bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of protein and energy in the diet of the early-weaned calf on the concentration of free amino acids in the blood plasma
Authors: Leibholz J
Published: March 2005

Three experiments were conducted with 108 male Friesian calves to determine the effect of protein and energy in the diet on the concentration of free amino acids in the plasma. In experiments 1 and 2, the diets contained 12 to 21 per cent crude protein, with urea or meat meal as the protein supplement. The diets were fed with and without sulphur supplementation. In experiment 3, the metabolizable energy content of the diets was changed from 2.2 to 1.8 Mcal kg-1 by the addition of 20 to 60 per cent roughage from lucerne meal or ground straw to the diets. Blood samples were collected from all calves at 11 weeks of age, and the concentration of free amino acids in the plasma was measured. As the protein content of the diets increased, the percentage of essential amino acids of the total amino acids in the plasma increased. The percentage of essential amino acids was also greater in the calves fed meat meal than in those fed urea. These changes were mainly due to increased concentrations of the branched chain amino acids and decreased concentrations of glycine and glutamic acid. The supplementation of the diets containing urea with sodium sulphate increased the concentrations of cystine and methionine in the plasma. As the metabolizable energy intake of the calves increased there was an increase in the concentration of total amino acids in the plasma. Hence, the effect of protein and energy in the diet must be considered in studying the concentration of amino acids in the plasma.
Revegetation of mine wastes at Mt. Isa, Queensland. I. The nature of the material and defining the problems
Authors: Hunter GD , Whiteman PC
Published: March 2005

A series of chemical and physical analyses in the laboratory and field were undertaken on the fine crushed rock material disposed of after ore extraction as large flat tailings dams, The aim was to define those factors limiting plant growth. Analysis showed that available phosphorus was extremely low. Nitrogen levels were also low. pH was approximately neutral between 6.7 and 7.6, due to the high levels of dolomite. Soluble salts, particularly NaCI, MgSO4 and CaSO4 were high, leading to high values of conductivity, up to 0.052 m Sm-1. The particle size distribution was dominated by fine fractions. In the field high bulk density values up to 1.57 g cm-3 , combined with strong surface crusting lead to low values of infiltration. Thus high salt levels are not readily leached. These factors as limitations to plant growth are discussed.
Correction - Studies in the nodulation of Kenya white clover (Trifolium semipilosum) under field conditions in south-east Queensland
Authors: Jones RM , Date RA
Published: March 2005

The nodulation of Kenya white clover (Trifolium semipilosum) was examined under field conditions to evaluate reported establishment problems attributed to poor nodulation. Two isolates of Rhizobium identified as strain CB782 were obtained from nodules of T. semipilosum located in separate field sowings each of which was considered an establishment failure but which had recovered to healthy stands at the time of sampling. The two isolates were compared with a laboratory maintained culture of CB782 for nodulation and nitrogen fixation. Both isolates and the original strain were equally effective in N-fixation and all three increased plant dry weight, per cent plants with effective (pink) nodules and amount of nitrogen fixed compared with an uninoculated control. Increasing the level of seed application of inoculum up to the normal rate increased effective nodulation, but excess inoculum levels resulted only in greater numbers of smaller effective (pink) nodules without any increase in nodule dry weight. High inoculum levels decreased the number of white and green nodules compared with the control. Over 50 per cent effective nodulation was obtained with less than 50 Rhizobium seed-1 at sowing. Serological identification and effectiveness tests of strains in nodules confirmed that most white and green nodules on T. semipilosum resulted from infection by naturally occurring white clover rhizobia. These were ineffective in nitrogen fixation with T. semipilosum but fully effective on T. repens. Serological typing of nodules also indicated that normal levels of inoculation resulted in more than 80 per cent of nodules being formed by the specific inoculum strain. We conclude that field sowings of T. semipilosum can be effectively nodulated by the specific inoculum strain CB782 which is both effective and persistent under south-east Queensland conditions. We suggest that most reported nitrogen deficiency symptoms of establishing T. semipilosum are due to infection by Rugose Leaf Curl Virus.
Pasture management and cultural methods for the control of annual ryegrass (Lolium rigidum) in wheat
Authors: Reeves TG , Smith IS
Published: March 2005

The effects of four pasture management treatments-haycutting, heavy grazing, burning and a control-and two cultural treatments,-mouldboard or disc ploughing-on the densities of annual ryegrass (Lolium rigidum) under subsequent wheat crops, was measured in 16 experiments conducted from 1961 to 1968. Pasture management treatments before cropping significantly reduced subsequent ryegrass populations in first, second, third and fourth year crops, compared with the untreated control and increased grain yields in the first and second year crops. Subsequent ryegrass populations were reduced more by mouldboard ploughing than by disc ploughing and this was reflected in higher yield for all crops. The results indicate that these management and cultural methods may obviate the need for chemical control in first and second year crops.
Effect of weaning age and post-weaning nutrition on the growth of calves and the liveweight of their dams
Authors: Bailey PJ , Halls MA , Bishop AH
Published: March 2005

