bluuebunny/crossref_metadata_2025 huggingface dataset:
Sheep carcasses and their appraisal. 1. Characteristics of commercial Australian lamb and mutton
Authors: Barwick SA , Thwaites CJ
Published: March 2005

Lamb and mutton carcases from abattoirs, and from wholesale and retail outlets, were studied to provide information on the characteristics of typical commercial Australian sheep carcases. Characteristics examined were the weight, length (pubic symphysis to first rib), subcutaneous fat depth (13th rib) and fleshing index (shape) of intact carcases, fat depths on the loin, shoulder and chump cuts, weights and proportions of wholesale lamb cuts, before and after trimming of excess fat, and Warner-Bratzler shear measures of tenderness for lamb and mutton. Lamb carcases studied varied considerably in weight, shape and fatness, with fat depth measurements of up to 30 mm being recorded on some chump cuts. The proportion of trimmed major cuts of lamb varied from 61.3 to 75.7% of cold carcase weight. Because of the large variability in fatness and the considerable variation in trimmed cut proportions, we consider that appraisal systems for lamb should aim to discriminate between carcases on these bases. Variation in eating quality of lamb may offer less ground for discriminating between carcases, as shear values for lamb were observed to be small. Shear values for medial M. longissirnus cores were generally greater than those for lateral cores in both lamb and mutton, though differences were significant (P < 0.05) only for lamb. Mutton carcases were more variable in their characteristics and yielded meat with greater shear values (P < 0.05) than lamb. However in many cases, shear values for mutton samples were also quite small. It was reasoned that potential could exist for greater utilization of two- and possibly also four-tooth animals as sources of table meat.
The measurement of, and factors affecting, the strength of attachment of wool to the skin of sheep
Authors: Gordon AJ
Published: March 2005

To measure wool loosening before and after treatment with defleecing agents a 2 kg spring balance was used to measure the force required to pluck wool staples from sheep. The results are expressed as g force per fibre or as g force per unit of staple linear density (kTex), where 1 kTex = area staple cross section (mm2) x wool specific gravity (1 -3). The linear density of each staple plucked can be determined by a gravimetric method or more simply and quickly by using a pair of hand calipers that have been previously calibrated. Where fibre diameter is known an estimate can be made of the number of fibres present. The average force required to pluck a fibre from the follicle (depilation force) is about 15 to 25% of that required to break the fibre. The optimum reduction in fibre strength for purposes of harvesting weakened wool lies somewhere between the depilation and breaking forces. There are breed differences in depilation force that cannot be entirely explained by differences in fibre diameter, SIP ratio, fibre density or follicle depth, although a high degree of follicle bending in fine-wool Merinos (mean score 5.6 vs 3.6 for other breeds) may cause the higher than expected values observed for depilation force in fine-wool Merinos. The depilation force was found to vary within animals from day to day as well as between animals. It increased (ca. 30%) following an increase in intake from 600 to 1200 g day-I and decreased rapidly (ca. 40%) for up to 3-5 hours after death. Oral dosing of four sheep with cyclophosphamide (CPA) at 12 mg kg-1 had no effect on the rate of wool loosening for the first four days, but there was an exponential reduction to 40% of the control values over the next six days. Injecting six sheep with a micronized preparation of dexamethasone-21 -isonicotinate (Voren �) caused an immediate loosening of the wool but at a slower rate, the maximum extent (25%of the control values) not being achieved until after 40 days, lnjecting 27 mg of L-thyroxine eight days after dosing had no effect on this response or the rate of wool regrowth. Voren and CPA given together to four sheep acted synergistically, resulting in depilation forces about 20% of the control values 30 days later.
Mineral and vitamin supplementation of diets for growing pigs. 5. Effects of supplementing grain/animal protein diets in commercial piggeries
Authors: Greer EB , O'Neill GH , Kirsop WT , Roese GJ , Paton DG , MacKenzie RJ , Hassab PR , Hollow RC , Tandy RC
Published: March 2005

In two co-ordinated field experiments, each involving five to eight replicates, grainlanimal protein diets were restrictively fed to growing pigs. In experiment 1 a mineral-vitamin premix improved performance during early growth, compared with the diet supplemented with vitamins A and D3 alone. The results of experiment 2 showed that this response was most likely due to the presence of 250 ppm copper in the premix. There was no difference in performance between vitamins A and D3 or the mineralvitamin premix without copper. However, when the premix contained 250 ppm copper, growth was increased by 4.6% and feed conversion improved by 4.3%. A supplement of vitamins A and D3 was all that was needed to ensure sound performance.
Studies of seed pelleting as an aid to legume inoculation. 5. Effects of incorporation of molybdenum compounds in the seed pellet on inoculant survival, seedling nodulation and plant growth of lucerne and subterranean clover
Authors: Gault RR , Brockwell J
Published: March 2005

Four molybdenum compounds were mixed with lime and applied as coatings to inoculated seed of lucerne (Hunter River) and subterranean clover (Mount Barker). The seed was sown immediately in molybdenum-deficient soil in the field or stored for periods up to 84 days before sowing. As storage time lengthened, the survival of both lucerne and clover rhizobia was adversely affected by sodium molybdate but not by molybdic acid, ammonium molybdate or molybdenum disulphide. This effect was reflected in poorer nodulation in the sodium molybdate treatments. Nitrogen fixation, using foliage nitrogen content as an index, was always higher in the molybdenum treatments than in the no-molybdenum controls. Both species appeared able to extract molybdenum from molybdenum disulphide. Otherwise, there were no treatment differences in plant growth, but there was a significant relationship between the proportion of seedlings nodulated by the inoculant strains and the amount of nitrogen fixation. It is concluded that seed-applied molybdenum would benefit pasture establishment in some circumstances and would not interfere with inoculant survival or seedling nodulation provided that sodium molybdate was not used for the purpose.
Effects of aphids on seedling growth of lucerne lines. I. Blue-green aphid in field conditions (Acyrthosiphon kondoi Shinji)
Authors: Lloyd DL , Turner JW , Hilder TB
Published: March 2005

