bluuebunny/crossref_metadata_2025 huggingface dataset:
Inheritance of two seedling characters in Sorghum almum Parodi, and cross pollination within S. almum and between S. almum and S. halepense (L) Pers.
Authors: Pritchard AJ
Published: November 2004

An albino seedling character in Sorghum almum Parodi was shown to be tetrasomically inherited. Segregation ratios for a pale green seedling character were very variable, and it is probable that more than one gene is involved. With the albino seedling character as a marker gene, it was found that the average natural crossing in S. almum was approximately 54% at one location and 70% at another. The maximum natural crossing between S. almum and S. halepense (L.) Pers. was 57%, but the mean was only 20%. This may indicate that some S. almum plants exhibit a degree of genetic isolation from S. halepense when these species are grown together under natural conditions.
Varietal variation in the isoflavone content of subterranean clover: Its estimation by a microtechnique
Authors: Francis CM , Millington AJ
Published: November 2004

The isoflavone content of 46 subterranean clover varieties was estimated by a microtechnique which allowed of the semiquantitative analysis of 100 leaf samples per day. The relative proportions of the three major isoflavones varied greatly between varieties. Twenty-four of the varieties tested were low in formononetin. When crushed leaf blade samples were allowed to stand prior to the addition of ethanol there was a decline in detectable genistein. The rate of decline was dependent on the temperature during standing.
Rumination in sheep. II. The circadian pattern of rumination
Authors: Pearce GR
Published: November 2004

The rumination responses of caged sheep were measured under conditions of once daily, twice daily, and ad libitum feeding. The amount of rumination per day, in terms of the number of boli, the number of chews, and the number of chews per bolus, varied according to the level of intake and the physical and chemical composition of the food. Under once daily (at 0900 hours) feeding conditions the circadian (24-hr) pattern of rumination was characterized by a period of inactivity (lag period) after eating, followed by a period of increasing intensity of rumination leading up to a maximum intensity in the early hours of the morning, then a period of reduced activity up to the next feeding time. Where the detail of this curve varied it did so in accordance with consistent trends. For example, a high level of roughage feeding was associated with a shortened lag period and a less skewed distribution curve, while a low level of feeding resulted in a prolonged lag period and a highly skewed distribution. The pattern retained its general characteristics despite changes in the chemical and physical composition of the ration and despite variation in the method of administration of the ration. Circadian patterns resulting from twice daily (morning and afternoon) feeding varied according to the ingredients of the respective meals. Ad libitum feeding resulted in a loss of definition of the pattern; rumination tended to be distributed without apparent order over the whole day. It is suggested that the initiation of rumination after feeding, and subsequent rumination activity, is governed by some inhibiting factor(s).
Some effects of leaf area control on the yield of wheat
Authors: Davidson JL
Published: November 2004

The effects on var. Olympic wheat of maintaining the leaf area index (LAI), once attained, at approximately 3 and 1, and of removing all leaves or half of each leaf at ear emergence, were assessed by comparison with an uncut crop (maximum LAI = 12). Leaf stripping at ear emergence had no significant effect on grain yield. Leaf area maintenance at LAI values of 3 and 1 greatly decreased grain yield by reducing both grain number per spikelet and mean grain weight by about 50%. These effects followed earlier reductions in the rate of development of the shoot apex. The results are discussed in relation to the yields obtained and conclusions reached by English workers, and to possible scope for yield improvement.
The transference of nitrogen from pasture legumes to an associated grass under several systems of management in pot culture
Authors: Simpson JR
Published: November 2004

The extent of underground transference of nitrogen from three pasture legumes, each growing in association with a grass, has been studied in pot culture under several systems of management during the first 12–18 months after sowing. The three legumes performed quite differently. Subterranean clover did not release any nitrogen until senescence and then produced a rapid transference. White clover was competitive for nitrogen until the autumn-winter period. Lucerne released nitrogen gradually over the whole experimental period. Frequent defoliation of the legumes reduced competition for nitrogen by white clover but also reduced transference from the other legumes. Killing the perennial legumes produced only a small temporary increase in transference. Wilting and temporary drying treatments also reduced the transference. Thus there was no evidence that the nitrogen transference from lucerne was due to a shedding or decay of nodules induced by defoliation; it could equally well be due to direct excretion of nitrogen from the intact root system. The significance of the results in pasture establishment in infertile areas is discussed.
Variations in the carbohydrate content of lucerne and the effect on ensilage
Authors: Melvin JF
Published: November 2004

Variations in the more accessible carbohydrates of lucerne were determined at different seasons, maturities, and times of day and their effect on ensilibility was examined. Sugar and starch contents were not affected by season of growth. Sugar contents decreased with increase in maturity, but starch was unaffected. Samples cut in the afternoon were higher in sugar and starch contents than those cut in the morning. The sugars were almost completely fermented in the first 2 days of ensilage. Fermentation of starch appeared to be limited. Silage pH was unrelated to sugar content, but its correlation with the ratio sugar/buffer index was highly significant.
Stem infection of tobacco plants with three strains of Peronospora tabacina Adam
Authors: Mandry M
Published: November 2004

