bluuebunny/crossref_metadata_2025 huggingface dataset:
Progesterone administered after insemination did not affect the fertility of cattle following a controlled breeding program
Authors: Munro RK , Bertram J
Published: March 2005

Oestrus and ovulation were induced in 112 suckled beef cows following intravaginal administration of progesterone (CIDR-B) and pregnant mare serum gonadotrophin (PMSG). Supplementary progesterone was provided during the induced luteal phase by re-treatment with CIDR-B from 6-21 or 10-21 days after initial insemination. A control group did not receive supplementary progesterone Supplementary progesterone did not affect the pregnancy rate to the initial insemination (59%). It did, however, tend to increase the proportion of non pregnant cows detected in oestrus 21-24 days after the initial insemination (17131 v. 3/14, P<0.05), but the fertility of treated and control cows inseminated at this second oestrus was not significantly different (30%).
Resistance in annual Medicago species to Phoma medicaginis under controlled environment and field conditions
Authors: Barbetti MJ
Published: March 2005

Seven Medicago species, comprising 11 cultivars and 9 seed lines, were screened for resistance to Phoma black stem disease (caused by Phoma medicaginis) at 3 temperature regimes (day/night) of 15/10, 17.5/12.5 and 20/15�C and at 3 plant ages under controlled environment conditions. The same cultivars and lines were screened in the field over 2 seasons. There were large differences among species, and between cultivars and lines of any 1 species, in the severity of Phoma black stem disease on plants 1,4 and 10 weeks of age and at the 3 temperature regimes under controlled environment conditions, and in field screenings. Under controlled environmental conditions the cultivar and line resistance rankings were influenced by plant age, in particular, and also by the temperature regime. Cultivar and line resistance to P. medicaginis on 10-week-old plants under controlled environment conditions was correlated with some field results but resistance to this disease on 1- and 4-week-old plants was not correlated with field data.
Distribution, ecology and control of Cassinia arcuata (sifton bush) in New South Wales
Authors: Campbell MH
Published: March 2005

The area of New South Wales infested with Cassinia aiwuta (sifton bush) increased from 93 000 ha in 1975 to 616 000 ha in 1988, indicating a need to investigate its biology and control. Of 6 samples of seed collected over 3 years from 2 sites, 5 germinated readily, emerged from a soil depth of 15 mm or less, and grew 7-48 times slower than pasture species in 28 days. The remaining sample had an after-ripening period of more than 5 months before full germination was achieved. Lime depressed growth of C. arcuata seedlings whilst superphosphate promoted growth. Preemergence herbicides simazine and atrazine killed seedlings in the cotyledon stage, while post-emergence herbicides glyphosate, triclopyr + picloram and hexazinone killed 40-, 78- and 139-day-old seedlings. Control on arable land could be achieved by burying seeds below 15 mm, followed by cultivation or herbicide application to remove establishing seedlings and addition of lime and spelling to allow sown species to smother late-establishing seedlings. On non-arable land burning to remove mature plants, spraying to kill establishing seedlings and aerial application of seed of improved species and superphosphate will contribute to control on soils that can support sown species without the application of large quantities of lime.
Effect of plant density on grain yield and yield stability of sorghum hybrids differing in maturity
Authors: Wade LJ , Douglas ACL
Published: March 2005

The extent and significance of the maturity x density interaction in dryland grain sorghum, and its implications for yield stability, were examined for 3 hybrids over 6 locations. Site mean grain yield ranged from 0.44 to 4.96 t/ha. Early maturity was superior in environments truncated by water stress, while late maturity was superior in favourable environments. Mid-season maturity provided greater stability of grain yield. Maximum yield by each hybrid at each yield level did not differ significantly from yield at a density of 75 000 plants/ha. The highest grain yields should be obtained with plant densities of 50000-100000 plants/ha under rainfed conditions, where yield expectations range from 0 to 5.0 t/ha. The results demonstrate the stability of sorghum grain yield over a wide range of plant density and crop maturity. Regression analysis aided data presentation and interpretation.
Field screening accessions of Phaseolus vulgaris for capacity to nodulate over a range of environments
Authors: Redden RJ , Diatloff A , Usher T
Published: March 2005

Nineteen lines of Phaseolus vulgaris L. were identified as promising for nodulation ability in a sequence of 2 screenings from 1462 germplasm accessions. These 19 lines plus 4 checks were further evaluated over 4 sites (Rocklea in 1985; Hermitage, Kingaroy and Applethorpe in 1987) and were sown within split-blocks with main treatments of nitrogen fertiliser, inoculum applied, and control with nodulation dependent on indigenous rhizobia. Nitrogen fertiliser significantly suppressed nodulation at Applethorpe and Hermitage sites only. Inoculation with Rhizohium phuseoli strain CC511 was most effective at Applethorpe, the least fertile site. The control nodulated most at Kingaroy. Accession ICA2 1573 was exceptional in its ability to nodulate with indigenous or supplied inoculum, and in the presence of nitrogen fertiliser. This nodulating ability was also shown, less consistently, by accessions Epicure and Amarillo 155. Some accessions were treatment specific for nodulation level: the superior nodulation ability of Campbell 20 was strongly inhibited by nitrogen fertiliser; specific cultivar-Rhizobium strain compatibility was shown by Selection 46, Small White 38, and Red Mexican; BAT1 198 and G6637 were apparently incompatible with Rhizobium strain CC511. Other accessions showed site and treatment specific nodulation responses, while the check entry, Gallaroy, was consistently poor in nodulation throughout the trial.
Comparison of selections of Vitis vinifera cv. Pinot Noir at Great Western, Victoria
Authors: Whiting JR , Hardie WJ
Published: March 2005

