Fertilization of Unreduced Female Gametes: A Technique for Genetic Enhancement within the Cenchrus-Pennisteum agamic Complex

Genetic enhancement programmes In apomictic species require either the identification of obligate sexual genotypes or facultative apomicts with high levels of sexuality.- Fertilisation of unreduced eggs (2n+n hybridisation) which occurs frequently within agamic complexes has received little attention as a method for breeding apomictic species. This paper describes attempts to obtain 2n+n hybrids within the Cenchrus-Penniseltim agamic complex. Both inter- and intraspecific n+n and 2n+n hybrids have been obtained using facultative accessions of C. ciliaris or P. flaccld11m as female parents. Interspecific 2n+n hybrids, which have been recovered at frequencies approaching 3%, are typically more fertile than interspeclfic n+n hybrids. Evaluation of 2n+n hybrids has indicated that this may be a useful technique for breeding apomictic species where sexual genotypes are not available to make conventional crosses

Herbage Intake, Digestibility Characteristics and Milk Production of a Diploid and Two Tetraploid Cultivars of Perennial Ryegrass

In a rotational grazing experiment with dairy cows on monocullures of a diploid and 2 tetraploid cultivars of perennial ryegrass (Lolium perenne L.), at a high herbage allowance the average daily production of fat and protein together was significantly higher on the tetraploids. This was associated with a difference in herbage intake of on average 0.6 kg/cow/day of organic matter and a higher concentration of volatile fatty acids and a lower pH in the rumen

Building Rural Resilience: A Rural and Farm Youth Safety and Well-being Curriculum

Mental health is a growing concern in today’s youth (CDC, 2023). The suicide rates in youth have been on a rise, increasing the need for mental health literacy (CDC, 2023). Mental health is often neglected in people’s lives, especially in rural areas (Boyd et al., 2008). This study answers four research questions: 1) Has the Building Rural Resilience: A Rural and Farm Youth Safety and Well-being Curriculum increased students\u27 knowledge to recognize stress factors among rural communities and farmers? 2) Has the Building Rural Resilience: A Rural and Farm Youth Safety and Well-being Curriculum increased students\u27 knowledge to recognize stress factors in their life? 3) Has the Building Rural Resilience: A Rural and Farm Youth Safety and Well-being Curriculum increased students\u27 knowledge to recognize the impact stress factors has on their body and mind (i.e., stress awareness)? 4) Has the Building Rural Resilience: A Rural and Farm Youth Safety and Well-being Curriculum increased students\u27 ability to manage their stress? The purpose of this study was to analyze student’s increased knowledge on the topics of recognizing farm stress, recognizing youth stress, recognizing the impacts stress has on their body and mind, and ability to manage stress in their lives before and after participating in the BRR curriculum. The 5-day curriculum was taught in three rural high schools in Kentucky. The study used a pre/post-test to answer each of the four research questions. There were 29 participants who completed the pre-test and 20 participants who completed the post-test. The results of the evaluation showed an increase in mean and an increase in the percent of change from the pre and post-test for the set of questions assessing student’s knowledge of stress and the set of questions assessing student’s knowledge on stress in rural communities and farmers. The results also showed a decrease in mean and a decrease in the percent of change from the pre and post-test for the set of questions assessing the impact of stress and the set of questions assessing stress management. The increase in the percent of change shows the curriculum was affective while the decrease in the percent of change shows the weak points of the curriculum and/or the evaluation

Effects of Increasing Stocking Rate and Feeding Maize Silage on Live-Weight Gain and Pasture Utilization by Beef Cattle in Southern Australia

Two systems of grazing management were compared in 3 trials conducted on annual or irrigated perennial pastures over different seasons in northern Victoria, Steers grazed either at low stocking rates or at high stocking rates together with maize silage feeding, The more intensely grazed steers grew faster on autumn perennial pastures but at similar rates to steers at low stocking rates on winter­spring annual and on spring perennial pastures, Higher stocking rates increased live-weight gain per ha by 90% on winter-spring annual pastures, 101% on autumn perennial pastures and 53% on spring perennial pastures. This was associated with improvements in utilisation of the perennial pasture by 60% in autumn and 39% in spring. Because of the high frequency of wet winters, the feasibility of opportunity feedlotting was investigated with 2 maize silage­based diets. The Inclusion of 48% wheat increased growth rates from 0.93 to 1.33 kg/day in finishing steers. These results show the potential for maize silage to be incorporated into year-round, pasture-based beef finishing systems in southern Australia