Twenty-three lucerne lines introduced into Australia from the United States of America and two Australian cultivars (Hunter River and Falkiner) were screened for resistance to the blue-green aphid (Acyrthosiphon kondoi Shinji) (BGA), in the seedling stage under rain grown field conditions. Considerable tolerance to BGA was shown by seedlings of all lines infested at the 2-3 trifoliate leaf stage, as no seedling mortality occurred in the presence of high aphid populations. Using the suppression of both plant height and dry matter production as indices, six imported lines exhibited greater resistance than the others. These were DK 167, AS 49, WL 31 8, AS 13, WL 51 4 and CUF 101. There was no relation between the resistance expressed and the aphid population carried.
A study of pollination of safflower (Carthamus tinctorius) cv. Gila
Authors: Langridge DF , Goodman RD
Published: March 2005

In a trial on safflower (Carthamus tinctorius) cv. Gila grown without irrigation in northern Victoria, no increase in yield of seed per plant, oil content or percentage germination was obtained from plots to which bees and larger insects had access as compared with plots enclosed in cages of 2.5 mm mesh to exclude these insects, nor was there any difference in weight of 1000 seeds. Honeybees and native bees were the predominant insects working the flowers for nectar and pollen. We conclude that cv. Gila is essentially self-pollinated or pollinated by airborne pollen.
Energy losses in the excreta of poultry: a model for predicting dietary metabolizable energy
Authors: Moir KW , Yule WJ , Connor JK
Published: March 2005

Twenty-four poultry diets with gross energy values ranging from 18.43 to 21.54 MJ kg-1 DM were fed to chickens using a standard metabolizable energy (ME) assay procedure. Gross energy as determined by bomb calorimetry was significantly related to gross energy as calculated from chemical composition (protein, fat, and carbohydrate), with an RSD of � 0.25 MJ kg-1 DM. Energy loss via faeces and urine (range 4.1 1 to 5.91 MJ kg-1 diet DM) was significantly related to crude fibre expressed as a percentage of the total dietary carbohydrate (range 3.7 to 8.6). The RSD was � 0.29 MJ. By treating the components of ME (gross energy and energy loss) separately, bias of biological origin was separated from random error in the prediction of ME from chemical composition.
Are some strains of subterranean clover (T. subterraneum) highly susceptible to low temperature stress?
Authors: Rossiter RC , Collins WJ
Published: March 2005

Two experiments, one with spaced plants and the other with swards, were conducted in a controlled-temperature glasshouse at Perth, Western Australia. Three strains-Phillip Island, CPI 18293 and CPI 68043H-were selected on the basis of field observations of apparent very poor winter growth in rows, and tested against Tallarook as a control. The temperature treatments were 22/17� (day/night) and 12/7�C. In the spaced plant experiment (occupying the first 48 days of growth), temperature and strain effects were highly significant, but there was no indication of a strain x temperature interaction. In the sward experiment (from days 51 to 77) temperature effects were small; and in only one strain, Phillip Island, was the decline in tops growth due to low temperature greater (P< 0.05) than for Tallarook. The experiments failed to provide support for the so-called 'winter dormancy' phenomenon. Possible explanations for the discrepancy between the present findings and the field observations are given.
Some water use responses of barley, lupin and rapeseed
Authors: Anderson WK
Published: March 2005

Barley, lupin and rapeseed were sown in the field on five occasions at Woogenellup, Western Australia. Dry matter accumulation, water use and meteorological data were measured for each crop and sowing time. Potential evapotranspiration functions were calculated for each crop, showing that barley required less water per unit of dry matter when water was not limiting than either of the other crops. Actual evapotranspiration functions were also calculated and showed only small differences between the relative water use of the species when soil water was limiting. The water use, yield and maturity characteristics of the three crops were used to estimate the likely range of sowing times for three locations in the Albany region based on average cumulative rainfall. Barley was found to have the highest water use efficiency (kg grain mm-1 of water used) of the three crops, especially under drier conditions, and was most suitable for late sowing. The yield and water use efficiency of lupin decreased with later sowing and rapeseed was the least efficient species in terms of water use. The results are also discussed in terms of dryland cropping strategies, water use in relation to dryland salt accumulation, and adaptive characteristics of the three crops.
Growth responses to various calcium sources in a yellow earth soil with low calcium status
Authors: Probert ME
Published: March 2005

