2011 Exam Flashcards

Question

Explain how you would go about monitoring for Coccidiosis

Answer 1

- Problems are not common in chicks under three weeks of age because the parasites take time to build up. -  Affected birds exhibit depression, loss of condition, paleness, ruffled feathers, drooping wings, pale and dry flanks, slight whitish soiling around the vent (only occasionally), diarrhoea and blood in the droppings. -  Often a large percentage of the chickens are sick. Birds may die suddenly before the above symptoms are obvious.

Answer 2

- Monitor using a sticky trap and plant leaf checks. Decide on a threshold level for aphids in your crop, above which you must spray and below which you can safely withhold spraying. -  Plan the layout of traps to identify hot spots and estimate overall aphid levels together with plant scouting. Place traps just above the plant tops. Do a weekly count of aphids on each trap and look for infected plants. Mark infected plants with tape for removal and replace sticky traps. -  Note any aphid hot spots and check aphid numbers on nearby plants to find the size of hot spots. Check for biological control activity. Record trap and scouting details. Check numbers on marked plants one to two days after spraying to check the results.

Answer 3

- Jersey cows that are mature and fat and graze on lush, clover-dominant pasture before calving are most susceptible. -  Regularly (at least twice daily) check cows that are close to calving and for about three days following calving. -  In typical cases, cows show some initial excitement or agitation and a tremor in muscles of the head and limbs. Then they stagger and go down to a ‘sitting’ position, often with a ‘kink’ in the neck, and finally lie flat on their side before circulatory collapse, coma and death. -  A dry muzzle, staring eyes, cold legs and ears, constipation and drowsiness are seen after going down. The heartbeat becomes weaker and faster. The body temperature falls below normal, especially in cold, wet, windy weather.

Answer 4

- Monitoring climatic conditions can help to predict blowfly activity. - The risk of flystrike increases once the temperature is above 17 °C, wind speeds are moderate (< 30 km per hour) and sheep fleece remains moist from rainfall for a few days. - Monitor blowfly populations through trapping. - Inspect sheep for maggots. - Catch, clip and treat individual blowfly-struck sheep.

Answer 5

A description of a well-planned strategy that includes timing of events.

Answer 6

- physical prevention activities (consider how the pest or disease could enter the property) -  a plan for monitoring -  a plan for preventative treatments -  a consideration of management options that are available if needed.

Answer 7

Disease agents and pests can be introduced to a poultry farm by the movement of eggs, birds, people, vehicles and equipment between farms, and by clothing, footwear, aerosols, water, feed, litter, wild birds, biting insects and vermin.

Answer 8

- Control weeds on field edges if scouting indicates that aphids are present, and control weeds within crops. - Destroy old crops immediately after the harvest has finished. - Use a fallow period, if possible, when no crop is grown to clear pest populations. - Do not plant new crops near or close to neighbouring infested weeds or old crops (greenhouse and open field). - Use seedlings that have been grown away from infested areas; that is, start with a clean crop. - Avoid moving aphids around the crop by staff moving from infested to clean areas. Do not work in old crops on windy days, especially when prevailing winds are blowing towards new plantings. - Mesh screening has been shown to effectively exclude aphids in covered/protected crops and the use of reflective plastic soil mulch can be beneficial in reducing aphid numbers. Rolls of yellow sticky tape may be useful in some greenhouse designs if placed near entry points and hot spots. - Monitor pest populations for early control. Use yellow cards to alert you of new infestations and scout plants by turning leaves to work out where they are. Control is simpler and less expensive when plants are young and spray coverage is not an issue.

