant survival, percent alfalfa in pregraze forage mass, and in the concentration and pool of total non-structural carbohydrates (TNC) and total nitrogen (N) in roots and crowns of alfalfa plants. Crioula and CUF-101 did not survive through the end of the trial, under either grazing method. Alfagraze showed the highest persistence under continuous stocking, with stand counts falling from 245.7 to 63.9 plants m -2 (26% survival). Under rotational stocking, ABT-805 had the highest persistence, with plot stands declining from 250 to 112.3 plants m -2 , a 44,9% survival rate. Among the dormant, non grazing tolerant cultivars, CUF-101 showed the poorest persistence. Two hundred and ten days after initiation of grazing, there was a mean 9.6% alfalfa in the total pregraze forage mass, a harbinger of the general degradation of the plot stands which materialized at the end of the experimental period. Three hundred twenty five days after the trial started, Alfagraze, ABT-805 and Pioneer 5432 stored TNC, in roots and crowns, respectively, with concentrations of 221 and 112.9 g kg -1 OM and pools of 406 and 210,7 g m -2, respectively. Mean TNC pools were reduced by 79.8% in roots and by 84.7% in plant crowns when plots were under continuous stocking and by 46 and 59%, respectively, under rotational stocking. Grazing tolerant cultivars accumulated N reserves in roots (168.9 g kg -1 OM, for pools of 331.6 g m -2 ) and crowns (231.2 g kg -1 OM, for pools of 326.9 g m -2 ). ABT-805 and Alfagraze seem to be productive and moderately adapted to grazing in the tropical latitudes of central Brazil, but their successful use will depend on climate and choice of grazing management method.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.