bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in the vaginal contents of the Merino ewe throughout the year.
Authors: Radford HM , Watson RH
Published: November 2004

In 201 of 212 oestrous cycles in 25 adult Merino ewes a fairly uniform sequence of changes occurred in the macroscopic nature of the vaginal contents. This sequence of changes or 'vaginal cycle' was characterized by the presence of mucus, frequently in great amount, during oestrus, and the appearance of quantities of material of a cheesy consistency within 3 days following oestrus. The cheesy material usually persisted for 3 or more days and was succeeded by small amounts of material of a semitransparent or clear serous nature. Two or three consecutive vaginal cycles occupied 32 interoestrous intervals of 31-61 days, most of which occurred during well-defined sexual seasons, and in two instances consecutive vaginal cycles continued throughout the whole of the interval between two well-defined sexual seasons. Some vaginal cycles also occurred during most other anoestrous intervals between sexual seasons. Forty oestrous periods were either associated unusually with a vaginal cycle or were not associated with any regular sequence of changes at all. Twenty-one of these periods occurred at the beginning or during the course of periods of reduced sexual activity.
Studies on the sultana vine. I. Fruit bud distribution and bud burst with reference to forecasting potential crop.
Authors: Antcliff AJ , Webster WJ
Published: November 2004

Fruit bud distribution and bud burst on sultana canes were studied by microscopical examination of bud samples in autumn and direct observation of vines in spring. The percentage of fruitful buds found by niicroscopical examination, and the percentage bud burst and percentage of fruitful shoots found in spring all showed highly significant differences between bud positions in all seasons. In all cases polynomial regressions could be fitted from which the bud position means did not differ significantly. Fruitfulness was always low at the base of the cane, rose to a maximum at about bud position 9, and then fell away. Bud burst also rose rapidly over the first few bud positions but did not show the same pronounced falling off after bud position 9. The percentage of fruitful buds and percentage of fruitful shoots also showed highly significant differences between seasons and between individual vineyards, and highly significant interactions between seasons and vineyards. The major sultana growing districts did not differ greatly in any respect, nor did the separate settlements within the Sunraysia district. The percentage of fruitful buds agreed with the percentage of fruitful shoots except in seasons of low fruitfulness. The examination of 20 canes from each of 10 Sunraysia vineyards gives a satisfactory estimate of the percentage of fruitful buds in May, and this gives a useful forecast of potential crop.
The thickness of cattle skin
Authors: Dowling DF
Published: November 2004

The mean total skin thicknesses (mm) for the breeds sampled were: Devon 8.15, Hereford 6.7, Zebu cross 6.43, Australian Illawarra Shorthorn 6.23, Friesian 6.0, Zebu 5.77, Aberdeen Angus 5.75, Shorthorn 5.69, and Jersey 5.46. The early maturing Shorthorn (Bos taurus L.) and the Zebu (Bos indicus L.) differed significantly in the depth of the papillary and reticular layers, and in the relative thickness of these skin layers. The mean thickness for the papillary layer; was 0.98 mm in the Zebu, 1.40 mm in the Zebu cross, and 1.70 mm in the Shorthorn. Thus the larger, more active sweat glands of the Zebu are more superficial. The corresponding reticular layer averaged 4.45 mm in the Zebu, 4.5 mm in the Zebu cross, and 4.08 mm in the Shorthorn. The thickness of the papillary layer relative to the total skin thickness was 18.3, 23.7, and 29.3 per cent., for the Zebu, Zebu cross, and Shorthorn respectively. The Zebu and the Jersey have relatively thin skins. Therefore a thick skin is not essential for adaptability to a hot environment. Inherent differences in the function of the follicles and the glands of the papillary layer may be critical characteristics for heat tolerance.
The inheritance of immunity to pea mosaic virus
Authors: Yen DE , Fry PR
Published: November 2004

F1, F2, F3, and backcross data from pea crosses between two mosaic-susceptible varieties and two immune varieties indicate that the immune condition is controlled by a single recessive gene, with the proposed designation mo.There is evidence from these data, and a further test of F1, to suggest that the susceptible heterozygote can be separated from the homozygote (mo mo) by: (i) Timing of the appearance of the mosaic symptom after inoculation; (ii) The type of symptom, three being described. The latter, however, appears to depend on the variety, or the parentage in the case of crosses, and the strain or isolate of the virus. These differential susceptibilities are discussed.
Sodium chloride supplementation of high-grain diets for fattening Merino sheep
Authors: McClymont GL , Wynne KN , Briggs PK , Franklin MC
Published: November 2004

