bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic returns from reducing backfat thickness in pigs by genetic and other means
Authors: McPhee CP
Published: March 2005

A major pig abattoir in Queensland grades carcases on the thickness of subcutaneous fat at three positions on the back. A model was developed for transforming grading results into a relationship between average fat thickness and average carcase price. This relationship was examined in a large sample of 60 to 70 kg carcases drawn from a year's killing. From highest to lowest, grades were designated GI, G2, G3 and G4. The distribution of carcases between grades was 84.0, 12.3, 3.5 and 0.2 per cent, the average fat thicknesses were 22.3, 27.8, 31.1 and 35.1 mm and average prices 111.0, 104.5, 96.0 and 81.0 c kg-1 respectively. A sigmoid relationship was found between fat thickness and price with the sampled population being close to the upper limit of price. The value of 1 mm reduction in fat thickness in the present population was estimated at 0.55 c kg-1. The same reduction in a population 1 standard deviation fatter was valued at 1.67 c kg-1. It was concluded that only populations fatter than the present one would be fully compensated for the increase in carcase lean which would accompany a reduction in back fat. Reference is made to the use of the derived relationship between fat thickness and carcase price in cost-benefit analyses and genetic improvement programmes.
Prediction of flowering in sunflowers
Authors: Goyne PJ , Woodruff DR , Churchett JD
Published: March 2005

Models based on growing degree day summations (G.D.D.) for the prediction of 50 per cent flowering (50F) were developed using phenological data obtained from monthly plantings of the open pollinated sunflower cultivar, Sunfola 68-2, and the hybrid, Hysun-30, at Biloela over the period September 1974 to August 1975. These models were tested on independent data obtained from plantings made from 1973 to 1976. The base temperatures for the computation of G.D.D. were found to be -1.3�C for Sunfola 68-2 and -5.9�C for Hysun-30. Daylength affected both phenology and leaf number during the emergence to head visible stage (E-HV). The data suggested that Sunfola 68-2 was either day-neutral or had a short-day response, and Hysun-30 a long-day photoperiod requirement. These differences led to the development of different models for the prediction of 50F. The model for Sunfola 68-2 used G.D.D. with no adjustment for daylength, but daylength adjustment was necessary for Hysun-30. Reliable predictions of 50F for Biloela were given by the equations : Sunfola 68-2 : G.D.D. (E-50F) = I351.7 � 51.8 (base -1.3�C) Hysun-30: G.D.D. (E-50F) = (2835.0-133.1 DL)+668.2 � 23.9 (base -5.9�C) where DL = (Daylength at planting + Daylength one month later)/2
Effect of date and final irrigation on yield and yield components of sunflowers in a semi-arid environment
Authors: Browne CL
Published: March 2005

In the semi-arid irrigation areas of south-western New South Wales, many sunflower crops receive no irrigation after flowering. In these dry climates, such premature termination of irrigation could be leading to substantial yield losses. The effect of date of final irrigation on yield and yield components of sunflowers (cv. VNIIMK 6540) was thus examined in two experiments. In the first experiment, seed yield was increased by 19 per cent when final irrigation was applied 22 days after mid-flowering, rather than at mid-flowering. The higher yield resulted principally from an increase in the number of harvestable seeds. Higher frequency of irrigation further increased seed yield by 9 per cent via increase in seed weight. Estimated total consumptive water use by treatments ranged from 546 to 677 mm and the regression of yield (kg ha-1) on water use (mm) was y = 3.9x - 47.4 (r = 0.77, P < 0.001). In the second experiment, in which all treatments were irrigated at a high frequency, seed yield was increased by 30 per cent and total oil yield by 48 per cent when final irrigation was applied 16 days after mid-flowering, rather than at mid-flowering. Both seed weight and seed number were increased by the later irrigation. No further yield improvement was achieved by extending the irrigation season to encompass physiological maturity (a mean 31 days after mid-flowering).
Incidence of currant borer moth, Synanthedon tipuliformis, in blackcurrants in Tasmania
Authors: Hardy RJ , Wilson SJ
Published: March 2005

The incidence of the currant borer moth, Synanthedon tipuliformis (Clerck), in blackcurrant plantations in southern Tasmania was assessed by a survey in 1973. On individual properties the mean larval density ranged from nil to 1.1 larvae m-1 of branch, but on most properties the larval density was considerably less than the overall mean of 0.21 larvae m-1. The survey suggested that the incidence of the moth was highest in a more inland district and in flat and north facing blocks; further, incidence increased with decreasing altitude.
Effect of molasses supplementation and copper, cobalt and anthelmintic therapy on weight gain of beef yearling steers grazing improved pastures in a wet tropical environment
Authors: Copeman DB , Sumbung FP , Poothongtong P , Haq S , Armstrong JR
Published: March 2005