Five selections of Pinot Noir grapevine were evaluated over 3 seasons at Great Western, Victoria. The yields of selection IC698104 were consistently higher than all other selections and were always significantly higher than selections IV692222 and IC688048. The greater yields of selection IC698104 were associated with a high number of bunches per vine and a high bunch weight. Selection IV622051 had the greatest bunch weight but fewer bunches per vine than IC698 104. Selection AV7 12340 had a similar number of bunches per vine to IC698 104, but a significantly lower bunch weight due to fewer berries per bunch. Selection AV7 12340 ripened consistently earlier than all other selections, with highest sugar concentrations and pH, and lowest titratable acid concentrations. At least some of the seasonal differences in yield and juice composition over all selections could be attributed to climatic differences. The higher yielding selections were not associated with lower sugar concentrations, nor was there a significant relationship between yield and bunch weight. Two selections, IV692222 and IC688048, are considered to be derived from the same source, Waedenswil B110116, and this was supported by the similar results from both selections in this study. Yield trends between selections differed from those described in other reports, suggesting that regional influences, such as environmental or cultural conditions, may interact to influence the relative performance of selections.
Effect of bovine somatotropin injected as a sustained-release formulation at three injection intervals on the production and composition of milk from dairy cattle grazing pasture and supplemented with a grain concentrate
Authors: Valentine SC , Ball GJ , Bartsch BD , Lowe LB
Published: March 2005

Milk production and composition were measured, during spring, in 63 autumn-calving Holstein-Friesian dairy cattle either not injected or injected subcutaneously with a sustained-release bovine somatotropin formulation. Injections were given at 28-, 21- or 14-day intervals over a period of 84 days commencing in the sixth month of lactation. The cattle grazed pasture and were supplemented with a grain concentrate. Mean daily yields of milk (L), fat (kg) and protein (kg) were significantly higher in cattle injected at 28-day (17.6, 0.73, 0.56), 21-day (18.1, 0.76, 0.59), and 14-day (18.8, 0.80, 0.61) intervals, compared with yields of cows not injected (15.9, 0.68, 0.51). Yields of fat and protein were significantly different between all the injection interval treatments. Yield responses to injection were greater in cows than in heifers. There were no significant differences between treatments in milk fat content. The milk protein content (g/kg) of cows injected at 21-day intervals (33.2) was significantly greater than that of cows not injected (32.7) and those injected at the 28-day (32.6) and 14-day (32.6) intervals. It was concluded that bovine somatotropin injected subcutaneously as a sustained-release formulation was effective at all injection intervals in increasing the production of milk and milk components in mid to late lactation in dairy cattle grazing pasture and supplemented with a grain concentrate.
Phenotypic variance of fibre diameter along wool staples and its relationship with other raw wool characters
Authors: Denney GD
Published: March 2005

The variance of fibre diameter along the staple was estimated in a flock of 198 two-year-old Merino sheep, whose management and nutrition were typical of grazing sheep in central-western New South Wales. In a subgroup of this flock, it was found that the estimated variance of fibre diameter along the staple was highly repeatable between duplicate staples sampled from the same sheep, and variation in fibre diameter along the mid-side sample was representative of that variation in the whole fleece. In the main flock, variance of fibre diameter along the staple varied from 0.74 to 6.98 �m2 between sheep, but there were no differences between castrated males and ewes. Differences were found between sire groups in their susceptibility to environmental change. Phenotypic correlation between variance of fibre diameter along the staple and staple strength was -0.30 (P<0.001), but correlations with other raw wool characteristics were not different from zero (P>0.05).
The influence of vaccination with Fecundin and supplementation with lupin grain on the reproductive performance of Merino ewes in Western Australia
Authors: Croker KP , Johns MA , Bell SH , Brown GA , Wallace JF
Published: March 2005

The reproductive performances of groups of 4-6-year-old medium wool Merino ewes that were vaccinated with Fecundin and/or fed sweet lupin grain prior to and during the early part of the joining period were compared with untreated ewes over 2 years. The rams were joined with the ewes in early January of each year. In both years the Fecundin and lupin treatments increased ovulation rates (between 0.13 and 0.56) and the incidence of multiple pregnancies (between 1 and 36%). The proportions of lambs born following treatment with Fecundin were larger than those from the ewes fed only lupins. When the treatments were combined, there were no increases in lambs born above that of Fecundin alone. Pregnancy significantly depressed wool production from individual ewes, while those with more than 1 lamb produced less wool than those with only 1 lamb. However, the average quantity (4.6 kg greasy) and quality of wool produced by the ewes each year was similar for all groups, indicating that the variation in the incidence of multiple pregnancies had not affected flock wool production. The average rate of growth of the progeny from marking to weaning was also similar for each group (191 and 238 g/head.day for years 1 and 2, respectively) even though there were more multiple-born lambs in the Fecundin-treated groups. On a flock basis, it would appear that the nutritional conditions experienced during this study were adequate to avoid significant penalties associated with multiple pregnancies.
Studies of wool growth responses to 2-hydroxy-4-(methylthio) butanoic acid, Alimet, an analogue of methionine
Authors: Stephenson RGA , Suter GR , Pritchard DA , Martin MDJ
Published: March 2005