In an experiment lasting 60 days the effect of adding sodium chloride to five types of diet was studied in young Merino wethers. The diets used were 100 per cent. oat grain, and 50 : 50 as well as 75 : 25 mixtures of oat grain with lucerne chaff on the one hand, and with wheaten chaff on the other. The addition of 0.25 per cent. sodium chloride to these diets resulted in increased food consumption and improved efficiency of food utilization, with significant increases of 19-58 per cent. in body-weight gains. The unsupplemented diets contained 0.009-0.062 per cent. sodium and 0.05-0.42 per cent. chlorine. There were indications that the lack of sodium was the limiting factor in these diets, and that the sodium requirement of these sheep was greater than 0.06 per cent. of the diet, or 0.88 g per day. Dietary sodium intake did not affect serum-sodium levels, except those of sheep fed on the 50 : 50 mixture of oats and lucerne chaff in which they were significantly higher. Serum-potassium levels were slightly, but significantly, higher in sheep fed on the low-sodium diets. In a second experiment the two groups which had received the 75 : 25 mixture of oat grain and wheaten chaff were fed on the mixture for a further 29 days, but the group which had not received sodium chloride was given 0.37 per cent. sodium bicarbonate. The response was similar to that of the group which received sodium chloride.
The pruinose scarab (Sericesthis pruinose Dalman) and its control in turf
Authors: Carne PB , Chinnick LJ
Published: November 2004

The pruinose scarab (Sericesthis pruinose Dalman) is native to the coastal districts of eastern Australia. It is found in pastures and turf generally, and is frequently the cause of severe damage to lawns and golf links. The biology and ecology of the species are discussed, and also the factors influencing the degree to which turf is damaged by the larvae. Field and insectary tests with DDT, BHC, aldrin, dieldrin, chlordane, and ethylene dibromide were carried out in 1955-1956. None of these insecticides effectively controlled infestations if applied during the winter months. Aldrin and dieldrin gave satisfactory results during warmer weather in autumn. Aldrin was particularly effective in controlling existing infestations. Dieldrin caused a less rapid kill, but owing to its superior persistence, it may serve to "proof" turf against reinfestation for several seasons.
A comparison of three low-persistence viruses of the strawberry
Authors: Stubbs LL
Published: November 2004

Three low-persistence viruses of mild, severe, and intermediate virulence, respectively, on strawberry (Fragaria vesca L.) seedlings have been isolated from Australian strawberry varieties. Studies concerned with the relationship of these viruses have shown that both the intermediate and severe types will multiply in F. vesea plants previously infected with the mild type of virus. Moreover, infection with this latter virus does not delay symptom development when the plants are inoculated with either the intermediate or severe types, and symptoms are intensified in each case. The mild and severe viruses were separated from mixed infections by serially transferring aphids (Pentatrichopus fragaefolii (Cock.)) bred on the infected plants. Separation was achieved by chance, and not as a result of different levels of persistence in the vector which the experiments were designed to exploit. In most instances both viruses were transmitted. The identity of the viruses is discussed in relation to known cross-protection phenomena.
Wool follicle development in the New Zealand Romney and N type sheep. II. Follicle population density during foetal development
Authors: Stephenson SK
Published: November 2004

Quantitative aspects of follicle initiation and development have been studied in a series of N-type and New Zealand Romney foetuses. Density of the follicle population and ratios of secondary to primary follicles were examined on 13 positions of the body which covered the main wool-bearing areas, the face and head, and the limbs. Primary follicle development is initiated first on the head and limbs and throughout subsequent development these regions are most advanced. Primary follicle density reaches a maximum between 75 and 90 days of foetal age, after which it decreases as a result of skin growth. Secondary follicle initiation is more rapid on the wool-bearing areas of the body, and higher ratios of secondary to primary follicles are recorded from these regions. No real differences have been found between N-type and New Zealand Romney foetuses in population density of the different follicle types at any age or in the number of secondary follicles developed per primary follicle. The growth of larger primary fibres and follicles in N-type foetuses is not accompanied by, and does not result from, a lower density of primary follicles. There does not appear to be any marked relation between the decreasing density of primary follicles after 90 days of foetal age and the initiation of secondary follicle anlagen. This fact, and the absence of any differences in the number of secondary anlagen formed per primary follicle in N-types, suggest that crowding in N-types is not a limiting factor in the formation of secondary follicle anlagen.
Effect of level of feeding on the variability of fibre diameter in four breeds of sheep
Authors: Short BF , Fraser AS , Carter HB
Published: November 2004

Primary and secondary fibres show a differential response to changes in nutrition. Distances between primary and secondary follicles are always greater than distances between secondary follicles irrespective of their relative fibre diameters. It is likely therefore that primary follicles have a higher competitive efficiency than secondary follicles, and that the efficiency concept must be reformulated to accommodate differential responses of adjacent follicles to changes in feed level.
Fleece characters and their influence on wool production per unit area of skin in Merino sheep
Authors: Young SSY , Chapman RE
Published: November 2004

