Agroecosystem Performances of Livestock Farms in a Mountain Area of Sicily

Agroecosystem performance indicators (APIs) represent instruments for studying agroecosystem performance via an input/output approach and a knowledge base, with the aim of improving the sustainability level of the farm\u27s activity (Tellarini & Caporali, 2000). This research used APIs to evaluate the influence of stocking rate on the performance (in terms of energy) of farms in a mountainous area of northern Sicily, Italy

The Timing of Daily Grazing on Annual Ryegrass or Sulla Forage: The Effects on Milk Yield and Composition of Comisana Ewes

The timing and duration of grazing greatly affect the response of animals. Night grazing, in addition to grazing during the day, seems to be one of the most important practices for improving animal performance (Bayer et al., 1987). Many authors have already underlined the major benefits of night grazing, such as improved body condition, reduced heat stress, increased forage intake and milk production. However, labour constraints, insecurity, damage to crops by animals are considered as the main reasons for not practising day and night grazing. The aim of this research was to improve knowledge about the effects of daily grazing time in ryegrass or sulla forage on milk yield and composition of Comisana ewes

Effect of defoliation management and plant arrangement on yield and N2 fixation of berseem-annual ryegrass mixture

The research was carried out in a Mediterranean semi-arid environment on berseem clover, annual ryegrass and their mixture to study the effect of defoliation management [date of \ufb01rst cut (FC) 85, 119, 140, 169 days after sowing] and different plant arrangements (sowing the two components in alternate rows or in the same row) on yields, N content, N2 \ufb01xation and N transfer. The experimental design was a split-plot with four replications. The 15 N isotope dilution technique was used (8 kg N ha \u20131 as ammonium sulphate at 10 atom% 15 N excess) to evaluate the N2 \ufb01xation. Total seasonal DM yield was, on average, signi\ufb01cantly higher for FC119 and FC140 (approx. 12.3 t ha \u20131 ) than for FC85 and FC169 (approx. 10.6 t ha \u20131 ). Plant arrangement did not signi\ufb01cantly in\ufb02uence total yield of the mixture. However, the legume yield was higher (+20%; P<0.0001) in the same row than in alternate rows arrangement. N content of ryegrass was signi\ufb01cantly higher in the mixtures than in pure stand and in the \u2018same row\u2019 plant arrangement than in the \u2018alternate rows\u2019. Intercropped berseem always had a signi\ufb01cant higher % of Ndfa than the monocropped one (on average 74.7% and 57.7% respectively). The apparent transfer of \ufb01xed N from berseem to ryegrass was not detected in either plant arrangement

Forage Quality and Yield of Berseem Clover and Annual Ryegrass Grown in Pure and Mixed Stands in Relation to Different N Application Rates

Grass-legume mixtures offer several advantages over monocultures in forage-animal production systems (Haynes, 1980). In fact, in grass-legume mixtures forage yield and quality are generally higher compared to grass monocultures also due to more efficient soil N-utilisation (Ta & Faris, 1987); furthermore grasses often utilise some of the N fixed by legumes (Malhi et al., 2002). Legumes do not generally require the addition of N fertiliser due to symbiotically fixed N, but the yield of the grass component in a mixture may be further improved with N application. The objective of this study was to investigate forage yield and quality of berseem and annual ryegrass grown in pure stands, and in mixture, at different N fertiliser rates

Trees and shrubs as sources of fodder in Australia

Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline

Effects of stubble height and cutting frequency on regrowth of berseem clover in a Mediterranean semiarid environment

Defoliation management of forage crops affects endogenous reserves (in the root and in the stubble), the residual leaf area, and, consequently, the regrowth and biomass yield. The aim of this study was to evaluate the effect of cutting frequency (28-d vs. 35-d intervals) and stubble height (3 vs. 6 cm) on forage yield, regrowth, and persistence of berseem clover (Trifolium alexandrinum L.). Neither cutting interval nor cutting height affected plant survival during the crop cycle. Frequent clipping reduced crop yield. Residual biomass and leaf area were less when plants were cut at a height of 3 cm compared with 6 cm, but stubble height did not affect the total amount of dry matter (DM) removed. However, with a cutting interval of 28-d, DM yield was greater with a stubble height of 6 cm compared with 3 cm, whereas stubble height generally had no effect with a cutting interval of 35-d. This study shows that severe defoliation, which substantially reduces residual photosynthetic area, forces berseem clover plants to mobilize reserves from the taproot. With frequent clipping, taproot reserves are depleted and regrowth is impaired, whereas less frequent clipping enables taproot reserves to be restored. In contrast, less severe defoliation, which results in a considerable residual leaf area, promotes rapid regrowth regardless of the frequency of defoliation

Productivity and canopy modification of Medicago arborea as affected by defoliation management and genotype in a Mediterranean environment

Medicago arborea is one of the most potentially valuable fodder shrubs in a Mediterranean environment because of its high preference by small ruminants and its nutritive value. Edible biomass production is affected by agronomic and environmental factors. A study, carried out in an inland area of Sicily in the growing seasons of 1994/95, 1995/96 and 1996/97, evaluated the forage production and canopy modification in a M. arborea plantation after (i) commencing defoliation 1 or 2 years after transplanting and (ii) defoliating only in autumn (A), only in early summer (S) or in both seasons (A and S). Six clones derived from five different Mediterranean populations were used. Plant age at the first defoliation did not significantly influence forage production. The genotypes differed in growth rate and forage production. The season and frequency of defoliation markedly influenced forage production and canopy size. The highest annual production was obtained by defoliating once a year in early summer (on average, 1Æ65, 2Æ85 and 4Æ50 tonnes ha)1 respectively in the three growing seasons). With the A and S, and A defoliation treatments, production decreased over 3 years by, on average, 0Æ19 and 0Æ57 respectively, but the differences became more marked over a 3-year period. Defoliating only in early summer, however, resulted in an excessive shrub height (>120 cm, 3 years after transplanting), thereby increasing problems of accessibility to small grazing ruminants, and possibly necessitating cutting. On the contrary, the A and S defoliation made it possible to limit the height to <90 cm