A factorial grazing experiment conducted during 1970,1971 and 1972 at the Pastoral Research Station, Hamilton, Victoria, studied two major management factors in beef production. Post weaning liveweight changes of calves and their dams were measured to compare the effects of either an eight or ten month weaning age and differing nutritional regimes applied from 8 to 12 months post calving. The cows stocked at the higher rate (1.7 cow ha -1) post weaning lost less weight or gained more weight during the test period in three out of four occasions than the cows stocked at the lower rate (1.5 cow ha-1). The results from this experiment confirm the finding of Bailey and Bishop 1972 and show that on perennial pastures in southern Australia, calves weaned at ten months old from autumn calving Hereford cows are likely to be heavier at 12 months old than are calves weaned at eight months onto dry pasture. However, weaning calves at eight months onto hay aftermath would be an effective alternative to ten month weaning. This would also reduce the risk of weight loss by the cow due to later weaning.
Whole wheat grain feeding of pregnant and lactating ewes and their lambs. 1. The influence of energy, sodium chloride and elemental sulphur on ewe productivity
Authors: Saville DG , Nicholls PJ , McManus WR
Published: March 2005

This experiment was designed to explore the influence of energy, sodium chloride and elemental sulphur on the productivity of pregnant and lactating ewes fed whole wheat grain diets. A central composite design was used to study the response over five levels of each factor. During the last 42 days of pregnancy, the energy treatments resulted in either maintenance of maternal body weights at about 42 kg, or losses of up to 5.5 kg. Ewe maintenance requirements were about 0.14 MJ ME kg-1 day -1 and their foetal requirement was 1 .I 5 MJ ME kg-1 day-1. Sodium chloride and elemental sulphur supplements had no influence on ewe liveweight change up to lambing, but wool growth increased with sulphur supplements of up to about 0.25 to 0.30 per cent. Energy intake and sodium chloride supplementation increased lamb birth weight. After lambing, ewes that had been offered low energy diets increased their liveweight gain and wheat intake with sulphur supplements whereas these supplements reduced the liveweight gain and wheat intake of ewes offered higher energy. Milk production measured on day 14 of lactation averaged 11 53 g day -1 and was not significantly influenced by treatment. These results are discussed in relation to the metabolism of pregnant and lactating ewes, and in the context of the composite design used.
An assessment of the nutritive value of vegetable protein meals for growing pigs using Silcock available lysine values
Authors: Taverner MR , Rayner CJ
Published: March 2005

The effects on the growth performance of pigs and the total and Silcock available lysine content of diets were studied when an equal amount of protein from rapeseed meal and soyabean meal, either expeller or solvent extracted, was included in diets based on wheat and meat and bone meal and fed in restricted amounts to 32 pigs from 20 to 45 kg liveweight. The total and available lysine content of the proteins and diets decreased in the order: solvent extracted soyabean meal, expeller extracted soyabean meal, expeller extracted rapeseed meal, solvent extracted rapeseed meal. The growth rates and food conversion ratios of pigs varied in the same order, and average growth rate and average food conversion were significantly correlated to both total lysine (r2 = 0.910, r2 = 0.918 respectively) and available lysine (r2 = 0.998, r2 = 0.998 respectively) in the diet. The weights of the thyroid glands of pigs fed either rapeseed meal were significantly greater than those of pigs fed the soyabean meals.'Pigs fed solvent extracted soyabean meal had more lean in their hams than pigs fed other supplements.
Subterranean clover as a winter forage crop in a subtropical environment
Authors: Kemp DR
Published: March 2005

The feasibility of using subterranean clover (Trifolium subterraneum) rather than oats (Avena spp.) or annual ryegrass (Lolium rigidum) as a low cost winter forage crop was studied over three years at Taree (lat 32�S) on the subtropical east coast of Australia. When sown in early autumn, with sufficient moisture, subterranean clover yields during the winter were equal to oats liberally supplied with nitrogen, though initial yields from oats were greater over the first two months from sowing. Subterranean clover and ryegrass yields were similar during winter when sown in early autumn. In a dry year, the best results were obtained from sowing subterranean clover in mid autumn. Late autumn or early winter sowings of subterranean clover were unsatisfactory. It was concluded that sowing subterranean clover at high rates (30 kg ha-1) in early autumn provides a suitable low cost, alternative, winter forage crop.
The comparative yield method for estimating dry matter yield of pasture
Authors: Haydock KP , Shaw NH
Published: March 2005

This paper describes a new method for estimating pasture yield in which the yields of random quadrats are rated with respect to a set of reference quadrats preselected in the field to provide a scale which is available for reference throughout the sampling. Three alternative calibration procedures are described based either on the dry matter yields of the reference quadrats or on the yields of quadrats rated and cut either during or at the end of sampling. The second and third procedures are shown to have advantages over the first. When testing the method with four observers and two types of calibration scales, estimates of mean yield were generally within 4 per cent of the actual mean with a maximum difference of 8 per cent. Methods are given for calculating the number of samples required to obtain minimum variance for the estimate of mean yield for a given cost in terms cf time spent in the field.
Effects of supplementary nitrogen fertilizer on nodulation, yield and seed characteristics of soybean (Glycine max) on the Darling Downs
Authors: Williamson AJP , Diatloff A
Published: March 2005