The variations in fleece characters and the dependence of wool production per unit area of skin on these characters were studied with 15 sheep in both a medium and a strong-wool strain of Merino. Small but significant differences in staple length and fibre diameter were found between regions on the body, whereas differences in density were large. The variation in density was about three times as large as those in staple length and fibre diameter. Distinct dorsoventral and anteroposterior gradients over the body existed for fibre density, but not for staple length and fibre diameter. The influences of the fleece characters on wool production per unit area were somewhat different in the two strains, and changed with level of production. Among the medium-wool sheep, fibre density had the largest effect on production, with staple length less and mean fibre cross-sectional area least. Among the strong-wool sheep, length was more important than density, which in turn was more important than fibre cross-sectional area. The combined data indicated that as mean wool weight per unit area increased, the influence of density rose to a maximum and then diminished, whereupon mean fibre volume became the main contributor to wool weight. For different positions on the body of individual sheep, the dependence of wool production per unit area on the fleece characters was found to be similar in the two strains. Fibre density had the major effect in determining the level of production, whereas the influences of staple length and fibre area were negligible.
Induction of mutation in the west Australian Blue Lupin (Lupinus digitatus forsk) by X-irradiation
Authors: Gladstones JS
Published: November 2004

Dry seeds of Lupinus digitatus Forsk. were given X-ray doses ranging from 10 to 125 kr. The highest doses tolerated were between 70 and 90 kr, but for the practical induction of mutations the optimum range is probably 40–60 kr or less. Altogether 132 mutations were recorded. One of these, an early-flowering mutant, could be of value. Nearly all the milder mutations segregated as simple recessives, but there was at least one dominant. Many of the more drastic mutations segregated irregularly. The progenies of individual X1 inflorescences were sown separately in the X2, and the pattern of appearance of mutations showed that, whereas the seeds produced in most individual X1 branch inflorescences were descended from a single cell in the irradiated seed, those in the apical inflorescences were often descended from two or more cells. In very few cases were all the seeds of an X1 plant found to be descended from the same original cell.
Significance of sweating in heat tolerance of cattle
Authors: Dowling DF
Published: November 2004

Evidence is presented that sweating is of importance to cattle as a method of regulating body temperature in a hot, dry environment. Cattle were covered with polyethylene coats, which prevented the vaporization of skin moisture from the body surface. They were then exposed to high atmospheric temperatures. Significant differences (P < 0.001) between their rectal temperatures and those of the control animals were demonstrated. It is concluded that, in conditions of high air temperature and radiation and low humidity, differences in heat tolerance between one animal and another may be due to differences in the ability to dissipate heat in the vaporization of sweat on the skin surface.
Flower initiation in Trifolium subterraneum L. 1. Analysis of the partial processes involved
Authors: Evans LT
Published: November 2004

The influence of various temperature and photoperiod regimes on flower initiation and flowering in eight strains of T. subterraneum has been examined, using the controlled environment facilities of the Earhart Laboratory. Flower initiation in subterranean clover appears to be under the control of three interacting partial processes, two of which are synergistic and promotive while the third is inhibitory. The promotive processes are possibly both light-independent, one being favoured by high temperatures and the other (the vernalization process) by low temperatures. The inhibitory process, on the other hand, is restricted to the diurnal dark period and is favoured by high temperatures. The interaction between the vernalization and dark inhibitory processes is such that in the absence of dark inhibition no vernalization is required by any strain, while on. the other hand sufficient vernalization can apparently overcome all dark inhibitory effects. Treatment with gibberellic acid eliminates the need for vernalization by plants of at least one early-flowering strain when. grown in short days at high temperatures. The strains of subterranean clover differ markedly in their responses to the three partial processes. In their response to the dark inhibitory process two strains are more affected by night temperature than by night length, while in two other strains the opposite is the case, which suggests that the dark inhibitory process could be resolved into more than one component.
Studies on the metabolism of detached tobacco leaves. 1. The influence of potassium nutrition on the growth of tobacco and the quality of cured leaf
Authors: Lovett WJ
Published: November 2004

Cured tobacco leaf of good quality was produced from plants grown in sand culture in a glass-house. A correlation was noted between potassium nutrition and quality, and moreover, poor quality leaf from low potassium levels showed similar symptoms to those of the 'trashy leaf' of commercial practice. It is concluded that potassium levels in the culture medium, and hence within the plant itself, are related to leaf area, leaf weight per unit area, and loss of fresh weight during curing-characteristics which find expression in the commercial grading system. Colour changes which appeared to be related to the level of potassium supplied were also observed during curing.
Wool follicle development in the New Zealand Romney and N type sheep. IV. Pre-natal growth and changes in body proportions
Authors: Stephenson SK
Published: November 2004

