bluuebunny/crossref_metadata_2025 huggingface dataset:
Basal metabolic rate in lambs and young sheep
Authors: Graham NMcC , Searle TW , Griffiths DA
Published: November 2004

Basal metabolic rate (BMR) was determined in 56 crossbred sheep, up to 10 observations being made on each animal between 1 week of age and 2¼ years. The level of feeding was varied amongst the sheep so that there was a wide range in growth rate at each age. BMR was estimated as heat production under standard conditions of fasting. Trends during fasting were studied in four sheep at ages 3 weeks, 2 months and 9 months. The effects on BMR of body weight (or fat-free weight), age, prior growth rate and prior nutrition were examined statistically by estimating the parameters of a series of model equations by a least squares iterative method. Analysis of lamb and sheep data separately and combined showed that all these variates contributed significantly to BMR. Of the variance of BMR, 89% was accounted for in a body weight term, kgx, in which the value of x was not significantly different from ¾ if one or more of the other variates were in the model; x was unity when fat-free weight was used instead of body weight. If body weight was used alone, x was smaller for both lambs and weaners, being c. 0.60; with fat-free weight the values for lambs and weaners were 0.71 and 0.96 respectively. Age, growth rate and level of feeding were of approximately equal importance, together accounting for a further 6% of the total variance. BMR declined by c. 8% per annum and was affected to the extent of 2.8 kJ per gram body weight gain and 46 kJ per MJ digestible energy intake before fasting (all values per 24 hr). Thus an increase in growth rate in a lamb from zero to maximal (0.3 kg/day) caused BMR to increase by 50%, and an increase of food intake by 1 kg/day in an average adult sheep caused BMR to increase by 10%. For any given set of these variates, BMR was 23% higher in milk-fed lambs than in weaned sheep. An equation was derived for sheep in general; the residual standard deviation was c. 300 kJ/24 hr, or 7-8% of BMR in an average adult sheep. Some evidence was cited to show that this equation may be used to predict BMR in growing and adult cattle by multiplying the whole expression by 1.3.
Selection for clean fleece weight in Merino sheep. II.* Correlated responses to selection
Authors: Barlow R
Published: November 2004

Correlated responses to selection for high and low clean fleece weight (W) in the Peppin Merino (Fleece plus and Fleece minus flocks respectively) are presented together with estimates of realized genetic correlations where appropriate. There were strong positive correlations between W and greasy fleece weight and between W and clean scoured yield, and a strong negative correlation between Wand crimp frequency. There was no consistent association between W and body weight. Selection for W caused little change in wool colour, a slight improvement in wool character, and an improvement in wool handle in the rams, but not in the ewes. There was an increase in face cover score and a decrease in birthcoat score in the Fleece minus flock, but there was no change in either trait in the Fleece plus flock. Possible reasons for these asymmetries are discussed. Most of the response in W in the Fleece plus flock arose through increases in fibre density, fibre diameter and staple length. Staple length was the major component associated with response in W in the Fleece minus flock. Decreases also occurred in fibre density and wrinkle score but there was no change in fibre diameter. Continued response in W in the Fleece minus flock was through staple length and, to a lesser extent, wrinkle score. The response in fibre density in both flocks arose through change in the ratio of secondary to primary fibres. Two-year-old and lifetime reproductive performances are reported for the two selection flocks. The Fleece minus 2-year-old ewes weaned significantly more lambs than their Fleece plus counterparts over the period studied. The lifetime reproductive performance of ewes was similar in both flocks, although there were significantly more multiple births in the Fleece plus flock. An examination of the divergence between the two flocks revealed no significant time trends. The asymmetrical pattern of response in W in these flocks is discussed in the light of the present data.

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*Part I, Aust. J. Agric. Res., 25: 643 (1974).
The growth of muscle, bone, fat and connective tissue in cattle from 150 days' gestation to 84 days old
Authors: Johnson ER
Published: November 2004

The growth of muscle, bone, fat and connective tissue was investigated in 30 half-sib Friesian foetuses and calves over five age phases from 150 days' gestation to 84 days old. Large changes in the growth coefficients of all four carcass tissues and most of the 'standard muscle groups' over the pre-natal growth phases confirmed this as a period of intense differential growth. Changes in the growth coefficients of muscle, bone and connective tissue showed that the post-natal growth patterns of these tissues differed greatly from their pre-natal growth patterns and were generally established by birth. Most large changes in growth impetus of the nine 'standard muscle groups' were observed in the pre-natal growth period, some further changes occurring up to 28 days post-natally. There were no significant changes in growth impetus of the muscle groups in the two growth phases beyond 28 days. High standard errors were associated with the growth coefficients of most fat depots and total dissected fat, reflecting the large variation in depot fatness and carcass fatness among animals of similar age. Problems associated with the dissection of fatty tissues made it difficult to interpret the growth of fat from 150 days' gestation to 84 days old. A functional basis is postulated for the growth of muscle, bone and connective tissue and for growth within the musculature.
The relation between nitrate reductase activity and grain nitrogen productivity in wheat
Authors: Dalling MJ , Halloran GM , Wilson JH
Published: November 2004