The pathogenicity of three strains of Peronospora tabacina Adam., APT1, APT2, and APT3, in stems of tobacco plants and their effect on the development and survival of plants were determined. (1) APT1, APT2, and APT3 are highly pathogenic in stems of cv. Virginia Gold and in two varieties of Oriental tobacco. Stems of cv. SO1 plants (resistant line) are unaffected by the original strain APTl but are severely infected by the two new strains APT2 and APT3. (2) Severe stem infection developed in injected plants at a temperature of 15–25°C and R.H. higher than 80°. Mycelium of the pathogen rapidly invaded all stem tissues. Of affected plants, 40–75% were killed and the survivors remained dwarfed with small and severely wilted leaves. Under humid and cool conditions APTl and APT3 were more destructive than APT2. (3) Mild stem infection developed at a temperature of 20–30°C and R.H. not higher than 70%. Under these conditions APT2 was more pathogenic than APTl or APT3. The mycelium of the fungus was associated mainly with the vascular system. General plant growth and leaf areas were only slightly reduced. (4) It is concluded that present methods of controlling blue mould in tobacco plants need extension. Consideration should be given to breeding for resistance to stem infection with due regard to the two new strains of P. tabacina described in this paper and the probable occurrence of further physiologic strains of this pathogen in the future.
The rates of production of volatile fatty acids in the rumen. III. Measurement of production in vivo by two isotope dilution procedures
Authors: Gray FV , Weller RA , Pilgrim AF , Jones GB
Published: November 2004

(1) Production of volatile acid in the rumen of sheep fed at 12-hourly intervals on a mixture of wheaten hay and lucerne hay has been measured by two isotope dilution procedures involving continuous infusion of 14C-labelled fatty acid into the rumen and determination of the concentration of 14°C in the rumen acid throughout the feeding cycle. In the first procedure the varying rate of production was matched by a varying rate of infusion so that a constant concentration of label was maintained in the rumen acid. In the second procedure a constant rate of infusion was maintained and a mean value obtained for the concentration of label in the rumen acid during the cycle. Production values calculated from the data from both procedures were similar: approximately 5 moles of volatile acid were produced per kilogram of dry fodder. (2) This same rate of production was found for rations of 360, 450, and 675 g dry fodder fed at 12-hourly intervals.
Urinary excretion of silica by grazing sheep
Authors: Nottle MC , Armstrong JM
Published: November 2004

Two series of field collections were undertaken to determine the excretion of silica, chloride, and various cations in grazing sheep, and the specific gravity and surface tension of their urine, and to assess the significance of these items in siliceous urinary calculus formation. Collections were made on four occasions in each series at intervals of 3 months, when urine was collected for three consecutive 24-hr periods from groups of 10 ewes. The concentration of urine fluctuated seasonally in both series, and was related inversely to urine volume and directly to environmental temperature. During summer and autumn the urinary silica concentration was significantly greater in an area 'affected' with urolithiasis than in the coastal plain, which is unaffected; and of the observations made, urine concentration was the only one which might account for the difference in incidence of fatal urolithiasis. In the second series, the mean urinary silica excretion in the affected area in September, December, March, and June was respectively 164, 95.3, 76.2, and 100 mg/ day, and the faecal excretion was 6.0, 14.6, 20.5, and 19.3 g/day, which suggests a greater availability of silica in green than in dry feed. Urine nitrogen ranged from 15.5 g/day in the flush of spring growth to 6.6 g/day in autumn. A hyperbolic relationship was found between urine silica concentration and urine volume, the point of inflexion occurring at a urine volume of about 600 ml/day. The significance of this observation and the excretion of a concentrated urine are discussed in relation to silica and mucoprotein precipitation.
Studies on salt tolerance of sheep. VI. The tolerance of wethers in pens for drinking waters of the types obtained from underground sources in Australia
Authors: Peirce AW
Published: November 2004

Seven groups, each of six wether sheep, were fed in pens for 15 months on a ration of chaffed lucerne and wheaten hays and were offered various solutions as drinking waters. These comprised: (1) rain-water (control group); (2) 1.30% sodium chloride; (3) and (4) synthetic waters containing salts in the proportions found in many underground waters in South and Western Australia (referred to in this paper as "chloride waters"), with total concentrations of 0.65 and 1.30% respectively; (5) and (6) synthetic waters resembling those obtained in Queensland from the Great Artesian Basin ("bicarbonate waters"), with total salt concentrations
of 0.20 and 0.50% respectively; and (7) sea-water diluted with rain-water to a total salt concentration of 1.30%The intake of all saline solutions, except that of the bicarbonate water with a concentration of 0.20% salts, was higher than that of rain-water, the increases
ranging from 80% for 1.30% sodium chloride to 15% for the more concentrated
bicarbonate water. The intake also increased in all groups with temperature, being
40-90 % higher in the hottest months than in the coldest months.Compared with the control group a significant decrease in wool production was observed only in the group receiving bicarbonate water with 0.50% total salts. These sheep also produced significantly less wool, for at least a portion of the experiment, than did those receiving the other synthetic mixtures of salts.The concentrations of potassium, calcium, and chloride in the blood plasma were not affected by the saline drinking waters. The concentrations of sodium at times were higher in the plasma of the control group and lower in the plasma of group 2 (1.30% sodium chloride) than in that of the remaining groups. Magnesium concentrations at times were higher in group 7 (diluted sea-water) and lower in group 2 than in the remaining groups. None of the solutions used in the experiment had any adverse effect on general health, food consumption, or weight increase.
Soil fertility changes in a red-brown earth under irrigated pastures. I. Changes in organic carbon/nitrogen ratio, Cation exchange capacity and pH
Authors: Rixon AJ
Published: November 2004