The effects of copper, cobalt and anthelmintic therapy on weight gain and serum copper values were measured in 240 Brahman cross yearling steers half of which were supplemented with a molasses, meat meal, urea, monoammonium phosphate mixture. Cattle grazed fertilized grass-legume pasture in a wet tropical area of north Queensland. Similar weight gains were observed in the non-supplemented groups treated with copper and cobalt as in the non-treated control group. In groups that received the molasses supplement, those treated with copper and cobalt gained significantly more weight than the non-treated control group. There was also a highly significant interaction between treatments with both copper and cobalt and supplementation. Supplementation did not reduce the effect of nematode parasitism on weight gain. Supplemented animals treated each three weeks with levamisole had a 10.2 kg greater weight gain response over the 132 days treatment period than similarly treated non-supplemented animals. Supplemented animals grew faster than non-supplemented animals only during the cool dry late winter and early spring corresponding to the period when pasture quality and availability were lowest. Serum copper values of all groups were within the range of values for healthy cattle.
Comparative performance of cattle and buffalo on the Sepik Plains, Papua New Guinea
Authors: Schottler JH , Boromana A , Williams WT
Published: March 2005

Fifty female Brahman-cross cattle and 50 water buffalo were run on the infertile native pastures of the Sepik lowland plains, Papua New Guinea; half the buffalo, and all the cattle, received mineral supplementation (phosphate, Ca, Cu and Co). After the beginning of the experiment all animals were able to maintain, but not improve, their weights. The liveweights attained were everywhere less than those attained on more fertile pastures elsewhere in Papua New Guinea, the discrepancy being greater for cattle than for buffalo. Supplementation improved both the mean liveweight of buffalo and the growth rate of the calves. Calf mortality was 18 per cent in both species. Despite the longer gestation period, the buffalo produced nearly 50 per cent more calves than the cattle; buffalo more often than not conceived while still lactating, whereas cattle did so only rarely. There was some evidence of a long-term improvement in fertility as a result of supplementation. It is concluded that under these difficult conditions buffalo are a better proposition than cattle.
Disease resistant flue-cured tobacco breeding lines for north Queensland I. Resistance to blue mould, Peronospora tabacina
Authors: Gillham FEM , Wark DC , Harrigan EKS
Published: March 2005

Blue mould, Peronospora tabacina Adam., is the most serious disease of tobacco in north Oueensland. Two cultivars were released in 1969 and one in 1972 which were resistant to the north Queensland strain of blue mould, APTI. During 1972 and 1973, a new strain of mould, APT2, became established in the area. The APT1 resistant cultivars, which carried resistance from Nicotiana debneyi or N. goodspeedii, were susceptible to APT2. Breeding lines carrying blue mould resistance from these species and from N. exigua, N. velutina or N. excelsior were introduced for screening for resistance to the new strain of mould. Some of these lines had been developed by backcrossing and selection, some from crosses between lines carrying resistance from different sources and others by following backcrossing by production of doubled haploids through anther culture. Following the screening of these lines for blue mould resistance and for commercial attributes, three backcross lines, three double haploid lines and one line carrying resistance from two sources were selected for further screening as potential commercial cultivars.
Disease resistant flue-cured tobacco breeding lines for north Queensland 2. Resistance to bacterial wilt, Pseudomonas solanacearum and black shank, Phytophthora nicotianae var. nicotianae
Authors: Gillham FEM , Harrigan EKS
Published: March 2005

Two soil borne diseases, bacterial wilt, Pseudomonas solanacearum, E. F. Smith and black shank, Phytophthora nicotianae (B. De Haan) var. nicotianae, cause economic harm to tobacco crops in certain parts of north Queensland. Host plant resistance is the main means of control for both diseases. During the period from 1969 until the closure of the Tobacco Research Institute at Mareeba in 1975, part of the plant breeding programme was directed towards combining black shank resistance and bacterial wilt resistance with resistance to blue mould, Peronospora tabacina, Adam in a commercially acceptable cultivar. As a result of this programme, fourteen lines have been selected which have a good level of resistance to the three diseases and an acceptable commercial potential. Further improvement can be expected from selection. The development of a new strain of blue mould will preclude the general release of these lines for commercial production but they will be of value as breeding lines and for restricted release in areas where either of the soil borne diseases is a problem.
Detection of cowpea aphid-borne mosaic virus in Queensland
Authors: Behncken GM , Maleevsky L
Published: March 2005

Cowpea aphid-borne mosaic virus (CAMV) is shown to cause a mosaic disease of cowpea (Vigna unguiculata) in north Queensland. The virus was identified on the basis of its host range and symptoms, particle morphology, transmission by sap, aphids, and in seed, and its serological reaction with a known antiserum to an East African isolate of CAMV. No resistance was found in 14 cowpea cultivars. The potential of CAMV as a cause of disease in beans grown in the Burdekin bean seed production area was investigated but most bean cultivars tested were resistant. Only the cultivars Black Turtle Soup, Climbing Blue Lake, Limelight, Pinto and the navy bean lines Actolac, Gallaroy and Kerman were susceptible and produced severe sumptoms.
Revegetation of alumina refinery wastes. 1. Properties and amelioration of the materials
Authors: Meecham JR , Bell LC
Published: March 2005

