bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the carbohydrate metabolism of sheep. I. The range of blood-sugar values under several conditions
Authors: Reid RL
Published: November 2004

The considerable volume of literature dealing with the normal range of blood-sugar values in ruminants and with the effect of varying nutritive conditions upon it is reviewed in some detail. Attention is drawn to differences between ruminant and non-ruminant mammals, and an attempt is made to explain them in the light of present knowledge of digestive processes in the ruminant. Data are presented on the normal range of blood-sugar values in sheep, both in Australia and in England, and on the effect of nutritive factors and of pregnancy on these values. The mean blood-sugar values determined by the author in non-pregnant ewes in Australia and in England were 34.8 ± 3.06 and 39.1 ± 3.37 mg. per cent. respectively. The observed range in both pregnant and non-pregnant ewes was 18-57 mg. per cent., but 94 per cent. of values fell between 25 and 46 mg. per cent. This range was obtained in sheep bled usually in the morning, before feeding. A delayed rise, which is slight and always below hyperglycaemic levels, was observed after feeding; the afternoon samples showed higher values than the morning samples. Thus, the normal range of blood-sugar values in fed sheep, at any time of day, is considered to be 25-50 mg. per cent. The level of blood sugar was affected neither by the plane of nutrition nor by the bodily condition of non-pregnant ewes. Gestation in ewes in good condition was observed not to affect the level, although evidence was obtained of lowered blood-sugar levels during the last two months of gestation in ewes in poor condition. Expressed as a percentage of the pre-fasting level, the decrease in blood sugar observed during a four-day fast was similar to that observed in non-ruminants, but the response was delayed. Fasting for a period of 24 hours had little effect on the blood-sugar level in non-pregnant sheep in good condition; in many cases there was little change after the period had been extended to 46 hours. On the other hand, a fast of 24 hours' duration produced a marked hypoglycaemia in ewes in poor bodily condition during the last two months of gestation, blood-sugar levels as low as 8.6 mg. per cent. being recorded.
Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. I. The preparation of antigens for the complement fixation test and the reactivity of the biochemical fractions of H. contortus
Authors: Stewart DF
Published: November 2004

All antigen was developed to detect circulating antibodies by means of the complement fixation test in sheep infested with Haemonchus contortus and Trichostrongylus spp. Extraction of worm material at 100°C. for 10 minutes was found to be the most satisfactory method for the preparation of antigens. Potent antigens were prepared from young adult H. contortus, from third-stage infective larvae, and from the eggs. Old mature adult H. contortus yielded antigens of low potency. No significant difference was found between the potency of antigens prepared from male and female adult H. contortus collected from the same sheep. Both adult Trichostrongylus spp. and third-stage infective larvae consistently yielded antigens of high potency. No significant difference was found in the results obtained with larval or adult H. contortus antigens, adjusted to the same potency and tested with natural H. contortus antisera. H. contortus and Trichostrongylus spp. absorbed the antiserum to each other. It was shown that a lipid was an essential constituent of the boiled antigen in the complement fixation reaction with natural antisera. Lipid-free antigens from H. contortus failed to react with natural antisera. The lipid was not antigenic when injected into rabbits. The carbohydrate fraction of H. contortus did not fix complement in the presence of natural antisera and was not antigenic when injected into rabbits. The lipid fraction of a variety of nematode parasites reacted with natural antisera to H. contortus infestation. Similar lipid fractions of two species of trematodes did not react with natural antisera to H. contortus infestation. Normal saline suspensions of the lipid-free material from a variety of helminths showed a greater degree of specificity when tested with artificially prepared antisera than did the lipid fractions.
The global distribution of tribes of the gramineae in relation to historical and environmental factors
Authors: Hartley W
Published: November 2004

An extensive survey of the literature on grass distribution throughout the world has been made to determine the average percentage of species of each of the major grass tribes in the total grass flora.
These average percentages for the six largest tribes are as follows: Agrosteae 8.2 per cent. Eragrosteae 8.1 per cent. Andropogoneae 11.9 per cent. Festuceae 16.5 per cent. Aveneae 6.3 per cent. Paniceae 24.7 per cent. The distribution of each of the above tribes is shown on world maps, and the relationship of this distribution to climatic, historical, and taxonomic factors is discussed. It is shown that the present distribution of each of the major tribes can be explained by a few readily recognizable factors. Climatic factors are of primary importance in relation to grass distribution and winter temperature has special significance.
The inheritance of resistance to Ascochyta pisi Lib. in Pisum sativum L.
Authors: Wark DC
Published: November 2004

A disease of peas caused by Ascochyta pisi is briefly described. The susceptibilities of over 200 varieties and strains of peas were tested by spray inoculation of the seedlings when they were six to eight inches in height. Austrian Winter was the least susceptible of the varieties tested. It was crossed with several other pea varieties and in all cases except one the F1 generation, when spray inoculated in the late seedling stage, was shown to be as resistant as Austrian Winter. Segregation in the F2 and later generations was such as to indicate that the resistance is due to a combination of three Mendelian factors, all of which are dominant. Other factors may have a modifying effect.
A number of Austrian Winter hybrids were shown to possess considerable field resistance to the disease a t Warncoort, in the Colac district of Victoria.
The resistant hybrids have all inherited some undesirable qualities from the Austrian Winter parent.
Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. III. The antibody response to infestation with Trichostrongylus spp.
Authors: Stewart DF
Published: November 2004