Organic matter and soil fertility changes under irrigated pastures were followed for 5 years at Deniliquin, N.S.W. The effects of three annual pastures and of three perennial pastures were studied. Four years after their establishment an organic matter layer (mat) had formed under all pastures, and after its formation there was no further accumulation of organic carbon in the 0–3 in. soil horizon. The mean annual increase in organic carbon was 625 lb/acre under annual pastures and 1146 lb/acre under perennial pastures. The carbon/nitrogen ratios of both soil and mats, and the relationships of both organic carbon and nitrogen to the cation exchange capacity of the mats, were similarly affected by the annual and perennial pastures. The heterogeneous nature of the mats obscured any differences in their carbon/nitrogen ratios, which ranged from 12.8 to 22.0. The cation exchange capacity of the 0–3 in. soil horizon remained unchanged. The cation exchange capacity of the organic matter of the mats was approximately 100 m-equiv./100 g. After mat formation the underlying soil had a pH of approximately 6.0 under clovers and 6.5 under ryegrasses. The pH values of the mats ranged from 5.9 to 6.6.
Chondrilla juncea L. in Australia. I. Some factors affecting flowering
Authors: Cuthbertson EG
Published: November 2004

The interaction between day length and vernalization, and the influence of growth temperature on flowering, in Chondrilla juncea L. (skeleton weed) have been studied. Bolting and floral initiation in unvernalized plants were suppressed in a 9-hr photoperiod. Increasing the photoperiod beyond 12 hr resulted in progressively earlier bolting and floral initiation, the critical day length being slightly less than 12 hr. Interrupting a 16-hr dark period by 1 hr of low-intensity light near its centre caused some plants to flower. Prior vernalization further accelerated bolting and flowering and reduced the dependence on day length. Vernalization, however, was not an obligate requirement. Post-bolting development was favoured by high temperatures. It was concluded that flowering in skeleton weed occurred in two stages. The first or photo-inductive phase was controlled by at least two partial processes. These were vernalization and a photoperiodic response in which the length of the dark period was the critical factor. The relationship of the flowering processes to the distribution of skeleton weed in Australia is discussed briefly.
Temperature and day length response of some cocksfoot populations
Authors: BrouT P , Williams CN , Neal-Smith CA , Albrecht L
Published: November 2004

Seedling plants of seven cocksfoot (Dactylis glomerata L.) populations were exposed to day/night temperatures of 20/15, 15/10, 12/7, and 9/4°C at day lengths of either 8 or 16 hr. Leaf size, rate of leaf appearance, and relative growth rate decreased as temperature decreased. At higher temperatures, relative growth rate was greater in long than in short days, but at 9/4° it was greater in short days. Long days increased leaf size but slightly reduced the rate of leaf appearance at higher temperatures; the increased leaf size, however, more than compensated for the slightly lower rate of leaf appearance, so that relative growth rate was greater in long than in short days. At 9/4°, however, greater leaf size did not compensate for the much slower rate of leaf appearance in long days. Growth rates were consequently lower in long than in short days at 9/4°. The populations showed a general similarity in response, although significant differences between populations were recorded for particular treatments. There was no apparent relationship between seedling growth rates at low temperatures in this experiment and winter growth of these populations under field conditions.
The growth of apricot fruit. II. The effects of temperature and gibberellic acid
Authors: Jackson DI , Coombe BG
Published: November 2004

The effect of temperature and gibberellic acid (GA3) applications on apricot fruit have been determined by measurements of fruit size and shape, mesocarp cell number, size, and shape, and endogenous gibberellin. Application of heat during the first 10 nights after anthesis increased the initial growth rate of fruit and of cells in the mesocarp and produced more rapid cell division in this tissue. It did not affect final fruit size or the number and diameter of cells in the mesocarp. Higher temperatures did, however, hasten maturity of fruit. GA3 perfused into branches before anthesis produced an increased drop of flower buds and fruit, raised the ratio of flower buds to leaf buds initiated that season, and resulted in elongated pedicels. Initially, fruit growth rate was increased by GA3, but subsequently it was depressed and final size was below normal. These effects on fruit size were mainly due to effects on the rate of cell division. Some differences were noted in the dimensions of cells but final radial cell diameter did not differ from untreated fruit. GA3-treated fruit ripened sooner than controls. Neither heating nor GA3 treatments affected the level of endogenous gibberellin-like substances in the fruit or their RF on paper chromatograms. There were no significant interactions between temperature and gibberellin in any parameter of apricot fruit growth.
Changes in particle size in the reticulorumen of sheep
Authors: Pearce GR
Published: November 2004