Different sources of calcium (carbonate, acetate, sulphate and silicate) were investigated with the aim of determining the nature of the response to lime that occurs on the yellow earths of northern Cape York Peninsula. Stylosanthes guianensis cv. Cook was grown in pots as the test plant in a calcium source x phosphorus rate experiment, which was harvested on three occasions. Initially each source, except CaSO4, increased soil pH and decreased extractable aluminium, but during the pot experiment, pH of all treatments decreased below that in the initial soil and extractable aluminium increased. No evidence was found of a calcium x phosphorus interaction, which might have been expected if aluminium was interfering with phosphorus uptake, nor was any effect found of calcium source or rate on phosphate sorption by amended soils. Dry matter yields responded to increased rates of application of calcium, and at the later harvests were closely related to calcium concentration in the dry matter. Aluminium concentrations in the plant tops (60-180 �g g-1) were not excessively high. It is concluded that the major response to 'liming' on this soil is in correcting calcium deficiency and not in overcoming an aluminium toxicity problem.
Effect of bloat on the milk production and grazing time of dairy cows
Authors: Stockdale CR , King KR , Patterson IF
Published: March 2005

Twenty cows previously shown to be susceptible to bloat were selected to study the effects of bloat on milk production and grazing time in mid-lactation. The cows were either treated with a bloat prophylactic so that no bloat occurred, or were left untreated. They grazed irrigated red clover (Trifolium pratense) pasture, receiving a fresh strip of pasture each morning. Over a period of 184 cow days, there were 116 observed cases of bloat; 16 of these were classified as severe. Milk yield was reduced by 0.14 kg for each hour of bloat (P< 0.01), but there was no significant difference in yield between those cows that suffered mild bloat, and those that suffered severe bloat, despite the obvious acute stress in the latter cases. There was also a loss of 20 minutes of total daily grazing time for each hour of bloat, whether mild or severe. A major part of this loss occurred whilst the cows were bloated. Under the system of management used, it is unlikely that bloat prevention could be justified by the increase in milk production. The only criterion for bloat prevention in these circumstances should be to prevent deaths.
Effect of nitrogen, sulphur and phosphorus fertilizer on the production, mineral content and cyanide potential of forage sorghum
Authors: Wheeler JL , Hedges DA , Archer KA , Hamilton BA
Published: March 2005

An experiment to determine the effect of nitrogen, sulphur and phosphorus fertilizer, applied at sowing, on the growth and chemical composition of a hybrid sorghum x sudangrass forage, is reported. The factorial design was repeated at six sites in northern New South Wales in one year, 1976-77. Urea (50 kg nitrogen ha-1) substantially reduced plant populations at three sites. At the first harvest, dry matter production, after adjustment for plant population, was more than doubled by 20 kg phosphorus ha-1; yields were depressed by nitrogen where phosphorus was withheld. Hydrocyanic acid (HCN) potential (mean 0.04%), was increased 28% by nitrogen fertilizer, and reduced 34% by phosphorus fertilizer. Sulphur content was increased from 0.15 to 0.17% by nitrogen fertilizer, and reduced from 0.175 to 0.142% by the phosphorus treatment; it was unaffected by 20 or 50 kg sulphur ha-1 applied at sowing. At two sites, phosphorus increased the sodium concentration but the enhanced levels were still below recommended dietary requirements. The ratio of nitrogen : sulphur (after adjustment for potential loss of sulphur in the detoxication of HCN), was increased from 25:1 to 29:1 by nitrogen fertilizer. The response to sulphur was slight, and the effect of phosphorus was inconsistent. Similar but reduced effects on growth and composition occurred in the second harvest. Hydrocyanic acid levels were much higher, and the adjusted nitrogen:sulphur ratios were exceptionally wide. On the evidence available it appears that the direct supplementation of animals is the most feasible means of ensuring adequate levels of sulphur and sodium in the diet.
Effects of subterranean, rose and cupped clovers on soil nitrogen and on a subsequent cereal crop
Authors: Watson ER , Lapins P , Barron RJW
Published: March 2005

Three annual clover species : subterranean clover, Trifolium subterraneum (cv. Geraldton), rose clover, T. hirtum (cv. Kondinin), and cupped clover, T. cherleri (cv. Yamina) were compared for yield of dry matter, for their effects on soil nitrogen, dry matter yield, and nitrogen uptake by a subsequent cereal crop. In one experiment, the three clover species and annual ryegrass (Lolium rigidum), were grown in lysimeters to provide measurements of dry matter and nitrogen yields of plant tops and roots. Half of the lysimeters, from which the plant roots had not been removed, were later sown with wheat. Rose clover produced the highest yield of root nitrogen, and this was reflected in higher nitrogen uptake in the succeeding wheat crop. Nitrogen yield of wheat after ryegrass was 60% of the average yield after clovers. The three clover species were also included in a pasture experiment, which was grazed by sheep for five years. Samples were taken from the field plots to provide soil for a glasshouse pot experiment, and for chemical analysis. In the pasture experiment, build up of soil nitrogen over six years did not differ significantly between the subterranean and rose clover treatments, although there were large differences in clover plant numbers and herbage production, and botanical composition of the pastures. However, inorganic nitrogen concentrations were much higher in soil from the subterranean clover plots than in soil from the rose or cupped clover plots, particularly in the later stages of the field experiment. Total nitrogen increase and mineral nitrogen concentration were lowest in soil from the cupped clover plots, although herbage yield was comparable with that of rose clover
The effect of nitrogen fertilizer and irrigation frequency on a semi-dwarf wheat in south-east Australia. 2. Water use
Authors: Cooper JL
Published: March 2005