An analogue of DL-methionine, Alimet, was evaluated for its commercial potential for increasing wool growth in Merino sheep in pen and grazing experiments. This was done by administering Alimet as a drench, in drinking water, or via rumen or abomasal fistula, and measuring wool growth rate and plasma methionine concentrations. In vivo data indicated that significant wool growth responses (23-35%) to Alimet as a drench or in drinking water occurred at low rates (estimated 5-6 g/sheep.day) of basal wool production when sheep were fed a lucerne diet to maintain liveweight. At higher rates of clean wool growth (10-12 g/sheep.day) when sheep were eating above-maintenance diets (lucerne ration or pasture), Alimet treatment was associated with variable and reduced response. A significant (P<0.05) negative correlation (r2 = 0.699, n = 11) between wool growth responses (x � s.d. = 0.11 � 0.067) to the 3 mL dose rate of Alimet and wool growth in control treatments (y �: s.d. = 0.70 � 0.202) confirmed the above trend. Four hours after administration of Alimet via either rumen or abomasal fistula, comparative plasma concentrations of methionine, 28 and 168 �mol/L respectively, suggest that Alimet is susceptible to degradation in the rumen. The corresponding values for DL-methionine, via either rumen or abomasal fistula, were 64 and 350 �mol/L, respectively. The small rises (40%) in plasma methionine values associated with significant increases in wool production indicate that a dose of 3 mL is as effective as 4 mL of Alimet when the basal nutritional regime is limiting. While administration of Alimet in drinking water during dry seasons is possible, the profitability of supplementation would need to be tested further.
Evaluation of two feeder designs for growing pigs
Authors: Blackshaw JK , Blackshaw AW
Published: March 2005

Two feeder types for self-feeding of grower-finisher pigs were assessed using behavioural and production criteria. The 2 types were a round feeder providing 9 feeding spaces and a 2-space rectangular feeder which allowed the pigs to hide the whole head. Feed utilisation did not differ between feeder types, and relative growth rate (%) corrected for initial body weight was the same for both feeders. Feeder use was similar for both types of feeder and was higher in the afternoon. The frequency of agonistic interactions were the same at both feeders.
Metabolisable energy content of diets based on oats grain
Authors: Oddy VH , Ewoldt CL , Jones AW , Warren HM
Published: March 2005

The metabolisable energy (ME) content of a range of oats-based diets, encompassing a wide range in dry matter digestibility of oat grain, was measured at maintenance in sheep. Dry matter digestibility was 66-82% and ME content was 11.4-15.9 MJ/kg DM for the range of oats-based diets studied. Chaffed lucerne hay, used as a control diet, had a dry matter digestibility of 61% and ME content of 9.7 MJ/kg DM. The ratio of ME to digestible energy content of oats diets was 0.88, compared with 0.81 for chaffed lucerne hay. The difference between the diets based on oats grain and chaffed lucerne hay was accounted for by increased urine energy and nitrogen loss on the lucerne diet and not by reduced methane output on oats-based diets. Cell wall organic matter and lignin content of the oats-based diets were strongly correlated with diet digestibility (r2 = 0.79-0.90).
The effects of moisture supply and defoliation during flowering on seed production and hardseededness of Trifolium subterraneum L
Authors: Archer KA
Published: March 2005

The effect of length of the flowering period on seed production characteristics of 3 cultivars of subterranean clover (Trifolium subterraneum L.) was determined by varying the period of watering postflowering. The subterranean clover cvv. Nungarin, Seaton Park and Woogenellup were grown in polystyrene boxes and given 1 of 4 watering treatments: continuous (WC); until approximately 34 days after flowering commenced (WE); until Nungarin finished flowering (WN); as for WE but with watering recommenced after plants became wilted (WEL). Plants were either undefoliated or were repeatedly defoliated during flowering. Flowering in all 3 cultivars was terminated early and seed yields were reduced by WE (e.g. WC v. WE for Seaton Park, 1620 � 61 v. 320 � 61 kg/ha), but each of the cultivars was able to produce appreciable numbers of viable seed on the WE treatment, ranging from 406 � 95 seeds/dm2 for Woogenellup to 791 � 95 seeds/dm2 for Seaton Park. WEL increased seed size in all cultivars by approximately 50%, and increased seed numbers in Seaton Park to 1083 � 106 seeds/dm2. Nungarin produced most seeds on the WN treatment (1232 � 104 seeds/dm2), but approximately half of these were lost if the soil was kept moist during seed maturation. In comparison, little loss of seed was detected from Seaton Park and Woogenellup under continuous watering, possibly due to differences between cultivars ii seed dormancy and periods of exposure of maturing seeds to moisture. The development of initial hard seeds in Nungarin and undefoliated Seaton Park was adversely affected by continuous moisture. Repeated defoliation during flowering reduced seed yields in all cultivars (e.g. UD v. D for Seaton Park, 1130 � 44 v. 310 � 46 kg/ha), due to decreases in both seed numbers and size. The results indicate that choice of maturity of subterranean clover cultivars for areas with unreliable spring rainfall is not necessarily restricted to those early maturing cultivars which will always finish flowering prior to moisture restrictions.
The importance of the carbon cycle to acidification of a grazed annual pasture
Authors: Ridley AM , Slattery WJ , Helyar KR , Cowling A
Published: March 2005