The seasonal patterns of leaf nitrate reductase activity were compared in five wheat cultivars which differ widely in their capacities to accumulate grain nitrogen. Significant differences in the average levels of nitrate reductase activity were observed between cultivars. Total seasonal nitrate reductase activity was closely related to total plant nitrogen at maturity. Grain nitrogen was only related to total seasonal nitrate reductase activity when allowance was made for significant differences between cultivars in nitrogen redistribution patterns. The significance of these results with respect to the possible use of nitrate reductase activity levels as a selection criterion for nitrogen productivity is discussed.
Agronomic studies on pigeon pea (Cajanus cajan (L.) Millsp.). I. Field responses to sowing time
Authors: Akinola JO , Whiteman PC
Published: November 2004

A split-plot design was used to investigate the vegetative and reproductive responses of two earlymaturing and two late-maturing Cajanus cajan accessions to eight sowing dates. Pre-flowering to pod-ripening durations varied, depending upon interactions between climatic factors and the photoperiodic responses of the accessions. Quantitative short-day, day-neutral or nearly day-neutral, and intermediate photoperiodic forms were identified. Relationships between day length, radiation, growing degree-days, and seed yield per hectare based on individual monthly harvests and harvest index were established for a sowing density of 2990 plants ha-1. Optimum sowing times were identified as late November-mid January for dry seed production in the latematuring accessions, and not later than December for periodic green pod picking in the earlymaturing accessions.
Field environment studies on lupins. I. Developmental patterns in Lupinus angustifolius L., the effects of cultivar, site and planting time
Authors: Perry MW , Poole ML
Published: November 2004

The development of early (Unicrop) and late (Uniharvest) flowering cultivars of Lupinus angustifolius was studied with eight planting times at two climatically contrasting sites representing the main lupin-producing areas in Western Australia. Differences in time from planting to floral initiation and from initiation to first flower, in duration of flowering, and in time of maturity were measured. The major differences in phasic development between the cultivars for the different planting times and sites were for the period from planting to initiation. This is explained in terms of the known vernalization requirement of Uniharvest. As a consequence, initiation of the two cultivars was closest with midwinter planting in the cool environment and farthest apart with eariy planting at the warmer site. For comparable planting times the differences between cultivars for the period from initiation to first flower were small. Duration of flowering and final maturity were mainly influenced by the definite end to the growing season brought on by moisture stress and high temperatures. Differences in photoperiod exerted little influence on development. Growth of the plant was indeterminate, but the presence of terminal inflorescences on the main axis and branches produced a series of easily identified orders of lateral branches. Inflorescences flowered in sequence, extending the duration of flowering as successively higher orders of laterals were formed. Late planting reduced the length of all growth phases but drastically reduced the duration of flowering. The results are discussed in relation to the Western Australian environment, and it is argued that, in such environments, indeterminate growth has potential adaptive advantage over the determinate growth pattern of the cereals.
Inheritance of scald resistance in barley. I. Resistance of genes of group A barley cultivars
Authors: Ali SM
Published: November 2004

The genetic basis of resistance and susceptibility of barley cultivars to Rhynchosporium secalis (Oud.) Davis was determined from F2 and F3 progenies of crosses among five resistant and four susceptible cultivars. The resistant cultivars Psaknon, Atlas 46, Atlas 57, Hudson and Turk were found to share a common gene in addition to other genes for resistance. No race of the pathogen found in Western Australia was able to overcome the resistance conferred by the common gene. The effectiveness of the identified resistance genes to two isolates of R. secalis was studied under glasshouse conditions in winter and summer, and in the field during winter.
Physiological responses of semiarid grasses. II.* The pattern of root growth in relation to external phosphorus concentration
Authors: Christie EK
Published: November 2004

The effect of the external phosphorus concentration on the pattern of root development in mulga, Mitchell and buffel grasses was examined. During seedling and early vegetative growth, the pattern of root growth suggested that the emergence of axes, their extension and branching were coordinated in such a way that the mean rate of extension and distance between branches remained fairly constant for each component of the root system. Phosphorus deficiency did not greatly affect the length of the seminal axis or the number of its primary laterals, but resulted in a significant reduction in the length of these laterals; the length and number of nodal roots were also greatly reduced. Species differences in the pattern of root development are discussed in relation to seedling drought survival on infertile soils.