In field experiments with soybeans (Glycine max) conducted over four seasons at Hermitage Research Station, Queensland, levels of applied nitrogen (as urea) up to 134 kg ha -1 were examined. Nodulated soybeans failed to respond to applied nitrogen in three out of the four seasons. A response was obtained in one season when abnormal climatic conditions of low rainfall and high temperatures resulted in a comparatively lower level of nodulation. The probability of such a response is discussed in relation to climatic data of the area over the past 108 years. Nodulation and nitrogen fertilizer increased seed size and nitrogen content of the seed in soils free of Rhizobium japonicum but nitrogen fertilizer had little effect on these characteristics in soils carrying R. japonicum. Oil content of the seed was negatively correlated with the nitrogen content in rhizobia-free soils. Nitrogen fertilizer had a depressive effect on nodulation. This effect was severe when inoculated soybeans were grown in soil free of R. japonicum particularly under conditions of declining soil moisture and high temperatures. In soils with R. japonicum the depressive effect was comparatively light.
The supplemental value of some inorganic sources of phosphorus for broiler chickens
Authors: Karunajeewa H
Published: March 2005

In three experiments with broiler-type chickens ten phosphate supplements were evaluated either singly or in combination. The biological values of monosodium phosphate, sodium tripolyphosphate and a deflurinated rock phosphate were higher than that of dicalcium phosphate, sterilized bone meal, monocalcium dihydrogen phosphate, triple superphosphate and mono-dicalcium phosphate which were intermediate; Christmas Island phosphate and Nauru Island phosphate had the lowest values. Chick performance was high when fed diets containing combinations of triple superphosphate, with either defluorinated rock phosphate, dicalcium phosphate, sterilized bone meal or mono-dicalcium phosphate. These mixtures of cheap and expensive sources of phosphorus are a potential method of lowering the costs of supplementing poultry diets with phosphorus.
A comparison of twenty-seven introduced grasses in two dry-tropical environments in northern Queensland
Authors: Edye LA
Published: March 2005

In a grazed sward trial to compare dry matter production from 25 grass accessions fertilized with 250 kg ha-1 urea annually over a period of four years at 'Lansdown', the highest yielding grasses were Cenchrus ciliaris (buffel grass) cvv. Nunbank and Biloela. Chloris gayana (Rhodes grass) accession 16059, Panicum maximum (green panic) cv. Petrie and C. gayana cv. Callide in that order. Several species failed to persist and some accessions of Chloris, Paspalum and Melinis were virtually non-existent by the end of the second season. In another experiment comparing dry matter production under grazing of 23 accessions sown with a standard legume mixture at two sites ('Lansdown' and 'Fanning River') over periods of five and four years respectively, the highest yields were obtained from Urochloa mosambicensis 6559, C. ciliaris cv. Tarewinnabar and accession 18019 at both sites. Urochloa was top yielder in the higher rainfall site at 'Lansdown' and the two buffel grasses were best at the drier site 'Fanning River'. Of the 23 accessions sown, only 12 at 'Lansdown' and only 7 at 'Fanning River' were persisting strongly when the experiment was completed. Grasses common to both experiments at 'Lansdown' were higher in nitrogen when grown with associated legumes than when grown alone and fertilized with urea. Grass nitrogen levels were low enough to reduce intake by cattle of nearly all accessions throughout the growing season under the urea fertilizer system and phosphorus levels in the grass were generally below that considered adequate for animal nutrition in the legume plots; however, the legumes would probably supply sufficient to meet the animal's requirements for at least part of the year. At 'Fanning River' the accessions were generally lower in nitrogen and phosphorus than at 'Lansdown'.
Control of St. John's wort (Hypericum perforatum var. angustifolium) on non-arable land
Authors: Campbell MH , Flemons KF , Dellow JJ
Published: March 2005

Methods for controlling St. John's wort (Hypericum perforatum var. angustifolium) on non-arable land were investigated in two experiments near Tuena, New South Wales. The effects of herbicides, seed, fertilizer and the timing of the application of these inputs on the establishment of surface-sown legumes and grasses, and on the control of St. John's wort were ascertained. The herbicides, amitrole, 2,4-D, 2,4-D + 2,4,5-T, and picloram were applied with and without 2,2-DPA (sodium 2,2-dichloropropionate) ; glyphosate (N-phosphonomethyl glycine) was applied alone. Establishment, survival and ground cover of sown species and the control of St. John's wort were recorded for up to two years after treatment. Herbicide application was essential for the establishment of cocksfoot (Dactylis glomerata) and phalaris (Phalaris tuberosa), but not for subterranean clover (Trifolium subterraneum), on land infested with St. John's wort. Establishment of grasses and legumes was achieved in one experiment by spraying in late summer and sowing in late autumn, and in another experiment by spraying in late autumn and sowing in early winter. Glyphosate was the most effective herbicide in controlling St. John's wort and associated weeds and in promoting the establishment and development of grasses and legumes. However, good establisment of improved species and good control of St. John's wort was also attained on the 2,4-D and 2,4-D f 2,4,5-T treatments. Thus, until glyphosate becomes commercially available, the most economical method for control of St. John's wort on non-arable land will be the aerial application of 2,4-D + 2,2-DPA three weeks after a distinct autumn break followed by seed and fertilizer three weeks later.
Effect of successive cropping with nitrogenous fertilizers on wheat yields
Authors: Mason MG , Toms WJ
Published: March 2005