Excess soluble salts (EC 30 to 48 mScm-1), high alkalinity (pH 9.2 to 11 .0) and potentially toxic levels of sodium (ESP 49 to 88 per cent) were characteristic of fly ash and bauxite wastes ('red sand' and 'red mud') from the Gladstone alumina refinery. In red sand, N and P levels were extremely low and Zn and Mn marginal; extremely low levels of N and P and a marginal amount of Zn were measured in the red mud. Fly ash was characterized by a potentially toxic level of B and deficiency levels of N and Zn. The physical limitations of low water holding capacity of red sand and the susceptibility of fly ash to wind erosion were reduced by mixing the wastes. Excess soluble salts in fly ash-red sand mixtures were effectively removed by leaching without an accompanying decrease in the saturated hydraulic conductivities of the solids. Following the reduction in salinity, the pH values of the wastes remained high (8.4 to 9.6). Incubation of the ash and sand with NH4NO3, superphosphate, FeSO4.7H2O, FeS2 and S for up to ten weeks demonstrated that FeSO4.7H20 was the most effective acidulant in the short term. Reduction of the excessive exchangeable sodium percentages in ash (49 per cent) and sand (88 per cent) to levels tolerable to plant growth was achieved by leaching and acidification.
Some effects of girdling, gibberellic acid sprays, bunch thinning and trimming on the sultana
Authors: Sarooshi RA
Published: March 2005

Girdling, thinning and trimming bunches and gibberellic acid (GA) treatments were imposed on sultana vines over three years to study their effects on berry size, yield, skin strength, pedicel features and bunch characteristics. A double cut stem girdle (4.8 mm) combined with three GA sprays of 60 p.p.m. (applied at bloom, shatter and two weeks after shatter) and bunch thinning and trimming produced large berries weighing up to 5 g each. However this treatmen1 delayed fruit maturity and produced more compact bunches. Similar sized berries with no delay in maturity and looser bunches were obtained by using the same combination of treatments but reducing the GA sprays to two, one at 10 p.p.m. applied at 50 per cent bloom and the second at 60 p.p.m, at 3-4 mm berry diameter, which was two weeks after shatter. A double cut was more effective than a single cut girdle. Bunch thinning and trimming were necessary for best results but there were no differences in results between trimming to four or six laterals per bunch. Thinning to 15 bunches per vine produced more compact bunches and lower yield than 20 bunches per vine. Berry skin resistance to puncture was increased more effectively by bunch trimming and thinning than by girdling or applying GA. Pedicel length and thickness were increased substantially by applying GA.
Genetic improvement of meat sheep. 4. Effect of age of dam on productivity of Dorset and Border Leicester sheep
Authors: Gregory IP , Roberts EM , James JW
Published: March 2005

The effect of age of the dam on the number of lambs born (LBL) and weaned (LwL) and the weight of lambs weaned (WLWL) per ewe lambing and on the number of lambs weaned per lamb born (LwB) and lamb weaning weight (WWT) has been estimated for Dorset and Border Leicester sheep. In both breeds, LBL, LWL and WLWL showed a clear association with age of the dam, rising to a peak at a dam age of five years in the Dorsets and at between four and six years in the Border Leicester. The association between age of dam and WWT and LWB was less marked. WWT rose to a peak in both breeds at a dam age of five years and LWB rose to a peak at four and three years in the Dorsets and Border Leicester respectively. The estimates of ewe productivity were used to calculate the productivity of Dorset flocks of differing age structures. It was found that maximum productivity would be achieved with a flock aged from two to six years.
A model of the breakdown of dichlorvos on grain
Authors: Desmarchelier JM
Published: March 2005

Predictive models of decay of dichlorvos residues and dichlorvos vapour concentrations were compared with breakdown observed in grain stored in six railway trucks and four commercial silos. Decay rates were adequately modelled by simple kinetic treatments and no variations in rate of decay caused by possible saturation of grain enzymes were observed. The discrepancies in various reported models for decay of dichlorvos may be due to pronounced differences in surface effects observed in commercial and laboratory applications.
Effect of shading on the seedling growth of the leguminous shrub Leucaena leucocephala
Authors: Egara K , Jones RJ
Published: March 2005

The growth of seedlings of the forage shrub legume Leucaena leucocephala cv. Cunningham was studied at three levels of shading (100, 57 and 35 per cent relative photosynthetic quantum flux) in a glasshouse. An additional treatment investigated the response of unshaded plants to nitrogen fertilizer applied twice weekly. Shading reduced total plant weight (3.83, 3.20, 2.46g), increased the shoot/root ratio, increased internode length and plant height. However, with increasing shade there was a linear increase in leaf area, and relative growth rate (RGR) of shoots was affected little. RGR of the roots declined sharply from 0.62 to 0.51g g -1 week-1 with shading. Only at the lowest luminance was the dry matter per cent of shoots decreased (32 per cent to 28 per cent). Leaves were larger and thinner in the shaded treatments but rate of leaf appearance was unaffected. Added nitrogen (= 225 kg N ha-1) increased uptake of nitrogen (by 68 per cent), nitrogen concentration (59 per cent) and leaf weight (24 per cent) but had no significant effect on plant height, number of leaves, RGR, or dry matter per cent of shoots. The poor seedling performance of leucaena in competition with other species does not appear to be due to a failure to tolerate shade. In this respect it appears to be better than some other tropical pasture legumes.
Survival of Rhizobium trifolii strains on inoculated seed held at 35°C
Authors: Philpotts H
Published: March 2005

Fifteen Rhizobium trifolii strains, selected from 62 isolations from naturalized white clover (Trifolium repens) plants on the far north coast of New South Wales, were tested for their tolerance to high temperature. They were compared with TAI (the current commercial strain) and CC275e, when used as peat cultures to inoculate seed held at 35�C. TAI showed the most rapid decline and its death rate was significantly higher than that of all except one of the isolates. CC275e showed good survival, and its death rate was similar to the lowest in two out of the three groups in which it was included. Differences between local isolates were small except for two which showed poorer survival.
Dry matter production from irrigated winter forage crops in the Murrumbidgee Irrigation Area
Authors: Michalk DL , Witschi PA
Published: March 2005