Soil samples to a depth of 60 cm were collected from 3 fields of a 73-year-old experiment in north-eastern Victoria. One field (unfertilised) had never received fertiliser, whereas, the other 2 fields (fertilised) had received 4.5 t/ha superphosphate. One of the fertilised fields also had a lime application history (fertilised and limed). The fields were particularly useful for estimation of the amount of acid added by the carbon cycle as records of lamb, wool and hay removal over a long period were available. The soil pH of the fertilised field had declined relative to the unfertilised field to a depth of at least 30 cm. The field receiving fertiliser and lime had a similar pH profile to that of the unfertilised field. Pasture improvement resulted in much higher stocking rates and consequent product removal (hay, wool and meat) from the fertilised and limed fields compared with the unfertilised field (68, 72 and 12 kmol H+/ha, respectively). Carbon and nitrogen cycle acidification accounted for 65 and 35%, respectively, of the net acid addition on the fertilised field. The acidification rates for the fertilised, fertilised and limed, and unfertilised fields over the 73-year period were 1.42, 2.37 and 0.16 kmol H+/ha.year. These acid addition rates are likely to be underestimates because the laboratory pH buffering capacity method used did not account for slow buffering reactions in the field (Ridley et al. 1990).
The effect of two forms of nitrogen fertiliser applied near anthesis on the grain quality of irrigated wheat
Authors: Cooper JL , Blakeney AB
Published: March 2005

In 1976, the feasibility of using nitrogen (N) fertiliser to raise the protein levels of irrigated wheat was investigated using 3 rates of fertiliser (0, 40 and 80 kg N/ha) applied either at anthesis or 3 days later to the soil surface (ammonium nitrate), or as a foliar spray (urea). Each 40 kg/ha increment in N applied as ammonium nitrate or urea produced a 1.1% increase in grain protein. Ammonium nitrate produced significantly (P<0.01) higher protein levels than urea. The relationships between grain protein level and several grain quality criteria (farinograph absorption, extensibility, loaf volume, bake score) were examined to determine whether protein quality was maintained when protein levels were increased by late application of N fertiliser. All the criteria examined indicate that protein quality was maintained. Although it is possible to raise protein levels with N fertiliser, large price premiums for high protein would be necessary to make the practice economic.
Soil pH and aluminium and their spatial variation in Western Australian acidic soils
Authors: Dolling PJ , Porter WM , Robson AD
Published: March 2005

Thirty-eight sites on acid soils (pH<5.5, 1:5 in water) in the medium rainfall region of Western Australia were sampled to examine spatial variation in soil pH and 0.01 mol/L CaCl2-extractable aluminium. We also examined the relationship between (i) the A1 and A2 horizon soil pH, (ii) the A1 and A2 horizon extractable aluminium, (iii) surface and subsurface soil pH and (iv) surface soil and subsurface soil-extractable Al. Soil at each site generally had a light-textured layer overlying a clay layer at varying depths (30-70 cm) and was classified as either Dy 5.21 or Dy 5.41 (Northcote 1979). Over 80% of the sites had surface soil pH values 4.8 or lower and extractable aluminium concentrations 2 �g/g or higher. There was a very poor correlation (r2 = 0.21) between the A1 horizon soil aluminium extracted in 0.01 mol/L CaCl2 and the pH measured in 0.01 mol/L CaCl2 over 1 ha sites. The relationship was slightly improved in the A2 horizon (r2 = 0.49). The coefficients of variation of soil pH varied from 1.2 to 5.1%, while the coefficients of variation for CaCl2-extractable aluminium varied from 10 to 50%. At many of the sites, low pH values and high aluminium concentrations extended down to 35-45 cm. At the B horizon the pH values generally increased and the aluminium concentrations decreased. The surface soil pH and extractable aluminium were not good indicators (r2 = 0.09-0.60) of the subsurface soil pH and extractable aluminium.
Effects of applied nitrogen fertiliser on the chemical composition of the essential oil of three Leptospermum spp
Authors: Diatloff E
Published: March 2005

Three native species of Leptospermum (L. petersonii, L. Flavescens, L. luehmannii) were grown in an amended podsolic soil under 4 nitrogen (N) levels, 0, 20, 40 and 60 kg Nha, supplied as NH4N03. Plants were harvested after 16 weeks growth, leaves were separated from stems, and essential oil was distilled from leaves by steam distillation. Extracted oils were analysed for their components by gas chromatography. Oil density from L. petersonii was also determined. Growth and oil yield of the 3 Leptospermum species showed no response to N fertilisation. However, the oil composition in L. petersonii and L. flavescens leaves was affected. The greatest response was in the geranial and citronella1 contents in L. petersonii, which peaked in the 40 kg N/ha treatment. This is the first known report of the manipulation of essential oil composition of Australian native plants by N fertilisation. The low optimal level of N fertiliser required for maximum production of valuable oil components indicates that Leptospermum spp. are suitable for infertile soils. The low �-pinene yield of L. luehmannii makes it unsuitable for commercial exploitation.
Effectiveness of some copper compounds applied as foliar sprays in alleviating copper deficiency of wheat grown on copper-deficient soils of Western Australia
Authors: Brennan RF
Published: March 2005

