bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of crossbred calves by Simmental and Friesian sires for some beef production traits
Authors: Gifford DR , Clark TJ
Published: March 2005

Hereford cows of mixed age and from the same herd in the south-east of South Australia, were mated to Simmental and Friesian sires in two consecutive years. Calving performance of 129 females and growth and carcase characteristics of their progeny were examined. Breed-of-sire differences in calving assistance and calf deaths were not significant. Assistance was given in 4.5 and 6.5 per cent of the Simmental and Friesian calvings respectively over the two calf drops. The percentage of calves dead at birth, or within twenty-four hours of birth, sired by Simmental and Friesian sires was 8.8 and 10.9 per cent respectively. Both before and after weaning, the growth rates of progeny sired by Simmental and Friesian bulls were similar, except in one pre-weaning period when the Simmental cross steers grew significantly faster than the Friesian cross steers. At both the 8 to 9- and 20 to 21 -month-old slaughterings, steers of either parentage had similar carcase weight, length and fat cover. However, the Simmental cross carcases had a significantly larger eye-muscle area. At both slaughterings, carcases of both crosses were leaner than desired by the local Adelaide market. We concluded that sires of the Simmental and Friesian breeds may be suitable as terminal sires in crossbreeding programmes, but that their role in the production of first-cross cows from the traditional purebred beef cow herds needs investigating.
Performance of F1 Brahman × Shorthorn and F1 Sahiwal × Shorthorn cattle from weaning to slaughter in north Queensland
Authors: Winks L , O'Rourke PK , Smith PC
Published: March 2005

Growth rates during the 18-21 months following weaning for 216 F1 Brahman x Shorthorn and 216 F1 Sahiwal x Shorthorn animals were studied during the years 1970-1975 in the dry tropics of north Queensland. Growth rates tended to favour Sahiwal crosses from weaning to 18 months and Brahman crosses from 18 to 30 months. Weight per day of age at about 800 days was similar in both genotypes in two of the three drafts. Steers outperformed heifers throughout and were 8 per cent heavier at 800 days. Carcase weight sof the steers were similar in two of the three drafts, but Sahiwal crosses had higher dressing percentages. In a group of steers boned-out under commercial conditions, Sahiwal crosses had more fat trim than Brahman crosses (7.4 vs. 5.9 per cent) and slightly less saleable meat (73.2 vs. 74.3 per cent). Birth weight, pre-weaning gain and corrected 180-day weight were positively correlated with final liveweight. Pre-weaning gain and post-weaning gain were poorly correlated. Yearling weight (approx. 500 days) was generally independent of cow age.
A comparison of Brahman × Jersey and Friesian calves when slaughtered as vealers at 250 days of age
Authors: Spiker SA , Hallett RH
Published: March 2005

Brahman x Jersey and Friesian calves were double-suckled on Jersey cows to 250 days of age and their growth rates and carcase production were compared. There was no difference in liveweight gain to slaughter between the two breed types. The Brahman x Jersey calves had a higher dressing percentage (61.0 per cent vs. 54.6 per cent), produced fatter carcases with less bone and lean than the Friesians. There was no difference in carcase quality when cuts off the round of each animal were assessed organoleptically.
The effect of strain, sex and diet on growth and carcase characteristics of meat-type ducks
Authors: Bagot I , Karunajeewa H
Published: March 2005