Between 1962 and 1964, 4 experiments were conducted at Leeton, New South Wales, Australia to examine the potential productivity of a range of irrigated winter forage crops in providing useful feed during the period of shortage in late autumn and early winter. In addition, the effects of sowing rate were examined for sowings using (a) prepared seedbeds or (b) sod-seeding into existing subterranean clover/Lolium rigidum cv. Wimmera pastures. DM yields at 74, 109, 144 or 173 days from sowing were compared with a subterranean clover/ryegrass control. Of the spp. evaluated the cereals were the most consistent both for initial production and subsequent regrowth. For the cruciferous spp. early cutting (100 days after sowing) proved detrimental to subsequent production, reducing the contribution of the sown spp. to 3% DM. Although the low proportion of the leguminous forages limited their potential production, they increased pasture quality relative to the clover/ryegrass control. DM production of wheat and rape increased with increasing sowing rate on (a) but for turnips there was a yield decline with increased sowing rate. Oats showed no response to sowing rate on (a), but increasing the sowing rate on (b) plots increased the proportion of oats in the pasture, although there was a consequent reduction in total yield. Increases in the contribution made by wheat to total yield as a result of increased sowing on (b) plots were small.
Identification of Australian barley cultivars by laboratory methods: gel electrophoresis and gel isoelectric focusing of the endosperm proteins
Authors: McCausland J , Wrigley CW
Published: March 2005

A range of laboratory methods was examined for their ability to distinguish between 19 barley cultivars currently grown in Australia. Aleurone colour, revealed after mechanical or chemical dehulling, differentiated Abyssinian, Atlas, Cape and Corvette from the other cultivars. Peroxidase and phenol testing were not useful. Seven different patterns were obtained for the hordeins of lowest mobility by starch gel electrophoresis. Further distinction was provided by flat gel isoelectric focusing of the water-soluble and hordein proteins for which 13 different pattern-groupings were obtained. The two electrophoretic techniques complemented one another, so that the use of both methods left only a few cultivars that could not be distinguished.
Yield, oil and protein content of oilseed rape as affected by soil and fertilizer nitrogen and phosphorus
Authors: Osborne GJ , Batten GD
Published: March 2005

The Zephyr cultivar of oilseed rape (Brassica napus) was grown on two sites at Wagga Wagga. Both sites had a wide range in levels of available phosphorus; one had a low and the other a high level of soil nitrogen. On both sites superphosphate applied prior to, and during, the current cropping phase caused significant increases in dry matter production, seed yield, oil and protein yields. Pod numbers increased significantly only on the high nitrogen site. On the high nitrogen site, seed, protein and oil yields (kg ha-1) were higher than on the low nitrogen site, even when the latter site was cropped using nitrogen fertilizer. Oil yields ranged from 237 to 1273 kg ha-1 on the high nitrogen site and from 229 to 91 6 kg ha-1 on the low nitrogen site. The rape crop responded to drilled superphosphate on sites with low to medium levels of 'available' phosphorus. Soil tests developed for wheat indicated sites with adequate soil nitrogen and phosphorus.
Control of alternate cropping of Valencia orange with ethephon and napthalene acetic acid
Authors: Gallasch PT
Published: March 2005

Three experiments were done in the Riverland district of South Australia with the aim of controlling alternate cropping of mature Valencia orange trees by chemical thinning. In experiment 1, 300 p.p.m. ethephon was applied in either October, November or December. In experiment 2, sprays of either 200, 250, 300 or 350 p.p.m. ethephon were applied in late November. In experiment 3, sprays of either ethephon, NAA or a mixture of both were applied in early December. Sprays of ethephon in December were more effective than in October, and resulted in a 40 per cent reduction of mature fruit weight in a heavy crop year. All concentrations of ethephon of 250 p.p.m, or more reduced the heavy crop load, and in the following year increased light crops. A 15 per cent reduction in crop load following sprays of 250 p.p.m, gave even cropping trees. Treated trees produced, over two years, 10 per cent more fruit weight than control trees. Fruit from treated trees were larger in the heavy crop year and smaller the following year. In the third experiment, 300 p.p.m. ethephon reduced the mature crop by 31 per cent and 500 p.p.m. NAA reduced it by 18 per cent. A mixture of the two chemicals effected a 51 per cent reduction in crop load, but the NAA did not significantly reduce leaf drop. NAA at 500 p.p.m. resulted in the most even cropping trees.
Water intakes, milk yield and grazing behaviour of Friesian cows with restricted access to water in a tropical upland environment
Authors: Cowan RT , Shackel D , Davison TM
Published: March 2005