In infestation of sheep with Trichostrongylus spp., both the intake of larvae and infestation with adult worms stimulated the production of antibodies. The character of the antibody response in infestation with Trichostrongylus spp. thus differed from that caused by Haemonchus contortus. Sera of sheep dying from infestation with Trichostrongylus spp. were negative to the complement fixation test. It was found that older sheep responded serologically earlier and more vigorously to infestation with Trichostrongylus spp. than did young sheep. Subsequent doses of larvae of Trichostrongylus spp. elicited a more rapid and grester serological response, even in young sheep, than an initial dose of larvae. Previous infestation with H. contortus did not result in resistance to Trichostrongylus spp., whereas previous infestation with Trichostrongylus spp. heightened the resistance of sheep to subsequent infestation with the same species. It is concluded that the relative resistance of older sheep to Trichostrongylus spp. is due, a t least in part, to an earlier immunological response which is strengthened by subsequent doses of larvae. When infective larvae of Trichostrongylus spp. were superimposed upon an existing infestation of the same species, the egg count declined ;apidly and the development of the superimposed larvae resisted Doses of infective larvae of Trichostrongylus spp. had no apparent effect on the egg counts of sheep infested with H. contortus.
Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. IV. The antibody response to natural infestation in grazing sheep and the 'self-cure' phenomenon
Authors: Stewart DF
Published: November 2004

Weekly tests, over a period of eighteen months, of the sera of a flock of grazing sheep showed a relationship between the serum titres and the faecal egg counts. This relationship was particularly obvious during the summer months. When egg counts fell, the titres rose, and as the titres dropped, the egg counts usually rose again. This relationship between egg counts and serum titres was more striking in individual sheep than in the whole flock because all the sheep did not behave similarly at the same time. The antibody levels rose in individual sheep irrespective of whether the sheep were heavily or lightly infested at the time. There was no evidence that a permanent resistance to Haemonchus contortus was acquired under field conditions. Seven periods of "self-cure" occurred in the grazing flock during the period of observation. On each occasion, the majority of sheep which showed a drop in egg count also showed a rise in serum titre. This behaviour was strikingly similar to the result when infective larvae of H. contortus were superimposed upon an existing infestation of H. contortus or Trichostrongylus spp. in penned sheep. 'Self-cure' was produced in the field by giving naturally infested sheep large doses of infective larvae of H. contortus by mouth. A statistically significant fall in the faecal egg count of H. contortus and Trichostrongylus spp., but not of Oesophagostomum columbianum was produced by this means. The fact that 'self-cure' takes place in naturally grazing flocks during the summer months after rain indicated that the intake of large doses of infective larvae of H. contortus was the exciting cause of the phenomenon.
Studies on the carbohydrate metabolism of sheep. III. The blood glucose during insulin hypoglycaemia
Authors: Reid RL
Published: November 2004

The response of sheep to intravenous insulin administration in doses of 0.5-10.0 units per kg. body weight has been studied in detail. The rate of fall of blood glucose following insulin injection is considerably slower than in non-ruminants. Increasing the dosage of insulin from 1 to 5 units per kg., and sometimes to 10 units per kg., does not increase the depth of hypoglycaemia, but merely increases its duration. The blood-glucose level following such doses of insulin falls, in most sheep, to a level of 5-10 mg. per cent. and remains relatively constant until it returns to normal. At these levels, severe hypoglycaemic signs were never observed, even when the hypoglycaemia was of several hours' duration. These results are compared with those obtained by others on cattle and goats and it is suggested that the response of sheep to insulin is similar in all respects to that shown by cattle and goats. From a consideration of the experimental results, it is suggested that the differences in response to insulin between ruminants and non-ruminants may be due to fundamental differences in endocrine balance which, in turn, are conditioned by differences in intermediary metabolism.
A simple macrorespirometer for studies in soil microbiology.
Authors: Swaby RJ , Passey BI
Published: November 2004

A simple macrorespirometer is described which is capable of providing a continuous record of oxygen consumption and an intermittent record of carbon-dioxide production by pure or mixed cultures of microorganisms in soil and compost.
Problems in tree replacement. 1. The root-lesion nematode Pratylenchus coffeae Zimmerman as a factor in the growth of replant trees in apple orchards.
Authors: Colbran RC
Published: November 2004