The effectiveness of copper oxychloride (CU2Cl(OH)3, 52% Cu) and chelated Cu (Cu-EDTA, 15% Cu) were compared with the effectiveness of copper sulphate (CuSO4, 25% Cu) as foliar sprays for alleviating Cu deficiency and obtaining maximum grain yields of wheat (1.93-2.5 t/ha). The experiments were conducted over 4 years at 4 sites in the Lake Grace and Newdegate districts, about 300-350 km south-east of Perth, Western Australia. Each source was sprayed at 6 or 7 rates of Cu to define the relationship between grain yield and the amount of foliar Cu applied for wheat grown on soils where Cu had not been previously applied. The levels of Cu sprayed in experiment 1 were 0, 21, 63, 125, 250, and 375 g/ha, and for experiments 2,3 and 4, the levels of Cu were 0, 25, 50, 100, 200, 400 and 800 g/ha. The relative effectiveness of foliar-applied chelated Cu and CU2Cl(OH)3, compared with CuSO4, was 1.72-2.24 and 0.47-0.63, respectively. Although the relative effectiveness of each product was different, similar quantities of each were required to achieve maximum wheat grain yield because of the difference in the Cu contents of each source of Cu. The amounts of Cu product sprayed for maximum grain yields of wheat varied within the ranges 0.9-1.8 kg/ha, 0.8-1.2 kg/ha and 0.8-1.8 kg/ha for CuSO4, chelated Cu and CU2Cl(OH)3, respectively.
The use of postharvest treatments to extend storage life and to control postharvest wastage of honeydew melons (Cucumis melo L. var. inodorus Naud.) in cool storage
Authors: Edwards ME , Blennerhassett RM
Published: March 2005

Three trials were undertaken to study storage conditions and handling procedures required to maximise the postharvest storage life of honeydew melons (Cucumis melo L. var. inodorus Naud.).Honeydew melons treated with chlorine (1000 mg/L), benomyl (250 mg/L) + guazatine (500 mg/L), shrink wrap (17 ym Cryovac XDR film), Semperfresh, wax, or combinations of these treatments were stored at 4 or 8�C, for 4 or 6 weeks. Benomyl plus guazatine reduced the development of storage rots associated with Alternaria and Fusarium spp. The use of shrink wrap and wax reduced water loss by melons but increased fungal infection in some cases. Shrink wrapping combined with the fungicide treatment effectively reduced the incidence of fungal breakdown in the storage period for up to 4 weeks. Wax coating with full strength Citruseal wax caused anaerobic tissue breakdown. Melons were affected by chilling injury at 4�C. Control of bacterial rots with benomyl + guazatine or with chlorine was variable. Semperfresh did not reduce the incidence of fungal breakdown or water loss from the melons. The results indicate that storage of honeydew melons for 4 weeks at 8�C by pretreating with fungicide is possible but the melons soften and rot after 6 weeks, making them unsaleable. Four weeks should be adequate to allow for sea freighting of honeydew melons to markets in South East Asia. Further research is required to determine the optimum storage temperature for honeydew melons.
Phaseolus vulgaris cv. Midnight
Authors: Wright RM , Redden R
Published: March 2005

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The performance of Brahman-Shorthorn and Sahiwal-Shorthorn beef cattle in the dry tropics of northern Queensland. 2. Reproductive rates and liveweights of F2et seq. females
Authors: Holroyd RG , James TA , Doogan VJ , Fordyce G , Tyler R , O'Rourke PK
Published: March 2005

The female reproductive rates and liveweight performance of F2 et seq. generations of 1/2 Brahman (1/2 B), 1/2 Sahiwal (1/2 Sah), 3/4 Brahman (3/4 B) and 3/4 Sahiwal (3/4 Sah) were evaluated in the dry tropics of northern Queensland from 1978 to 1986. The balance of the breed composition was predominantly Shorthorn. A preliminary comparative analysis of F2 and F3 data showed no differences between the filial generations and data were subsequently pooled. Crossbreed differences between groups had a small effect on pregnancy rate and were not a major determinant of fertility compared with age and year effects. Any crossbreed differences were counteracted by inconsistent cross x year effects. For mature cows, 3/4 Sah had significantly (P<0.05) lower weaning rates than other crosses. The percentage unit difference between pregnancy rate and weaning rate was higher in Sahiwal cross than Brahman cross cows (19 v. 9%). In lactating cows, calving dates were an average 10 days later in 3/4 than 1/2 Bos indicus cows. Generally Brahman crosses were heavier than Sahiwal crosses. In the dry season, Brahman crosses were 16, 30, 36 and 43 kg heavier than Sahiwal crosses for 2-year-old heifers and 3-, 4- and 5-9-year-old cows, respectively. There was little difference between 1/2 and 3/4 B. indicus, except in mature cows, where 1/2 Sah were 27 kg heavier (P<0.05) than 3/4 Sah at start of mating. There were pronounced year effects on all of the reproductive and growth parameters of both heifers and lactating cows. Pregnancy rate and mating liveweight were negatively correlated with date of seasonal break of the dry season (r = -0.71 to -0.88, r = -0.84 to -0.98, respectively). Cross x year interactions for pregnancy rate, calving date and mating liveweight were attributed to factors other than the type of year.
Intensive observations during lambing in a goitre-affected flock, with special reference to behaviour of lambs
Authors: Alexander G , Stevens D , Bradley LR
Published: March 2005