Wheat was grown for twelve successive years at three sites with five rates of nitrogen either as calcium ammonium nitrate, ammonium sulphate or urea applied each year to the same plots. There was a long term yield decline, with and without nitrogen, on the site at Wongan Hills, but not at Merredin or Beverley. At each of the three sites there was no indication of a need for higher rates of nitrogen fertilizers with time to maintain yields. At Wongan Hills and Merredin, yields were depressed in most years when the highest rate of ammonium sulphate was used each year. Grain protein contents were low and did not decrease with time.
Performance of sheep and cattle grazed together in different ratios
Authors: Hamilton D
Published: March 2005

On annual pasture, autumn-lambing ewes and steers were grazed together in ratios of 20 to 80 per cent sheep, at a rate of stocking equivalent to 7.4 ewes or 2.1 steers ha-1, and their performance was measured against that of similar ewes and steers grazed separately each at five rates of stocking. In three years of good pasture, the annual performance of steers was not affected by mixed stocking and that of sheep, mainly lamb performance, benefited to an increasing degree as the proportion of sheep in the ratio decreased. The fraction of the mixed-stock area required to have achieved the same performance per animal with separate stocking ranged, with a decrease in the proportion of sheep, from 1.13 to 1.32 for the combination of steer and lamb production and from 0.96 to 1.05 for the combination of steer and wool production. In one year of drought, the effect of mixed stocking was generally the same for sheep as in the earlier years but for steers performance was now depressed, and to a similar degree at all ratios. There was now little or no overall benefit from mixed stocking. The main effects of mixed stocking occurred when green pasture was short or sparse. However, a consistent result early in the year, when there was only dry pasture for most of the time, was a slight depression in steer performance but a slight increase in wool production with mixed stocking. In years of good pasture this effect on steers was eliminated later in the year.
A comparison of the effects on reproductive performance in sheep, of two methods of estimation of ovulation rate
Authors: Oldham CM , Knight TW , Lindsay DR
Published: March 2005

A comparison was made between the reproductive performance of ewes after either laparotorny, in which the uterus and ovaries were exteriorized, or laparoscopy, in which the uterus and ovaries were examined in situ through a telescopic instrument. There was no difference between ewes subject to laparoscopy and their unoperated flock mates. By contrast, in groups examined by laparotomy 10.2 per cent less ewes lambed per 100 ewes joined (P < 0.001). Ewes were most sensitive to laparotomy during the period 15-28 days after mating. There was no effect of laparotomy when the operation was performed before the ewe's first mating.
A comparison of biosuper and superphosphate on a sandy soil in the monsoonal tropics of north Queensland
Authors: Jones RK , Field JBF
Published: March 2005

Biosuper, a biological fertilizer consisting of rock phosphate, elemental sulphur and an inoculum of sulphur-oxidising thiobacilli was compared with superphosphate as a source of phosphorus for Townsville stylo (Stylosanthes humilis) pastures on a deep sandy soil in Cape York Peninsula. The fertilizers were applied in the first year only, at rates varying between 24 and 84 kg of phosphorus ha-1. Harvests were made at the end of the first, second, and third growing seasons. Biosuper tended to be inferior to superphosphate in the first year with respect to dry matter and phosphorus yields, but over the three-year period the two fertilizers gave comparable results. At the higher rates of application, biosuper gave higher yields of sulphur ha-1, presumably because of its higher sulphur content and greater resistance to leaching then superphosphate. Under the conditions of the experiment (i.e. without maintenance dressings of phosphorus and sulphur) biosuper compared quite favourably with superphosphate and, for example, gave 3-year yields of 14,000 kg dry matter ha-1 at the lowest rate of application (24 kgP ha-1).
Comparative salt tolerance of some tropical and temperate legumes and tropical grasses
Authors: Russell JS
Published: March 2005

The dry matter yield of 11 tropical legumes, 10 temperate legumes and 11 tropical grasses was examined in pot experiments on a clay soil with increasing levels of sodium chloride. A mathematical model was fitted to the yield-salt level curves for each species and both the half yield soil salinity level and zero yield soil salinity level were estimated. Species were ranked in relation to their salt tolerance at half and zero yield and these values were expressed in terms of the electrical conductivity of the soil saturation extract. Grasses showed a greater ability to persist at high salt levels than the legumes. The most tolerant grasses were Chloris gayana, Panicum coloratum, Pennisetum clandestinum, Sorghum almum and Digitaria decumbens. Medicago sativa, which was included in both temperate and tropical groups, was the most tolerant legume of both groups. The tropical legumes Macroptilium lathyroides and Macroptilium atropurpureum were almost equivalent to M. sativa in their salt tolerance. The least tolerant grass was Setaria anceps and the least tolerant tropical and temperate legumes were Desmodium uncinatum and Trifolium semipilosum respectively. Both Na and Cl percentages in the plant generally increased with increasing salt but no consistent relationship was found between plant salt tolerance and Na and Cl content. The field implications of the high salt tolerance of certain grasses is discussed in relation to the establishment of permanent grass-legume pastures on saline-sodic soils.
Effect of fertilizer nitrogen, stocking rate and autumn deferment of grazing in association with hay cutting on the root structure of annual pasture species
Authors: Doyle JJ , Sharkey MJ
Published: March 2005