Eight Friesian cows in early lactation and eight in late lactation were used in crossover experiments to measure the effects of allowing drinking water for 24 hours a day or for 20 minutes before each milking. Experiments were done during summer in the tropical upland environment of the Atherton Tablelands, Queensland. Free water intakes averaged 78 and 60 kg cow-1 day-1, and milk yields 13.8 and 8.9 kg cow-1 day-1 for cows in early and late lactation respectively. Cows with restricted access to water drank 84 per cent of the water intake of cows with unrestricted access to water. Maximum water intake at one drink averaged 67 kg cow-1 for cows with restricted access to water. Water intake was positively related to maximum air temperature and hours of sunshine a day (P < 0.05), and negatively related to rainfall and relative humidity (P < 0.05). Milk yield, composition and freezing point were unaffected by system of water supply. Grazing time from morning to afternoon milking was similar for cows on both treatments, though the pattern of grazing was changed. There was some evidence that milk yield of cows was depressed during the two days immediately after removal of paddock water. In two investigations there was no loss in milk production when drinking water was removed from the paddock for the one inter-milking interval, morning to afternoon milking.
An evaluation of some methods of predicting carcase composition of sheep
Authors: Murray DM
Published: March 2005

Data from animals of known carcase composition were used to test the accuracy of published prediction equations for carcase composition based on carcase weight, carcase water, carcase protein, and carcase chemical fats. The data from the animals of known carcase composition were also used to derive predictive equations which were tested on other published data. The results showed that there was considerable disparity between actual and predicted composition of carcases, indicating that such prediction equations should be used with considerable caution.
Effects of pasture availability on the composition and quality of the diet selected by sheep grazing native, degenerate and improved pastures in the Upper Shoalhaven Valley, New South Wales
Authors: Leigh JH , Holgate MD
Published: March 2005

Sheep exhibited a high degree of species selection when grazed at different seasons on three contrasting pastures typical of the mosaic of communities occurring over the Shoalhaven Valley. They were 1 . a Themeda australis grassland-typical of native grasslands, 2, a Phalaris tuberosa-Poa labillardieri- Trifolium repens pasture-typical of semi-improved pastures, and 3. a P. labillardieri grassland-typical of degenerate pastures resulting from ineffective attempts to establish improved pasture. Under light stocking, associated minor pasture constituents such as Hypochoeris radicata, Trifolium repens, or both were selected avidly and made a major contribution to a diet of adequately high quality. However when these minor species had been consumed, sheep were forced to eat the dominant grasses and diet quality fell appreciably. The T, australis grassland was substantially inferior to both the P. tuberosa- P. labillardieri-T. repens and P. labillardieri pastures. Cutting or burning P. labillardieri improved its quality and intensive grazing is recommended for areas in which this species predominates.
Effect of dietary protein composition on the optimum time of change from starter to finisher diets for broilers
Authors: Guirguis N
Published: March 2005

Three experiments were conducted to examine the amino acid requirements of broilers at various growing stages to eight weeks of age, and the optimum time of change to finisher diets. The practical diets contained balanced proportions of ten essential amino acids (EAA) and were expressed collectively as per cent of diet. Protein composition influenced the optimum time of change to finisher diets. With males, the EAA concentrations of diets determined the optimum time of change. Optimum conditions to maximize growth and feed utilization efficiency were obtained when males were fed 7.6 per cent EAA in an 18.6 per cent protein starter diet for two weeks, followed by a finisher diet having 6.5 per cent EAA in 16.6 per cent protein to eight weeks of age. Feeding a lower concentration of EAA in the finisher diet was acceptable if birds were fed the starter diet for longer time. Non-essential amino acid (non-EAA) content of diets influenced the optimum time of change from starter to finisher diets for female chicks, The female chicks required a higher ratio of non-EAA to EAA in their diets after three weeks of age. Further examination of the requirements for non-EAA in diets where excesses of EAA are eliminated is required.
Effects of various proportions of wheat, bran or pollard in sorghum grain fattening diets on liveweight gain, feed efficiency and carcase composition of Hereford and Hereford × Santa Gertrudis cattle
Authors: Gartner RJW
Published: March 2005

A 3 x 2 x 2 factorial design was used to examine the wheat by-products pollard and bran as a replacement in all-sorghum grain feedlot diets. The by-products replaced either 10, 30 or 50 per cent of the sorghum. Fourteen groups each of five Hereford steers of a mean initial shrunk liveweight of 251.5 � S.E. 0.16 kg and seven groups each of five Santa Gertrudis x Hereford cross bullocks of 391.7 � 0.16 kg were used. They were slaughtered at a mean final shrunk liveweight of 407.0 � 3.54 and 534.5 � 5.04 kg respectively. Production results from cattle receiving 50 per cent by-products were significantly inferior to lower levels of by-product. There were no significant differences between 10 and 30 per cent by-product. Cattle receiving pollard performed significantly better than those receiving bran. The growth rate of the Hereford steers of 1.24 kg day-1 was inferior (P < 0.01 ) to that of 1.41 for the Santa Gertrudis x Hereford bullocks, but the estimated gain in carcase weight of 0.75 kg day-1 was the same. The feed conversion ratio per unit of carcase weight gain favoured the Hereford steers (9.91 vs. 11.95; P < 0.01), but the feed conversion ratio per unit of liveweight gain was not significantly different (6.29 vs. 6.06). The total body fat figures were comparable for steers and bullocks -(mean 20.4 per cent). Both the percentage total yield of saleable meat and the percentage yield from the hindquarter were significantly greater (P < 0.01) in the Santa Gertrudis x Hereford cross bullocks (71.4 vs. 69.5 and 36.8 vs. 35.5 respectively).
Summer infertility in pigs: its incidence and characteristics in an Australian commercial piggery
Authors: Paterson AM , Barker I , Lindsay DR
Published: March 2005

