The Production Potential of \u3cem\u3eFestuca\u3c/em\u3e spp., \u3cem\u3eLolium\u3c/em\u3e spp. and Festulolium Hybrids in the Southern Cape of South Africa

Researchers are continuously searching for species that can improve the productivity and sustainability of pasture systems under adverse environmental conditions such as drought and extreme temperatures. Plant breeders have bred hybrids between ryegrass (Lolium spp.) and Fescue (Festuca spp.) in an attempt to combine the high forage quality of the former with the stress tolerance of the latter (Kopecky et al., 2008; Akgun et al., 2008). The resultant hybrids are commonly referred to as Festulolium spp. These species include Festulolium pabulare which is a cross between Tall Fescue (F. arundinacea) and Italian ryegrass (L. multiflorum var. italicum), and Festulolium braunii, which is a cross between Meadow Fescue (F. pratensis) and Italian ryegrass. All hybrids are back-crossed with their fescue or ryegrass parent species to obtain festucoid and loloid varieties, respectively. There is currently limited scientific data describing the production potential of such Festulolium varieties compared to that of ryegrass and fescue under irrigation in the Southern Cape of South Africa. The aim of this study was to determine the dry matter production potential of Festuca spp., Lolium spp. and Festulolium spp. in the southern Cape of South Africa

Seasonal changes in plasma testosterone levels in the male South African hedgehog (Atelerix frontalis)

Testosterone levels in plasma collected ait monthly intervals from 6 to 15 male South African hedgehogs (Atelerix frontalis) housed in captivity showed a marked seasonal pattern. Values were relatively low (< 0,25 ng/ml) from February to June but increased significantly from July to August. Testosterone levels peaked in August (x̄ = 2,85 ± 1,37 ng/ml; n = 15) and December (x̄ = 2,73 ± 0,36 ng/ml; n = 6) remaining relatively high from August to January. This seasonal pattern is similar to that recorded in the European hedgehog (Erinaceus europaeus)

Revisiting Nitrogen Fertilisation Rates of Kikuyu and Kikuyu-Ryegrass Pastures

Irrigated pastures are used for dairy production in South Africa. Minimum-tillage and nitrogen (N) fertilisation are important management practices for kikuyu (Pennisetum clandestinum) and ryegrass (Lolium spp.) pastures. Nitrogen fertiliser application rates as high as 500 kg N ha-1 year-1 have been reported. Conventional tillage as well as cutting and removal of herbage material (opposed to removal through grazing) are the basis on which these fertiliser guidelines were developed. The current management practices have substantially changed the soil organic carbon and N stoichiometry. The aim of this study was to determine an optimum rate of N application of kikuyu and kikuyu-ryegrass pastures. Five fixed N fertiliser rates (0, 20, 40, 60 and 80 kg N ha-1 grazing cycle-1) were evaluated. Soil characteristics and pasture performance were monitored over a two year period. Nitrate concentrations and total mineral soil N were substantial, compared to the control, when more than 40 kg N ha-1 grazing cycle-1 were applied, leading to potential losses to the environment. Differences in biomass production were mostly due to seasonal variation, while N treatment effects within a season were generally small. As N treatments increased on both the study sites, the self-sown clover component decreased. Agronomic nitrogen use efficiency was similar across treatments and seasons on both sites, with the exception of winter in the first year on the kikuyu-ryegrass site. The results indicate that the soil could be saturated with N, at least to a point where herbage production response is minimal. A positive response in terms of crude protein was observed in some of the higher N treatments, but up to a point where it was no longer favourable for milk production. It is therefore concluded that the current N guidelines needs to be revisited as they pose a risk to the environment and farm economics

The Production Potential of Kikuyu (\u3cem\u3ePennisetum clandestinum\u3c/em\u3e) Over-Sown with Ryegrass (\u3cem\u3eLolium\u3c/em\u3e spp.) in a No-Till System

Pastures for milk production in the southern Cape of South Africa are based on no-till systems where kikuyu (Pennisetum clandestinum) is over-sown with ryegrass during autumn to improve seasonal pasture production and forage quality. The aim of the study was to quantify the pasture and milk production potential of kikuyu over-sown with Italian ryegrass (Lolium multiflorum var. italicum), Westerwolds ryegrass (L. multiflorum var. westerwoldicum) or perennial ryegrass (L. perenne). The study was conducted for 2 years on existing kikuyu pastures grazed by Jersey cows. Growth rate, dry matter (DM) production, botanical composition, forage quality, grazing capacity, milk composition and milk production were determined. Whilst each pasture type reached their peak growth rates during different months, the perennial ryegrass treatment maintained DM production during periods when the remaining pastures experienced a decrease in production. As a result, perennial ryegrass pasture maximised annual DM production and annual grazing capacity, and achieved a more constant grazing capacity. The butterfat and milk production per lactation were lowest for the perennial ryegrass treatment, but it recorded the highest milk production per ha. As ambient temperatures increased from winter to summer, the proportion of kikuyu increased for all pastures as did the DM and NDF content, although the ME content decreased. In summary, grazing capacity is the determining factor for milk production per ha on kikuyu-ryegrass based systems

The production potential of Kikuyu (Pennisetum clandestinum) pastures over-sown with Ryegrass (Lolium spp.)