The root-lesion nematode Pratylenchus coffeae Zimmerman is widely distributed in apple orchards in the Stanthorpe district. It is restricted to the non-suberized fibrous roots which are destroyed as a consequence of heavy infestations. Apple seedlings grown in soil infested with P. coffeae were stunted when compared with seedlings grown in the same soil after pretreatment with "D-D" or formalin. The parasite appears to be the most important factor causing the unthrifty growth of replant trees in many old orchards. No apple rootstocks available in the district are immune to the parasite. Fumigation of heavily infested soil before replanting offers a partial solution to the problem.
The root-nodule bacteria as factors in clover establishment in the red basaltic soils of the Lismore district, NSW. I. A survey of "Native" strains.
Authors: Vincent JM
Published: November 2004

Tests of 84 cultures of root-nodule bacteria isolated from four species of clover growing in the Lismore district of New South Wales (three soil types, 18 localities) showed them to be generally effective in association with white and red clovers, but almost always parasitic on subterranean and crimson clovers. Successful seed inoculation with beneficial strains of rhizobia is, therefore, essential to the introduction of subterranean and crimson clovers in these soils. Field observations have also demonstrated the need to inoculate seed of Medicago species, cowpea, and vetch.
The root-nodule bacteria as factors in clover establishment in the red basaltic soils of the Lismore district, NSW. II. Survival and success of inocula in laboratory trials.
Authors: Vincent JM , Waters LM
Published: November 2004

Plant growth, nature of nodulation, and serological identification of cultures isolated from nodules have been used to determine the success achieved with inocula of clover rhizobia. The Lismore krasnozems offer difficulties in the way of successful seed inoculation. Milk and phosphate supplements with the inoculum do not obviate the difficulty, but heavier rates of inoculation give a reasonable degree of nodulation even with untreated soils. The unfavourable nature of these soils is reflected in their relatively low rhizobial population and the failure of added cells to persist or multiply at a rate comparable with other soils and conditions. Raising pH to c. 7 by the addition of Ca(OH)2 or CaCO3 markedly improves the soil as a medium for survival and multiplication of clover rhizobia. Even a small rise in pH gives appreciable improvement. Strains of root-nodule bacteria differ markedly in their ability to compete with each other for growth and nodule formation on a host. The relative performance of strains can be affected by such factors as the nature of the soil and the presence and nature of the host. Competition for nodulation need not be related in any simple way to competition for growth. Competition by :"native" strains can be an important factor contributing to success or failure with added inoculum.
The histotropic phase of the nematode parasite, Ostertagia circumcinta.
Authors: Sommerville RI
Published: November 2004

The histotropic phase of Ostertagia circumcincta in the abomasal mucosa of the sheep has been investigated. Larvae were found to enter the gastric pits and glands and there pass the third ecdysis, three days after oral administration to the host. Some of these larvae failed to grow after ecdysis, and were found in the mucosa as long as three months from the date of infestation. Other larvae migrated into the lumen of the abomasum immediately after ecdysis. Still others developed in the mucosa, and migrated to the lumen of the abomasum either when adult or else during the fourth stage. The greater number of larvae were found in the mucosa in the pyloric region and around the cardiac orifice. A small proportion were found in the fundic region, where they formed large, flattened nodules. Histological examination showed that the peptic, parietal, and mucous chief cells had been replaced in these nodules by foveolar cells. This cycle of degeneration and subsequent regeneration of the specialized gastric cells appeared to follow a pattern which has been recognized in the dog and some other animals. Larvae in the histotropic phase are unlikely to be affected by drenches. The significance of these larvae in the epidemiology of ostertagiosis is unknown. It is suggested that larvae which develop in the mucosa utilize cellular secretions for nourishment.
Changes in the major chemical constituents of subterranean clover (Trifolium subterraneum L.) during growth. I. The carbohydrates.
Authors: Hardwick NE
Published: November 2004

The carbohydrates of a series of subterranean clover samples of combined leaf and petiole tissue, cut a t intervals during the growing season, were determined. The percentages of free and total reducing sugars remained relatively constant in the young plant, increased markedly during budding and flower formation, and subsequently fell to a very low level. A "reserve carbohydrate" fraction, which may include starch, was present in very small amounts, but fructosans appeared to be absent. Of the structural carbohydrates, cellulose percentages were almost constant until the beginning of wilting, after which there was a steep rise. The percentages of hemicelluloses not isolated in the cellulose fraction, when calculated as pentosan, remained fairly steady throughout. The total weights per acre of the total sugars, cellulose, and the hemicelluloses were calculated.
Cyclic salt as a dominant factor in the genesis of soils in South-Eastern Australia.
Authors: Downes RG
Published: November 2004