Length, weight, branching and chemical composition of roots of barley grass (Hordeum leporinum) and subterranean clover, (Trifolium subterraneum), the main components of a non-irrigated pasture were measured in the fourth year of an experiment on pastures grazed by Corriedale wethers. The grazing treatments were in a factorial design (2 x 2 x 3) replicated three times, with three stocking rates, two levels of nitrogen fertilizer and two methods of management. Grass and clover density was reduced progressively as stocking rate was increased from 10 to 12 to 17 wethers ha-1 but the surviving plants at maturity had vigorous root systems. This performance of annual species contrasts with that of perennial pasture species where root development and root branching may be expected to decline with increase in grazing pressure. Applications of nitrogen fertilizer annually at rates of 0 or 67 kg ha-1 had little effect on density of grasses or clovers but clover roots were lighter and had fewer rhizobia nodules where nitrogen fertilizer had been applied. The management of pasture by deferment of grazing during regeneration was beneficial to clover plants in that their root structure was larger at maturity; similar effects were not evident in grass roots.
Effect of waterlogging on the growth, grain and straw yield of wheat, barley and oats
Authors: Watson ER , Lapins P , Barron RJW
Published: March 2005

Wheat, barley and oats were grown in undrained plastic buckets containing soil collected from upper, mid and lower slopes of a valley that was subject to winter waterlogging. Two weeks after planting, the water content for each soil was either maintained at 80 per cent of full water holding capacity or subjected to intermittent or continuous waterlogging for six weeks. In a second experiment, using lowerslope soil only, the same three cereals were subjected to similar waterlogging treatments commencing at two or six weeks after planting or at ear emergence. In this experiment the plants received either no nitrogen fertilizer or 100 kg nitrogen ha-1. Both soil composition and waterlogging had a significant effect on plant yield but the effect of waterlogging was much greater. Waterlogging reduced root growth and penetration, the production of tillers and fertile heads, and delayed ear emergence and plant maturation. Reduction in plant growth rate was measurable within three days from the onset of waterlogging. In the first experiment intermittent and continuous waterlogging reduced vegetative growth yield (mean of three cereals in three soils) by 37 per cent and 55 per cent respectively; and wheat grain yields by 40 per cent and 53 per cent respectively. However, there was no differential effect of the two waterlogging treatments on the grain yield of barley and oats, the mean reduction being 39 per cent for barley and 48 per cent for oats. In the second experiment waterlogging at the earliest growth stage resulted in the greatest reduction in root, herbage and grain yield. Waterlogging at ear emergence killed some tillers and roots and reduced the plants stability at maturity. Grain size was reduced in some treatments. Application of nitrogen fertilizer compensated, either partially or fully, for reduction in grain yield due to waterlogging treatments on all three cereals. Some reasons for yield reduction in the three species and the practical implications of the results are discussed.
Insecticides for control of light brown apple moth and codling moth in Australia
Authors: MacQuillan MJ
Published: March 2005

Spray treatments of chlorpyrifos, chlorpyrifos-methyl, leptophos, mexacarbate, Bacillus thuringiensis and standard recommendations for control of Epiphyas postvittana Walk. and Cydia pornonella (L.), were compared in six field experiments on apples in Victoria and Tasmania in 1971/72 and 1973/74 and in New South Wales in 1971/72. In all four experiments in southern Victoria and Tasmania, chlorpyrifos 250 p.p.m. applied at two week intervals from calyx formation was as effective against E. postvittana as the standard azinphos methyl, In the same region chlorpyrifos-methyl 500 p.p.m. gave results as good as the standard in two experiments and mexacarbate 500 p.p.m. and Bacillus thuringiensis 37.5 g 100 l-1 in one. Alternate sprays of B. thuringiensis 25 g 100 l-1 and either chlorpyrifos 375 p.p.m. or leptophos 375 gave results as good as the standard in two experiments. Azinphos methyl 375 p.p.m. sprays alternated with B. thuringiensis 25 g 100l-1 gave results as good as the standard in a single experiment. In one experiment, leptophos 500 p.p.m. gave better control than the standard. In two experiments in central and southern Victoria, chlorpyrifos 250 p.p.m. applied every two weeks from calyx formation was as effective against C. pornonella as the standard azinphos methyl treatment. Leptophos 500 p.p.m. used at four- and two-week intervals in central and southern Victoria respectively gave results equal to the standard which were also equalled by chlorpyrifos 250 p.p.m. and 375 p.p.m. respectively applied every two weeks. In an experiment in NSW with spray applications at four-week intervals from calyx formation, chlorpyrifos 500 p.p.m. was not as effective against C. pornonella as the standard azinphos methyl treatment. Chlorpyrifos methyl 500 p.p.m. and mexacarbate 500 p.p.m. did not reduce damage below the untreated. Leptophos 500 p.p.m. was as effective as the standard.
Early weaning of grazing sheep. 2. Performance of ewes
Authors: Corbett JL , Furnival EP
Published: March 2005