Sheep fitted with 10-cm rumen fistulae were used to measure the changes occurring in the particle size of digesta under conditions of once daily feeding. Particle size distributions were determined by separation through sieves of various mesh sizes. In one experiment digesta samples were obtained from serial emptyings of the reticulorumen several times within 24-hr periods. In a second experiment particle size distributions resulting from various levels of food intake were measured 24 hr after feeding.
Studies on Paratylenchus nanus. II. Population changes around apple roots
Authors: Fisher JM
Published: November 2004

The numbers of fourth-stage larvae, males, and females of Paratylenchus nanus in soil around apple roots have been examined and found to be partially correlated with seasonal changes in the trees. Bulking subsamples did not give sufficient information, and so trends were determined from individual samples. Numbers of females were assessed: (a) per soil sample; (b) per weight of apple roots in each soil sample. In soil, all stages showed a decline in numbers in winter and summer and an increase in spring (Sept.). At other times numbers remained stationary except for a decrease in larval numbers in October and an increase in numbers of females between November and January. Males always exceeded females in number and larvae always exceeded adults, but the proportion of females in the adult population increased from 27% in winter to 41% in summer. Numbers of females – the only parasitic stage recovered – per gram of apple root decreased in winter, increased in spring, and decreased again in summer. Survival of the different stages under an adverse environment suggested that high temperatures in summer and low temperatures with high moisture levels in winter were partly responsible for the decreases in number at these times.
Effects of feeding frequency on energy and nitrogen balance in sheep given a ground and pelleted forage
Authors: McCGraham N
Published: November 2004

Wether sheep were fed at intervals of 3 hr, 24 hr, and 4 days, and their energy utilization studied at several levels of feeding. The diet consisted of ground and pelleted lucerne containing 19% crude protein and 28% crude fibre. Digestibility was a few units lower when feeding was less frequent; crude protein and fibrous constituents were affected most. The relation between methane production and digestible energy was the same for daily as for 3-hourly feeding, but methane production was depressed by feeding every fourth day only. Metabolizable energy was a slightly greater proportion of digestible energy when feeding was infrequent. A larger fraction of metabolizable energy was dissipated as heat when feeding frequency decreased. This was attributed to the cost of alternating between energy storage and oxidation of reserves: activity differences were not a cause. Overall, the net energy value of the food decreased as frequency of feeding decreased. Prediction from chemical composition or digestibility was not reliable. Measurement of hour by hour changes in metabolism indicated that there was an intense phase of fermentation and lipogenesis immediately after feeding. With 3-hourly or daily feeding, the oxygen consumption, carbon dioxide production, and methane production increased respectively by 0.7, 2.5, and 0.3 l/hr/100 g food eaten in the first hour: with the highest level of feeding, these represent increases up to 2.4-fold and an R.Q. of 1.15. With feeding every fourth day the responses were very much less, indicating depressed rumen activity; blood urea levels were also relatively low.
Naturalized subterranean clover strains in Western Australia: A preliminary agronomic examination
Authors: Gladstones JS
Published: November 2004

Ninety naturalized and four commercially introduced subterranean clover strains present in Western Australia were examined. Flowering time, hardseededness, contents of the oestrogenic isoflavones formononetin, genistein, and biochanin A, and plant morphological characteristics were measured in spaced plants. Probabilities of random relationships were calculated for all character pairs. Wide variation was found among strains for all characters measured. A number of strains had low oestrogenic isoflavone contents. Levels of the three isoflavones appeared to vary independently of each other and of all other characters. Hardseededness decreased with lateness of maturity, but evidence is adduced that the relationship was not causal. Correlations were recorded among several morphological characters. Some 20 naturalized, non-commercial strains were selected as worthy of further agronomic study.
Follicle curvature and crimp size in some selected Australian Merino groups
Authors: Nay T , Johnson H
Published: November 2004

A method of measuring the degree of follicle curvature in Australian Merino sheep has been devised. It was found that the degree of follicle curvature and the follicle curvature chord were highly correlated with the crimp size. It is suggested that the fibre, "setting" in a more or less curved follicle canal, acquires a bend which contributes to the mechanism of staple crimp formation.
The pathogenicity of experimental infections of Cooperia pectinata Ransom, 1907 in calves
Authors: Keith RK
Published: November 2004

Studies are reported on the pathogenicity of experimental infections of Cooperia pectinata in calves. Infections arising from doses of 100 000 infective larvae resulted in the passage of soft to diarrhoeic faeces, anorexia, loss of weight or reduction in weight gain, and, in some calves, hypoproteinaemia. Calves dosed with 500 000 infective larvae showed similar but more severe signs of infection, and polycythaemia. The animals became moribund 3 to 4 weeks after infection. There was no direct association between faecal egg count and pathogenic effect.
Effect of cold shock, liquid storage, and pellet-freezing on successive ram ejaculates
Authors: Salamon S , Lightfoot RJ
Published: November 2004