A theory is presented suggesting that during the Recent Arid Period the rainfall was approximately half that of the present day and enabled cyclic salt to be accumulated in areas in south-eastern Australia, where it does not 'accumulate at present. The salinization and subsequent desalinization during the wetter conditions since the Arid Period have operated with varying degrees of intensity to produce solods, solodic and solonized soils over large areas. However, irrespective of the degree of intensity, some of the pre-Arid soils because of their chemical or physical properties have been able to resist these processes and remain unaffected. Five "pedogenetic zones" have been defined according to the degrees of intensity with which the salinization and desalinization processes are thought to have operated, and it is found that soil distribution and morphology is correlated with these defined zones. The zone in which the effect has been most intense has an average annual rainfall at present of between 20 and 30 in., and the most widespread soils, those formerly called red and yellow podzolics, are solodic soils and solods. The theory provides a reasonable explanation for the anoxalous distribution of soils within the "podzol" zone where those showing the greatest degree of horizon differentiation (solods and solodic soils) occur in the driest parts. In addition, the postulated processes for the formation of the soils provide a reason why molybdenum deficiency is so common on these soils in zone 3.
Development of virus-free stock of Green Mountain Potato by treatment with malachite green.
Authors: Norris DO
Published: November 2004

A technique for deriving and multiplying an aseptic clone of potato in culture solution is described. Using such a clone and adding malachite green to the culture solution it was possible to derive a growing tip free from virus X. This was subsequently multiplied to give a virus-free stock of the variety Green Mountain (Early Carman).
A comparison of methods of classing flock ewes.
Authors: Riches JH , Turner HN
Published: November 2004

In the Australian sheep industry breeding ewes are usually selected by eye appraisal in the wool at from 18 months to 2 years of age. This paper reports a study of the improvement obtained in a flock by applying such methods, compared with improvement through selection on. wool weight. The possibility of selection at an earlier age was also investigated. Eye appraisal at any age was shown to be only approximately 30 per cent. efficient in raising wool weight per head, and approximately 45 per cent. efficient in raising money return per head, when compared with selection on wool weight. Selection on wool weight at 9 months of age was 80 per cent. efficient in raising wool weight per head, and 70 per cent. efficient in raising money return per head, when compared with selection on wool weight at 21 months of age. Selection on wool weight, in the flock under consideration, did not lead to a decrease in quality number of the wool
Phosphorus, sulphur, and molybdenum deficiencies in soils from eastern Australia in relation to nutrient supply and some characteristics of soil and climate.
Authors: McLachlan KD
Published: November 2004

Subterranean clover (Trifolium subterraneum L.) was grown on 32 virgin soils in pot cultures, and the yield responses to phosphorus, sulphur, and molybdenum were determined for each soil. The soils were collected from a wide area in eastern Australia, extending from south-western Victoria to southern Queensland. Sulphur deficiency occurred almost as frequently as phosphorus deficiency. In fact, 75 per cent. of the soils were deficient in both phosphorus and sulphur. Thirty-one per cent. were deficient in all three elements. The effect of the interaction between the elements on the occurrence and intensity of the deficiencies is shown. Molybdenum responses were obtained only after the other deficiencies had been corrected. A deficiency in one of the elements is no indication of deficiency or sufficiency of either of the other two. There was no correlation between the occurrence or intensity of the deficiencies and the geological origin of the soil parent material, the climate of the regions from which the soils were collected, or such soil characters as colour, organic matter, and texture. Responses to phosphorus were less on the black earths than on the red or yellow podzolic soils; those on the red earths were intermediate. The intensity of sulphur deficiency increased, and the intensity of molybdenum deficiency decreased, with increasing soil pH.
Studies on the sultana vine. III. Pruning experiments with constant number of buds per vine, number and length of cane varied inversely
Authors: Antcliff AJ , Webster WJ , May P
Published: November 2004

Pruning experiments are described in which the number of buds per vine was kept constant, and the number and length of canes was varied inversely. The position of the pruning cut affected per cent. bud burst at only the two terminal bud positions, and did not affect per cent. fruitful shoots a t any bud position. For any length of cane likely to be used in practice, per cent. bud burst in the most fruitful region would not be affected. For a constant pruning level there were no significant differences in yield when length of cane was varied from 11 to 18 buds, but in years of high fruitfulness yield was significantly depressed when the canes were 25 buds long. Apical dominance could also be demonstrated on vines with canes of variable length, and it was shown that the inhibiting agent did not move transversely.
Selection for economic characters in Australian Merino sheep. VI. Inheritance and interrelationships of some subjectively graded characteristics
Authors: Morley FHW
Published: November 2004

Genetic and phenotypic relationships among subjectively graded characteristics were examined in a flock of Merino sheep a t Trangie Agricultural Experiment Station. Estimates of heritability were: wool handle, 0.30; wool colour, 0.63; wool character, 0.38; back wool, 0.00; hocks, 0.14; face cover, 0.38. The genetic correlation between face cover and fleece weights suggested that selection for fleece weight would increase "wool-blindness", with possible diminution of reproductive efficiency. Selection for wools of good character (well-defined crimp) would improve softness and would not decrease fleece weight. The conclusion emerging from this and previous studies is that intense selection for high fleece weight will be rewarded by substantial increases, and will be offset only partly by adverse changes in a few of the several characters investigated.
Seasonal changes in soil salinity at Tintinara, South Australia
Authors: Jackson EA , Blackburn G , Clarke ARP
Published: November 2004