The semi-dwarf wheat WW15 was grown under four irrigation frequencies and two nitrogen rates in the Murrumbidgee Irrigation Area of south-eastern Australia. The irrigation treatments, which were scheduled using pan evaporation and rainfall, ranged from natural rainfall alone to seven flood irrigations. Water use was determined using the water balance equation, and measurements or irrigation water applied, rainfall, change in soil-stored moisture, and surface drainage. The water-use figures were high in comparison with values obtained overseas, ranging from 408 mm with no irrigation to 818 mm at the highest irrigation frequency. Despite the high water use, water-use efficiency was comparable with that for semi-dwarf wheat in other parts of the world, with a mean value of 10.4 kg grain ha-1 mm-1. Nitrogen fertilizer had little effect on plant growth and no effect on crop water use.
Selection for resistance to Colletotrichum trifolii in the lucerne cultivars Hunter River and Siro Peruvian
Authors: Irwin JAG , Lloyd DL , Bray RA , Langdon PW
Published: March 2005

Seedlings of lucerne (Medicago sativa) with increased resistance to anthracnose caused by Colletotrichum trifolii, were obtained from cvv. Hunter River and Siro Peruvian by selection through two generations under laboratory conditions. Glasshouse screening of half sib F1 and F2 families confirmed that rapid progress was made in increasing the level of resistance in both populations. In the field, after two years, F1 derivatives had lower percentages of plant mortality and disease indices than their parent cultivars, and F2 derivatives had lower values than their F1 parents. The F2 population of Siro Peruvian, in the second year, yielded 55% and 45% more dry matter than the unselected populations of Siro Peruvian and Hunter River respectively. However, the level of resistance in the field of the Siro Peruvian F2 population was only the equivalent of the unselected Hunter River population, and was inferior to the F1 and F2 populations of Hunter River.
Effects of aphids on seedling growth of lucerne lines. 2. Spotted alfalfa aphid (Therioaphis trifolii f. maculata (Monell)) in field conditions
Authors: Lloyd DL , Turner JW , Hilder TB
Published: March 2005

Seedlings of 23 lucerne lines introduced from the USA, and 2 Australian cultivars (Hunter River and Falkiner), were screened for resistance to the spotqed alfalfa aphid (Therioaphis trifolii f. maculata (Monell) (SAA) under field conditions during summer. This was assessed by measuring changes in plant mortality and yields from surviving plants in plots infested with SAA at the unifoliate leaf stage, compared, over a period of 19 days, with controls sprayed with insecticide. Cultivar Hunter River was extremely susceptible to SAA. It was the only line in which all seedlings died. Cultivar Falkiner was relatively susceptible, but no more so than 12 imported lines. Seven imported lines (WL 508, WL 512, WL 514, WL 600, CUF 101, UC Cargo and PS 572, all of which are known to be winter-active) exhibited greater resistance than the others. There was no association between the total number of SAA carried and their seedling resistance among the imported lines.
Seedling survival, yield and seed production of three species of annual medics exposed to lucerne aphids
Authors: Lodge GM , Greenup LR
Published: March 2005

The effects of spotted alfalfa aphids and blue-green aphids on the seedling survival, yield and seed production of Medicago truncatula var. truncatula cultivars Cyprus and Jemalong, M. polymorpha var. vulgaris and M. minima var. minima were investigated in field plots to which three insecticide treatments were applied: sprayed continuously to the post-flowering and haying-off stage; sprayed only until flowering ; and unsprayed. In the unsprayed plots all four medics were suitable hosts for both aphid species. The highest number of blue-green aphids developed on M. truncatula cv. Cyprus and the highest number of spotted alfalfa aphids on M. polymorpha var. vulgaris. Aphid numbers were relatively low from emergence to establishment and had no effect on the seedling mortalities of the medics in the unsprayed plots. The relatively low aphid numbers through winter also had no effect on dry matter production, but as numbers of both species increased in the spring the mean yields from all the unsprayed plots at successive harvests in September, October and November were reduced by 50, 54 and 55%, respectively. Flowering commenced in M. truncatula cv. Cyprus, M, polymorpha and M. minima before aphid numbers were high enough to reduce herbage yields in the unsprayed plots. However, M. truncatula cv. Jemalong flowered 10-1 4 days after the other medics, and its seed yields from the unsprayed plots were significantly lower than those of M. truncatula cv. Cyprus. The germination percentage of seed produced in the unsprayed plots of M, polymorpha was significantly lower than that of the other unsprayed medics.
Prediction of yield responses to phosphorus by established Greenleaf desmodium/grass pastures in south-east Queensland using chemical tests
Authors: Rayment GE , Bruce RC , Cook BG
Published: March 2005

Phosphorus topdressing experiments (rates to 60 kg P ha-1) on 18 commercial Desmodium intortum cv. Greenleaf/grass pastures were conducted over a 4-year period in south-east Queensland. The aim was to determine whether yield responses, which occurred only in the Greenleaf component at six sites, could be predicted using soil or plant chemical tests. Acid-(0.005 M H2SO4) and bicarbonate-(0.5 M NaHCO3) extractable tests of phosphorus status in 0-10 cm soil samples each explained about 60% of the variance in Greenleaf relative yields. The residual variance was not significantly reduced by the inclusion of terms for total soil nitrogen, total soil phosphorus, exchangeable calcium and pH into the independent variable. These empirical soil phosphorus tests had higher predictive value than plant tests based on phosphorus concentrations in tops and diagnostic samples of Greenleaf. With both acid- and bicarbonate-extractable phosphorus, yield responses are likely in the Greenleaf component when phosphorus levels in most soils are below 22 ppm. Above 29 ppm, no response would be expected
The distribution of ultra-low volume sprays from a light aircraft equipped with rotary atomizers
Authors: Nguyen NT , Watt JW
Published: March 2005