Two similar groups of Corriedale ewes were formed from a flock of 231. These were grazed on separate phalaris (Phalaris tuberosa) pasture at 8.6 or 17.3 ewes ha-1, respectively high and low nutritional planes, from seven weeks before their first lambing in spring 1968 until after their second lambing. Within each group the 1968 lambs were weaned by removal to other pastures at six or 12 weeks of age, or were left unweaned for 21 or 29 weeks in the high and low planes respectively. Birth weights in 1968 did not differ between planes, and for all ewes an increase of 1 kg in lamb birthweight was associated with a reduction in clean wool production during the last seven weeks of pregnancy of 0.22 � 0.11 g d-1. Pregnancy appeared to reduce by about one half the expression of genotypic differences between sheep in wool producing ability, and reduced 12 months clean fleece weight by about 5 per cent. Low plane ewes produced significantly less milk containing less solids. Liveweight gains and rates of wool growth were reduced by lactation and increased after weaning, wool growth the more slowly. Both rates of recovery were less in the low plane where, unlike the high plane, lactation appeared to reduce expression of genotypic differences in wool production. Clean fleece weights were reduced by about 5 and 10 per cent by lactations of respectively six weeks and five months duration. At subsequent joining a smaller proportion of the low compared with high plane ewes was marked by the ram and of these a smaller proportion produced lambs. Within the low plane, the longer the preceding lactation the lower the liveweight at second joining and lambing, and the lower the mating and lambing percentages. The results indicated that when there was a shortage of feed at and after lambing the performance of ewes would be improved by weaning their lambs at about six weeks. Ewe liveweights were consistently greater after six week weaning than after later weaning, a result confirmed in other experiments on weaning within fixed total areas of pasture.
Studies on the supplementary feeding of sheep consuming mulga (Acacia aneura). 2. Comparative levels of molasses and urea supplements fed under pen conditions
Authors: Entwistle KW , Baird DA
Published: March 2005

Sheep maintained on a mulga (Acacia aneura) diet plus 2 g phosphorus (P) day-1 were supplemented with molasses at levels of 0, 50, 100 or 200 g DM day-1 with or without 8 g urea day-1. The supplements were offered for a period of 18 weeks and were then withdrawn and animals maintained on the basal mulga diet plus P for a further eight weeks. Provision of urea had no effect on mulga dry matter (DM) intakes or on any of the production measurements made. Daily DM intakes of mulga were significantly increased by molasses supplementation, intakes being 41 per cent, 57 per cent and 62 per cent higher than controls at levels of 50, 100 or 200 g DM molasses day-1 respectively. Liveweight gain followed a similar pattern, and at the end of the supplementation period liveweights for the 50, 100 and 200 g DM molasses day-1 were respectively 29 per cent, 42 per cent and 48 per cent heavier than the controls. Wool growth rates were significantly higher in all groups receiving molasses, the response being linear with increasing levels of molasses supplementation. Fleece yields also showed a linear trend with increasing levels of supplementation, the major response being attributable to the provision of the first 50 g molasses. Cessation of supplementation resulted in a rapid decline in mulga DM intake to levels approximately that of the controls. Liveweights of supplemented animals also declined during the post-supplementation period although in groups receiving either 100 or 200 g DM molasses day-1, they only declined to pre-experimental levels.
The value to Merino ewes and lambs of continued superphosphate topdressing on a subterranean clover pasture ley
Authors: Southwood OR , Saville DG , Gilmour AR
Published: March 2005

In an experiment at the Agricultural Research Station, Temora, New South Wales, Merino breeding ewes with their lambs grazed continuously from 1966 to 1970 at three stocking rates, 5, 7.5 and 10 ewes ha-1, on annual Trifolium subterraneum clover pasture topdressed every autumn with superphosphate fertilizer at nil, 94 or 188 kg ha-1. Stocking rate had an effect on ewe body weight in autumn each year and in winter and spring of the last year but it had no effect no wool production per ewe. Apart from the dry year, stocking rate had no effect on lamb performance. Superphosphate had little effect on ewe body weight and none on wool production but there were more lambs on the fertilized treatments than on the unfertilized pastures in 1967 when rainfall was low. Fertilizer encouraged barley grass dominance whereas the pasture not topdressed grew more clover and produced more burr. With no topdressing, available soil phosphate declined steadily over the five years to less than half the initial level. The results indicate that in a spring lambing, Merino ewe enterprise in the southern New South Wales wheat belt, where clover-ley farming is the general practice, annual pasture topdressing is no longer necessary after approximately 1000 kg ha-1 superphosphate has been applied to the soil and the fertilizer is continued through the cropping phase.
Photosynthesis and transpiration in the heads of droughted grain sorghum
Authors: Pasternak D , Wilson GL
Published: March 2005

The effect of water deficits on the relative photosynthetic rates in heads and leaves of sorghum was measured. When water was withheld, photosynthesis virtually ceased in the leaves but continued in the heads at the same rate. The photosynthetic activity of heads increased from about 12 per cent of the total in a well watered plant to about 88 per cent for a plant at high moisture deficit. Relative transpiration of heads also increased as water status declined. In watered plants, loss from heads was, like photosynthesis, about 12 per cent of the total but increased with water shortage to about 35 per cent.
Alternatives to monthly sampling in herd recording
Authors: Munro GL
Published: March 2005