*Part I, Aust. J. Agric. Res., 26: 423 (1975).
Variation in the fertility of ewes during the joining period and its modification by prior contact with rams
Authors: Knight TW , Oldham CM , Lindsay DR , Smith JF
Published: November 2004

The reproductive performance of ewes mated for the first time in the first, second and third 2 weeks of joining was determined in 19,666 Merino ewes from 46 commercial flocks in the south of Western Australia. The percentage of ewes failing to lamb was higher for ewes mated in the first 2 weeks of joining than in ewes mated for the first time in the second 2 weeks (8.4%, P < 0.001). This difference was not associated with the age of the ewes, but it was related to the stage of the breeding season (19.2%, P < 0.001, in October–November; 4.1%, P < 0-01, in February–March). The difference resulted from the lower fertility of the ewes mated in the first period and was not associated with either an adverse ram/oestrous-ewe ratio or low fertility of the rams early in the joining period. The data on returns to service suggested that the low fertility of the ewes in the first 2 weeks of joining was associated with a low level of fertilization and/or a high level of early embryonic death. Placing vasectomized rams with the ewes for 2–4 weeks before joining reduced this difference in fertility between ewes mated in the first and the second 2 weeks of joining. The fertility of maiden ewes improved from the first to the third 2 weeks of joining. Older ewes were more fertile when mated in the second 2-week segment than in the first, but those mating for the first time in the third 2 weeks were least fertile of all.
Field environment studies on lupins. 2. The effects of time of planting on dry matter partition and yield components of Lupinus angustifolius L
Authors: Perry MW
Published: November 2004

Dry matter partition, seed yield, and yield components were examined in two lupin cultivars at eight planting times. Dry matter production and seed yield both declined with later planting primarily as a result of the foreshortened growing season which reduced the production of lateral branches and consequently the number of inflorescences per plant. For a given inflorescence, planting date appeared to have no systematic effect on pod number, although pod numbers on the main stem inflorescence varied with planting date. Mean seed weight declined slightly with later planting. Unicrop, the earlier-flowering cultivar, gave higher seed yields owing to greater development of higher order lateral branches and heavier individual seeds. Flowering began when only 17-25 % of maximum dry matter had accumulated, and subsequent dry matter partition between main stem and successive orders of lateral branches emphasized the characteristic structural development of the lupin. Seed filling occurred in the last 4-6 weeks of growth when vegetative development had nearly ceased, and was almost concurrent in both cultivars, all planting times and all lateral orders irrespective of the time of pod set.
Metabolic studies on daily and weekly feeding of ruminants given all-wheat diets. 3. The activities of enzymes in sheep tissues
Authors: Watson HR , Watson MJ
Published: November 2004

The activities of gluconeogenic, glycolytic and lipogenic enzymes have been measured in tissues from sheep given either 300 g of wheat each day or 2100 g wheat each week. The mean activities of gluconeogenic enzymes did not differ between the two feeding regimens; however, in sheep on the weekly feeding regimen, the activities of some gluconeogenic enzymes decreased after feeding and increased again at the end of the feeding cycle. On both feeding regimens the activities of glycolytic and lipogenic enzymes appeared to be increased by the all-wheat diet, although the activities of these enzymes did not differ between the regimens.
The effect of plant structure on the intake of tropical pasture. III.* Influence of fertilizer nitrogen on the size of bite harvested by Jersey cows grazing Setaria anceps cv. Kazungula swards
Authors: Stobbs TH
Published: November 2004

The effect of fertilizing Setaria anceps cv. Kazungula swards with nitrogen on the size of bite harvested by cattle was determined and the influence of sward canopy structure upon bite size was investigated in two experiments. The first experiment measured the effect of nitrogen at 0, 40, 60 and 100 kg/ha on 6-week regrowth, and the second measured the effect at 50 and 100 kg/ha on 4- and 6-week regrowths of both unfertilized swards and others which had received 350 kg nitrogen per hectare in each of the previous three years. The mean bite size of cows grazing immature (4-week) regrowths increased linearly with increasing applications of nitrogen, averaging 0.29, 0.33 and 0.37 g organic matter (OM) per bite on the 0, 50 and 100 kg/ha treatments respectively. Swards which allowed the largest bites to be prehended had the highest leaf yields and the highest leaf bulk densities. The mean bite size on 6-week regrowths was lower (0.28 g OM/bite) than on 4-week regrowths (0.33 g OM/bite). Cows selected leaf from the upper layers of the swards, and inaccessibility of leaf resulting from a high stem and inflorescence content prevented animals from taking larger bites. In both experiments high levels of nitrogen fertilizer advanced the maturity of 6-week regrowths, and the bite size of cows grazing these pastures did not increase beyond the level recorded at intermediate nitrogen levels. It was concluded that fertilizer nitrogen increases dry matter and leaf yields, particularly in the uppermost layers of the sward, allowing cows to harvest large bites of immature herbage. A higher stem and inflorescence content in heavily fertilized swards can result in inaccessibility of leaf when mature herbage is grazed.

