Mixed Sheep Research Articles

Influence of food quality and temperature on fedundity ofKiefferulus barbitarsis(Kieffer) (Diptera: Chironomidae)

Influence of larval (i.e. mixed algal powder, sheep manure, vegetable waste and silt) and adult nutrition (i.e. glucose, amino acids and glucose and amino acid mixture) and temperature (20–40°C) on fecundity of Kiefferulus barbitarsis was studied. Larvae raised in mixed algal powder medium gave rise to females that oviposited a maximum of 232.0 eggs. The fecundity decreased by 7.3, 4.2 and 26.3% in those raised as larvae in sheep manure, vegetable waste and silt media respectively. At 25 and 30°C fecundity and hatchability were very high. Above and below this temperature, fecundity and hatchability were significantly lower. The simple correlation coefficient (r = 0.95, and 0.99) for the relation between number of egg rafts or hatchability of eggs and temperature was statistically significant (P < 0.05; N = 6). Adult feeding on glucose, amino acids and glucose + amino acid mixture did not influence fecundity (P > 0.05).

Inhibition of Antigen‐ and Mitogen‐Induced Activation of Mouse Splenocytes by Uterine Secretions From Pregnant and Progesterone‐Treated Ewes

Pregnant and progesterone-treated, ovariectomized ewes accumulate secretory products in the uterus that are immunosuppressive in mitogen-stimulated and mixed lymphocyte sheep cell cultures. In this study, uterine secretions from pregnant (Preg-UTM) and progesterone-treated, ovariectomized (P-UTM) ewes were equally effective in suppressing 3H-Tdr incorporation in mouse spleen cells stimulated with PHA. P-UTM inhibited PHA-stimulated, purified T-cells and separated L3T4+ and Lyt2+ T-cell subpopulations more than Preg-UTM, however. Both fluids were slightly inhibitory to conA-stimulated mouse spleen cells, enriched T-cells, and Lyt2+ T-cells but neither inhibited L3T4+ T-cells. For LPS-stimulated cells, P-UTM caused more suppression than Preg-UTM of enriched B-cells; however, suppression was similar for the two fluids on unseparated splenic cells. In antigen-stimulated mouse spleen cell cultures, both fluids inhibited antibody-forming cell responses to sheep erythrocytes, a thymus-dependent antigen, but neither suppressed antibody-forming cell responses to TNP-Ficoll, a thymus-independent antigen. These data indicate that uterine secretions in the ewe produced under the influence of progesterone or pregnancy contain immunoregulatory molecule(s) which modulate the activity of both homologous sheep and unrelated mouse lymphocytes. These studies establish the mouse as a useful in vivo model for studying the biological actions of these molecules.

Cardiac echinococcosis with fatal intracerebral embolism in a seven year old child

Hydatid disease caused by the tapeworm Echinococcus granulosus is an unusual disease in childhood and most commonly affects the liver and lungs. Cysts may remain asymptomatic for a number of years and presenting symptoms and signs, such as abdominal discomfort, jaundice and biliary colic, are related to the mechanical effects of growth and compression of adjacent parenchyma and ducts. Fatal outcomes are unusual. The following case, however, demonstrates a unique occurrence of sudden collapse with death due to cerebral infarction from embolised hydatid cyst fragments. Case report: A previously well 7 y.o. boy presented with sudden loss of consciousness and fitting 15 minutes after a fall in the school ground. His only relevant past history was that he lived on a farm in a mixed sheep and wheat growing area. On hospital admission he was unconscious, fitting, with marked opisthotonus and bilateral papilledema without localising neurological signs. Further deterioration was followed by brain death 16 hours after collapse. At autopsy the brain was markedly oedematous with herniation. A ruptured hydatid cyst was found in the left ventricle of the heart with embolised fragments of laminated hydatid cyst wall found in both middle cerebral arteries associated with early ischaemic changes in both cerebral hemispheres. A second hydatid cyst, which showed the characteristic external laminated cuticule, internal germinative membrane and hydatid sand was present within the liver. Death was attributed to acute cerebral infarction due to bilateral middle cerebral artery hydatid embolism from a ruptured hydatid cyst of the left ventricle. This case is reported to 1) demonstrate the clinicopathological features of disseminated echinococcosis, and 2) draw attention to the possibility of sudden embolic death in childhood due to previously undiagnosed hydatid disease.