As a preliminary basis to work on a method of chemical control of Australian plague locust nymphs, the influences of wind speed, emission height and droplet size on deposits of small insecticide droplets applied by a light aircraft equipped with Micronair rotary atomizers were investigated in a number of single-swathe trials. Deposits were sampled with small sensitive papers attached to the vegetation. The volume-median diameter of recovered droplets varied from 50 �m to 80 �m depending on the rotational speed of the atomizers. Results indicated that a strong wind (> 3 m s-1) would give good recovery of these small droplets, relatively uniform coverage and large swathe; but excessive drift could result if spray droplets were very small (60 �m) or if the emission height was too large (> 10 m).
The effects of stocking rate and nitrogen fertilizer on the productivity of irrigated perennial pasture grazed by dairy cows. 1. Pasture production, utilization and composition
Authors: Stockdale CR , King KR
Published: March 2005

The effects of stocking rate and nitrogen (N) fertilizer on the productivity of irrigated perennial pasture grazed by dairy cows was studied for 2 years at Kyabram, Victoria. There were ten treatments: five stocking rates ranging from 4.4 to 8.6 cows ha-l at both 0 and 224 kg N ha-1 year-1 . Although weeds did not invade the pasture, increases in stocking rate resulted in reduced daily pasture growth, and this was related to the level of residual pasture after grazing. Annual pasture production in both years declined by 0.394 t DM ha-1 for every additional cow per ha. The levels of the herbage minerals, N, P, K, Ca, Mg and Na were adequate from an animal health point of view at all stocking rates, at least in the short term. The response to N fertilizer declined from 17 to 3 kg DM kg-1 N applied, as stocking rate increased from 4.4 to 8.6 cows ha-1, and it appeared that this response was due mainly to an increase in the growth of the grasses. Apart from the stocking rate responses, which are specific to the Kyabram environment, a number of relations were found, which showed how residual pasture after grazing, pasture allocation and pasture utilization at a single grazing, influenced pasture intake. Providing allowances are made for pasture type and the level to which any particular pasture type can be grazed, these relations could be expected to give a reasonable assessment of pasture intake in other environments.
Milk yield response following sodium chloride supplementation of cows grazing a tropical grass-legume pasture
Authors: Davison TM , Murphy GM , Maroske MM , Arnold G
Published: March 2005

Twenty cows in early- to mid-lactation were used in a 12-week experiment to determine the effect of Na supplementation on milk yield. All cows were fed 1 kg maize/cow day-1 and half received 40 g coarse salt/cow day-1. There was an immediate response in milk yield to Na supplementation. Average yields over the 12-week period were 10.8 and 12.0 kg/cow day-1 (P< 0.05) for the unsupplemented and Na supplemented groups, respectively. At the start of the experiment, the mean saliva Na levels of 88.6 � (S.D.) 4.9 mmol l-1 indicated that all cows were deficient in Na. Saliva Na levels in the supplemented group had returned to normal (> 145 mmol l-1) by week nine of the experiment.
Estimation of selenium concentration in the diet using oesophageally fistulated sheep
Authors: Langlands JP , Bowles JE , Donald GE , Smith AJ
Published: March 2005

Dietary selenium concentration was estimated from the selenium concentration of whole and squeezed extrusa collected from oesophageally fistulated sheep. Neither estimate was reliable, and variability between sheep was large. 75Se-selenomethionine was injected intravenously into fistulated sheep and was then used to correct for salivary contamination, but while this correction reduced the difference between selenium concentrations in feed and extrusa, it did not reduce variability between sheep.
The use of leaf development rate to determine time to irrigate pangola grass
Authors: Blunt CG , Jones RJ
Published: March 2005

The leaf development rate (LDR) of pangola grass (the number of new leaves produced on a shoot per unit of time) growing in swards on Cununurra Clay in the Ord Valley was found to decline linearly with cumulative net pan evaporation (+Ep) and ceased at a +Ep of 201 mm. The LDR of vegetative shoots, which have hairy nodes, was 3-5 times greater than that of reproductive shoots, which have glabrous nodes. Nitrogen increased the LDR of only the reproductive shoots. Vegetative shoots were preferred for measuring the response of pangola grass to moisture stress because of their insensitivity to nitrogen fertilizer level and faster LDR. Moisture availability (M) was calculated for each day as follows: M = 201 -+Ep for +Ep < 201, or otherwise M = 0. In an irrigation trial covering two 3-month periods there was a linear relation between M and dry matter yield within each period, and at each of four N rates. It is suggested that LDR measurements could be used to determine irrigation frequency of pangola grass for any site where pan evaporation is also measured. On Cununurra Clay in the Ord Valley the most frequent irrigation schedule (every 2 weeks) gave the highest dry matter yields.
Growth and fibre development of ginger (Zingiber officinale Rosc.) in south-east Queensland
Authors: Whiley AW
Published: March 2005

The growth pattern and fibre development of field-grown ginger were studied over a crop cycle in a sub-tropical environment at Nambour in south-east Queensland. Eleven sequential harvests were taken at 4- and 2-week intervals from 10 to 32 weeks after planting, and at 40 weeks. Fresh and dry weights of rhizomes, leaf areas and the percentage of fibre-free rhizomes were recorded. Crop growth rate, C, net assimilation rate, E, and leaf area index, LAI, were calculated for each harvest period. Maximum C and LA1 were 39.7 g m-2 day-1 and 13.4, respectively. C and E showed normal patterns by declining with age up toflowering, and then increasing during the latter period of rhizome bulking. The rises were attributed to an increased photosynthetic efficiency in response to greater demand for assimilates. Choice grade (fibre-free) rhizome recovery declined rapidly from flowering onwards. It was concluded that investigation of nutritional practices relating application of nitrogen to the rhizome bulking period was warranted.
Effects of atrazine treatment of sorghum on growth of a subsequent rice crop
Authors: Swain DJ
Published: March 2005