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*Part II, Aust. J. Agric. Res., 24: 821 (1973).
Herbage intake and grazing behaviour in ewes of four breeds at different physiological states
Authors: Arnold GW
Published: November 2004

The digestible organic matter intakes (DOMI) of dry, pregnant, and lactating Border Leicester x Merino, Merino, Corriedale and Dorset Horn ewes of similar age were estimated when they were grazing Phalaris tuberosa –Trifolium subterraneum pastures at four levels of pasture availability. Both total DOMI and DOMI per unit liveweight differed significantly between breeds, reproductive states and pasture levels. No interactions were detected. In absolute terms the intake of 140 Corriedales = 121 Merinos = 116 Border Leicester x Merinos = 100 Dorset Horns. In terms of intake per unit liveweight Corriedales and Border Leicester x Merinos ate less than Merinos and Dorset Horns. DOMI was greater in pregnant or lactating than in dry ewes; it also increased at higher levels of available pasture. Different intakes were achieved by variation in grazing times and/or rates of intake. The ewes of all breeds responded in the same way.
Skeletal muscle, liver and wool protein synthesis by sheep infected by the nematode Trichostrongylus colubriformis
Authors: Symons LEA , Jones WO
Published: November 2004

Incorporation of radioisotopically labelled L-leucine into skeletal muscle proteins was measured in vivo and in vitro, and into liver proteins in vivo in three groups of sheep: (1) infected by Trichostrongylus colubriformis, (2) uninfected, pair-fed with the infected animals, (3) uninfected, fed ad lib. Incorporation of [14C]L-leucine by an homogenate of wool follicles from infected and uninfected sheep was also measured. Incorporation of leucine by muscle, and hence muscle protein synthesis, was equally depressed in the anorexic infected sheep losing weight, and in pair-fed animals, whether measured in vivo or in vitro, or expressed in terms of either RNA or DNA. Incorporation into protein was elevated equally in vivo in the livers of the infected and pair-fed sheep when expressed in terms of content of tissue nitrogen, but not in terms of cither nucleic acid. Incorporation by the wool follicular homogenate was appreciably depressed by the infection and is consistent with the poor wool growth in nematode infections. These results show that the same depression of skeletal muscle and, possibly, elevation of liver protein synthesis occur in a ruminant as were reported earlier for laboratory monogastric animals with intestinal nematode infections. Pair-feeding uninfected animals in both this and the earlier experiments emphasized the importance of anorexia as a major cause of these effects on protein synthesis. The importance of these effects upon production is discussed briefly.
Corrigendum - Skeletal muscle, liver and wool protein synthesis by sheep infected by the nematode Trichostrongylus colubriformis
Authors: Symons LEA , Jones WO
Published: November 2004

Incorporation of radioisotopically labelled L-leucine into skeletal muscle proteins was measured in vivo and in vitro, and into liver proteins in vivo in three groups of sheep: (1) infected by Trichostrongylus colubriformis, (2) uninfected, pair-fed with the infected animals, (3) uninfected, fed ad lib. Incorporation of [14C]L-leucine by an homogenate of wool follicles from infected and uninfected sheep was also measured. Incorporation of leucine by muscle, and hence muscle protein synthesis, was equally depressed in the anorexic infected sheep losing weight, and in pair-fed animals, whether measured in vivo or in vitro, or expressed in terms of either RNA or DNA. Incorporation into protein was elevated equally in vivo in the livers of the infected and pair-fed sheep when expressed in terms of content of tissue nitrogen, but not in terms of cither nucleic acid. Incorporation by the wool follicular homogenate was appreciably depressed by the infection and is consistent with the poor wool growth in nematode infections. These results show that the same depression of skeletal muscle and, possibly, elevation of liver protein synthesis occur in a ruminant as were reported earlier for laboratory monogastric animals with intestinal nematode infections. Pair-feeding uninfected animals in both this and the earlier experiments emphasized the importance of anorexia as a major cause of these effects on protein synthesis. The importance of these effects upon production is discussed briefly.
Host resistance to cattle tick (Boophilus microplus) in Brahman (Bos indicus) cattle. I. Responses of previously unexposed cattle to four infestations with 20,000 larvae
Authors: Wagland BM
Published: November 2004

Four purebred Brahman and four beef Shorthorn cattle which had not previously been exposed to Boophilus microplus were infested four times with 20,000 B. microplus larvae. On first infestation, the yield of engorged female ticks on all animals was about 25% of the larvae applied. Aftcr three further infestations, the mean yield of engorged females on the Brahmans decreased to 7.5% whereas there was no decrease in the yield of ticks on the Shorthorns. On the Brahman cattle. development of larvae to engorged females took 1–2 days longer and the engorged females weighed less. However, there was no difference in the reproductive index of female ticks engorged on either Brahmans or Shorthorns. Increases in rectal temperatures occurred in all cattle 15–17 days after the first infestation and in some cattle on days 6–7 as well as on days 15–17 after reinfestation. It was concluded that resistance to B. microplus is an acquired phenomenon in Brahman cattle.
Effectiveness of selection for growth rate in Zebu × British crossbred cattle. II.* Post-weaning growth and genetic estimates
Authors: Seifert GW
Published: November 2004