This study documents an outbreak of congenital goitre in a flock of sheep under intensive observation for behaviour during lambing on pasture containing a high proportion of white clover (Trifolium repens). Thyroids were palpably enlarged in half of the lambs and much enlarged in 12% of lambs, reaching 42 g/kg bodyweight. The incidence of goitre increased as lambing progressed and with increasing ewe age, but tended to decrease with increasing litter size. Gestation period increased with increasing thyroid size. Lamb mortality was 3-fold higher in lambs with moderately or grossly enlarged glands than in lambs with little or no gland enlargement. Major factors contributing to death were poor vigour of lambs at birth, possibly due in part to impaired thermoregulation, and difficult or prolonged birth. Lambs with severe goitre were susceptible to heat stroke apparently through tracheal constriction. Activity of lambs was depressed according to the degree of thyroid enlargement. The correlations between various lamb behaviours and plasma thyroxine were no better than with the thyroid enlargement score. Twins had a higher mortality and less vigorous behaviour than singles with similar thyroid enlargement. Twins with much enlarged glands were particularly at risk. It is suggested that slight to moderate thyroid enlargement might not be detected in practical farming and could be more common than usually supposed. In the presence of other factors that prejudice survival, such as cold weather, prolonged and difficult birth and multiple birth, this 'subclinical' goitre could contribute to death of lambs.
Grazing management studies with Australian cashmere goats. 1. Effect of stocking rate on the growth and fleece production of weaner goats grazing tropical pastures
Authors: Norton BW , Wilde CA , Hales JW
Published: March 2005

Australian cashmere weaner goats were continuously grazed on either nitrogen (N) fertilised Pangola grass or mixed tropical legume-pangola grass pastures at 3 stocking rates (15, 30, 60 goats/ha). Grazing commenced in January and was terminated in May (18 weeks). Three parasite control treatments (Seponver, Avomec, Systemex) were superimposed on each treatment. Parasite egg counts, liveweight change, cashmere growth and changes in pasture components were measured. Intestinal parasite burdens were low (<400 eggs/g faeces) in all animals throughout the trial, and there were no significant effects of parasite control treatment on goat productivity. The liveweight gain of goats decreased with increasing stocking rate and time on pasture. Mean values for the liveweight change of goats on the legume-grass pasture were 66, 37 and 14 g/day at stocking rates of 15, 30 and 60 goats/ha, respectively. Comparable values for goats grazing N-fertilised pangola grass were 40, 39 and 23 g/day for stocking rates of 15, 30 and 60 goats/ha. Goats grazing the legume-grass pastures at the lowest stocking rate (15 goats/ha) had significantly higher liveweight gains than did goats on all other treatments. There were no significant effects of stocking rate, pasture type or worm control treatment on fleece growth in these goats. Mean values were 191 g, 39 g and 15.0 �m for fleece weight, cashmere weight and mean cashmere fibre diameter respectively. The major legume in the legume-grass pasture was siratro, with axillaris, greenleaf desmodium and cassia forming minor components (10-300 kg/dry matter (DM)/ha). During the first 6 weeks of grazing, all legume components increased under stocking rates of 15 and 30 goats/ha. Thereafter, there was a significant decline in siratro yield to less than 200 kg DMha at all stocking rates. During this same period, the yields of the other legumes generally increased, suggesting that at low stocking rates the goats preferred grass to legume, and when grass was limiting, siratro was the legume preferred over all others. Weed yields increased with time in all except the high stocking rate treatments. It was concluded that weaner goat growth can be maximised on tropical legume-pangola grass pastures when stocking rates and intestinal parasite burdens are low. Protein intake may be limiting growth on N-fertilised grass pastures.
Milk permeate as a dietary supplement for lactating dairy cows
Authors: Cowan RT , Upton PC , Reid A
Published: March 2005

Milk permeate was evaluated as a supplement to replace part of the concentrate or roughage in the diet of lactating dairy cows. The basal d i e t was 6 kg cracked sorghum grain and 6 kg ryegrass dry matter, and permeate was offered ad libitum in place of either 3 kg of sorghum or 3 kg of ryegrass. Intake of permeate stabilised at 30 kg/cow.day (1.7 kg DM) after 6 weeks, with considerable variation among replicate groups. Milk fat percentage was increased from 3.8 to 4.5% (P<0.05) when permeate replaced grain in the diet. Where permeate replaced pasture there was apparently large variation among cows in permeate intake, and this was associated with large variation in the fat and protein contents of the milk. Milk yield (volume) was reduced in proportion to the reduction in total dry matter intake (r = -0.99). With high intakes of permeate, the C18:0 acids in milk fat were reduced and the C16:0 acids increased. It was concluded that permeate could replace about 1.7 kg grain in the diet and that, at this level, there would be advantages in milk fat percentage.
Effect of seed source and seed phosphorus concentration on the yield response of yellow serradella to superphosphate applications
Authors: Bolland MDA , Baker M
Published: March 2005