Growth, and the relative growth gradients over the body, have been studied in N-type and normal Kew Zealand Romney foetuses. Body weights, and a series of linear measurements taken between different points over the body, have been obtained from a series of foetuses of known ages. Huxley's allometric growth ratios have been calculated from these measurements by using the least squares regression. There are no significant gromth differences between foetuses belonging to the different AT-genotypes of the New Zealand Ronmey. Foetuses belonging to the New Zealand Romney and some British breeds grow at a faster rate than South African Merino foetuses studied by Malan and Curson (1936a) and Cloete (1939). Relative growth gradients over the body are, in general, similar to those of other mammals, but the results do not support the theory of Cloete (1939), that the relative growth rate of a part of the body is solely a function of the age of the part.
Wool follicle development in the New Zealand Romney and N type sheep. V. The pre-natal relationships between growth, skin expansion, and primary follicle number
Authors: Stephenson SK
Published: November 2004

A method is presented for estimating changes in primary follicle number on different regions of the body of the sheep foetus from linear growth measurements and primary follicle density determinations. The major factor controlling the initiation of new primary follicle anlagen on different regions is shown to be rate of skin expansion, and therefore it appears probable that there is a competition effect between anlagen during this phase of development. After allowance is made for area increases, there are still real differences between regions in the rates of initiation of primary anlagen. There is also evidence that, during the period of primary anlagen initiation, foetuses with a greater surface area have a greater total number of primary anlagen.
The breaking of seed dormancy of some legumes by carbon dioxide
Authors: Lipp AEG , Ballard LAT
Published: November 2004

Treatment of imbibed seeds with an atmosphere of 2.5 per cent. carbon dioxide is shown to be a powerful means of breaking the dormancy of seeds of a range of small-seeded legumes. On the bases of amount and rate of germination this method is at least as effective as, and usually superior to, holding imbibed seeds at 3-5°C for 3 days. Moreover, the carbon dioxide treatment was effective in most of the cases where cold treatment was ineffective. Some implications of these findings are indicated.
Ratios as criteria for selection in animal or plant breeding, with particular reference to efficiency of food conversion in sheep
Authors: Turner HN
Published: November 2004

Ratios are frequently advocated as criteria for selection, in either animal or plant breeding; for example, production per unit of food eaten is currently receiving attention, particularly with Merino sheep. Clean wool weight per head (W) is already widely used as a selection criterion, but suggestions have been made that wool weight per pound of body weight (B) or per unit skin area (estimated as B0.6, or measured) should be used instead, as estimates of the efficiency of conversion of food into wool. This paper develops formulae for writing the heritability of any ratio, as well as its genetic correlations with its numerator and its denominator, in terms of the relationships between the numerator and the denominator. From these formulae the likely result of selecting for the ratio can be predicted, for a given range of values of the genetic and phenotypic parameters of the numerator and denominator. The formulae can be used for any ratio, provided gene x environment interactions and epistasis can be neglected. In particular, it is shown that the genetic correlation between W and W/B or W/B0.6 is consistently positive for a wide range of values of the parameters of W and B, so that selection for high wool weight will also increase efficiency, as measured by either ratio. The genetic correlation between B and W/B or W/B0.6, on the other hand, is nearly always negative, sometimes very strongly so, and selection for high values of W/B or W/B0.6 will decrease body weight. The theoretical predictions are confirmed by results from experimental selection groups, in which the observed correlated responses are all in the predicted direction, and in most cases agree well in magnitude. It is suggested that more information is required on the importance of body size itself, in relation to factors such as fertility and survival, before the value of selection on W/B or W/B0.6 can be accurately assessed.
Seed soaking as a method of supplying the molybdenum requirements of lettuce and tomatoes
Authors: Wilson GL , Notley LF
Published: November 2004

Lettuce and tomato seeds were soaked in solutions of sodium molybdate in an attempt to provide the whole of the molybdenum requirements of these species. Dry weight comparisons were made between plants grown from soaked seed in molybdenum-deficient solutions, and those grown from untreated seed in complete solution. The requirement of tomatoes was met by soaking seeds in solutions containing 5000 and 50,000 p.p.m. of molybdenum for 8 hr, but satisfactory results were not obtained with lettuce. The ability of soaked seeds to retain molybdenum against outward diffusion during germination is important. Well-washed, soaked seeds may lose much in this way. The implications of such loss to the soil are discussed.
The determination of milk yield in the Merino ewe
Authors: McCance I
Published: November 2004

Yield was measured by hand milking following injection of posterior pituitary extract (PPE) to obtain milk ejection. Lambs put with ewes hand milked after 2 doses of 5 i.u. of PPE could obtain little or no milk. Yield depended on the interval between milkings, the rate of secretion being apparently faster in the first 2 hr. The effect was less marked as lactation declined. Yields were independent of time of day and speed of milking. When successive yields were used to rank ewes in order of performance, the rankings were always significantly concordant. Earlier applications of the method had no detectable effect on later lactation. It is concluded that the method provides a simple means of obtaining useful estimates of milk production.
Method for continuous urine collection from unrestrained wethers and other large animals
Authors: Budtz-Olsen OE , Dakin HC , Morris RJH
Published: November 2004