(1) Nine successive ejaculates were collected from each of four Merino rams on three occasions at intervals of three days. The mean time intervals between successive ejaculates on the first, second, and third collecting days were respectively 41, 28, and 30 min. Aliquots from alternate ejaculates (first, third, fifth, seventh, and ninth) were cold-shocked before and after 1 : 4 dilution with an egg yolk–glucose–citrate diluent. Similarly diluted aliquots were stored at +2°C for 16 days and also frozen in pellet form after addition of 6% glycerol to a final 1:8 dilution. (2) Both undiluted and diluted spermatozoa showed increased susceptibility to cold shock with succession of ejaculates. Egg yolk–glucose–citrate diluent ameliorated the deleterious effect. (3) There were no marked differences in reanimation at thawing of pellet-frozen successive ejaculates. During a 6 hr incubation of the thawed semen at 37°, however, there were significant ejaculate differences in viability, the ninth collection having the lowest value. The mean reanimation of pellet-frozen spermatozoa after thawing was 58.7°. During incubation periods of 2,4, and 6 hr at 37°C, 47, 60, and 70% respectively of the original post-thawing motile spermatozoa became immotile. (4) During storage for 16 days at +2°C, the third and fifth ejaculates gave the best viability values. There were, however, no marked differences between ejaculates during the first 6 days of storage. (5) No firm relationships were found between cold shock values and subsequent viability during liquid storage or recovery after pellet-freezing.
Factors limiting the intake of feed by sheep. II. Studies with wheaten hay
Authors: Weston RH
Published: November 2004

A study was made of factors limiting the sheep's intake of a wheaten hay diet having an organic matter digestibility of approximately 57% and containing 4.4% crude protein and a mineral supplement. Voluntary consumption of chopped wheaten hay increased by 8–13% when protein was infused per abomasum, or when the protein content of the diet was raised to 7 or 15% by the addition of wheat gluten. A similar change in voluntary feed consumption (VFC) was observed in one of two experiments in which urea was infused per abomasum. The VFC response to protein infusion per abomasum persisted for at least 2 weeks after the infusion was terminated. Voluntary consumption of a diet of chopped wheaten hay + gluten (85/15) did not change when additional protein and micronutrients were provided. When the wheaten hay was ground or ground and pelleted, VFC increased and digestibility declined; the intake of digestible energy showed little change. The addition of protein to the ground and pelleted hay was accompanied by substantial rises in feed intake, digestible energy intake, and digestible fibre intake and in the quantity of organic matter transferred through the alimentary tract. The provision of protein and grinding and pelleting increased the intake of wheaten hay to 189% of that attained when chopped hay was offered. The intake of wheaten hay + gluten (85/15) was lower than that of lucerne hay when the diets were in either chopped or ground and pelleted forms; these diets had similar organic matter digestibilities and protein contents. The results were considered to support the conclusion that the primary factor limiting the intake of the wheaten hay was a deficiency of nitrogen, and that after this had been remedied, the next limiting factor was the resistance of the diet to removal from the rumen. The mechanisms whereby various factors limit intake are discussed, and it is suggested that digestibility is likely to be unreliable for predicting the VFC of non-pregnant, non-lactating ruminants.
Heritability and genotypic and environmental correlations of creeping root and persistency in Medicago sativa L.
Authors: Daday H
Published: November 2004

This study examines the relationships between creeping-rootedness, plant diameters, and persistency in lucerne. Highly significant positive genetic correlations were found between all three plant characters among families under continuous grazing. The investigations disclosed several trends in genetic and environmental correlations, the significance of which is discussed. The heritabilities for the proportion I of creeping plants (0.41), plant diameter (0.32–0.45), and survival (0.23–0.46) were all high, indicating that response to selection is possible. The results showed that plant density decreased under continuous grazing; 66% of the creeping-rooted plants but only 8% of Hunter River plants survived after 17 months of continuous grazing.
The effect of cold shock and deep-freezing on ram spermatozoa collected by electrical ejaculation and by an artificial vagina
Authors: Quinn PJ , Salamon S , White IG
Published: November 2004

Spermatozoa collected with an artificial vagina (AV) were more resistant to cold shock as judged by motility and staining reaction than when ejaculated electrically (EE). Dilution of AV spermatozoa in AV seminal plasma caused some increase in susceptibility to cold shock, particularly as judged by motility scores, but the evidence suggests that EE seminal plasma renders spermatozoa more susceptible than does AV seminal plasma. Spermatozoa exposed to cold shock immediately after collection were most permeable to Congo red and became increasingly impermeable when incubated at 30°C; the increase in resistance of AV spermatozoa was greater than that of EE spermatozoa. When 10 successive ejaculates were collected from rams by the artificial vagina there was no great change in volume but the spermatozoal concentration declined. After cold shock, the percentage of unstained spermatozoa fell to very low levels by the fifth ejaculate and there was also a decline in motility. The viability of semen thawed after freezing to –79°C by rapid freezing method was better than when a slow freezing method was used, particularly when the semen was collected with an artificial vagina.
Nychthemeral and seasonal patterns of thermoregulation in cattle
Authors: Berman A
Published: November 2004