The records of five years' production in an 800 sow commercial piggery were examined and the relationships between summer temperatures, returns to service and litter size were considered. When mean daily maximum temperature exceeded 32�C during the week of service there was an increase in the number of sows failing to hold to service. The number of sows that returned to service 15-25 days after mating remained constant throughout the year, and summer infertility was characterized by an increase in the number of sows that exhibited extended, irregular return-to-service intervals. The litter size of sows that conceived during the period of summer infertility was not significantly different from that of sows conceiving at other times of the year. The data suggest that summer infertility is not due simply to fertilization failure, embryonic mortality or an increased incidence of abortions in sows mated during periods of high temperature. Neither does boar fertility appear to be in question. It seems most likely that heat stress around the time of mating may affect ovarian function, resulting in temporary infertility and an endocrine imbalance, which causes delayed, irregular returns to oestrus.
Differences between Tasmanian forage genera in the relation between in vitro and in vivo digestibility
Authors: Michell P
Published: March 2005

In vivo and in vitro organic matter digestibilities (OMD's) were determined on cuts of Lolium perenne (perennial ryegrass cv. Tasmanian No. I ) , Lolium perenne (long rotation ryegrass cv. Grasslands ariki), Lolium perenne x L. multiflorum (short rotation ryegrass cv. Grasslands Manawa), Lolium multiflorum (tama ryegrass cv. Grasslands Tama) Dactylis glomerata (cocksfoot cv. Grasslands Apanui), Dactylis glomerata (cocksfoot cv. Currie), Festuca arundinacea (tall fescue cv. Demeter), Avena sativa (oats cv., Blythe), Phalaris tuberosa (phalaris cv. Australian), Trifoleum repens (white clover cv. Grasslands Huia) Medicago sativa (lucerne cv. Hunter River), Brassica napus (rape cv. Rangi) and Brassica oleracea (kale cv. Chou moellier). Linear regressions relating in vitro and in vivo OMD were calculated for the individual generic groups. There were no significant differences between the regressions of ryegrass, cocksfoot, phalaris, oats and lucerne (P > 0.05) (group A) or between clover and brassicas (P > 0.05) (group 6). However, the combined regression for group A (y = 0.78 x + 13.0) was significantly different from that of group B (y = 0.76 x + 19.1 ) (P < 0.01 ) and both were significantly different from the fescue regression (y = 1.23 x - 24.4) (P < 0.01 ). The in vitro technique underestimated the in vivo OMD of white clover and the brassicas by about 4.5 units and over-estimated that of fescue by about 3 units, relative to the other species. These differences were not caused by a modification of the in vitro method in which final residues were collected by filtering through sintered glass crucibles rather than by centrifuging. However, the filtering method gave in vitro results averaging 7.2 per cent higher than the centrifuging method.
Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 3. The balance of native species in the pasture
Authors: Shaw NH , Dale MB
Published: March 2005

The percentage frequency of all herbaceous species in a native pasture oversown with S. humilis (T.S.) was measured at the beginning and end of an eight-year grazing experiment. Treatments imposed were three levels of molybdenized superphosphate (nil; 125 kg ha-1 annually; 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) in factorial combination with four stocking rates and two sowing methods for T.S. (ground sowing into spaced cultivated strips or aerial sowing). Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beast ha-1. Treatments did not induce any major changes in the proportions of native species in the pasture. Heteropogon contortus remained dominant and its frequency increased in all treatments. Of the total of 113 species recorded, only 18 reached 10 per cent frequency in at least one paddock on one occasion. Several of these showed statistically significant changes in response to treatment, but their relative importance was not greatly changed. Examination of the results by principal co-ordinate and canonical analysis, showed that the first vectors of the two data sets were highly correlated, indicating that the major control on floristic composition was not changed by oversowing with T.S. or by the treatments imposed. Treatment effects dominated in the second and third vectors in the final year. The controlling vector was found to be highly correlated with soil calcium, potassium, total exchange capacity and organic carbon, but the basis for the correlations remains undetermined.
Effect of variation in light intensity on sheep movement through narrow and wide races
Authors: Hitchcock DK , Hutson GD
Published: March 2005

The movement of flocks of 14 Border Leicester x Merino sheep through narrow and wide races was observed. A high partition across the race allowed light intensity to be varied independently on each side. The effects of various combinations of four levels of illumination, 1.4, 88, 350 and 1400 lux (i.e. dark, low, medium and bright, respectively) were examined. Different light intensities had little effect on the movement of sheep. Sheep moved more readily through or into brightly lit areas, and this response was clearly dependent upon the behaviour of the first sheep leading the flock. There was no evidence to suggest that the degree of contrast between different levels of illumination or the direction of change in light intensity, e.g. dark to bright vs bright to dark, were important. The results suggest that strong contrasts in light cannot be used to attract sheep to move along a race. However, they confirm that shearing sheds should be well lit to encourage sheep movement into and within the shed
Mineral and vitamin supplementation of diets for growing pigs. 4. Effects of copper, zinc and iron supplements in a wheat/animal protein diet on performance, liver mineral stores and backfat quality
Authors: Greer EB , Lewis CE , Croft MG
Published: March 2005