In an experiment at Yanco Agricultural Research Centre in the Murrumbidgee Irrigation Area, rice was grown on land that had been cropped with sorghum for the preceding 1, 2 or 3 years, and had received applications of atrazine at rates of 0, 2, 5 and 10 kg ha-1 on each sorghum crop. Rice yield was not adversely affected by previous herbicide applications, and growth was often more vigorous on plots receiving atrazine in previous years. The removal of volunteer plant growth by cultivation or non-residual herbicides during the winter fallow periods had no consistent effect on subsequent rice growth.
Effect of serving capacity of the ram syndicate on flock fertility
Authors: Kilgour RJ , Wilkins JF
Published: March 2005

Serving capacity was measured in nine Merino rams during two pen-mating tests each of 2 hours duration. Two groups each of four rams were subsequently formed; a high serving capacity group (group H) of mean serving capacity 11.50 � 0.50 (SEM) in two hours, and a low serving capacity group (group L) of mean serving capacity 3.50 � 0.62. Each group was then mated to separate flocks of approximately 200 ewes each, for 6 weeks. Group H rams raddled significantly more ewes during the first 16 days of mating and inseminated a significantly greater proportion of the raddled ewes than did group L rams. Estimates of fertilization rates and embryo loss were similar for both groups. The proportion of ewes lambing as a result of the 6 weeks mating was similar in both groups (95.3% in group H and 93.5% in group L).
Liveweights and ration digestibilities for steers fed oat or wheat rations at near maintenance level
Authors: Hamilton D , Maden JJL
Published: March 2005

Steers of 252 kg initial mean liveweight were fed 0.44 kg of hay dry matter (DM)/head day-1 plus five rates of whole oats, crushed wheat or whole wheat, with the crushed wheat rations providing 0.7 to 1.3 times the estimated energy for maintenance. All-grain rations at these energy levels had been attempted, but resulted in digestive upset, and were abandoned. The results obtained, listed in the order of the above grains, were : 1 ) grain in ration to maintain liveweight: 1.31, 1.41 and 1.85 kg DMIhead day-1 ; 2) additional grain for each 10 kg improvement in liveweight over I2 weeks: 434,466 and 61 3 g DMIhead day-1 ; 3) mean digestible organic matter content (DOM) of rations, tested at the highest and lowest rates of grain : 69.4, 84.5 and 68.3%. The DOM of the oat rations declined by 8.1 units from the lowest to highest rate of grain. The relative liveweight change on oats could not be explained by the DOMs. Nevertheless, the results suggest, for similar conditions to those applying in our experiment, that: 1) whole oats may be at least as good a feed as crushed wheat, and both will be much better than whole wheat; 2) the feed requirement for maintenance may be about 20% less than standard recommendations; 3) even a little hay in the ration, compared with grain only, may greatly reduce the likelihood of digestive upset
Management of Acyrthosiphon kondoi Shinji, blue-green aphid, and Therioaphis trifolii (Monell) f. maculata, spotted alfalfa aphid, by grazing and cutting lucerne
Authors: Bishop AL , Greenup LR , Holtkamp RH
Published: March 2005

Three experiments were carried out in New South Wales to assess the effects of grazing, forage harvesting and haymaking on populations of blue-green aphid (BGA) and spotted alfalfa aphid (SAA) and some of their predators. In experiment 1, at Tamworth, grazing by sheep at light, medium and heavy intensities reduced BGA numbers after 10 days by 52%, 74% and 93%, respectively, from the ungrazed control in dryland Hunter River lucerne. Grazing had no significant effect on the numbers of SAA and had little direct effect on the small numbers of predators present. A resurgence of both aphid species resulted in numbers significantly higher on regrowth in grazed areas than in the area left ungrazed. In experiment 2, at Tocal, grazing cattle on irrigated CUF101 at light, medium and heavy rates initially reduced BGA numbers by 30%, 53% and 75%, respectively, from their untreated levels. Grazing had little direct effect on the low number of predators present. In experiment 3, forage harvesting and mowing for hay reduced BGA and its predators more than did grazing at normal rates. It was concluded that while grazing or harvesting may reduce aphid numbers and damage initially, problems may result on regrowth.
Effect of sulphur, sulphuric acid and gypsum on the yield of rice on the Cununurra soils of the Ord Irrigation Area, Western Australia
Authors: Chapman AL
Published: March 2005