Simple equipment is described by which accurately timed, continuous collection of uncontaminated urine from freely mobile wethers may be carried out.
The significance of petiole length, leaf area, and light interception in competition between strains of subterrranean clover (Trifolium subterraneum L.) grown in swards
Authors: Black JN
Published: November 2004

Three strains of subterranean clover differing in leaf development were grown in pure swards and in all combinations in mixtures. The strain Yarloop has relatively few large leaves held on long petioles; Tallarook has many small leaves and short petioles; Bacchus Marsh is intermediate in all these respects. The swards were grown in boxes and were sampled on four occasions during the period of vegetative growth. Leaf area in each 2 cm layer of the sward was determined separately, and for both strains in the mixed swards, and measurements of the light intensity reaching each layer were obtained. Root weights were determined for all swards and separately for each component of the mixed swards. Examination of the dry weights showed that the growth of the strain having the lesser petiole elongation was suppressed. In the extreme instance Tallarook was so suppressed when grown with Yarloop that in the final inter-sampling period it grew completely in the dark, and lost about half its dry weight. Bacchus Marsh also suppressed Tallarook, but to a lesser extent, while Bacchus Marsh was itself suppressed in competition with Yarloop. The amount of light energy intercepted by the two components of the mixed swards was calculated from the leaf area and light profiles, and confirmed the importance of the spatial distribution of leaves in plant competition. It was concluded that, in the absence of defoliation, the success of a strain under competition was associated with its potential petiole elongation.
Comparison of estimates of repeatability and heritability for some production traits in Merino rams and ewes. 2. Heritability
Authors: Young SSY , Newton Turner H , Dolling CHS
Published: November 2004

Heritability estimates were calculated for 10 traits in rams and ewes of a medium-woolled strain of Australian Merino sheep. The traits were greasy wool weight, clean scoured yield, clean wool weight, body weight, wrinkle score, face cover score, fibre population density, fibre diameter, staple length, and crimps per inch. Estimates were made by dam-offspring correlations, measurement on the dams being at 15-16 months, on daughters at 15-16 months, and on sons at both 10-12 and 15-16 months. All estimates for both sexes lay between 0.3 and 0.6, except for fibre population density (0.24) and fibre diameter (0.12) in rams at 15-16 months and for clean wool weight (0.29) and face cover score (0.29) in rams at 10-12 months. The only significant sex difference lay in the lower figure for fibre diameter in rams at 15-16 months, but this is of doubtful importance as the corresponding figure for rams at 10-12 months (0.37) did not differ significantly from the ewe figure. All traits may be considered highly heritable, and the high values for the yearling rams indicate that consideration might be given to the selection of rams for production traits at an earlier age than the traditional one of 18 months or older.
The significance of coat type in cattle
Authors: Turner HG , Schleger AV
Published: November 2004

A system of subjective scoring of cattle coats, ranging from very sleek to very woolly, is described. It has been applied to about 1600 animals, of which 500 were Hereford and Shorthorn cows and the rest their progeny from matings in four years to British breed and Zebu bulls. Consistency of scoring within and between observers is satisfactory. Highly significant differences between animals of the same breed persist through different seasons. The repeatability of coat score is 0.6 or more over intervals of up to 17 months. Effects of season, age, and sex are described. Heritability of coat score is estimated at 0.63. Coat scores are well correlated with body temperatures and respiration rates. Coat score and post-weaning growth rate of British breed calves are correlated to such a degree that coat score can be superior to a record of body weight as an estimate of growth capacity. The genetic correlation between coat score and growth rate is high in the British breeds. Evidence of the relation between coat score and growth rate in Zebu cross calves is inconclusive. The observed relationships are discussed with particular reference to their physiological causes. The results indicate the potential value of coat characters in selecting tropical beef cattle. The degree to which these results may be applicable to other populations in other environments is discussed. It is concluded that a sleek coat is important in favouring heat dissipation, but it may have even greater significance as an indicator of metabolic efficiency or of capacity to react favourably to stress.
The effect of varying row spacing and seeding density within rows of the perennial grass component of a mixed sward
Authors: Andrew WD
Published: November 2004

With a Phalaris tuberosa L.–Trifolium subterraneum L. association, seeding the grass in widely spaced rows in 1950 increased the total productivity of the pasture over the first 6-year period (1951–1956) by comparison with normal 7 in. row seeding. The annual production was greater in four years and did not differ significantly in the other two. At first the increased yield was due to annual species, mostly T. subterraneum, exploiting the larger inter-row environment. This was followed by greater production of perennial grass in the wide row treatments. It is suggested that this was the result of greater availability of soil nitrogen provided by symbiotic fixation. Reducing the sowing rate, by halving the seeding density within rows, had no effect on the yield per acre of any of the species in the pasture.
Bitter pit in the apple variety Cleopatra in Tasmania in relation to calcium and magnesium
Authors: Martin D , Lewis TL , Cerny J
Published: November 2004