Measurements have been made of seasonal changes in soil salinity and soil water at Tintinara in the Coonalpyn Downs of South Australia. Five separate sites representing different soil profiles were selected for study. All soils contained saline water-tables and four of the five had varying depths of sand over finer-textured subsoils; the fifth soil was fine-textured throughout. The investigations were conducted over a 12-month period, salinity and water determinations being made every 8 weeks. Data on soil salinity are presented as:
(1) Conductance of soil pastes, determined on replicates and statistically analysed.
(2) Percentage of total soluble salts, derived from conductivities of 1:5 soil-water suspensions determined on composite sample.
(3) Percentage of chlorides expressed as NaCl, determined on composite samples. All sets of data show that soluble salts moved upwards through the soil profile during spring and summer and down during the rainy season. Where the summer water-table was within 4 ft of the surface large amounts of saline material accumulated in the top inch of soil; in one case there was an increase of from 0.019 per cent. NaCl in winter to 3.2 per cent. in summer. Data are also presented showing that the salinity of the ground-waters increased to a maximum of 2-3.5 per cent. total salts in spring or summer. Seasonal soil water changes are recorded and discussed in relation to salinity changes. The climatic, soil, and ground-water factors influencing salt movements are discussed and the agronomic implications of seasonal salinity changes are stressed. Suggestions on the basis of the results obtained are made respecting the sampling of saline soils.
Grazing management of natureal pastures at Trangie, NSW
Authors: Biddiscombe EF , Hutchings RJ , Edgar G , Cuthbertson EG
Published: November 2004

Results of a 5-year grazing experiment on Stipa-Chlaris natural pasture are presented. Treatments were three rates of stocking each tested with continuous grazing, autumn deferment, and spring deferment. These were studied in relation to: (a) body weight and wool production of Merino wethers; (b) available feed; (c) density and basal area of the perennial grasses. Lighter stocking (one sheep/2 ac) showed little superiority in production per animal under the generally favourable rainfall conditions. There was only one interval of acute feed shortage in which heavier stocking (one sheep/ac) caused extreme body-weight loss and lower fleece weight. The spelling treatments gave no advantage over continuous grazing, either to sheep or to pasture. Effect of stocking rate on perennial grasses mainly depended upon the amount of rainfall received during certain growth stages of the species, e.g. the winter vegetative growth of Stipa, and the March-April maturation of Chloris and Digitaria. Generally, lighter stocking was favourable to plant density and basal area in seasons of average or below average rainfall; heavier stocking was best in wet seasons. Probable reasons for these relationships are discussed.
Effect of intensity of defoliation on regrowth of pasture
Authors: Brougham RW
Published: November 2004

A pasture association comprising short-rotation ryegrass, red clover, and white clover was subjected to three different intensities of defoliation by cutting down to 1, 3, and 5 in. At 4-day intervals over a period of 32 days, measurements were taken of herbage dry matter yield, the leaf area per unit area of ground, and the percentage of light penetrating to a level 1 in. above the ground surface. Where pasture was defoliated to 1 in., light interception was almost complete (95 per cent. or over) approximately 24 days after cutting, whereas pastures defoliated to 3 in. and 5 in. intercepted almost all the incident light 16 and 4 days after cutting respectively. At these stages of growth the leaf area was approximately 5 sq. ft per sq. ft of ground and the herbage yield approximately 1450 lb dry matter per acre, regardless of treatment. The rate of pasture growth increased until complete light interception was approached, and thereafter an almost constant maximum rate was sustained. Leaf efficiency (the rate of increase of herbage dry weight per unit area of leaf) was greatly influenced by intensity of defoliation. Efficiency was initially lower following severe defoliation than following less severe treatment. It increased rapidly to a maximum and thereafter declined gradually. Maximum efficiency in the 3 in. and 5 in. cutting treatments was attained when maximum growth rate was first reached. For pasture defoliated to 1 in., it reached a maximum level during the phase of accelerating growth.
Hair follicle group and skin follicle population of Australian Merino sheep
Authors: Carter HB , Clarke WH
Published: November 2004

Skin specimens from 495 Australian Merino ewes were collected from 22 flocks, including 9 parent studs out of the 17 identified in the contemporary population. Flocks from all of the 4 important strains of the Australian Merino are represented. The skin samples were collected by a standard biopsy method devised for the purpose by the authors, and histological sections prepared. The techniques are described and data for the following estimations presented: mean total (np+z) follicle population density; mean primary (np) follicle population density; ns/np ratio; mean primary (dp) fibre diameter; mean secondary ( da ) diameter; mean fibre diameter of the composite population (dp+s); mean ratio of primary and secondary fibre diameters (dp/ds). For each flock the mean and standard error of the estimations are tabulated and the range of individual values observed summarized for each of the four Merino strains. The data are presented as the material on which further more detailed analyses will be made; the need is stressed for extending these studies, which form an important basis for genetic studies of fleece structure in the Merino and other breeds. Attention is also drawn to certain extreme variants in the hair follicle group, one of which (a very small group) may prove to have a simple hereditary origin.
Dieldrin-resistant cattle ticks, Boophilus microplus (Canestrini) in Queensland
Authors: Stone BF , Meyers RAJ
Published: November 2004