Studies of growth and body composition of two strains of ducklings reared to nine weeks of age on a high or a low plane of nutrition were made in a factorial experiment. The 168 ducklings, half male, half female comprised two strains, Commercial Pekin (K) and Pekin x White Orpington (S). Ducklings on the high plane of nutrition received diets (R) with 24.7 per cent protein and 12.14 MJ ME kg-1 from 0-3 weeks and 18.7 per cent protein and 12.43 MJ ME kg-1 during weeks 3 to 9. Ducklings on the low plane of nutrition received diets (C) with 20.6 per cent protein and 11.09 MJ ME kg-1 and 14.1 per cent protein and 10.72 MJ ME kg-1 between weeks 0 to 3 and 3 to 9 respectively. At three weeks of age Strain K ducklings and those fed diet R were heavier and converted feed more efficiently than either Strain S or those given diet C. At nine weeks of age, strain K ducklings were heavier than those of strain S when fed diet R but not when fed diet C. Dressing percentage of ducklings fed diet C was higher than that of those fed diet R largely because of their lower feather weight. The heavier weights of ducklings fed diet R resulted from higher intakes and better feed conversion efficiency than that obtained on diet C. Males had higher performances than females, but the treatment differences for strains and diets were not significant for weights at time of cooking, cooked carcase weight, total edible meat, breast meat, bone or fat drip.
Residual ethylene dibromide and inorganic bromide levels in some fruit and vegetables after fumigation with ethylene dibromide or methyl bromide
Authors: Hargreaves PA , Wainwright DH , Swaine G , Corcoran RJ
Published: March 2005

Residues of ethylene dibromide (EDB) were determined at periods up to seven days after fumigation of capsicum, mango, papaw, passionfruit, pumpkin and zucchini. Residues of inorganic bromide were also determined at periods up to seven days after EDB fumigation for capsicum, cucumber, mango, papaw and passionfruit. All commercially recommended EDB treatments, with the exception of that for zucchini, resulted in EDB residues at three days from 6 to 16 times the recommended maximum residue limit (MRL) of 0.1 mg kg-1, specified for a with-holding period of two days. All the inorganic bromide residues determined up to seven days after EDB fumigation were below the current recommended MRL values. Inorganic bromide residues were also determined for avocadoes fumigated with methyl bromide. After seven days the residues for full ripe fruit slightly exceeded the recommended MRL of 75 mg kg-1, while thosefor mature green and for mixed green and ripe fruit were slightly less than the recommended MRL.
Beef cow performance from tropical pastures on semi-arid brigalow lands under intermittent drought
Authors: Silvey MW , Coaldrake JE , Haydock KP , Ratcliff D , Smith CA
Published: March 2005

The value of perennial tropical pastures for breeding cows was examined over a five year period (1 968-1 973) as part of a long-term land use study on semi-arid fertile brigalow clay soils. Pastures were established to Panicum maximum var. trichoglume (green panic) and Chloris gayana cv. Pioneer (rhodes grass) grown alone or with the legumes Macroptilium atropurpureum cv. Siratro, Glycine wightii cv. Cooper and Medicago sativa cv. Hunter River. These pastures were rotationally grazed at 1.75, 1.24 and 0.87 cows ha-l during 1968-69 and at 1.31, 0.93 and 0.66 cows ha-1 in subsequent years. Pastures received either no fertilizer or 188 kg superphosphate ha-1 year-1 (grass/legume treatments) and in mixture with 250 kg ammonium sulphate ha-1 year-1 (grass-alone treatments). During the first seven months of 1968-69, increased stocking rate from 0.87 to 1.75 cows ha-1 significantly increased cow liveweight (LW) loss from 5 kg to 84 kg and reduced conception rates from 100 per cent to 68.8 per cent. Compared with pure grass pastures (GA), cows grazing grass/legume (GL) pastures lost significantly more LW during this period. These effects occurred during a severe drought which lasted for over a year. As the drought intensified and feed ran out, pasture treatments were individually destocked. A progressive botanical change from GL to pure grass pastures occurred in the GL treatments following the drought. After restocking in late 1969, cows gained an average of 121 kg and recorded an average calving rate of 93 per cent over a 45-month period despite below average annual rainfalls. Stocking rate and to a lesser extent pasture type significantly influenced annual cow LW and gains during mating, gestation and lactation periods, but the actual effects were small. Cows grazing at the highest stocking rate (HSR) of 1.31 cows ha-1 and on GL treatments recorded significantly poorer gains only in the first year after the drought. However, cows grazing GL treatments at HSR required supplementary hay feeding during winter-early spring each year. Although main treatment effects were not significant, a strong interaction between stocking rate and pasture significantly affected time of conception and both conception and calving rates. Application of fertilizer showed only small though consistent advantages for cow LW and fertility responses. It was concluded that sown tropical pasture based on pure green panic allowed high LW and reproductive performances of breeding cows stocked near 0.93 cow plus calf ha-1. This pasture-animal system was resilient to the climatic variability experienced in the semi-arid brigalow environment.
Response to partial selection for fecundity in Merino sheep
Authors: Mann TLJ , Taplin DE , Brady RE
Published: March 2005