The pasture ryegrass plant, what is it?

Detailed studies of plant growth processes are important in understanding the performance and persistence of species in pastures, particularly in response to uncharacteristic environmental stress. The morphology of perennial ryegrass plants in mixed sheep grazed pastures was determined in self contained farmlets undercontrasting managements of rotational grazing, set stocking or a combination of both. Average size was 90 mg total DW, with 4- 5 tillers and 12-13 leaves, little different to white clover. Ryegrass exhibits strong clonal growth, with extension at the apex and death of the basal stem releasing branches to form new plants at regular intervals, maintaining a stable population structure of small plants all year. The normally short internodes on ryegrass stems can elongate to form stolon and elevate the apex to a more favourable position if survival is threatened. On average only 2530% of plants contained stolon at any one time. Because of high plant density the quantities of ryegrass stem present was often in excess of that produced by white clover in the same swards. Grazing management did not affect plant structure (numbers of tillers, leaves etc) only their size (dry weight), but had marked effects on pasture structure and subsequent survival of plants under stress. Keywords perennial ryegrass, plant morphology, grazing management, seasonal variation, plant survival, stolon formation

Assessment of the potential of dual-purpose goats in northeast Brazil

Farmers in Paraíba, Pernambuco and Rio Grande do Norte, states of Northeast Brazil where most dairy goats are found, were surveyed with purposive sampling. Goat milk production played a minor role on the survey farms, the majority of which were characterized by mixed production systems, including crops, cattle, sheep and goats. Milk production per goat was very low compared to dairy goats in other areas of the world. Does produced an average of 0.8 liters milk per day with an average lactation period of 134 days, yielding 107 total liters per lactation per goat. To be commercially viable, milk production will have to be increased substantially over what is necessary to feed kids. Research efforts must focus on improving milk production, developing management recommendations for extension agents and farmers, and evaluating the market potential of goat milk and related products.

The integration of a ewe flock with the dairy herd

The benefits of mixed grazing sheep and cattle have been reviewed by Nolan and Connolly (1977). Sheep performance was improved in practically all comparisons and cattle perfomance in the majority of reports. As dairy producers manage their milk quota through various efficiency options, surplus land may become available for alternative use. Based on results from other sheep/dry stock studies the introduction of sheep onto the dairy farm, to utilise surplus/waste grass throughout the year, should lead to increased pasture utilisation and improved overall farm efficiency. The sheep enterprise may be established as a distinct unit and strategically used to exploit feed surpluses on the dairy unit throughtout the year. Alternatively, the full integration of a sheep enterprise with the dairy cows to exploit the benefits of mixed species grazing, may be considered. This latter approach is being evaluated and this report covers the first year of an on-going study.

GOAT FARMING PRACTICES ON HIGH PRODUCING PASTURES

Few farmers have firm ideas about the long-term aims of their goat enterprises. Since profit is the primary motive, breeding objectives may change rapidly. Goats are generally a small proportion of total stock numbers and are given preferential grazing. Goat grazing improves pastures by increasing clover content and reducing the number of thistles and weed grasses. Although most farmers feed hay there is no indication this is necessary for high animal performance. The most productive goat management systems on high producing pastures have yet to be defined, especially integration with other livestock dasses. Preliminary data from mixed goat and sheep grazing trials in Canterbury suggest there are benefits in liveweight gain to sheep, but not necessarily to goats by integrating grazing. Areas for future research are considered.