Infestation by cattle ticks in a herd a t Mt. Gravatt, near Brisbane, in southern Queensland, could not be controlled by repeated spraying of the cattle with 0.05 per cent. w/v dieldrin. Ninety-eight per cent. of engorged females of this strain, which fell from an artificially infested beast in the 48 hr following spraying with 0.05 per cent. w/v dieldrin, laid normal batches of viable eggs. Spraying cattle with 0.05 per cent. w/v "Diazinon", however, readily controlled infestation by this strain. Laboratory concentration-response tests on a culture of the dieldrin-resistant ticks indicated that the median lethal concentration of dieldrin for the larvae was over 2000 times higher than for those of a reference strain. There was also strong evidence from laboratory tests of dieldrin resistance in the engorged adult female ticks.
Size of sweat glands in shorthorn strains and Zebu x Shorthorn crossbred cattle
Authors: Nay T , Dowling DF
Published: November 2004

A relatively simple technique for measuring the size of apocrine glands in biopsy cattle-skin sections was shown to be reliable. Duplicate skin samples were compared and the repeatability of the sweat gland size measurements found to be 81.0 per cent., and that of density 95 per cent. There were highly significant differences in sweat gland size between strains of cattle, and between cattle within strains.
Effects of inbreeding on four families of Peppin Merinos. II. The influence of inbreeding on age trends
Authors: Doney JM
Published: November 2004

The effect of inbreeding on age trends in lambing performance and fleece characters is discussed. Inbred ewes take longer to reach their peak reproductive performance (5 years as against 4 pears for non-inbred ewes) and maximum fleece weight (4–5 years against 3–4 years). For fleece components, age trends and differences between inbred and non-inbred sheep do not appear to be large. In this material, differences between normal and inbred sheep exist only in characters which normally show big changes with increasing age. Dry ewes, in both groups, grow more wool than those rearing a lamb. This appears to be mainly due to the greater staple length in dry ewes. Differences in fibre diameter may be present, but would be masked by the flock sampling procedure.
Sulphur and phosphorus in some Eastern Australian soils
Authors: Williams CJ , Steinbergs A
Published: November 2004

One hundred and fifty-five soils of differing soil types and collected from a wide range of parent materials, climatic conditions, and topography were examined for carbon, nitrogen, sulphur, and phosphorus. A close relationship between carbon, nitrogen, and non-sulphate sulphur was found, although alkaline soils contained a slightly higher relative proportion of non-sulphate sulphur than did acid soils. Water-soluble sulphate comprised only a small proportion of the total sulphur in the majority of the soils. Organic phosphorus, although correlated with carbon and nitrogen, showed much wider variation than did sulphur, and it seemed likely that part at least of the organic phosphorus was not closely associated with the carbon, nitrogen, and sulphur in the soil organic matter. The mean relative proportions of carbon, nitrogen, non-sulphate sulphur, and organic phosphorus were 150: 10: 1.26: 0.66.
The influence of the poll gene on certain production characters of Merino sheep
Authors: Dun RB
Published: November 2004

The results of a series of matings of Merino sheep of the form heterozygous poll rams (Pp) x knobbed ewes (pp), are presented. The phenotypic ratio poll progeny : horned progeny was 75:73 for rams and 81:94 for ewes. These were not significantly different from the expected 1:1 ratio. The 75 Pp rams had horn growth varying in length from 1/2 in. to 13 in. One known poll ram phenotype, depressions at the horn sites, was not seen. Comparisons were made within sires of Pp and pp progeny for a series of production measurements. Pp rams cut 4.09 per cent. more clean fleece weight than pp rams, while Pp ewes cut 4.47 per cent. less than pp ewes. This genotype-sex interaction was further examined by comparing sexes for the ratio of positive to negative within-sire differences. There were highly significant chi-square values for greasy fleece weight, clean fleece weight, and body weight. The differences in clean fleece weight were largely accounted for by differences in body weight and staple length. Fold score differences were negligible. The hypothesis suggested as an explanation for these results is that the Merino poll gene P is associated with a small deleterious effect when heterozygous. The effect is apparent only in ewes where the specific effect is the removal of small bony knobs. A subsidiary hypothesis is that in rams the deleterious effect of P is over-compensated by the nutritive benefits derived from the absence of the large ram horns. The practical importance of these findings is discussed.
Comparison of two formulations of DDT as dipping fluids for the control of the cattle tick
Authors: Roulston WJ , Norris KR , Schnitzerling HJ , Meyers RAJ
Published: November 2004