When spray treatments were applied to half-trees of Cleopatra apples, it was shown that magnesium nitrate increased the incidence of pit and calcium nitrate decreased it. There was a suggestion that borax decreased the effectiveness of the calcium nitrate treatment. Magnesium or calcium nitrate, with or without borax, did not affect the potassium, magnesium, phosphorus, or nitrogen content of the fruit cortex. Calcium nitrate in 1959 increased the calcium content but magnesium nitrate had no effect. There was no significant difference in the content of potassium, magnesium, or phosphorus between 1958 and 1959, but the calcium content was 3.3 times as high in 1958. Pit incidence was low in 1958 and high in 1959. No significant difference in content of these four elements could be demonstrated between sound and pitted fruits. The results support the view that calcium is the critical element in pit incidence and that magnesium may play an important part.
Hornedness na polledness in sheep. III. The inheritance of horns in Dorset Horn ewes
Authors: Dolling CHS
Published: November 2004

Horns in Dorset Horn ewes have been shown to result from the action of the dominant gene P' which leads to horns in Merino ewes, or from a dominant gene closely linked with P'. If they result from P' itself, which is more likely, the Dorset Horn breed is homozygous for P'.
The synthesis of vitamins in the rumen of sheep. I. The effect of diet on the synthesis of thiamine, riboflavin, and nicotinic acid
Authors: Buziassy C , Tribe DE
Published: November 2004

The levels of thiamine, riboflavin, and nicotinic acid in the rumen of sheep, fed a variety of diets, were determined by chemical methods. The intakes of dry matter, B vitamins, protein, non-protein nitrogen, and energy were recorded, and the rumen volumes on each diet were estimated. The diets were mainly of a semi-synthetic type, consisting of sodium hydroxide-treated straw supplemented with varying amounts of casein, urea, starch, sugar, and minerals. When the intake of the B vitamins was high, little microbial synthesis took place in the rumen. However, when the diet offered was deficient in the R vitamins the levels of synthesis were high. There was no apparent relationship between the levels of the vitamins in the food and the levels in the rumen liquid. However, a relationship between the nitrogen intake and the vitamin levels in the rumen was found. This relationship was marked when widely differing levels of B vitamin were fed. The total substitution of the dietary protein (casein) by non-protein nitrogen (urea) did not influence the synthesis of thiamine and riboflavin but did depress the synthesis of nicotinic acid.
Cyclic changes in the follicles and hair coat in cattle
Authors: Dowling DF , Nay T
Published: November 2004

Evidence is presented to show that in cattle the hair follicles undergo two resting and two active phases in a year, even in a tropical environment.
Rate of absorption of hexoestrol from the ear of sheep
Authors: Lamond DR
Published: November 2004

Pellets containing varying ratios of hexoestrol to lactose were implanted into ears of sheep, and the proportion of hexoestrol absorbed during periods of 7 to 56 days, was determined. The results of two factorial experiments showed that absorption was more rapid when pellets were placed in the base of the ear and that absorption from individual pellets was not influenced by implanting in pairs. In addition, hexoestrol in pellets containing high proportions of lactose to hexoestrol was more rapidly absorbed than in those containing small proportions of lactose.
Influence of nutritional level during pre-natal and early post-natal life on adult fleece and body characters
Authors: Schinckel PG , Short BF
Published: November 2004

The effect of high and lox- levels of feed intake during pregnancy in ewes, and from birth to 4 months of age in their lambs, on adult body weight and wool production has been studied. As compared with the corresponding high intake groups, lambs from the low intake ewes were 34% smaller at birth and 9% smaller at maturity. They also had c. 15% fewer wool follicles per sheep, and produced c. 8.5% less wool as adults. Low levels of feed intake between birth and 4 months resulted in a slower growth rate and a reduction (c. 10%) in mature body weight. The maturation of the follicle population was delayed by a low feed intake in this period but no permanent reduction in numbers was observed. The post-natal low intake group produced c. 12% less wool as adults, owing to a smaller (c. 10.5%) fibre weight. The major effect on wool growth potential of low levels of nutrient supply during pre-natal life was a restriction of body size and total number of follicles, while restriction of nutrient intake during early post-natal life reduced the capacity of the individual follicles to produce fibre.
Studies on mineralization of sulphur from soil organic matter
Authors: Barrow NJ
Published: November 2004