A field experiment was conducted at Kimberley Research Station near Kununurra, Western Australia, to compare elemental sulphur, sulphuric acid and gypsum as soil ameliorants for drill-sown rice on the Cununurra clay of the Ord Irrigation Area. The application of sulphur (0.5-4 t ha-1) and concentrated sulphuric acid (800-1 600 1 ha-1) to Cununurra clay temporarily decreased soil pH, improved seedling establishment and increased the mean grain yield of Bluebonnet 50 and IR661-1-170-1-3 rice from 4.27 to 5.32 t ha-1. Plant growth during the first 6 weeks was better and the transient iron chlorosis, which often develops after permanent flooding, was largely eliminated. Gypsum (1-4 t ha-1) had no significant effect on soil pH, seedling establishment, early growth or grain yield. Mean pH of the flooded soil (0-5 cm) one month after permanent flooding was 6.60, 6.56, 6.07 and 5.52 in the untreatad, gypsum, sulphur and sulphuric acid plots, respectively. Mean grain yield increased linearly as the pH of the flooded soil (0-5 cm) one month after permanent flooding decreased over the range of 6.5-5.5. The pH values of air dried soil samples takgn at 3, 6, 9 and 11 weeks after sowing and determined at the saturation moisture content fell by 0.5 to 2 units after the addition of sulphur and sulphuric acid. The decrease in pH at 3 weeks after the application of 800 l ha-1 sulphuric acid was five times greater than that due to an equivalent amount of elemsntal sulphur, but the effect of the acid was short-lived. Calcium and magnesium concentrations in the saturation extracts of the air-dried soil samples taken at 3 and 6 weeks after sowing were increased by the application of sulphur and gypsum. All ameliorants increased the nitrogen concentration in the plant tops at 3 weeks after sowing but only sulphur and sulphuric acid increased phosphorus, potassium, manganese, zinc or iron concentrations at one or more sampling dates.
The effect of feeding hay in autumn or winter on the liveweight gain and carcase characteristics of beef steers
Authors: Saul GR , Clark AJ
Published: March 2005

Each year from 1975 to 1977, three groups of six beef steers, 9 months old, were stocked at 2.6 ha-l and managed under one of the following treatments: (1 ) Pasture only (PO), no supplementary feeding, (2) Winter feeding (WF) ; pasture hay was cut from 33% of the grazed area, stored and fed back the following winter while the steers were at pasture. (3) Autumn deferment (AD) ; 33% of the grazed area was cut for hay and rolled using an Econ fodder roller. For 8-11 weeks after the opening rains, the steers were fed a complete hay ration of fodder rolls while confined to a tenth of the grazed area. Thereafter the steers grazed the whole area. The AD and WF hay averaged 11% crude protein, and 56% digestible organic matter. The growth rate of all groups during autumn was similar and averaged 0.1 5 kg day-1. During winter, the average growth rates of the PO, WF and AD groups were 0.26, 0.44 and 0.61 kg day-1, respectively. In spring the respective growth rates were 1.09, 0.81 and 0.77 kg day1 and the overall growth rates were 0.40, 0.37 and 0.42 kg day-1. The results show that when using average quality hay produced within the grazing system, AD is more effective than WF in increasing the winter liveweight gains of steers. However, the yearly beef production from each system was similar due mainly to compensatory growth by the PO steers in spring.
Digestibility of sawdust estimated by the nylon bag technique
Authors: Hunter RA , Purser DB , Barron RJW
Published: March 2005

The digestibilities of sawdust from one hardwood species, Spotted Gum (Eucalyptus maculata), and two softwood species, Hoop Pine (Araucaria cunninghamii) and Pinus pinaster, were estimated by the nylon bag technique. The dry matter digestibilities were 8.3, 1.7 and 4.4%, respectively. Lignin concentration was possibly a major factor affecting digestibility as the values were 16.4,32.3 and 27.8%, respectively. For each species the ruminal digestion was completed within 48 h.
Early assessment of sweet sorghum as an agro-industrial crop. I. Varietal evaluation
Authors: Ferraris R
Published: March 2005

Thirty-seven sweet sorghum (Sorghum bicolor) cultivars were evaluated for sugar, solubles, grain, fibre and leaf production in first and ratoon crops under irrigation at Ayr, North Queensland, over the winter-summer period. Highest sugar yields were from cv. Rio, which produced 3.6 and 1.6 t ha-1 over 145 and 79 days from first and ratoon crops, respectively. Highest solubles (brix) yields of 7.6 and 4.8 t ha-1 were produced by cv. Italian over 141 and 81 days. The highest grain yield was 5.7 t dry matter ha-1 in the first crop by cv. FS26. Stem fibre yields of about 9 t dry matter ha-1 were realised from the higher yielding cultivars. In the first crop, sugar and solubles yields were found to be negatively correlated with grain yield, early development rate and fibre yield. They were positively correlated with time to maturity, plant leaf area and leaf area index at anthesis, a low position of the largest leaf on the stem, dry matter yield of plant fractions, high stem-juice extraction rates, and degree days and accumulated radiation received. In the ratoon crop, age and environmental variables showed a weaker association with yields. Productivity of fermentables appeared to be comparable with that of sugar cane for the region.
Critical phosphorus levels in sunflower plants
Authors: Spencer K , Chan CW
Published: March 2005

To provide a basis for a tissue test for the diagnosis of P deficiency in sunflower crops, the influence of plant part and age on the critical P percentage (P concentration in tissues required to sustain 90% of maximum yield) was examined. In a glasshouse experiment, the known mobility of phosphate within the plant was reflected in the occurrence of the highest P concentration in the youngest leaves. Laminae contained more P than petioles on a dry-weight basis. Stem internodes contained less P than the adjoining petiole near the base ofthe plant but more near the apex. Three field experiments indicated that the lamina of the youngest fully-expanded leaf was a suitable plant part for diagnosis. Critical P concentrations for this tissue decreased from about 0.35% at the fourth week from sowing to 0.20% at the tenth week.
Pattern of infiltration with furrow irrigation and evapotranspiration of kenaf (Hibiscus cannabinus) grown on Cununurra clay in the Ord Irrigation Area
Authors: Muchow RC , Wood IM
Published: March 2005