Midwinter thaw: Parsnips and people

(Rrceiwd 10 Februor>, 1986) SOME~ME in late January or early February. after Lake Erie has frozen over and the lake effect snow squalls have stopped, there is a midwinter thaw in Western New York. A short break in the fierce cold and snowy weather that we anticipate as keenly as the arrival of the delights of winter: cardinals and evening grosbeaks. wood stove warm kitchen, seed catalogs, Dickensian Christmases. cross country skiing, and parsnips. Melting snow turns the horse paddock into a quagmire, the driveway into a temporary creek, and the 120-year-old fieldstone portion of the basement into a puddle. The grass over the septic tank and tile field pipes reappears as miraculously as do the unharvested turnips. parsnips, and cold resistant spinach: incongruous, refreshing gray-green against the leafless trees. snow, and gray sky. When the conditions are right dense ground fog, just like the moor mist in the old Sherlock Holmes Hound of the Baskervilles movie, settles in over fields still covered with snow. Of course it is only a matter of time before real winter returns, but for a few days we scurry about in shirts and down vests doing chores that have been put ofi transferring hay to the top of the horse barn, spreading the accumulated ashes from several cleanings of the fireplace and wood stove on the garden, hauling more logs to the bottom of the big barn to replace those that have been split and burnt. The softening squash and pumpkins are culled from the baskets of vegetables in the cold room and put out for the birds and field mice to eat. Fences are hastily patched with hopes that the repairs will last until spring. Loose straw and hay from the barns are raked up and spread over the exposed perennial beds to protect them against the frigid temperatures sure to come. Without a good sized layer of insulating snow the tender shoots of early spring flowering plants will be frost killed. Anticipating the appetite for fresh fruits and vegetables that accompanies the warming trends of spring yet to come, one of the dormant rhubarb plants is enveloped by a bottomless wooden keg filled with manure and straw. In March when the spring melt is in full Aood, this rhubarb plant, growing into the fertile warmth of its winter manure coat? will be undressed and the partially blanched stalks stewed and savored. A favorite chore of these rare midwinter thaw days is to dig parsnips. Now that the boys have grown up and away, the chores of the sheep and poultry have been relinquished. Jeremiah, the champion ram, is as vigorous as ever but he is tending to a larger flock of mixed Dorset sheep in an adjoining town. Without the reliability of youth the day to day animal work done by an increasingly busy and reluctant father began to suffer. So in the winter of 1985-1986, Susan and I savor the seed catalogs, our neighbor’s dozen

A soil enrichment technique for the recovery of predacious fungi

Summary Recovery of predacious (nematophagous) Hyphomycetes from soil samples supplemented with 25% by weight of autoclaved, mixed sheep and cattle dung and held for various periods at room temperature, was significantly greater than from corresponding unenriched samples. Greatest recovery was obtained after 6 week's storage. This technique is suitable for improving recovery of predacious Hyphomycetes, Zoopagales, and endozoic parasites of nematodes in routine examination of soil samples.

The limitation of individual cells to the production of a single specificity of antibody in response to a coupled hapten-antigen complex

Examination of 6·1 million spleen cells from five immunized with arsanilazo pigeon red blood cells yielded a total 5675 anti-pigeon and 6990 antiarsanilazo plaques in a mixed arsanilazo sheep red blood cell plus pigeon red blood cell test system. Concentric lysis of both types of red blood cells was observed in twenty-one of these 12,665 plaques. This is less than the number of cross reacting plaques to be expected in the absence of any cells producing antibodies against both pigeon and arsanilazo determinants. The number of overlapping but non-concentric plaques was shown to be n o greater than the number calculated from geometric considerations. It is concluded that we found no evidence for there being any antibody-forming cells which produced detectable amounts of antibodies against both the pigeon rbc and the attached arsanilazo groups similtaneously, and the quantitative limitations on this conclusion are discussed.

THE ROLE OF GRASSLAND IN MANAGEMENT

THE PROPERTY to be discussed is a mixed sheep and cropping unit, situated ei ht a miles east of Ashburton and midway between the Ra aia and the Ashburton rivers. Average annual rainfall is 27 in., evenly spread, but there is very high summer evaporation and therefore frequent droughts. On average, the soil is below wilting point for 40 to 50 days each summer. Winters are cold with the soil temperature being below 48°F for about four months each year. The soil is a Lismore stony silt loam averaging 9 in. in depth over gravel.