The effects of supplementing a wheat/animal protein diet with copper (nil, 125 or 250 ppm), zinc (nil or 150 ppm) and iron (nil or 150 ppm) were studied in a 2 x 2 x 2 x 3 factorial experiment with 48 pigs. The diet was restrictively and individually fed to barrows and gilts between 18 and 73 kg liveweight. Daily rate of gain, feed conversion ratio and carcase score were not affected by the supplementary minerals. Supplementary copper increased the storage of manganese, zinc and copper in the liver. Although liver copper levels were greater in both sexes at 250 than at 125 ppm copper, barrows stored more copper than gilts at the higher level. Adding 150 ppm zinc at the same time as 250 ppm copper reduced liver copper storage in the barrows to the level of that in gilts given the same amount of copper. The iodine number, i.e, softness, of backfat in barrows was increased to that of gilts by 250 ppm copper; gilts were unaffected. Zinc supplementation also increased backfat softness in barrows but not in gilts. Despite this, 150 ppm zinc partially reduced the effect of 250 ppm copper on backfat in barrows.
Effects of parasite control in the peri-parturient period on lamb birth weight and liveweight gain
Authors: Johnstone IL , Coote BG , Smart KE
Published: March 2005

The effect of pre- and post-lambing anthelmintic treatment of the ewe on subsequent lamb production was studied. Sixteen groups of 25 maiden Border Leicester x Merino ewes were given combinations of a pre- and post-lambing 'drench' with thiabendazole. All groups were pastured on separate paddocks giving four replicates of each treatment program. Lamb liveweight changes were recorded for 19 weeks. A pre-lambing drench was found to increase lamb birth weights, and this advantage persisted until the lambs were drafted for slaughter in the nineteenth week from the beginning of lambing. The advantage was greater for twin compared with single lambs. The post-lambing drench had no effect on liveweight gain up to week 13, but had a significant effect over the next six weeks. This result seemed to have been related to the lower parasite burdens being passed from the ewe to the lamb, as a result of the post-lambing drench. This drench controlled the rapid rise in faecal egg counts which was observed in the lambs of untreated ewes after the eleventh week. At the time of lambing, pasture contamination was probably lower than under many practical field situations and results of the same magnitude may not occur regularly. The implications, however, are greatest in flocks with a high twinning performance where early drafting of a high percentage of twin lambs is important for economic or pasture management considerations.
A comparison of the grain and protein yield potential of some annual legume species in South Australia
Authors: Laurence RCN
Published: March 2005

Field experiments are described comparing a wide range of annual, winter-growing legume species with regard to their grain yield and protein content in South Australia. In 1974, a year when rainfall was considerably above average, Vicia faba (fieldbeans) outyielded all other species at each of two sites, eighty lines producing a mean yield of 8.2 t ha-1 of air-dry grain. In 1975, when rainfall was again generally above average but poorly distributed, V. faba, V. sativa and certain Lathyrus species yielded well, while other crops maintained average yields or failed in specific environments. The relative merits of new crop species in the diversification of rotations in dry land farming are discussed and it is concluded that field beans could be developed rapidly into a valuable alternative grain crop.
Nematicide treatment of banana planting material
Authors: Broadley RA
Published: March 2005

Numbers of burrowing nematodes (Radopholus similis) in banana planting material were reduced by paring the infested tissue from the planting bit, or by dipping the bits in water at 53-55�C for 20 minutes or in nematicides at ambient temperatures (ethoprophos 600 ppm for 20 minutes; fenamiphos 250 ppm for 10 minutes; oxamyl 1000 ppm for 20 minutes; dibromochloropropane 5000 ppm for 1 minute). Heavy paring was necessary before hot water treatment for good nematode control, but with dips of ethoprophos, fenamiphos and DBCP, good control was achieved with light paring. In a field trial, germination, early growth and bunch weights of plants from bits dipped for 20 minutes in 1000 ppm of oxamyl, benomyl or thiabendazole at ambient temperatures (23 to 25�C) or at 53 to 55�C were not increased when compared with the standard hot-water treatment.
Citrus meal as an energy supplement for dairy cows
Authors: Bartsch BD , Wickes RB
Published: March 2005

Nine cows in each of four treatment groups consumed an estimated 70% of metabolizable energy requirements as hay and an estimated 30% of metabolizable energy requirements as a supplement consisting of either 1. 3.9 kg rolled barley, 2. 0.7 kg citrus meal and 3.2 kg rolled barley, 3. 1.9 kg citrus meal and 2.0 kg rolled barley or 4. 3.4 kg citrus meal. Milk production showed no consistent response to changes in the proportions of citrus meal and rolled barley in the ration. Production of fat, solids-not-fat and protein were similar for all treatments. Milk solids-not-fat concentrations were lower (P < 0.05) from cows consuming 1.9 or 3.4 kg of citrus meal (87.5 and 85.9 g L-1, respectively) compared with those of cows consuming 0 or 0.7 kg of citrus meal (90.0 and 91.0 g L-1, respectively). Milk protein concentrations were also lower (P < 0.05) from cows consuming 1.9 or 3.4 kg of citrus meal (30.8 and 30.9 g L-1, respectively) compared with those of cows consuming 0 or 0.7 kg of citrus meal (33.1 and 34.8 g L-1, respectively). Organoleptic gradings showed that the cream from cows fed 3.4 kg of citrus meal was abnormal in flavour compared with cream from cows fed no citrus meal. Milk fat from cows fed 3.4 kg of citrus meal compared with that from cows not fed citrus meal contained more C18:1 fatty acid (1 8.4 and 15.2%, respectively), less C12 fatty acid (4.1 and 4.9%, respectively) and less C8 fatty acid (1.7 and 1.8%, respectively). Citrus meal can replace up to 2 kg of rolled barley on a dry matter basis in dairy concentrate mixtures without any detrimental effect on milk production, cow liveweight or flavour of the milk. However, citrus meal is not a suitable energy substitute for cereal grains in concentrate mixtures fed primarily to increase the solids-not-fat or protein content of milk.
Estimation of milk consumption in beef calves using a tritiated water dilution technique
Authors: Dove H , Axelsen A
Published: March 2005