Two investigations were made in South Australia to assess the accuracy of methods alternative to monthly sampling in herd recording. In the first, lactation records for 15,482 cows completing lactations in 1971-72 and tested monthly at that time were examined. The average lactation yields were 3988 kg, 3974 kg, 4033 kg, 3971 kg and 4004 kg for monthly testing, bimonthly testing (even months), bimonthly testing (odd months), alternate p.m.-a.m. testing, alternate a.m.-p.m. testing respectively. Only 5 per cent of all alternate p.m.-a.m. and alternate a.m.-p.m. estimates differed by more than 5 per cent from monthly estimates, whereas 12.3 per cent of bimonthly (even) and 19.7 per cent of bimonthly (odd) estimates differed by greater than 5 per cent. The second investigation was made over six months using a Research Centre herd to determine the accuracy of alternate a.m.-p.m. sampling for milk fat and milk protein. Cows recorded six times gave average fat percentages of 3.56, 3.65 and 3.60 under alternate p.m.-a.m., alternate a.m.-p.m. and monthly testing schemes. Average protein percentages were 3.47, 3.44 and 3.46 respectively. It is concluded that alternate a.m.-p.m. sampling could be satisfactorily adopted as an alternative method of sampling in herd recording,
A study on the effect of frequency of urea ingestion on the utilization of low quality roughage by steers
Authors: Romero A , Siebert BD , Murray RM
Published: March 2005

Steers were fed a low quality roughage supplemented with 50 g urea day-1 administered at different frequencies. The effect of the different treatments was measured in terms of intake, digestibility, nitrogen balance and changes of some rumen fermentation measures in two different but complementary experiments. Utilization of the roughage was enhanced as the frequency of ingestion of urea increased. Organic matter digestibility was unaffected but voluntary intake was stimulated by all urea treatments. There was negative nitrogen balance in control animals but all treated were in positive nitrogen balance. However, the greatest retention was produced when urea was sprayed onto the ration. Possible reasons for the better utilization of urea as the frequency of ingestion spreads over the day are suggested by the results observed in the fermentation measures considered.
Reproductive performance of ewe lambs: genetic correlation with weaning weight and subsequent reproductive performance
Authors: Barlow R , Hodges CJ
Published: March 2005

The reproductive performance of Merino ewe lambs was examined in flocks with different selection histories for growth to weaning and net reproductive rate. These ewes were drawn from selection flocks maintained at the Agricultural Research Station, Trangie. There was evidence of a positive genetic correlation between weaning weight and reproductive performance of ewe lambs. Selection for weaning weight had a significant effect on the percentage of ewes lambing (P < 0.05). This appeared to be a function of a higher level of fertility (P <0.05) and a higher proportion of ewes mating (n.s.). The proportion of ewes apparently in oestrus during a 39 day teasing period, prior to joining, was significantly influenced by selection for weaning weight (P < 0.05). Simultaneous selection for increased net reproductive rate, weaning weight and clean fleece weight did not result in higher ewe lamb performance than that achieved by selection for increased weaning weight alone. No conclusion could be drawn from these data about the correlation between net reproductive rate and reproductive performance of ewe lambs.
Short-term studies on the response of grazing dairy cows to dietary supplementation
Authors: Jeffery H , Buesnel RF , O'Neill GH
Published: March 2005

Milk production of grazing dairy cows receiving 3 kg per day of wheat, sorghum, maize, oats or barley was measured. In general, only small differences were observed in the yield and composition of milk produced from cows consuming the different grains. Two experiments were conducted to investigate the relationship between the milk response of grazing dairy cows to 3 kg supplement and their level of production, stage of lactation, and age. Similar mean responses to supplementation were found in both experiments but no consistent relationship between response and either level of production, stage of lactation or age was found. A further experiment examined the response of grazing dairy cows, grouped into four groups according to their level of production, to 3, 4.1/3 5.2/3, 7 or 8.5 kg supplement per day. These treatments had a non-significant effect on milk composition; as the rate of supplementation increased, the yield of milk and its constituents first increased then commenced to decrease. The response obtained from both low and high producing cows was similar. It was thus concluded that in the short-term neither the type of grain fed, the cow's age, level of production nor stage of lactation affected its response to supplementation. The dichotomy between this conclusion and the widespread view that high producers respond better to supplementation is discussed.
Induction of parturition in sheep using oestradiol benzoate
Authors: Restall BJ , Herdegen J , Carberry P
Published: March 2005

The efficacy of oestradiol benzoate (ODB) in inducing parturition in Dorset Horn x Merino ewes was examined in two trials conducted at the Agricultural Research Station, Condobolin during the autumn and spring of 1974. In the first trial ewes were given either 10, 20 or 40 mg of ODB i.m. as a single dose between days 140 and 144 of gestation. In the three days following treatment 50 per cent of untreated ewes lambed. Of the treated ewes, 14.7 per cent lambed on the first day after treatment, 79.4 per cent lambed on the second day after treatment and 5.9 per cent lambed on the third day after treatment. Abortion was induced in 40 to 70 per cent of ewes inadvertently treated on days 126 to 130 of gestation, with all lambs born dead or dying. In a second trial ODB was effective in inducing parturition at doses as low as 7.5 mg. For ewes treated at 141 days of gestation optimal synchrony of parturition, between 35 and 50 hours after treatment, was obtained with doses of 20 and 30 mg ODB. Lamb losses (19 to 23 per cent) in treated ewes were similar to those for untreated ewes. ODB was superior to either a short or long acting corticoid (Dexamethasone) in synchronizing and inducing parturition in ewes treated at 141 days of gestation. Lambs born prematurely grew at least as well as lambs born at the normal time.
Effect of timing of glyphosate and 2,2-DPA application on establishment of surface-sown pasture species
Authors: Campbell MH
Published: March 2005

