As the global population continues to grow, food needs will increase as well. The amount of land and other resources devoted to agriculture production is not expected to grow significantly, leading most to agree that the substantial increases in food production to meet food security needs will come through the development of technologies that improve production efficiency. Diseases are constant threats to efficiency in all segments of agriculture. In livestock production, many of the bacterial pathogens that infect food animals are controlled through the use of antimicrobials. Antimicrobials are currently used in the United States not only to treat specific diseases, but also as feed additives to prevent bacterial disease in general or to improve growth performance. In recent years, there have been several proposals in the United States, both at state and federal levels, aimed at curtailing or dramatically reducing the use antimicrobials as feed additives, creating a policy similar to that of the European Union. Here we review the current policies on antimicrobial use in the European Union and their impact on food animal production. In addition, we discuss the future of antimicrobial use in food animal production in the United States and the increasing role of biosecurity programs. Finally, we discuss the role of Cooperative Extension Service in creating improved biosecurity programs and extension programs that provide policy makers and voters information on modern food animal production practices and technologies so that policies and regulations are effective and appropriate.

Bituminaria bituminosa (L.) C.H. Stirton, commonly known as tedera, is a perennial legume of interest in Australia due to its adaptation to Mediterranean environments. Field experiments were conducted at two sites in Victoria, Australia, a high rainfall site at Hamilton and a low rainfall site at Bealiba, to evaluate tedera var. albomarginata lines against other forage species. At Hamilton, tedera achieved similar seedling densities to lucerne (Medicago sativa L.) following sowings in late spring 2009 and early winter 2010 (30–60 seedlings/m2). Forage production from the spring-sown tedera was between 1.0 and 2.3 t DM/ha at harvests in March and May 2010, but from May onwards the species failed to remain productive and its content in the swards decreased to become <10%. Forage production from all early winter-sown tedera swards was low (<0.5 t DM/ha). At Bealiba, some of the tedera lines outyielded lucerne. The tedera at Bealiba had a vigour rating of 8.3, on a scale of 1–10, in the summer of 2008–09, after surviving three summers. The tedera lines evaluated are unlikely to persist in cold wet winter environments but in drier zones tedera may persist and offer good DM yields of high nutritive value.

Severe outbreaks of toxicosis caused by the natural endophyte Neotyphodium lolii in perennial ryegrass (Lolium perenne L.) have occasionally resulted in heavy loss of livestock in Victoria and Tasmania. Meteorological records were examined from locations where acute toxicosis was recorded. High rainfall (>350 mm) in spring–summer was an obvious common feature; typically, it prolonged the period of high growth rate of pasture, increasing predicted spring–summer (September–March) growth (by ~36%) and increasing the predicted digestibility of organic matter of summer pasture (1 February) by 2.7% units (up to 55.6%). In years when severe toxicosis occurred, such rainfall was accompanied by dry, warm conditions in March and April, viz. mean maximum daily temperatures on the mainland of ≥21°C (March) and ≥18°C (April). During summer–autumn 2002, pastures from 10 Victorian farms on which acute perennial ryegrass toxicosis resulted in the loss of >7000 sheep/deer, were found to be dominated by perennial ryegrass. The ryegrass endophyte-produced toxins, ergovaline and lolitrem B, were detected in 74% and 100%, respectively, of composite faecal samples collected from acutely affected animals. The populations of perennial ryegrass all tested positive for Neotyphodium lolii endophyte, with a mean infection frequency of 90.5% (s.e.m. 1.81). The mean mycelial mass in basal tillers of perennial ryegrass was estimated at 66.00 (s.e.m. 3.40) from a sample of 20 plants, each of which was assessed on a scale of 1–5. Mycelial mass accounted for 19–20% of the variation in the concentration of ergovaline and lolitrem B in perennial ryegrass. Toxin concentrations in the plants where acute toxicosis was observed exceeded the tolerance levels for sheep (ergovaline 0.8 mg/kg; lolitrem B 1.8 mg/kg) in the minor (green) fraction of the plant in all but one affected pasture for ergovaline and all but two for lolitrem B. Maximum concentrations recorded were 4.3 and 4.6 mg/kg for ergovaline and lolitrem B respectively. Ergovaline increased in an asymptotic relationship with lolitrem B, which accounted for 45% of the variation in ergovaline. The concentrations of ergovaline and lolitrem B in the whole plant (green and dead fractions combined) were not greater than those recorded from randomly sampled pastures in earlier seasons, when only occasional mild cases of toxicosis were reported. Further examination of stored grass samples collected during the 2002 outbreak recently revealed unidentified peaks on the chromatograms for both ergovaline and lolitrem B; peaks that are not seen on chromatograms for toxic perennial ryegrass from New Zealand, where the expression of perennial ryegrass toxicosis is usually milder and rarely fatal.

There is an absence of drought tolerant herbaceous perennial forage legume and herb options other than lucerne (Medicago sativa L.) for environments with Mediterranean-like climates common in extensive areas of Southern Australia, the Mediterranean basin, and Chile. Therefore, a collection of 174 forage perennial legume and herb entries from 103 species and 32 genera was evaluated for adaptation in a diverse range of Mediterranean climatic environments in Southern Australia. The seasonal rainfall distribution varied from moderately to highly winter dominant with long term average annual rainfall ranging from 318 to 655 mm. The entries were rated for productivity and persistence over 3 yr. The 12 entries identified as the most promising for winter, summer, or all-year round production included Bituminaria bituminosa (L.) C.H. Stirt. var. albomarginata; Cichorium intybus L.; Cullen australasicum (Schltdl.) J.W. Grimes; Dorycnium hirsutum (L.) Ser.; Kennedia prostrata R. Br.; Lotononis bainesii Baker, Lotus pedunculatus Cav.; L. corniculatus L.; L. cytisoides L.; Medicago sativa subsp. sativa L.; Medicago sativa subsp. caerulea (Less. ex Ledeb.) Schmalh., and M. sativa subsp. falcata (L.) Arcang. These entries maintained production and persisted for the period of the evaluation, with the exception of C. intybus and L. corniculatus that declined in persistence over time. The potential role of these species in extensive grazing systems in Mediterranean climatic zones, their attributes and limitations, and current progress in developing them as useful forage plants was discussed.

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