A field experiment at Medina, Western Australia, was designed to test whether seed produced at different locations and containing different phosphorus (P) concentration in the seed would change the relationship between yield and the level of superphosphate drilled with the seed. To produce the seed for the experiment, subsamples of the same source of seed of yellow serradella (Ornithopus compressus cv. Madeira) were grown at Medina and Esperance, Western Australia. Seed of the same size produced at each location, and containing 3 different P concentrations, was sown in the experiment at Medina. Three levels of superphosphate were drilled with the seed. Yields (of dried herbage and seed) were increased 2- to 4-fold as the amount of P drilled with the seed was increased from 5 to 40 kg P/ha. Although the Medina seed contained >0.40% P and the Esperance seed contained <0.40% P, plants grown from Esperance seed produced larger yields than plants grown from Medina seed for each of the 3 levels of P drilled with the seed; yield difference increased from about 14 to 70% as the level of P drilled with the seed increased from 5 to 40 kg P/ha. Higher P concentration in the sown seed increased herbage and seed yields by 35-70% when 5 kg P/ha superphosphate was drilled with the seed, and by about 616% when 40 kg P/ha was P drilled with the seed. Seed grown at Esperance produced larger yields for each seed P concentration than Medina seed; yield differences were about 30-90%. The P concentration measured in dried herbage and seed depended only on the amount of P drilled with the seed. It was unaffected by the P concentration in the seed sown, and for dried herbage, it was unaffected by where the seed sown was produced. However, for seed production, the relationship between yield and P concentration in the seed differed depending on where the seed was grown.
The responses of maize and grain sorghum hybrids to nitrogen fertiliser in south east Queensland
Authors: Hibberd DE , Hall BD
Published: March 2005

We investigated, over 3 seasons, 1973-74 to 1975-76, the responses of 5 selected maize hybrids and 5 sorghum hybrids to applied nitrogen (N) under irrigation on N-deficient, black earth soils in South East Queensland. Five levels of N (0, 60, 120, 180 and 240 kg/ha) were applied as urea at sowing to 5 maize hybrids, XL81, Q739, PQ500, PX50, RX404, at 1 location. The same rates were applied to sorghum hybrids NK212, P846, E57, Goldfinger and Goldrush at another location. Higher grain yields were obtained from maize hybrids XL81 and RX404 than from 4739, PX50 and PQ500. A mean grain yield of 6660 kg/ha was produced from XL81 over the 3 seasons for the application of 180 kg N/ha. A hybrid x N interaction occurred only in the year with highest yields. Over all years, grain yield of each hybrid was linearly related to mean site yield and slopes were not significantly (P>0.05) different. Hybrids XL81 and RX404 showed significantly (P<0.05) higher grain yields than other hybrids over the range of grain N concentrations obtained. We conclude that 180 kg N/ha applied at or prior to sowing would optimise maize yields on N-depleted soils in South East Queensland. Highest grain yields of sorghum were obtained from all hybrids when N application was in the range 120-180 kg N/ha. The grain yields of all 5 hybrids converged in the 5000-7000 kg/ha yield range, indicating no superior yielding potential in any 1 hybrid. Goldrush, however, showed significantly (P<0.05) higher grain N concentrations than the other hybrids over the range of grain yields.
Effect of nitrogen on the yield and quality of irrigated onions (Allium cepa L.) cv. Cream Gold grown on siliceous sands
Authors: Maier NA , Dahlenburg AP , Twigden TK
Published: March 2005

The effect of nitrogen (N), at rates up to 590 kg N/ha, on the yield and quality of Cream Gold onions grown on siliceous sands was investigated in field experiments conducted during 1987-88 (1 site) and 1988-89 (2 sites). As the rate of applied N increased there was a significant (P<0.001) increase in the fresh weight of tops harvested when the largest bulbs were 25-30 mm in diameter. Fresh weight of tops was significantly (P<0.001) correlated with final marketable yield of bulbs. Nitrogen application accelerated top senescence. Nitrogen-deficient plants had erect green tops at harvest. Marketable yield was significantly (P<0.01) increased and the yield of culls (unmarketable bulbs) was significantly (P<0.01) decreased as the rate of N increased at all sites. Nitrogen rates in the range 299-358 kg N/ha were required for 95% of maximum yield. Scale thickness increased significantly (P<0.05) and glucose and fructose concentrations decreased significantly (P<0.05) at 2 sites as the rate of applied N increased. Soluble solids and dry matter of bulbs were not affected by N. Bulb size increased as the rate of applied N increased, however, the magnitude of the effect varied between sites. Number of days to 10% sprouting during storage at 15 � 0.5�C was significantly increased as the rate of applied N increased up to 40 kg N/ha at 2 sites. We have concluded that for the cv. Cream Gold grown on siliceous sands, the high rates of fertiliser N required to maximise marketable yield and bulb size were not detrimental to quality.
Prediction of conception rate in extensive beef herds in north-western Australia. 2. Continuous mating and minimal management
Authors: O'Rourke PK , Doogan VJ , Robertson DJ , Cooke D
Published: March 2005

Data from a continuously mated, unweaned and unsupplemented herd of 400 Bos indicus cross cows at 'Kidman Springs', from 1981-85, were used to develop statistical models for conception rate and pattern. At the annual muster in June, an average of 49% of cows were rearing a calf; 15% of these and 75% of those not rearing a calf were pregnant; and 54% conceived within the next 12 months. Cows non-pregnant in June had higher conception rates than pregnant ones (75 v. 33%), and among pregnant cows, those which had reared a calf had higher conception rates than those which had not (40 v. 26%). Cows that had not reared a calf were much heavier and in better condition in June than those that had, while pregnant cows were slightly heavier and better conditioned than non-pregnant ones. The effect of liveweight or condition score in June on subsequent conception rate was consistent across years, reproductive classes and cow ages. Conception rates responded linearly to increases in liveweight, in the range 250-400 kg, by 11 percentage points up to October and by 24 points up to June. Similar linear responses to condition score in the range poor-good condition were 8 points by October and 15 points by June. Reproductive wastage was high, with 20% of cows diagnosed pregnant in June failing to rear their calf to branding. Low-cost management options to improve reproductive efficiency should be aimed at reducing nutritional stress and improving seasonal nutrition. To improve on the norm of a calf every second year in this environment, the class of cows not rearing a calf but pregnant and expected to calve by December has the greatest potential to conceive in consecutive years and should be segregated for preferential management. Conversely, aged cows not rearing a calf have comparatively low fertility and non-pregnant younger cows not rearing a calf are likely to be a survival risk following an out-ofseason conception. Both groups should be culled.
Subclinical selenium insufficiency. 2. The response in reproductive performance of grazing ewes supplemented with selenium
Authors: Langlands JP , Donald GE , Bowles JE , Smith AJ
Published: March 2005