The response to one generation of selection for weight per day of age at 18 months (W/Af), in Africander cross (AX) and Brahman cross (BX) cattle, was evaluated in the female offspring of the up and down selected parents. The high W/A< line gained significantly more than the low line over a year from weaning. The advantage of the high W/A line occurred during flush nutritional periods. The realized heritability (h2) of W/Af at 18 months was 0.52, while the estimates of h2 from mid-parental means computed within sires was higher. Heritability estimates for birth weight (Wb), weaning weight per day of age (W/Aw), pre-weaning average daily gain (Gbw) and total average daily gain from birth to final weight (Gt) were all high, while the estimate for post-weaning average daily gain from weaning to final weight (Gpw) was low. The correlated responses of all the traits were high. The genetic correlations estimated from the response and the parent-offspring regressions were all positive and high. Birth weight was the most highly correlated with Gt. All phenotypic correlations were positive but lower than the genetic correlations, the correlation between Gbw and Gpw being the lowest. Environmental correlations between birth weight and pre-weaning traits were essentially zero, and between birth weight and post-weaning traits and Gt, negative. Weight per day of age at 18 months appeared to be the most efficient and practical single trait to select beef cattle for increased growth rate.
An application of multivariate analysis to selection for quality characters in wheat
Authors: Bhatt GM
Published: November 2004

A set of 12 genotypes of bread wheat (Triticum aestivum L.) was grown in four different environments involving sites and years. Multivariate analysis according to the D2 technique was performed on six quality characters measured on material harvested from each environment and on the data pooled over four environments. The analysis offered meaningful grouping criteria with regard to quality performance. The clustering pattern was stable in different environments. This environmental stability was found to be independent of the stability of six individual characters. The application of multivariate analysis to selection for quality characters in a wheat breeding program is discussed.
Root growth of wheat. I. Early patterns of multiplication and extension of wheat roots including effects of levels of nitrogen, phosphorus and potassium
Authors: Tennant D
Published: November 2004

Wheat root growth was followed to 30 days from planting in wheat supplied with standard, twofold, half and nil levels of nitrogen, phosphorus and potassium. Root numbers and lengths followed consistent patterns of increase in the seminal and nodal root systems of all treatments. Most root components demonstrated their highest rates of relative increase in length and number immediately after first appearance. Within a few days this decreased to a constant rate of increase which continued until the end of the experiment. Rates during the stages of constant relative increase were higher with increasing order of lateral, and the same for all treatments, except when nutrient deficiency seriously suppressed root growth. Potassium deficiency stopped root growth completely within 10–12 days of planting. Nitrogen and phosphorus deficiencies gave increasing delays in root component appearance with increasing order of lateral. Increasing suppression of seminal lateral numbers and a severe suppression of nodal root growth followed. Lower root numbers caused by nitrogen deficiency were compensated by greater lateral lengths in the seminal but not the nodal root systems. Some reduction in root growth resulted from application of the half and twofold levels of nitrogen, phosphorus and potassium. All responses to applied nutrient levels were more obvious with increasing order of lateral and with the nodal rather than seminal root systems. The nodal root system reflected plant response better than the seminal root system.
Temperature effects on flower initiation in sweet orange (Citrus sinensis)
Authors: Moss GI
Published: November 2004

The effects of temperature on flower induction in sweet orange were studied over a range of shoot and root temperatures representing the conditions found in the field in commercial growing regions. Rooted cuttings of the orange cultivar 'Late Valencia' were used in the Canberra phytotron, with an extended photoperiod of 16 hours and a photo-temperature of 8 hours' duration. Following low temperature inductive conditions (5 weeks at 15/10°C), profuse flowering occurred at 24/19°; flowering was only slightly less at this air temperature with a root temperature of 30°, and at an air temperature of 30/25°. At 36/31° few flowers were formed and these abscissed before opening. However, when the root temperature was maintained at 22° with this shoot temperature a few flowers were formed. In another experiment a root temperature of 30° and shoot temperature of 24/19° reduced the number of flowers that formed (86 cf. 137). Only a small part of the effect of high temperature in inhibiting flower initiation was due to root temperature. Two attempts were made to induce flowering under non-inductive temperatures (27/22°) with low root temperatures (15 and 11°). Flowering could not be induced under these conditions, and the lack of flowers apparently was not due to inhibition of growth by low root temperature. Although few flowers were formed at 27/22° without any previous inductive treatment (15 flowers per plant), profuse flowering was induced by 27/13° (141 flowers/plant), which indicated that a low night temperature will induce flowering. A high root temperature (29°) during inductive conditions (15/10°) had little effect on the number of flowers formed. It appeared that the site of flower stimulation by temperature was in the shoot only, and that subsequent high root temperature effected floral development. It was concluded that flowering could be induced in the field during the summer by low night temperature, and root temperatures would probably have little influence on floral development.
Changes in body composition associated with weight loss in early- and later-maturing types of steers
Authors: Price MA
Published: November 2004