1. The nychthemeral (24 hr) and seasonal cycles in thermoregulation at high (Fh) and standard (Fs) levels of feeding were studied in Holstein heifers during spring (mean daily air temperature 18.2°C) and late summer (mean daily air temp. 27.5°). 2. In the two seasons the percentage respiratory evaporative cooling (% RC) and rectal temperature (Tr) displayed marked nychthemeral cycles in both feeding groups, while heat production (Hp) cycles were evident in the Fh group only. 3. In both seasons the effect of the 22.4% larger Hp in the Fhgroup was to prolong the duration of higher % RC; Tr was relatively increased in the summer only. 4. The seasonal changes were: a 20% reduction in Hp in both groups; a larger amplitude of Hp cycling (19% of the mean in summer and 12.9% in spring) in the Fh group; a higher Tr (+ 0.40°C in the Fs group and + 0.63° in the Fh group), cycling with a larger amplitude (0.33° v. 0.52°); a 21° depression in feed intake in the Fh group and 9° in the Fs group. 5. Within each season Tr and the rate of change in Tr were significantly correlated with Hp in the Fh group only. On a between-season basis Hp and Tr were significantly correlated in both feeding groups. These suggest that the relationship between body temperature and heat production follows different patterns in nychthemeral cycles from those in seasonal changes. 6. The nychthemeral patterns of respiratory, %RC, Tr, and Hp responses indicated that the animals were acclimatized to the seasonal change in Tr, possible through a shift in the set-point for temperature control. The depression in heat production and feed intake did not prevent the maintenance of a normal rate of growth.
Effect of restricted access to water on the intake of salty foods by Merino and Border Leicester sheep
Authors: Wilson AD , Hindley NL
Published: November 2004

Sheep were fed on diets containing 7.5, 11.25, and 15% added sodium chloride to simulate diets containing up to 100% saltbush (Atriplex spp.). When access to water was restricted to once daily, there was a reduction in food intake, the reduction being more severe with the more salty diets. When fed on the diet containing 15% added sodium chloride and when their access to water was restricted to once daily, Merino sheep drank 5.01 l/day and Border Leicester sheep 7.6 l/day. Food intakes differed in approximately the same proportion, and on a body weight basis (kg0.73) the Border Leicesters ate 22% more food than the Merinos. It is concluded that Merino sheep will need to drink more often than once daily when their water intake exceeds 5 l/sheep/day, and that this would occur when the saltbush intake reached 500–600 g/day.
The relationship between sugar-cane mosaic virus and mosaic viruses of maize and Johnson grass in Australia
Authors: Taylor RH , Pares RD
Published: November 2004

Two isolates of maize dwarf mosaic virus originating from maize (MDMV(M)) and Johnson grass (MDMV(J)) were distantly related to an Australian and a Californian strain of sugar-cane mosaic virus (SMV). MDMV(M) was shown to be distantly related serologically to a Californian strain but not to an Ohio strain of MDMV; MDMV(J) was not shown to be related serologically to either the Californian or the Ohio strain of MDMV. MDMV(M), MDMV(J), and the Australian SMV produced similar symptoms on sweet corn (Zea mays var. saccharata (Sturtev)), which under glasshouse conditions included an initial necrotic phase not previously described for MDMV. The three isolates showed different characteristics when purified from sweet corn by an identical procedure. The yields of MDMV(M) and MDMV(J) were higher than that of SMV, and these two isolates produced strong zones in density gradients whereas SMV produced a very weak zone. The normal length of MDMV(M) was 773 ± 6.35 mµ and that of MDMV(J) 778 ± 6.35 mµ and the particles of both were uniform. By contrast the particles of SMV were very uneven in length; the most common length was 650–750 mµ, but many longer and shorter particles were observed.
14C Translocation patterns in peach and apricot shoots
Authors: Kriedemann PE
Published: November 2004

14CO2 was supplied under laboratory conditions to the terminal leaves of peach and apricot shoots taken from orchard trees over the period from flowering to fruit maturity. The distribution of 14C assimilates along the shoot, and the patterns of deposition within the developing fruit were recorded on X-ray film. In both peach and apricot shoots, the terminal leaves, soon after emergence, exported assimilates to adjacent fruit which competed successfully with nearby expanding leaves, although isolated leaves (in peach) were capable of importing. At a more advanced stage only the fruits imported assimilates from the terminal leaves, and the labelled substrates were deposited in both flesh and inner seed structures despite the hardened stone. The fruit continued to accumulate 14C photosynthate even when completely ripe. Following fruit removal, export from the terminal leaves on the peach shoot was minimal, and labelled photosynthate was detected only in the main stem; whereas in apricot shoots, mature lower leaves showed extensive import of current assimilates.
The effect of particle size of superphosphate on the availability of its phosphorus and sulphur to pasture plants
Authors: Williams CH , Lipsett J
Published: November 2004

In glasshouse experiments, the responses of plants to the phosphorus and sulphur in top-dressed superphosphate were affected by its particle size. On four soils, yields of subterranean clover differed by 12–25% owing to differences in particle size of applied superphosphate. Both rate of solution and spatial distribution of the fertilizer affected plant response. Under non-leaching conditions, the sulphur in large particles of superphosphate was always less available than that in fine. The phosphorus in large particles was slightly less available when superphosphate was applied to soils of low, or moderate, capacities to sorb phosphate but more available when applied to a soil of high capacity to sorb phosphate.Pastures would probably respond better to granulated superphosphate than to normal on sulphur-deficient soils subject to strong leaching, or on soils of high capacity to sorb phosphate. On many soils, however, no difference would be expected, and on some sulphur-deficient soils the granulated product may even be inferior in some seasons.
Pigmentation of sheep. II.The inheritance of colour patterns in black Merinos
Authors: Brooker MG , Dolling CHS
Published: November 2004