Merino and Border Leicester x Merino ewes grazed improved pastures at 6.3 or 12.5 ewes/ha for 4 years and were supplemented or not supplemented with intra-ruminal selenium (Se) pellets. The Merino and crossbred ewes were mated to Merino and Dorset Horn rams, respectively, and various measures of reproductive performance were recorded. Two cases of muscular dystrophy were observed in 2-3-day-old lambs, but the incidence of oestrus and fertility was not affected by differences in stocking rate, genotype or Se supplementation. Fecundity was higher in crossbreds than Merinos (1.64 v. 1.25, P<0.001) but was not affected by stocking rate or Se status. Survival of lambs was increased (P<0.05) by Se supplementation -- at the high stocking rate (0.74 v. 0.86) but not at the low (0.84 v. 0.83), and a significant (P<0.01) genotype x litter size x Se interaction reflected greater sensitivity to Se supplementation by Merino singletons (from 0.75 to 0.95) than twins (from 0.75 to 0.69) and by crossbred twins (from 0.76 to 0.87) than singletons (from 0.89 to 0.87). Number of lambs weaned per ewe mated increased following Se supplementation from 0.81 to 1.04 at the high stocking rate, and decreased from 1.08 to 1.00 at the low; the interaction approached significance (P<0.09). It is suggested that the response to Se supplementation is sensitive to factors in addition to Se status, and such factors may explain some of the variability in responsiveness reported in the literature.
Subclinical selenium insufficiency. 3. The selenium status and productivity of lambs born to ewes supplemented with selenium
Authors: Langlands JP , Donald GE , Bowles JE , Smith AJ
Published: March 2005

Measurements were made of blood selenium (Se) concentrations and liveweights of Dorset Horn x (Border Leicester x Merino) and Merino lambs born in October to ewes which were supplemented or not supplemented with intra-ruminal Se pellets and grazed at 6.3 or 12.5 ewe/ha for 4 consecutive years. Lambs were not supplemented with Se and most observations were made between birth and weaning. In some years the Merino lambs were grazed as a single flock for a further 18 months after weaning, and liveweights and fleece characters were recorded at 10 and 22 months of age. Blood Se concentrations of lambs at birth varied with the Se treatment of their dams but were generally lower in the lamb and declined during lactation. In lambs born to unsupplemented ewes, concentrations were lower at the high stocking rate, and declined with increasing rainfall in the preceding January-June period. Selenium concentrations were reduced in twins and this was particularly evident in lambs born to supplemented ewes. Liveweights at birth, in mid-lactation and at weaning were significantly increased in lambs born to Se-supplemented and crossbred ewes, and in lambs born as singletons. The response in liveweight following Se supplementation was greater in lambs reared at the high than at the low stocking rate, and in Merino than in crossbred lambs. The response to Se supplementation was correlated with rainfall during the preceding February to July, and was greater in early lactation. Clean fleece weight at 10 months of age was increased by 9.5% and fibre diameter by 0.3 pm in lambs born to ewes which had received supplementary Se. Differences in fleece weight were not detected at 22 months.
Plasma, liver and fat alpha-tocopherol concentrations in sheep given various oral and subcutaneous doses of vitamin E
Authors: Judson GJ , Babidge PJ , Babidge WJ
Published: March 2005

Alpha-tocopherol concentrations were measured in plasma, liver and adipose tissue of young sheep given dl-alpha-tocopherol acetate, orally or subcutaneously, at dosages of 0, 15, 30, 60 or 120 mg/kg liveweight while the sheep consumed a pelleted diet containing less than 10 mg/kg dry matter alpha-tocopherol. Significant responses in plasma alpha-tocopherol concentrations were observed after 1 and 4 days in sheep given oral doses of the vitamin but not in those given subcutaneous injections. Variation between animals within treatment groups was not reduced by expressing plasma alpha-tocopherol as a ratio of various plasma lipid fractions. Oral doses of 30 and 120 mg/kg liveweight of alpha-tocopherol increased the mean liver alpha-tocopherol concentrations at 7 days, but only the highest dose significantly increased liver concentrations above that of untreated sheep at 1 and 2 months. Increases in mean liver alpha-tocopherol concentrations were observed 1 month after subcutaneous injections, at dosages above 15 mg/kg liveweight, suggesting a slow mobilisation of the vitamin from the injection site. Concentrations of alpha-tocopherol in adipose tissue were not altered by alpha-tocopherol treatment. Plasma and liver alpha-tocopherol concentrations were positively correlated, although vitamin E treatments and time from treatment had small but significant effects on this relationship. The results suggest that oral dosage is preferable to subcutaneous injection when administering alpha-tocopherol acetate to sheep. An oral dose of 120 mg/kg liveweight will probably maintain adequate liver alpha-tocopherol concentrations for a period of about 2 months in sheep consuming diets of low vitamin E content.