A trial is reported with eight steers in a 2 x 2 factorial design to compare the effects of weight loss in two maturity types of steers, Charolais x Hereford (C x H) and purebred Hereford /H x H), having similar estimated initial carcass fat contents (30% and 32% respectively) but different liveweights (402 kg v. 332 kg). The steers were aged about 61 weeks at the beginning of the trial, when a pair of C x H and of H x H steers (group 1) were slaughtered. The initial body composition was established by sample cut dissection and half-carcass chemical analysis. The remaining two pairs of steers (group 2) here slaughtered and analysed following 234 days of grossly submaintekmce feeding. During the submaintenance period the C x H steers lost considerably more liveweight (134 kg v. 107 kg) than the H x H steers; however, the percentage loss was similar in all four steers. All cattle consumed identical weights of feed. It is estimated that in losing about 30% of their initial liveweight, the four steers lost about 40% of their carcass weight and 20% of their offal weight, regardless of initial liveweight differences. The carcass loss in both breeds consisted of about 70% of the initial fat weight, 40% of the muscle weight, and less than 10% of the bone weight. Breed differences in the distribution of carcass tissues and retail cuts were small and generally not significant. Three classes of body components are defined and listed: class 1, those which lost weight at a relatively greater rate than the carcass; class 2, at a similar rate; class 3, at a slower rate. Estimated 'negative growth coefficients' (k in the allometric equation y = bxk) for carcass, offal, bone, muscle and fat weights, relative to liveweight, were about 1.4, 0.5, < 0.25, 1.3 and > 3.0 respectively.
Temperature/light interactions and the effect of seed source on germination of annual ryegrass (Lolium rigidum Gaud.) seeds
Authors: Gramshaw D
Published: November 2004

Germination of Lolium rigidum seeds, in the light (12 hr day length) and in the dark, was studied at constant and alternating (12/12 hr) temperatures in the range 8–35°C. Seeds had after-ripened for 22 weeks. Different constant temperature optima for germinability were found: 27° in light and 11° in dark. Germinability at alternating temperatures in darkness was determined solely by the minimum temperature of the alternation, and there was no response to thermoperiodicity per se. In contrast, light and alternating temperature appeared to interact to increase germinability, although the highest germinability occurred only when the maximum temperature was close to the optimum constant temperature, i.e. about 27°. Germination in both light and dark was most rapid where either the constant or the average temperature of an alternating regime was between 18 and 29°. Below 18° germination rates decreased markedly, and at 8°, rates were one-third of those at 18°. Seeds germinated more slowly in light than in darkness at all temperatures, but the differences were small relative to the effects of low temperatures.In another study, seeds collected from plants naturalized in eight different localities in the cereal belt of Western Australia and subsequently planted together in two contrasting environments were examined for germinability at 24/12°C in light and dark 18 weeks after harvest. Dark germinability differed between seed sources but not between planting sites, and ranged between 78 and 93%. Exposure of germinating seeds to light substantially alleviated dormancy in seeds from all sources.
Effects of seed bed conditions on the germination of four Stylosanthes species in the Northern Territory
Authors: Mott JJ , McKeon GM , Moore CJ
Published: November 2004

Since the proposed use of low input management practices in the Northern Territory will require the establishment of Stylosanthes species in the native grasslands with the least possible disturbance, the effects of soil surface, soil type and seed treatments on the germination of four Stylosanthes species were studied. The species were the annual S. humilis, the facultative perennial S. hamara cv. Verano, and two obligate perennials, S. scabra CPI 40289 and S. viscosa CPI34904. The study was carried out on microplots in burnt and unburnt pasture near Katherine in the Northern Territory. Although all species germinated in both burnt and unburnt grassland, germination was much better under the grass sward. The two perennial species germinated much more slowly than either S. humilis or S. hamata, and the removal of grass cover caused low germination of these species, especially under the poor moisture conditions existing on the surface of sandy soils. Under the existing method of establishment with burning late in the dry season followed by sowing in the early wet season, the germination of the perennials S. scabra and S. viscosa will not attain the same levels as that of S. hamata and S. humilis. Our results suggest that field germination of the perennials could be enhanced by either pretreating the seed to improve its potential rate of germination, or by sowing later in the wet season to take advantage of the greater probability of prolonged moisture conditions.
An evaluation of cereal stubbles for sheep production
Authors: Mulholland JG , Coombe JB , Freer M , McManus WR
Published: November 2004

The production of young crossbred wethers grazing oat, barley and wheat stubbles was measured in each of three years at stocking rates ranging from 15 to 30/ha. In one year, production on 'weedy' stubbles was compared with that of 'clean' (weed-free) stubbles, and also the effect of a wheat–urea–mineral supplement on the production of sheep was measured on oat stubble. Liveweight change and wool production were significantly influenced by the availability of green plant material and by stocking rate, but not by supplementation. The maximum liveweight loss in any year was 7.5 kg and the maximum gain 6.0 kg, both recorded over 11 weeks' grazing. Mean daily clean wool production was 9.9 g/sheep at the lower stocking rate and 6.6 g/sheep at the higher rate, but production per hectare was 10–60% higher at the heavier stocking rate. The ranking of the crop stubbles with respect to animal production was not consistent from year to year. Intense selection for green plant material by sheep resulted in the proportion of green in the diet being nearly always greater than 80%, when the weight of this material on the plots was more than 40 kg dry matter/ha. It appeared that a low intake of nitrogen was not the main limitation to animal production. A maximum of only 36% of the crop residue which disappeared during the experiment could be accounted for as animal intake. Thus it is unlikely that the potential of cereal residues as a source of food for animal production will be realized with grazing sheep.
Effect of geographic location of growth on wheat milling yield, farinograph properties, flour protein and residue protein
Authors: O'Brien L , Orth RA
Published: November 2004