Within homozygous recessive Black Merinos (ww), in which pigmentation is due to a single recessive gene w, three patterns of pigmentation have been observed – Badger-face (BF), Reversed Badger-face (RBF), and Self-colour (SC). These are shown to be initiated by a series of alleles, wl, we, and ws respectively in decreasing order of
dominance, which are allelic with W, the gene inhibiting pigmentation of the wool-growing
area in the Merino.The dominance of wl over w2 and w3, and of w2 over w3, is not always complete. An "overlap" pattern is described with characteristics of two alleles and whose
occurrence is sex-influenced.
Iron pyrites as a sulphur fertilizer
Authors: Banath CL
Published: November 2004

Iron pyrites (FeS2), without any special treatment other than grinding, was found to be highly effective as a sulphur fertilizer for Trifolium subterraneum L. The dry weights of tops of plants fertilized with iron pyrites at 170 lb/acre (50% by weight of particles < 9 µ in diameter) or at 340 lb/acre (14% < 9 µ in diameter) were more than three times those of plants which did not receive applied sulphur (P < 0.001), and were similar to those of plants receiving 40 lb sulphur per acre (sulphur sufficiency) as either sodium sulphate or sublimed sulphur. The smallest mean particle size used (65% < 9 µ in diameter) did not produce any further increases in dry weights. Iron pyrites at very high rates of application (1360 and 680 lb/acre) of the smallest mean particle size were not toxic to the plants. Small quantities of sublimed sulphur applied with the iron pyrites did not increase the dry weight responses to the iron pyrites. Sterilization of the iron pyrites, or inoculation of sterilized iron pyrites with either an American or a Tasmanian culture of iron-oxidizing bacteria similar to Thiobacillus ferrooxidans, had no effect on the dry weight responses. No indications were found that the presence of phosphate ions decreased the dry weight responses to iron pyrites. It is suggested that in warmer humid climates, smaller applications or larger mean particle sizes of iron pyrites might suffice to alleviate a similar degree of sulphur deficiency.
Inheritance of a broad leaf phenotype in the tobacco cultivar hicks
Authors: Gordon IL
Published: November 2004

This study has shown that a broad leaf phenotype, known as Hamilton Hicks, was homozygous for one allele at one locus (hh). It is believed that the inheritance of this phenotype has not been reported previously. However, plants of this type have been present in the Queensland strain of the Hicks cultivar for several years, with a frequency in the commercial crop of about 0.02%. The non-Hamilton phenotype was homozygous for another allele at the locus ( +h +h), and the heterozygote was of intermediate phenotype. The heterozygote demonstrated changing expressivity during ontogeny. In the juvenile stages, the heterozygote appeared very similar to the Hamilton phenotype, but, when mature, it was similar to the non-Hamilton phenotype. Descriptions of all phenotypes are given. Some suggestions comparing this locus with others affecting leaf shape are presented.
Production of new races of Puccinia graminis var Tritici
Authors: Sharma SK , Prasada R
Published: November 2004

To study the phenon~enon of somatic recombination in stem rust of wheat, seedlings of selected wheat cultivars were inoculated with these six pairs of races: 15CM x 14, 15CM x 17, 15CM x 21, 15CM x 24, 15CM x 42, and 15CM x 117. Recombinants were isolated from only the first two mixtures. As a result of mixing races 15CM x 14, eight races and biotypes were isolated of which three were previously undescribed. From the recombinants of races 15CM x 17, six races and biotypes were identified, of which three were new and previously undescribed.
Efficacy of cobalt pellets for providing cobalt for penned sheep
Authors: Dewey DW , Lee HJ , Marston HR
Published: November 2004

Cobalt pellets introduced into the rumens of sheep, either singly or accompanied by an abrasive steel grinder or by a second pellet, have been shown to be equally as effective, over a period of more than 5 years, as a supplement of 1 mg Co/day per os in maintaining health, body weight, and adequate concentrations of vitamin B12 in liver and serum of sheep fed on a cobalt-deficient ration in pens. Comparison of the weight losses of pellets recovered from the rumens in which they were carried, either singly or together with another heavy object, and studies with pellets containing 60Co have shown that release of cobalt from a pellet which is accompanied by an abrading device is significantly greater than when a single pellet is carried in the rumen. Increase of the calcium acetate content of the diet increased the rate of release of cobalt from the pellet.
Resistance to the cattle tick, Boophilus microplus in a herd of Australian Illawarra Shorthorn cattle: Its assessment and heritability
Authors: Wharton RH , Utech KBW , Turner HG
Published: November 2004