The infiltration characteristics of Cununurra clay, the dominant soil in the Ord Irrigation Area, were examined in a furrow-irrigated experiment with kenaf. The irrigation treatments, which were scheduled on leaf water potentials at dawn and solar noon, ensured that water was applied over a wide range of soil moistures. Flowmeters were used in the supply and drainage channels, and the difference between the flows in these meters was taken as the amount of water infiltrating the soil. The efficiencies of application ranged from 50 to 85% and were inversely related to the frequency of application because the infiltration rate on this heavy swelling soil declined with increasing soil moisture content. Crop water use patterns of kenaf in this semi-arid tropical environment were also determined. Evapotranspiration was estimated from the changes over time in soil moisture in the profile. Clear patterns were established for the changes in the ratio of evapotranspiration to free water evaporation with growth under soil moisture regimes ranging from almost stress-free to severely stressed. A peak value of 1.52 was recorded for the period 14-1 6 weeks after sowing in the most frequently watered treatment.
Growth, yield and preliminary selection of seedling guavas in Queensland
Authors: Chapman KR , Paxton B , Saranah J , Scudamore-Smith PD
Published: March 2005

Five guava seedlines of Hawaiian origin, namely GA9-37, GA12-1 6, GA10-48, GA11-56 and GA9-39 were yield tested in coastal sub-tropical south-eastern Queensland. The work demonstrated that seedling guavas produce attractive yields comparable with overseas countries. First crop mean yields were 30.72 kg/tree after 18 months in the field, demonstrating the precocious bearing of the guava. Yields for second and third cropping years were 45.6 and 77.9 kg/tree. These yields equate to 24.7, 37.2 and 61.5 tonnes ha-1 at a planting density of 805 trees ha-1. Third crop yields give the attractive gross returns of around $15,000 ha-1, at current prices paid by processors in Queensland. No differences were found between seedlines in annual yields, accumulated crop yields, fruit Number/tree, annual yield per unit cross sectional area of butt (an index of fruitfulness) and accumulated yield per unit cross sectional area of butt. Within seedline, variability masked differential response and these aspects are discussed. Fruit yields and relative increase in butt cross sectional area of butt varied with cropping year. Fruit. number per tree and yield per unit cross sectional area of butt varied with years, as did fruit number per kg (an index of fruit size). The latter also varied with seedlines. These effects were attributed to water rationing in spring of the second crop year. Preliminary selection based on fruit quality aspects of individuals identified four individuals which are undergoing detailed processing assessment, namely GA9-39R1T2, GA11-56T7, GA11-56R5T2 and GA1 1-56R5T1. Two further individuals were selected for fresh fruit market testing, namely GA11-56T3 and GA11 -56R1T1. We believe that market development rather than horticultural problems to be overcome will dictate the success of the guava as a crop for Australia, since the guava is comparatively easy to grow and manage.
Milk yield of dairy cows given restricted access to water in a Mediterranean-type climate
Authors: King KR , Stockdale CR
Published: March 2005

During summer in the Goulburn Valley, two herds of Jersey- Friesian crossbred cows were used to study the effects of restricted access to drinking water. There were three treatments applied to two herds-(1) free access, (2) 20 min. access before each milking, and (3) 20 min. access before the night milking only. One herd was individually penned and had free access to shade while the other was grazed with no access to shade. Both herds were fed irrigated perennial pasture containing 24.5% dry matter. Maximum air temperature averaged 33.7�C. Over the whole experiment, restricting the access of dairy cows to drinking water did not significantly reduce mean milk yield (mean 12.6 kg/cow day-1) or mean liveweight of cows (mean 41 1 kg) in either herd. However, during the first 4 days of treatment, mean milk yield and mean liveweight were lower (P < 0.05) for cows on a once-a-day access than for those on either free or twice-daily access. In the pen experiment, intake of drinking water averaged 67,45 and 49 l/cow day-1 for treatments 1, 2 and 3, respectively; dry matter intake was unaffected by treatment (mean 15.6 kg/cow day-1). Because of the modifying influence of shade on the environment of the penned cows, there was no significant effects of climate on their water intake. It was concluded that farmers need not supply drinking water to dairy cows in all paddocks.
Responses of laying hens to gradual and abrupt increases in ambient temperature and humidity
Authors: Daniel M , Balnave D
Published: March 2005

White Leghorn x Australorp laying hens were gradually or abruptly exposed to natural summer climate regimens in which high relative humidities and temperatures in excess of 35�C were simulated. Food intake, feeding patterns, egg production, egg weight, egg quality and time of oviposition were recorded. Mortality was high when hens were subjected to abrupt increases in ambient temperature but no deaths from heat stress were observed when hens were able to acclimatize to high temperatures. Food intakes were reduced significantly at high temperatures but less marked reductions were observed in egg production. Therefore, food was used more efficiently in heat-stressed hens. Food conversion ratios of heat-stressed and control hens were, respectively, 2.99 and 3.07 (Experiment 1 ), 2.82 and 3.04 (Experiment 2), and 2.09 and 2.45 (Experiment 3) g food/g egg. Heat-stressed hens consumed less food during the hot afternoon period. Extending the daily photoperiod from 16 to 20 h had no beneficial effect on total food intake or egg production. Egg quality, including egg shell thickness, did not deteriorate at high temperatures and this appeared to be related to a high atmospheric concentration of carbon dioxide produced by excessive panting