The relationship between farinograph dough breakdown and the proportion of flour protein insoluble in 0 . 0 5M acetic acid (residue protein) was investigated for a number of wheats each grown at six locations in the Mallee and Wimmera regions of Victoria. At each location a highly significant correlation was obtained (R ranging from 0.84 to 0.93), which indicated that the 'residue test' could be used as a selection tool in wheat-breeding programs. Regressions of flour milling yield, flour protein content, farinograph water absorption, dough development time and dough breakdown, and the proportion of residue protein were calculated for each parameter for the wheats grown at Dooen against those for wheats grown at each other location. Variables largely dependent on protein 'quality', viz. dough breakdown, dough development time and residue protein, ranked the wheats similarly at each location of growth. Rankings according to milling yield, farinograph water absorption and flour protein content differed more markedly between locations.
Black leg (Leptosphaeria maculans (Desm.) Ces. et de Not.) of rapeseed in Victoria: crop losses and factors which affect disease severity
Authors: McGee DC , Emmett RW
Published: November 2004

Surveys made of rapeseed crops in Victoria during 1971, 1972 and 1973 showed that black leg was widespread, but its severity depended on field location and sowing date. In crops sown on or adjacent to fields growing rapeseed in the previous year, black leg sometimes caused crop failure. In fields sown before August, the disease caused major yield losses, whereas in those sown later it caused only minor losses. There were no apparent differences in severity of infection between cultivars or districts. Infections which resulted in serious stem cankers were shown to occur before flowering.
Genotype × environment interactions and environmental adaptation. II. Assessment of environmental contributions
Authors: Shorter R , Byth DE , Mungomery VE
Published: November 2004

A pattern analysis approach, based on classification and ordination, is presented for the characterization of environmental contributions to differences among lines in mean performance and response across environments. Other approaches to the analysis of line performance and environmental interactions are also considered. A population of soybean lines is used to illustrate the analyses for two characters, seed yield and seed protein percentage. In general, correlation of line performance over environments indicated that only moderate similarity of relative line performance existed over years or locations. These associations did not provide a clear basis for rationalization of test sites. Partitioning of variance components allowed a general strategy for sampling environments to be defined. Marked differences existed among environments for their contribution to environmental interaction, and these generally were consistent among locations for the two years of testing. Classificatory and ordination analyses were applied separately, and the contributions of each of the test environments were determined. These procedures confirmed that large differences in line response existed among environments, and provided additional and complementary information about the contributions of particular test environments to those differences. The effect of abandoning particular test sites on the recognition of differences among lines was examined by pattern analysis. The implications of the information gained through the pattern analysis approach in the development of testing strategies, and in the selection of test environments for specific objectives, are discussed.
Effects of sowing time and sowing density on the growth of subterranean clover at Adelaide
Authors: Silsbury JH , Fukai S
Published: November 2004

Growth curves have been constructed for undefoliated swards of subterranean clover (cv. Woogenellup) established at three plant densities (1,2 and 4 x l03 plants per m2) at three times of the year (May, June and August). The swards grew without any apparent water stress, until early December. The time course of shoot dry matter increase is examined by the use of a logistic function and by the recognition of three growth stages. Maximum crop growth rates ranged from 10 to 15 gm-2 day-1. The rate decreased with increase in density but increased with lateness of sowing, so that the highest crop growth rate was obtained with the lowest plant density sown in August. Estimated end-of-season yields were independent of density but decreased from about 1500 g m-2 for May sowing to 1000 g m-2 for August sowing. Effects of sowing density on the growth pattern persisted throughout the whole season. Swards took 70–100 days to attain a leaf area index (LAI) of 3, after which crop growth rates were almost constant with time and independent of short-term fluctuations in the level of daily solar radiation and average daily temperature. Swards reached a maximum LAI of about 6, LAI being linearly related to the amount of shoot dry matter up to about 600 gm-2 independent of density and sowing time. No evidence was found of an optimal relationship between crop growth rate and LAI.It is concluded that end-of-season yield is independent of plant density above 1000 established plants per m2, and that swards established as late as August have the capacity to attain a yield of 10 tonnes ha-1 provided the growing season is extended.
Reduction of superficial scald in apples with monoterpenes
Authors: Wills RBH , Scott KJ , McBailey W
Published: November 2004

The monoterpenes geraniol, nerol, citronellol, linalool, α-terpineol, menthol, menthone and pulegone reduced the incidence of superficial scald in Granny Smith apples when added to the fruit as an injection. Naphthaleneacetic acid markedly increased scald, while abscisic acid, SKF525 (a proprietary inhibitor) and glutathione also increased the disorder.
Evaluation of residual nutrient effects in soils
Authors: Russell JS
Published: November 2004

Some nutrients applied to soils remain available to plants well beyond their time of application. Efficient use of fertilizers requires better definition of these residual effects. In this paper the behaviour of nutrients applied to soils is expressed as a mechanistic model comprising two differential equations:A / dt = F(t) + K3U − (K1 + K2) − P(t)
dU / dt = K1A − K3U,
where A and U are the available and and unavailable soil nutrient levels and K1, K2 and K3 are the fixation, loss and release coefficients respectively. The applied nutrient F(t) and the nutrient removed in harvested plant products P(t) are considered as impulses to the system.
The solved form of these equations can be fitted to appropriate field experimental data by using iterative least squares procedures and parameters estimated.