Kikuyu (Pennisetum clandestinum) is highly productive during summer and autumn and capable of supporting high cattle stocking rates., The winter and spring production of kikuyu, however, is low, while forage quality, and consequently milk production per cow, is also low compared to temperate grass species. The aim of this study was to determine the dry matter yield, botanical composition, nutritional value, grazing capacity and milk production potential of irrigated kikuyu over-sown with Italian ryegrass (Lolium multiflorum var. italicum), Westerwolds ryegrass (Lolium multiflorum var. westerwoldicum) or perennial ryegrass (Lolium perenne) under an intensive grazing system with Jersey cows. Calibrations for the rising plate meter (RPM) were developed for the kikuyu-ryegrass systems. These calibrations were evaluated for seasonal variation, linearity and were also combined over seasons, treatments and years to develop a calibration equation that could be used by dairy farmers in the region. The three kikuyu based pasture systems reached their peak growth rates during different months and seasons. All treatments experienced lower growth rates during winter, while peak growth rates occurred during spring for the Italian ryegrass treatment; summer for the Westerwolds ryegrass treatment and late spring/early summer for the perennial ryegrass treatment. All three treatments had similar total annual dry matter yields (kg DM ha-1) during the first year of the study. However, during year 2 the PR treatment had a higher annual DM production than IR and WR treatments. The ability of the PR treatment to maintain DM production during periods when the other treatments underwent a dip in production (WR during spring and IR during summer) enabled the PR treatment to maintain a higher annual DM production during year 2 than the systems based on annual ryegrass species. As the kikuyu component increased in kikuyu-ryegrass pastures from winter to summer, the DM and NDF content increased, while the ME content decreased. All three treatments were deficient in Ca throughout the study and deficient in P during summer and autumn for high producing dairy cows. The Ca:P ratio was below the recommended ratio of 1.6:1 for high producing dairy cows throughout the study. The grazing capacity of all three kikuyu-ryegrass systems was lower during winter and autumn than during spring and summer. The seasonal grazing capacity of the perennial ryegrass treatment, however, was more evenly distributed than that of the Italian and Westerwolds ryegrass treatments. The perennial ryegrass treatment had a lower butterfat and milk production per lactation than the Italian and Westerwolds ryegrass treatments during both years, but had the highest milk production per ha. The latter was a result of the higher annual grazing capacity achieved by the perennial ryegrass treatment. It was thus concluded that, because kikuyu over-sown with perennial ryegrass supported a higher number of animals and had a more evenly distributed fodder-flow, it allowed for higher animal production per ha than kikuyu over-sown with annual ryegrass varieties such as Italian and Westerwolds ryegrass. The pre-grazing and post-grazing regressions of all three the kikuyu based pastures developed for the RPM differed over seasons and years, primarily due to the change in botanical composition from ryegrass based pastures during winter to kikuyu-based pastures in the summer and the associated change in pasture structure. The post-grazing regressions developed during the study did not have a lower degree of accuracy (R2 values) than the pre-grazing regressions. The generalised RPM regression equations developed for kikuyu-ryegrass pastures (consisting of large data sets pooled over treatments and years) could be of use to farmers in the surrounding area, but are not recommended for research purposes due to the large errors and variation associated with such regressions. In the event that farmers employ these calibrations it is important that pasture type and pasture management practices be similar to those utilised during the study. The decision on which kikuyu-ryegrass system to utilize should be based on the specific conditions prevalent on a particular farm, an economic analysis on and a comparison between the three systems, as well as the particular fodder-flow program requirements within the pasture system.Dissertation (MSc(Agric))--University of Pretoria, 2010.Plant Production and Soil Scienceunrestricte

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The Effect of Planting Date on the Dry Matter Production of Italian and Westerwolds Ryegrass in the Southern Cape of South Africa

Perennial pasture species such as lucerne (Medicago sativa), kikuyu (Pennisetum clandestinum), perennial ryegrass (Lolium perenne) and perennial clovers (Trifolium spp.) make an important contribution to the fodder flow programmes for dairy production in the southern Cape. One of the main challenges when these species make up the primary pasture base within a pasture system is the mutually low growth rates during winter (Van Heerden et al., 1989; Swanepoel et al., 2014). In order to bridge pasture shortages during the critical winter months, producers establish annual Italian (Lolium multiflorum var. italicum) and Westerwolds ryegrass (L. multiflorum var. westerwoldicum) either as pure swards, mixtures or over-sown it into perennial pastures. The production potential and seasonal growth of annual ryegrass varieties are affected by climate and may not follow the same pattern of production as in other regions. The aim of this study was to determine the production potential of Italian and Westerwolds ryegrass planted at different planting dates in the southern Cape of South Africa

Calibration of the Rising Plate Meter for Pasture Yield Determination in Kikuyu (\u3cem\u3ePennisetum clandestinum\u3c/em\u3e) Over-Sown with Ryegrass (\u3cem\u3eLolium\u3c/em\u3e spp.)

Accurate feed budgeting and management of forage in grazing systems requires frequent assessment of forage mass and growth of pastures (Gabriёls and Van den Berg 1993; Sanderson et al. 2001). The rising plate meter (RPM) developed by Earle and McGowan (1979) has been used widely by researchers and farmers to estimate pasture dry matter (DM) production. The advantages associated with using the RPM for the estimation of pasture DM yield include its low sensitivity to environmental conditions, stability of calibration equations across years and seasons (if pasture composition remains similar), and the fact that its robustness and ease of use makes it operator friendly, allowing a large number of readings to be taken in a short period of time (Earle and McGowan 1979; Michell 1982; Fulkerson and Slack 1993, Douglas and Crawford 1994, Martin et al. 2005). There is limited data available for the calibration of the RPM for kikuyu (Pennisetum clandestinum) pastures over-sown with ryegrass (Lolium spp.) and grazed by dairy cows in the Western Cape Province, South Africa. The aim of this study was to evaluate the calibration equations developed using the RPM for irrigated and grazed kikuyu pastures over-sown with ryegrass