In two experiments on unploughed hill country near Turondale, New South Wales, the effects were examined of applying glyphosate and 2,2-DPA before and after the autumn break and at various intervals before sowing on the establishment of surface-sown Medicago sativa, Trifolium subterraneum, Dactylis glomerata and Phalaris tuberosa. Good control of resident species was obtained by applying herbicides from 10 to 30 days after autumn rain had promoted germination of winter annuals; poor control resulted if herbicides were applied before the autumn break. Glyphosate was more efficient in controlling resident species than 2,2-DPA. The establishment of all species except subterranean clover depended on good control of the resident plants. It was also necessary to have an adequate period between spraying and sowing to allow the residual herbicide to dissipate; 10 days was sufficient for the grasses, 20 days for lucerne and longer for subterranean clover. A 4.5 kg a.e. ha-1 rate of glyphosata had a more serious residual effect than a 1.5 kg a.e. ha-1 rate or the 2,2-DPA treatment. Results showed that good establishment of surface-sown legumes and grasses can be obtained by applying 0.5 to 1.5 kg a.e. ha-1 of glyphosate, or 8.7 kg a.e. ha-1 of 2,2-DPA, 10 to 30 days after autumn rain and then sowing 10 to 20 days later.
Plant nutrition studies on some yellow and red earth soils in northern Cape York Peninsula. 2. Phosphorus: plant response and soil retention
Authors: Winter WH , Gillman GP
Published: March 2005

The response of a Stylosanthes guyanensislBrachiaria decumbens pasture to phosphorus on a yellow earth soil in northern Cape York Peninsula was studied over three years. Establishment rates of 0 to 130 kg ha-1 P were used followed by various combinations of 0 or 20 kg ha-1 P in the next two years. With comparisons made at the same cumulative P rate the dry matter and nitrogen yields were not affected by timing of application but P yield was increased in the third year when P was freshly applied. The dry matter yield response was modified by the botanical composition of the pasture. In the first year the pasture was 90-95 per cent legume and 110 kg ha-1 P was required to give 90 per cent of the presumed maximum yield whereas in the third year when the legume content was lower, (increasing from 10 to 40 per cent with P rate) this requirement had been reduced to about 90 kg ha-1 P. The third year P yield data were used to show that the value of applied P declined by about 70 per cent each year. After three years all the applied P was recovered in the 0-60 cm zone and the distribution was not affected by timing of application. In the 0-10 cm zone the acid extractable P increased from 0 with no P applied to 40 p.p.m. with 150 kg ha-1 P applied.
Soil water conservation under cultivated fallows in clay soils of south-western Queensland
Authors: Pressland AJ , Batianoff GN
Published: March 2005

Three field experiments to study the effect of time and method of cultivation during fallow on soil moisture accretion and crop growth were established at a site near Charleville, Queensland. The soil was a grey-brown cracking clay (46 per cent clay) typical of the Mitchell grass (Astrebla spp.) downs. In the first experiment, soil moisture accretion was followed on plots cultivated in November 1966 with either a disc plough or scarifier or not cultivated. Soil moisture was increased in the 90 cm deep profile by cultivation, but remained almost constant for the duration of the summer fallow. There was no difference in soil moisture under the disced and scarified plots. The remaining experiments were designed to study the effect of cultivations during fallow on soil moisture at the time of sowings. One early summer cultivation resulted in soil moisture levels similar to that gained from two or more ploughings. However, crop yields were highest following three cultivations. It is concluded that two or three cultivations during fallow decreases loss of soil water through transpiration of weeds and should increase the number of years a forage crop can be expected in south western Queensland.
Wheat root penetration and total available water on a range of soil types
Authors: Tennant D
Published: March 2005

Depth of root penetration was examined over three years on a range of soil types in Western Australia. A consistent pattern was recognized. Roots penetrated rapidly to 5 to 10 cm from the soil surface within the first week from planting. Subsequent penetration was slow to 6 weeks, at which stage, depending on soil types, depth of root penetration was 15 to 30 cm. Rates of root penetration increased after 6 weeks from planting with greatest penetration occurring between 8 to 13 weeks. Respective maximum depths of root penetration in the deep sand, sandy loam, grey clay and sand over clay soils investigated were 169, 173, 31 and 73 cm. These depths were reached between 10 to 14 weeks after planting. Potential available soil water to maximum depths of root penetration were 2.6, 20.1, 5.6 and 8.1 cm for the deep sand, sandy loam, grey clay and sand over clay respectively. More than half of this available soil water was accessible for crop exploitation over the 9 to 14 week period after planting, except with shallow water and root penetration in the grey clay.