The model has been fitted to 6 years' experimental data where pasture responses to 16 different superphosphates regimes were measured on a soil with a high phosphate retention capacity.

The estimated rates of fixation (K1), loss (K2) and release (K3) of available phosphorus as percentages per month on this soil were 1.29, 1.48 and 0.072 respectively, with release extremely low.

To maintain pasture production on this soil the model suggests that high rates of phosphorus
will be required for a long time, that it is wasteful to apply phosphorus above a specified maintenance level (as such phosphorus is either fixed or lost) and that biennial application is more efficient than annual.
From the model the theoretical maximum residual available nutrient, c, in a soil at time t after application, is
c(t) = [(K1exp{− (K1 + K3)t + (K3] / (K1 + K3),

with the decay curve asymptoting to the value K3/ (K1 + K3) at equilibrium. On the soil studied this value was 5.3%. In practice, because of losses and plant removal, residual nutrient levels are usually less than the theoretical maximum.

It is postulated that if the ratio of available to unavailable nutrient in a soil at equilibrium is
1 / z, then the theoretical maximum proportion of available applied nutrient at equilibrium is 1 / (z + 1).

The model is likely to be most useful for major nutrients where residual effects are important
in practice, e.g. phosphorus, sulphur, potassium and magnesium.
Cervical mucus and reproductive efficiency in ewes after exposure to oestrogenic pastures
Authors: Adams NR
Published: November 2004

A total of 227 cervical mucus samples was studied in ewes from 12 flocks with varying histories of clover disease, and the results related to the reproductive performance of the ewes. The mucus of ewes from flocks known to be affected with clover disease had a lower spinbarkheit than that of controls (54 v. 92 mm, P < 0.05). The spinbarkheit of cervical mucus at first mating was inversely correlated with the return-to-service rates of the ewes at subsequent matings (r = −0.181, P < 0.01). The low value of this correlation indicates that most of the variability in mucus spinbarkheit was due to other factors; the stage of the breeding season, and the total amount and the proportion of dry weight of the mucus collected, were also related to the mucus spinbarkheit. Variability was decreased by adjusting the spinbarkheit for the time of the breeding season at which the sample was collected. There was a threshold value of 60 mm for mucus spinbarkheit, above which fertility was independent of mucus spinbarkheit value. The proportion of samples with sub-threshold spinbarkheit values collected from a flock was related both to flock return-toservice rate (r = 0.663, P < 0.05) and the proportion of non-lambing ewes in the flock (r = 0.605, P < 0.05). Neither mucus spinbarkheit nor the proportion of non-lambing ewes was associated with any abnormal increase in the proportion of ewes which failed to lamb in successive years. It is concluded that cervical mucus spinbarkheit may be used to measure the lowered reproductive performance of ewes which have been exposed to oestrogenic pasture.
Variation in the pre-anthesis development of spring rape (Brassica napus L.)
Authors: Thurling N , Das LDV
Published: November 2004

Fifteen cultivars of spring rape (Brassica napus L.) were each sown at four different times between April and October at Perth in either natural photoperiods or continuous light. Under natural photoperiods, flowering of the Japanese cultivars Chisaya and Isuzu was delayed in later sowings, but the flowering times of all other cultivars were advanced with each successive delay in sowing. When plants were grown under continuous light another two groups of cultivars could be recognized. One group comprised early-flowering Canadian cultivars which flowered later in the June sowing than in the other sowings. The other group comprised late-flowering European cultivars characterized by a slight delay in flowering in the last sowing. The direct effects of temperature on growth rate were more important than inductive responses in determining time of flowering in all cultivars except Chisaya and Isuzu, which had substantial vernalization requirements. Other cultivars such as Komet, Bronowski, Masoweicki and Norin 16 had low vernalization requirements which were largely masked by the increase in the rate of growth with higher temperatures in later sowings. In controlled environments, considerable variation in response to vernalization, temperature and photoperiod was detected between six spring rape cultivars. The early-flowering Canadian cultivars Target and Oro were the least responsive to vernalization and under continuous light did not respond at all. European and Japanese cultivars used here responded more markedly to vernalization, and their responses were greatly influenced by temperatures experienced after the completion of vernalization. Under continuous light and high temperature, the Japanese cultivars responded markedly to 4 weeks' vernalization which apparently saturated the system. The European cultivars Bronowski and Masoweicki, on the other hand, only responded moderately.