Determination of the sulphate in water extracts of soil by the method of Freney (1958) was shown to overestimate available sulphur. Further, changes in sulphate as measured by this procedure sometimes bore little relationship to presumed changes in available sulphur. Extraction of the soil with a 0.15% solution of calcium chloride seemed to give a better indication of available sulphur. When soils were dried there was an immediate increase in inorganic sulphate. It was suggested that this inorganic sulphate split from organic sulphates present in soil and it was shown that it was available to plants. This can greatly affect the results of pot experiments with sulphur, for even if two soils are dried at the same temperature the relative availability of sulphur may be no indication of the relative availability when the soils were fresh. Incubation of a soil taken from beneath unfertilized native pasture did not result in any mineralization of sulphur. It was concluded that this was a consequence of a low sulphur content in the decomposing portion of the soil organic matter. When the organic matter content of the soil was increased by applying superphosphate and growing clover, sulphur was mineralized when the soil was incubated.
The renal response of sheep to prolonged ingestion of sodium chloride
Authors: Potter BJ
Published: November 2004

The renal function of sheep; after the ingestion of solutions containing 0.89% sodium chloride and 0.5% sodium sulphate, 1.14% sodium chloride and 0.2% sodium sulphate, and 1.3% sodium chloride offered as the only source of drinking water for a period of 6 months, was studied and compared with that of sheep fed on an identical diet and provided with rain-water. The daily fluid intake and the quantity of urine excreted increased in proportion to the concentration of the sodium chloride ingested. The glomerular fi1tration rate and filtration fraction were increased in the sheep drinking the saline water, but the renal plasma flow was only slightly reduced. The observations indicate that the sheep is able to tolerate relatively high salt water by virtue of a renal adjustment which favours increased filtration and so the elimination of the ingested salt.
Opal phytoliths and mineral particles in the rumen of the sheep
Authors: Baker G , Jones LHP , Wardrop ID
Published: November 2004

Examinations of various plant feeds and the contents of the rumen of sheep have revealed the presence of opal phytoliths both free and in situ in the plant tissues. Opal phytoliths make up much the greater proportion of the total particulate mineral matter in both the feeds and the rumen contents but adventitious particles of minerals and other inorganic or metallic fragments have been detected. All these particles have a higher specific gravity than plant feed and so tend to gravitate to the ventral regions of the rumen. Observations on the rumeri walls of sheep suggest that opal phytoliths and other mineral particles may affect the depth of the strata corneum and granulosum.
Seasonal and regional variations in coat characteristics of dairy cattle
Authors: Berman A , Volcani R
Published: November 2004

The annual cycle in coat growth and shedding rates was investigated in Holstein and Syrian x Holstein cattle (3.1-6.2% relationship to the Syrian) under natural conditions in three different climatic regions of Israel. Hair quantity, coat thickness, and hair diameter were tested monthly on an area of 100 cm2 on the thigh. 541 samples were taken during 1 year. Cows were tested in two herds in the Jordan Valley (mean annual temperature 23�C), one herd in the Coasral Plain (mean annual temperature 20.4�C), and one in the Jerusalem area (mean annual temperature 17.5�C). Hair quantity and coat thickness in the Jordan Valley were very- significantly smaller than in the other two regions. A clear cycle was observed in these three factors. Weight of hair reached the peak In January, then decreased to 50% of the maximum weight during April-Nay and increased again during May-June, reaching 75% of the maximum weight. From October hair growth continued, to the peak in January. Variations in coat thickness differed from those in weight of hair during summer, when coat thickness stayed lox and stable until autumn. Hair fibre diameter was lowest between December and March, then increased sharply until June. Hair quantity and coat thickness decreased more and faster in the Jordan Valley. These results show that day length is not the only factor influencing the annual cycle of hair quantity and coat thickness but that, apparently, the air temperature? are of influence too. In this experiment hair diameter was influenced only by variations in day length.
Comparative effects of summer and winter conditions on the growth of six species of pasture legumes subjected to various nutrient levels
Authors: Millikan CR
Published: November 2004