Fertile cattle ticks matured on cattle dipped at fortnightly intervals in 0.5 per cent. pp'-DDT as a wettable powder preparation; but none matured on cattle dipped at fortnightly intervals in 0.5 per cent. pp'-DDT as a "colloidal" preparation, although numerous larval ticks attached to the cattle between dippings. This difference in performance was considered to be due largely to pronounced differences in the amounts of DDT left on the hair of the cattle by the two formulations. Hair samples clipped from cows immediately after dippings in the wettable powder carried more or less uniform amounts of DDT throughout the series of dippings. The quantities of DDT deposited on the hair by the freshly prepared "colloidal" fluid were of the same order as those from the wettable powder; but there were greatly increased deposits at subsequent dippings, particularly those carried out a fortnight after fresh concentrate had been added to the vat. Cattle dipped in both formulations removed more DDT from the vat than could be accounted for by the volume of fluid contained in the hair. This "stripping" effect was most marked in the older "colloidal" preparations. The amounts of DDT remaining on the hair a fortnight after dipping were of the same order in both preparations, and showed a progressive increase with the increasing age of the dipping fluid.
Distribution of zinc in subterranean clover (Trifolium subterraneum L.) grown to maturity in a culture solution containing zinc labelled with the radioactive isotope 65Zn
Authors: Riceman DS , Jones GB
Published: November 2004

Subterranean clover (T. subterraneum L. var. Bacchus Marsh) was grown to maturity in a culture solution containing zinc labelled with the radioactive isotope 65Zn. The distribution of zinc in the plants at different stages of growth was determined by means of radioautographs. These show that zinc is always present in very high concentration in the terminal portions of the main axis, runners, and laterals, in young, expanding leaves and petioles, in root tips and at points along the roots, in parts of the inflorescences, and in developing and mature seeds. The concentrations decrease in the vegetative organs as they expand and mature. In mature vegetative organs there is usually a higher concentration of zinc in the vascular tissue than in the tissue surrounding it. A higher concentration of zinc is found in the nodes of the runners and laterals than in the internodes. In the nodes themselves the concentration is highest where the amount of vascular tissue is increased by the presence of the vascular traces of petioles and of runners, laterals, or branches.
Earthworms and soil fertility. III. The influence of earthworms on the availability of nitrogen
Authors: Barley KP , Jennings AC
Published: November 2004

When young growing worms of the species Allolobophora caliginosa (Sav.) were fed with a soil containing finely ground plant litter, about 6 per cent. of the non-available nitrogen ingested by the worms was excreted in forms available to plants. The presence of worms in cultures of well-aerated moist soil increased the rate of oxygen consumption and the rate of accumulation of ammonium and nitrate during the early stages of decay. Part of the increase in oxygen consumption was due to an interaction between the earthworms and other decomposers.
The onset of lactation in the Merino ewe and its modification by nutritional factors
Authors: McCance I , Alexander G
Published: November 2004

The results of five series of observations on the type of udder content's and rate of milk secretion in the Merino ewe at about the time of parturition are presented. In general the type of secretion underwent a sequence of changes from a slowly secreted, very viscous material to the rapidly secreted "normal colostrum" and normal milk. It is suggested that the very viscous material should not be described as "colostrum" even when it appears at parturition, and that "colostrum" is a mixture of normal milk with the pre-existing mammary secretions. In ewes fed to gain weight during pregnancy the viscous material had usually been replaced by later-appearing types at parturition; copious lactation usually commenced at parturition or some hours earlier. In ewes fed to lose weight during the last 2-6 weeks of pregnancy, the changes were delayed; prior to parturition the incidence of expressible secretion was lower than in well-fed ewes; the viscous material, or no secretion at all, was often present at parturition, and copious lactation was often not apparent until up to 12 hr after parturition. The delay in onset was not associated with the shorter gestation period of the poorly fed ewes. After the onset of copious lactation, the rate of secretion by poorly fed ewes was about half that of ewes fed to gain or maintain weight during pregnancy. That the Merino is a relatively poor producer of milk even when well fed is indicated by comparison with published data for other breeds. It is concluded that the delayed onset of lactation and reduced rate of production of milk by poorly fed ewes would substantially reduce the chance of survival of lambs in early life.
Fertility investigations on the black earth wheatlands of the Darling Downs, Queensland. III. Mineral nitrogen in the soil and its relation to the wheat crop
Authors: Waring SA , Teakle LJH
Published: November 2004

The level of mineral nitrogen in the soil under fallow and crop was measured for the years 1951 to 1953. Relationships of mineral nitrogen at planting to yield and nitrogen content of wheat grain and straw were examined. Values for nitrate nitrogen at the end of the fallow period ranged most commonly from 10 to 20 µg/g in the surface 2 ft and from 0 to 10 µg/g at 2-4 ft. Approximately one-third of the sites showed an increase from the third to the fourth foot. One site showed extremely high values throughout the profile, particularly at 3-4 ft where a value of 127 µg/g was recorded. Values for ammonia nitrogen were most commonly in the range of 0-3 µg/g . Under the growing crop, mineral nitrogen declined for most depths in the period from planting up to September or October, after which there was little further change to harvest. Uptake of mineral nitrogen was normally greatest from the surface 2 ft of soil. Below 3 ft there were two groups of sites. One group showed moderate to high uptake and the second group low uptake. The low uptake in the latter group provides a reason for mineral nitrogen accumulation below 3 ft at some sites. Mineral nitrogen to 4 ft at planting averaged 126 lb/ac, excluding the one site with exceptionally high values. This was double the mean value of 63 lb/ac for nitrogen recovered in grain and straw, for crops planted in May-June. These figures, combined with trends in the soil under crop, suggest that most of the nitrogen used by the crop was derived from that in the soil at planting. Correlations between mineral nitrogen at planting and grain yield were mostly non-significant, suggesting that in general nitrogen was not an important factor limiting yield. Low grain yield and protein percentage were recorded at a number of sites which had been cultivated more than 50 years.
An effect of lime of residual phosphorus in soil
Authors: Paton DF , Loneragan JF
Published: November 2004