A Response of Angora-Type Goats to Increases of Legume and Chicory Content in Mixed Pastures

Live-weight gain of angora-type year-old wethcr goats in the spring and summer of 2 years was compared with the total legume and chicory content of 9 different grass, legume, chicory ( Cichorium intybus) mixtures. These pastures were grown in a cool moist temperate climate on fertile silt loam soil. The goats were held on a self• contained rotationally grazed system on each pasture type, leaving a post-grazing residual height of 10 cm. The live-weight gain of the goats responded quadratically to increasing legume and chicory content in both spring and summer. Live-weight gain was optimised when approximately 40% of the herbage on offer before grazing was legume and/or chicory, with little increase in live-weight gain above this. Although mean live-weight gain in spring (116 g/hcad/day) was higher than in summer (57 g/head/day) the shape of the curves was similar in both seasons. Most of the variation in live-weight gain between years was explained by the changing legume and chicory content in the pasture mixtures

Integrating Pasture Technology Research with Farm Management

An applied research programme which involved farmers in a continuum of trials measuring pasture, soil and milk responses to the application of nitrogen fertiliser to tropical grasses is described. Pasture responses were consistent across farms, grass species and, within limits, rainfall zones and soil types. Soil pH declined by 0.03 lo 0.2 units each year. Additional milk production ranged from 4 to 14 I/kg nitrogen, the response being greater at lower levels of application. Results from farm and research station experiments were consistent. The high adoption rate, reaching 68% in 6 years, was \u27 attributed to the integration of farm trials in the research programme

Changes to Sheep Grazing Systems in Response to Climate Change

Simulation models were used to predict changes in pasture growth and sheep farming systems as a result of changes in climate due to global warming. The results of long•lerm mean climate and 10 years\u27 individual climate simulations show Iha! increases in stocking rate of up to 40% may be possible with climate change. Benefits of climate change included increased lamb carcass weight and pasture cover. Climate change also resulted in the feasibility of autumn lambing systems in an environment in which these systems are currently difficult lo maintain. A change from 100% spring lambing to 40% of the flock lambing in the autumn resulted in even larger increases in lamb carcass weight and the lamb kill was spread over n greater part of the year, Both of these may be of benefit lo the meat industry. However, there appeared 10 be lillle difference in the profitability of spring or autumn lambing systems as the benefits were balanced by lower stocking rate and the costs of inducing ewes to cycle

Effects of Defoliation Height and Time of Initital Defoliation on Regrowth Components in a Poa pratensis- dominated sward

Two experiments on swards dominated by Poa pratensis L. were conducted in 2 climatically contrasting (wann/dry and cold/wet) years. There were either 4 or 3 initial defoliation dates in spring and 3 defoliation heights (2, 6 and 10 cm). Regrowths were harvested 4 weeks after the initial defoliation. The swards received a total of 80 kg/ha nitrogen split into 2 dressings. Regrowth characteristics, based on samples cut to ground level, depended on weather conditions. The yield of vegetative shoots was affected most by shoot size, which in turn was determined by initial defoliation date, in the dry year. In the wet year, however, the factor most influencing yield was shoot number, which increased with close defoliation, Close spring defoliation resulted in the lowest production of reproductive tissues. Neither the time of initial defoliation in spring nor the defoliation height had any impact on the total production of vegetative shoots in the wet year

Persistence of Phalaris aquatica L. in Response to Grazing

Cultivars of phalaris (Plialaris aquatica L.) bred in Australia for seedling vigour and winter activity are reported to be less persistent in response to heavy_ grazing than the original introduction, cv. Australian. In an experiment comparing the morphological characters of cultivars, Australian was shown to possess a morphology well adapted to grazing. In contrast, the bred cultivars formed more erect pastures with low basal area, more prone to invasion by annual grasses and retaining less leaf area after grazing. In a second experiment, sheep displayed preference during July for grazing the winter-active cultivar Sirosa over cv. Australian, probably because of the more erect, accessible tillers and greater herbage on offer of cv. Sirosa, Preferential grazing of the bred cultivars in winter and of all cultivars in spring, when competing annual grasses are heading, may be an additional factor affecting persistence. The bred cultivars of phalaris may benefit from rotational grazing during winter to assist recovery after grazing and to allow greater herbage mass to accrue from their improved winter activity