Divergent selection for fecundity in a South Australian Merino flock was carried out over a 10 year period at Roseworthy Agricultural College, South Australia. Comparisons were made between two flocks of sheep in which selection was restricted to ram replacements. Analyses showed that very little response was achieved. Pooled estimates of repeatability by analysis of variance were 0.04 for lambs born per ewe joined (LBJ) and 0.14 for lambs born per ewe lambing (LBP). Pooled half-sib estimates of heritability were 0,10 for LBJ and 0.10 for LBP. The realized heritability of LBP was 0.03, averaged over age groups. The lack of response was due to limited selection pressure and the time taken for improvement to pass through the breeding flock.
The effect of frequency of feeding a lupin grain supplement at mating on the reproductive performance of maiden and mature Merino ewes
Authors: Kleeman DO , Cutten IN
Published: March 2005

Two groups of South Australian strong-wool Merino ewes, each consisting of maiden and mature ewes, were supplemented with lupin grain either once or three times weekly. Both groups received 1.75 kg of supplement per head per week from two weeks before joining to three weeks after joining. A third group of ewes received no supplement. All groups grazed a cereal stubble. Mature and maiden ewes supplemented once weekly and maiden ewes supplemented three times weekly did not respond in ovulation rate, fertility or fecundity. However, the mature ewes supplemented three times weekly had a 16 per cent higher incidence of multiple ovulations (0.05 < P < 0.1), an 11 per cent higher ovulation rate (ns.) and a 21 per cent higher fecundity (P < 0.05) than unsupplemented mature ewes. Under the conditions of this experiment we conclude that the supplement needs to be offered more frequently than once weekly to stimulate reproductive activity.
Prevention of ovine congenital goitre using iodine-releasing intraruminal devices: preliminary results
Authors: Mason RW , Laby R
Published: March 2005

Pregnant ewes in a goitre-prone area of northern Tasmania were treated with an intraruminal device designed to release a regular quantity of iodine into the rumen. Compared with untreated controls the treatment greatly increased the iodine concentration of ewes' milk and reduced thyroid enlargement in newborn lambs as determined by palpation and histological scores, thyroid weights and thyroidlbody weight ratios.
Restricted feeding of egg-strain chickens during growth and throughout an extended laying period
Authors: Robinson D , Horsnell G , McMahon PJ
Published: March 2005

White Leghorn x Australorp crossbred pullets were either fed ad libitum or given restricted access to food from 8 to 20 weeks of age. Birds from each of these rearing treatments were thereafter distributed among five feeding regimes: ad libitum and four allowances representing reductions of 3, 6, 12 and 24 per cent of the food intake of the birds fed ad libitum throughout life. Biological and economic performance data were examined for the rearing period and for three periods of lay terminating at 66, 78 and 90 weeks of age. From 8 to 20 weeks of age the restrictively reared pullets ate 30.5 per cent less food, suffered 1.7 per cent higher mortality, cost 19 cents per bird less to rear and were 20.5 per cent lighter in weight at 20 weeks than the pullets fed ad libitum. Compared with ad libitum feeding, restricted feeding in the rearing period gave higher values for hen-housed egg production and hen-housed gross margin when food intake in lay was restricted by 0, 3 and 6 per cent, and lower values for these criteria when food intake in lay was restricted by 12 and 24 per cent. Birds whose food intake was restricted by 6 per cent in the laying period laid about 25 more eggs to 90 weeks of age than birds fed ad libitum in lay. Optimum slaughter time (age at which average gross margin per week was maximized) was at about week 90 for the ad libitum/12 per cent restriction and ad libitum/24 per cent restriction treatments, and between weeks 66 and 78 for all other treatments. The highest weekly average gross margin was achieved with the birds that were restrictively reared and restricted by 6 per cent throughout a laying period terminating at 78 weeks of age; at this stage their gross margin was $2.30 per bird higher than that of the birds fed ad libitum throughout life
Response by cattle grazing sorghum to salt-sulphur supplements
Authors: Archer KA , Wheeler JL
Published: March 2005