Heavy dressings of lime increased the yield of subterranean clover grown on an acid sand. This increase in yield was mainly due to an increased uptake of phosphorus by the plant. Phosphorus was shown to be leached from the surface of this soil. Lime reduced the leaching of phosphorus. It is suggested that the effect of lime in increasing phosphorus uptake by subterranean clover was due in part to the prevention of the leaching of phosphorus.
Total number of fibres on sheep. II. Estimation by greasy fleece and fibre weights
Authors: Weiler H , Chapman RE , Doney JM
Published: November 2004

The total number of fibres on a sheep (NT) was calculated by the formula NT = GT/g, where GT is the greasy fleece weight and g the mean greasy fibre weight. The variation over the sheep's body of the mean greasy fibre weight and the accuracy of estimation of NT by the above formula were investigated. The latter accuracy was compared with that obtained by means of the formula NT = WT/w, where WT is the clean fleece weight and w the mean clean fibre weight. It was found that the standard error of the estimate based on greasy fleece weight was not much larger than that based on clean fleece weight. (For about 2000 counted fibres, the standard error was of the order of 4.5 per cent. for clean and 6 per cent. for greasy wool.) Moreover, good agreement was found between the number N'T based on the formula NT = WT/w and the number N"T, based on the formula NT = GT/g, which suggests that no appreciable bias is introduced when estimating NT by greasy instead of clean fibres.
Frequency of annual species of Medicago on the major soil groups of the Mcquarie region of New South Wales
Authors: Andrew WD , Hely FW
Published: November 2004

The frequency of eight annual species of Medicago was determined on 10 soil groups in a region climatically favourable for medics. They occurred on nine of these, the overall frequency being in the order M. minima (L.) Bart. > M. denticulata Willd. > M. laciniata (L.) Mill., M. praecox DC., M. tribuloides Desr., and M. orbicularis (L.) Bart. > M. arabica (L.) Huds. and M. confinis Koch. M. minima was more tolerant of variation of soil habitat than any other medic in the region. M. denticulata was most commonly found on the soils of high soluble salt content and showed the greatest tolerance of poor drainage conditions. M. laciniata occurred in greatest abundance on soils of the well-drained brown acid group. M. praecox was most commonly found on soils with a compact gravelly surface. M. tribuloides was recorded on five soil groups but was common only on the black earths. M. orbicularis was confined to the black earth and red loam soils. M. arabica was rarely found, being restricted to lower, fertile, well-drained parts of the landscape, and M. confinis occurred only occasionally and then in association with M. denticulata.
Corrigendum - Frequency of annual species of Medicago on the major soil groups of the Mcquarie region of New South Wales
Authors: Andrew WD , Hely FW
Published: November 2004

The frequency of eight annual species of Medicago was determined on 10 soil groups in a region climatically favourable for medics. They occurred on nine of these, the overall frequency being in the order M. minima (L.) Bart. > M. denticulata Willd. > M. laciniata (L.) Mill., M. praecox DC., M. tribuloides Desr., and M. orbicularis (L.) Bart. > M. arabica (L.) Huds. and M. confinis Koch. M. minima was more tolerant of variation of soil habitat than any other medic in the region. M. denticulata was most commonly found on the soils of high soluble salt content and showed the greatest tolerance of poor drainage conditions. M. laciniata occurred in greatest abundance on soils of the well-drained brown acid group. M. praecox was most commonly found on soils with a compact gravelly surface. M. tribuloides was recorded on five soil groups but was common only on the black earths. M. orbicularis was confined to the black earth and red loam soils. M. arabica was rarely found, being restricted to lower, fertile, well-drained parts of the landscape, and M. confinis occurred only occasionally and then in association with M. denticulata.
The significance of the coat in heat tolerance of cattle. II. Effect of solar radiation on body temperatures
Authors: Dowling DF
Published: November 2004

An experiment was performed to test the effect of solar radiation on the body temperatures of cattle, both clipped and with hair coat, in a clear transparent plastic covering as compared with cattle in a white reflective plastic covering. The mean body temperature of the animals in white plastic coats was 0.15°F lower than that of animals in clear plastic coats. This difference was highly significant statistically (P< 0.001). Animals in both clear and white coats had higher body temperatures than controls without plastic coats. The difference was highly significant, and was about 1.5°F in the clipped animals.