The milk intake of crossbred and Angus calves in the first 6 weeks of life was estimated from their water turnovers measured using tritiated water (TOH) dilution. Corrections were made for increase in TOH space occurring during the periods of measurement. The corrections were smaller than those noted in lambs at a similar stage of life, and there were no consistent differences between breeds or weeks. In crossbred calves, estimated milk intake rose (P < 0.05) from 8.65 1 day-1 in week 1 to 11.21 l day-1 in week 6. The corresponding intakes for Angus calves were 6.31 and 10.02 l day-1 but the difference between breeds was not significant. Liveweight gains ranged from 659 to 1170 g day-1 for crossbred calves and from 532 to 925 g day-1 in Angus calves. Total liveweight gain and dryweight gain were closely related to total milk intake (r= 0.94, P < 0.001, and r= 0.85, P < 0.01, respectively). Dryweight gain was also closely related to dry matter intake (r= 0.85, P < 0.01). Estimated milk intakes are compared with those previously reported, and it is concluded that, provided changes in pool size are taken into account, the TOH dilution technique is well suited to the estimation of milk intake in beef calves. It is suggested that, in converting water turnovers into milk intakes, an assumed factor of 0.96 would save time and effort, and involve little error.
A comparison of potatoes with grain sorghum in feedlot diets for production of prime lambs
Authors: Archer KA , Rogan IM , Bowen RW
Published: March 2005

A feedlot experiment was conducted to compare diets using either potatoes or grain sorghum, each fed with or without a protein meal supplement, for production feeding of Border Leicester x Merino lambs. Diets also included chaffed pasture hay, urea and a mineral-vitamin mix. The protein supplement consisted of a mixture of soybean, cottonseed and fishmeal, and was added to provide an extra 10% crude protein in the basal diet. The experiment ran for 11 weeks, which included an introductory period of 3 weeks and an experimental period of 8 weeks. Liveweight gains (g head-1 day-1) and feed conversion ratios (g dry feed eaten/g liveweight change) for the diets based on potatoes only, potatoes plus protein, grain only and grain plus protein during the experimental period were 11 5 and 9.1:1,178 and 7.0 : 1,96 and 7.6 : 1 and 184 and 5.6 : 1, respectively. Liveweight gains were similar for potato and grain diets, but potato diets at both levels of protein were utilized less efficiently than grain sorghum (P < 0.05). Protein supplements increased liveweight gain (P < 0.05) and improved feed conversion ratios for both energy sources (P < 0.01). It is concluded that potatoes are a feasible alternative to grain for use in feedlot diets for lambs where normal marketing of potatoes is not considered practical.
Sheep production on the north coast of New South Wales. 2. A feasibility study of prime lamb production
Authors: Cohen RDH
Published: March 2005

Lamb production was studied in an experiment that ran for four years, 1968 to 1972, at Grafton, New South Wales, in a region where no commercial sheep are grown. Merino and Dorset Horn x Merino ewes stocked at 15 ewes ha-1 were mated in spring to Border Leicester rams and the lambs sold for slaughter in October. The mean number of lambs born per 100 ewes mated was 81.7 for crossbred ewes and 48.4 for Merino ewes (P< 0.05) and the mean carcase weights of the lambs were 14.8 kg and 12.7 kg, respectively (P< 0.01). The mean weight of fleeces cut from Merino ewes (3.24 kg) was greater (P< 0.01) than that from crossbred ewes (2.58 kg). The ewes were treated with anthelmintics either every four weeks or according to climatic conditions. There were no significant differences between the anthelmintic treatments for lamb liveweights at birth, weaning or slaughter; carcase weight; ewe fleece weight; or mortality rate. Treatment every four weeks increased ewe live weight during only one short period from August 1971 to February 1972 (P< 0.05). Data from this experiment compared favourably with survey data for the high rainfall zone in Australia and it was concluded that prime lamb production on the north coast of New South Wales is biologically feasible.
Amaranthus edulis: an ancient food source re-examined
Authors: Connor JK , Gartner RJW , Runge BM , Amos RN
Published: March 2005

The nutritional potential of an ancient food grain, A. edulis, was appraised by chemical analyses and in two feeding experiments with chickens and rats. The outstanding feature of the grain was its very favourable essential amino acid composition. The sample of grain used in these experiments contained 0.94% lysine, 0.66% methionine plus cystine, 1.54% arginine and 0.59% threonine in the dry matter. Raw and heat-treated grain contained 13.1 6 and 14.54 MJ kg-1 dry matter of nitrogen-corrected metabolizable energy. The raw grain contained a heat-labile toxin that affected hepatic function and depressed growth. Heat-treated A. edulis supported both chicken and rat performance, which approached or equalled that on a control diet. The heat-treated grain replaced over 70% of the grain and protein concentrate components of the control diet.