The results of a series of water culture experiments is reported in which the comparative effects of summer or winter conditions respectively on the growth of subterranean clover (Trifolium subterraneum L. var. Dwalganup), red clover (T. pratense L. certified), white clover (T. repens L. 'mother strain' certified), cluster clover (T. glomeratum L.), suckling clover (T. dubium Sibth.), and barrel medio (Medicago tribuloides Desr. strain 173), in a complete nutrient solution and in solutions deficient in either potassium, phosphorus, or magnesium were studied. In the complete nutrient solution, the mean daily increment in dry weight (T+R) for each species was less in winter than in summer. Rates of growth (T+R) of red clover, white clover, cluster clover, and suckling clover were each reduced more by winter as compared with summer conditions than was that of barrel medic, while a similar comparison also showed that white clover and suckling clover were more affected than subterranean clover. For subterranean clover and barrel medic (T+R) differed little as between the summer and winter tests respectively, but (T+R) for red clover, white clover, cluster clover, and suckling clover was significantly depressed under winter conditions. Significant season X species interactions occurred. Differences in seasonal conditions had no effect on the percentage top of five of the species when grown in the complete nutrient solution, but in the sixth species (barrel medic) winter conditions when compared with summer conditions favoured top growth at the expense of root growth (i.e. increased percentage top). Within any species there was no significant seasonal effect on the depression in (T+R) caused by a deficiency of either potassium, phosphorus, or magnesium. Between species certain significant effects were unrelated to seasonal conditions for potassium or phosphorus deficiencies, but with magnesium deficiency significant species x season interactions occurred for (T+R). Within species, the mean effect of potassium deficiency in reducing percentage top in all tests was significant for white clover, barrel medic, and suckling clover, but the season x potassium level interaction was significant for cluster clover only. There were no significant differences between species. Phosphorus deficiency caused a significant reduction in percentage top within all species under both summer and winter conditions, but no significant season x phosphate level interaction occurred. The percentage top of white clover was reduced more than that of subterranean clover in summer, but not in winter. Magnesium deficiency produced a significant reduction in the percentage top of white clover and barrel medic in winter, but not in summer. The season x magnesium level interaction effect was significant for white clover. Several significant species x magnesium level interactions for percentage top were also recorded.
The life cycle of Psorergates ovis Womersley, the itch mite of sheep.
Authors: Murray MD
Published: November 2004

The life cycle of Psororgatos ovis is completed in 5-6 weeks, and there are six stages : the egg, larva, protonymph, doutonymph, tritonymph, and the male or female adult. All stages are found under the stratum corneum, but adults and occasional tritonymphs are also found on the surface of the skin. Only the adult is motile and is responsible for the spread of infestation over the body of sheep. Adult mites transferred most readily to cloths which were placed next to the skin, which indicated that they primarily are responsible for transference of infestation from sheep to sheep. Adults did not leave the skin rapidly; at 20�C, they survived away from sheep for only 24-48 hr at R.H. 92 and 100% and they died of desiccation within 24 hr at R.H. 54 and 75%. These findings suggest that natural transference of infestation is mainly by adults when the fleece is short, which would explain the slow spread of infestation which has been observed in the field.
The effect of constant and fluctuating temperatures on the permeability of the hard seeds of some legume species
Authors: Quinlivan BJ
Published: November 2004

Hard seeds of Lupinus digitatus Forsk., Lupinus luteus L., Medicago tribuloides Desr., and Trifolium subterraneum L. (Mt. Barker, Dwalganup, and Geraldton strains) were subjected to constant temperatures of 60 and 140°F, and to fluctuating temperature ranges of 60–115°F, 60–140°, and 60–165°, for a period of 5 months. The temperature fluctuation treatments were set to follow patterns similar to those experienced on the soil surface during the summer months in the agricultural districts of Western Australia. Increased permeability, i.e. an increase in the percentage of seeds permeable to water, took place under all temperature conditions. The lowest increase occurred at a constant temperature of 60°F. A constant temperature of 140° gave a relatively higher increase. All three temperature fluctuation treatments increased the permeability as compared with the constant temperatures, with maximum effect at a range of 60-140°F. Increasing the range to 60–165° did not increase the permeability. With the exception of L. digitatus all species subjected to temperature fluctuations showed a rapid increase in permeability over the first 2 or 3 months. Beyond this point the rate of increase was very slow. The permeability or softening pattern followed by L. digitatus was almost the direct opposite to that of the other species. Of the three strains of T. subterraneum, Mt.. Barker showed the highest increase in permeability under temperature fluctuations and Geraldton the least.
Energy metabolism in the starved new-born lamb
Authors: Alexander G
Published: November 2004

New-born lambs were treated in one of three ways: (a) killed within 2 hr of birth; (b) starved at 23°C in 'still air'; (c) starved at approximately 9°C in moving air. Starved lambs became hypothermic and hypoglycaemic and lapsed into coma or convulsions shortly before death, which occurred between 16 hr and 5 days. Survival was generally longer when starvation was at the higher temperature. The size of the energy reserves was estimated from the fat and glycogen content of lambs killed at birth or near death from starvation; protein utilization during starvation was estimated from nitrogen excretion in the urine and the increase in urea in the blood. Fat and carbohydrate reserves appeared to be exhausted near death from starvation. Fat was the largest source of energy, and there was twice as much fat available at birth in lambs from well-fed ewes as in lambs from poorly fed ewes. Carbohydrate reserves in the liver and muscle appeared unaffected by pre-natal nutrition. Protein utilization increased progressively throughout starvation at a rate independent of pre-natal nutrition, and the total amount of protein utilized depended on the period of survival. Total energy reserves in lambs from well-fed and poorly fed ewes were approximately 1000 and 400 kcal respectively estimated as above or from calorimetric studies during starvation.