An Australian Illawarra Shorthorn herd of 24 cows was mated in three consecutive years with an AIS bull. The cows and their progeny were rated for tick resistance at frequent intervals from August 1959 to December 1965 by counting the numbers of semiengorged female ticks on the right side. The mean of log counts for all counts on a particular animal was adopted as the reference value for its degree of susceptibility. The ranking of cattle generally showed a high level of consistency with mean repeatability of counts (r = 0.47, P < 0.01). Discrimination between animals was more reliable (P < 0.01) in summer (r = 0.52) than in winter (r = 0.27). The repeatability of tick counts increased with mean count, from r = 0.27 when the mean count was 3 to r = 0.67 when it was 100. The reliability of counts on the cows decreased with age and with lactation. Supplementary information on a larger herd showed no effect of pregnancy on mean count or on discrimination between susceptible and resistant animals, but showed that there was a partial breakdown of resistance during lactation. In calves infested naturally, no effects of age or sex on tick counts or their repeatability were detected, though male calves yielded significantly larger numbers of ticks than females when infested artificially. The mean yield of mature female ticks on the cows following two artificial infestations with known numbers of larvae ranged from 0.2 to 27.4% of the potential. Natural and artificial assessments of susceptibility were closely correlated. The rank of the bull was similar to that of the more resistant cows. Mean estimates of the heritability of tick resistance based on single counts were 39 % from dam-calf correlations and 49 % from full-sib correlations. Estimates based on summer counts only were 42 and 64% respectively. These results provide strong encouragement for selecting for tick resistance.
Chemical control of flower development in sweet orange (Citrus sinensis)
Authors: Moss GI
Published: November 2004

Several growth retardants (2-chloroethyltrimethylammonium chloride, 2,3,5- tri-iodobenzoic acid, maleic hydrazide, morphactin IT3456) and also ethylene chlorhydrin were screened for possible effects on the flowering of sweet orange. No stimulation of flowering was found. In two experiments in the field, applied gibberellic acid (GA) decreased flowering though it increased the proportion of the more leafy inflorescences (and usually more fertile inflorescences); in some instances an increase in percentage fruit set also occurred, although the total number of fruits formed was less than in the control. The increase in percentage fruit set by some GA treatments appeared to be the result of fewer inflorescences, and thereby reduced competition, rather than an enhancement of the fertility of inflorescences. These effects of applied GA were greatest when applications were in late June or early July. It is suggested that floral initiation was occurring at that time. Increasing the concentration of GA above 25 p.p.m. did not cause any further reduction in flowering, but increased the proportion of leafy inflorescences. The possibility of using GA to prevent alternate bearing is discussed.
Synthesis of microbial protein in the rumen. IV. The influence of the level and form of dietary sulphur
Authors: Hume ID , Bird PR
Published: November 2004

When sheep were fed on a diet supplying 0.61 g sulphur per day, 82 g microbial protein was produced daily in the rumen. Raising the sulphur intake to 1.95 g/day increased protein production to 94 g/day (P .: 0.05), but there was no further increase when the intake was raised to 3.42 g/day. Protein production was not influenced by the s form of the supplementary sulphur. Sulphur as cystine resulted in higher rumen fluid sulphide levels than sulphur as inorganic sulphate. Nevertheless, measurable amounts of free cystine flowed out of the rumen when cystine was given. This may explain the higher nitrogen balances supported by cystine than by sulphate. Sulphur balances were always positive, and there were no differences between treatments. At least 0.44 g sulphur was recycled daily when the basal die twas given. This accounted for 42% of the total sulphur flowing out of the rumen. The importance of sulphur recycling is discussed.
Urea excretion in ruminants. I. Studies in sheep and cattle offered the same diet
Authors: Thornton RF
Published: November 2004

Cattle and sheep were offered the same diet in amounts according to the ratio of their metabolic body size, and were intravenously infused with urea in amounts according to the same ratio. An apparent limit to the transfer of urea from the blood to the rumen occurred at lower plasma urea and rumen ammonia concentrations in cattle than in sheep. Associated with ingestion of feed there was a decline in the concentrations of both rumen ammonia and plasma urea, and in urinary urea excretion. It is suggested that (a) the transfer of urea from the blood to the rumen and the urinary excretion of urea are reciprocally related, and (b) the transfer of urea from the blood to the rumen and the consequent reduction in plasma urea concentration associated with feed ingestion may account for the decline in urinary urea excretion after ingestion of feed, rather than changes in the urine flow rate and in renal tubular mechanisms.
Response of Mitchell grasses (Astrebla F. Muell.) to photoperiod and temperature
Authors: Jozwik FX
Published: November 2004

Controlled environment experiments were carried out to determine the effect of temperature and photoperiod on Astrebla pectinata, A. lappacea, A. elymoides, and A. squarrosa. Photoperiod had little effect on growth and development of tillers and on floral initiation, but did affect numbers of emergent inflorescences. Usually, inflorescence production increased with decreasing photoperiod. Temperature had significant effects on all parameters measured (number of main tillers and emergent inflorescences, elongation of main tillers, and number of leaves and axillary tillers per main tiller). Growth per tiller and leaf production increased with temperature (up to 30/25�C) but for tiller numbers the optimum was about 28/23�, Geographically separated strains of A. pectinata generally exhibited similar responses to photoperiod and temperature while different species from the same location differed in their response.