Answer 9

- There is no infective agent, so normal biosecurity measures do not apply. -  Milk fever is a disorder mainly of dairy cows close to calving. It is a metabolic disease caused by a low blood calcium level (hypocalcaemia). Between 3% and 10% of cows in dairying districts are affected each year, with much higher percentages occurring on some properties. Jersey cows that are mature and fat and graze lush, clover-dominant pasture before calving are most susceptible. -  About 80% of cases occur within one day of calving because milk and colostrum production drain calcium (and other substances) from the blood, and some cows are unable to replace the calcium quickly enough. High producers are more susceptible because the fall in their blood calcium level is greater. Selecting cows for high production may, therefore, increase the problem with milk fever. Some individual cow families or breeds (for example, jerseys) are more susceptible than others. -  Age is important. Heifers are rarely affected. Old cows increase in susceptibility up to the fifth or six calving because they produce more milk and are less able to replace blood calcium quickly. -  The feeding management of dry cows in the two weeks before calving is very important, because it affects both the amount of calcium available to replace blood calcium and the efficiency with which the available calcium can be used. -  When the amount of calcium in the diet is greater than is needed, the efficiency of absorbing calcium from the intestine and the efficiency of transferring calcium from the skeleton both become very sluggish and the chance of milk fever is greatly increased. -  Also, grazing pastures in southern Australia in winter and spring results in alkaline blood which creates unfavourable conditions for the availability of calcium in the body and predisposes the cow to milk fever. Feeding hay prior to calving and restricting access to green feed results in acidic blood which favours calcium mobilisation from bone and improves calcium absorption from the intestines, both of which are important factors in preventing the occurrence of milk fever. -  Fat cows are at a greater risk than thin cows. This is partly because their feed and calcium intake has been higher and partly because fat cows produce more milk at calving time. -  Some cows get milk fever several days or even weeks before or after calving. This is usually due to the feed, especially the dietary calcium, being insufficient to meet the heavy demand due to the rapidly growing foetus or milk production in early lactation. -  In early lactation, cows should receive as much calcium as possible, and clover- dominant pasture is therefore desirable. They will help to prevent both milk fever and grass tetany.

Answer 10

- Any flystrike prevention program must be aimed mainly at Lucilia cuprina. As this fly breeds almost exclusively on susceptible living sheep, prevention of flystrike will reduce the numbers of this fly. This in turn reduces the pressure on any sheep that do become susceptible to flystrike. Small flystrikes early in the season provide the means for numbers of Lucilia cuprina to build up from the relatively few maggots that survive the winter. These can be greatly reduced by: 1. correct tail docking 2. mulesing of sheep kept for wool (surgical mulesing ceased in 2010, but non-surgical alternatives are under development) 3. preventing scouring by using a good worm control program o breeding breech-strike resistant sheep 4. selectionawayfromharsh-woolled,wrinklysheep. - Destruction of flystruck crutchings kills many maggots that would otherwise survive. Jetting should not be used as a substitute for other management practices, but can be a valuable aid. Trapping - The LuciTrap system consists of a specifically designed trap with a patented blend of chemicals to attract and capture the Australian sheep blowfly (Lucilia cuprina). - It is designed to reduce blowfly numbers and fly strike. - The LuciTrap system is an adjunct to other blowfly control procedures and must be combined with them in an IPM program to minimise pesticide use and residues on wool.

Answer 11

Advantages of using this type of biotechnology (genetically modified Roundup Ready Canola) include: -  time saving -  simpler spray equipment and regime -  crop not contaminated with weeds -  crop not harmed -  no, or less, tillage and fewer herbicide applications -  higher yielding genetically modified varieties -  earlier sowing -  reduced traffic, resulting in less compaction -  reduced fuel, labour and machinery -  use of cheaper, broad-spectrum herbicides. Disadvantages of using this type of biotechnology (genetically modified Roundup Ready Canola) include: -  higher volumes of spray used -  not allowed to save seeds -  drift to other areas -  safety risks with greater use of herbicide -  potential for cross species pollination -  escaped canola may be a problem elsewhere (for example, for neighbours) -  higher seed prices -  need for buffer zones -  threat to organic growers -  diminished gene pool -  weed resistance to herbicide may be increased  may reduce the saleability of the product.

Answer 12

- risks of spray drift causing damage to the environment, neighbouring crops/pastures, people, fauna, flora and or soil/water - cross pollination with neighbouring crops or related wild species resulting in herbicide resistance.

2011 Exam Flashcards

(36 cards)