An experiment is reported in which cattle grazed fertilized sorghum x sudangrass. The sodium content of the forage was 0.006-0.014 per cent and sulphur 0.08-0.12 per cent (dry matter basis). Liveweight gain was increased by approximately 200 g head-1 day-1 by the provision of salt blocks containing 18 per cent sulphur (P < 0.01) and to a lesser extent by salt alone.
Hybrid vigour and lamb production. 1. Reproductive performance of the purebred and crossbred matings
Authors: McGuirk BJ , Bourke ME
Published: March 2005

An experiment was conducted at Cowra Agricultural Research Station, New South Wales, to determine the importance of hybrid vigour to the productivity of crosses between Border Leicester and Merino sheep. In five years, 1963 to 1967, Border Leicester (BL) and Merino (M) rams were paddock-joined to a mixed flock of ewes of both breeds for five weeks in March-April. The results of these purebred and crossbred matings have been compared. Cummulative weekly raddle counts were similar for both purebred mating groups (BL x BL and M x M) and by the end of joining over 95 per cent of ewes in both groups had been raddled. When the mating data for the Border Leicester ewes were examined, Merino rams raddled fewer ewes than did Border Leicester rams. This breed difference between rams was significant for the number of ewes raddled by the end of both the first and second week of joining (P < 0.05) and the difference in favour of the Border Leicester rams was still apparent at the end of joining (97 vs. 86 per cent, not significant). The reproductive performance of the Merino ewes (M x M) was superior to that of the- Border Leicesters (BL x BL), with 1.05 vs. 0.93 lambs born per ewe joined. The Border Leicester flock had higher incidences of both dry ewes (63.7 vs. 79.3 per cent ewes lambing of those joined) and multiple births (1.47 vs. 1.33 lambs born per lambing ewe). Because of the difference in the mating activity of the two Border Leicester ewe flocks (M x BL vs. BL x BL), the most reliable estimates of the relative performance of purebred and crossbred matings were given by the number of lambs born per lambing ewe, and the number of ewes lambing to first service. The crossbred matings were superior for both characteristics, by 4.6 and 5.7 per cent respectively, but neither difference was statistically significant.
Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 1. Pasture production
Authors: Shaw NH
Published: March 2005

Changes in the yield, botanical composition and chemical composition of a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.) were measured in a grazing experiment from 1966 to 1973. The 24 treatments were factorial combinations of two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing), three levels of molybdenized superphosphate (F0 = nil ; F1 = 125 kg ha-1 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) and four stocking rates. Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha 1 T.S. establishment by ground sowing was much more reliable than from aerial sowing, giving twice the average percentage frequency, and this proportion was maintained over years. High fertilizer improved establishment and the best legume stands were in the high fertilizer high stocking rate treatments. Total presentation yield of pasture was increased by fertilizer and reduced by high stocking rates. Over the last two years the means for March, adjusted by regression to the overall average stocking rate of 0.98 beasts ha-1, were 31 20,4020 and 5370 kg ha-1 for F0, F1 and F2 respectively, but these yields were reduced by ca 25 per cent for an increase of 0.5 beasts ha-1. H. contortus remained dominant and its mean contribution to total yield increased from 48 per cent in 1969 to 67 per cent in 1973. This proportion was reduced by 12.8 per cent over the range from 0.55 to 1.65 beasts ha-1, but high fertilizer had the opposite effect so that differences between the extremes low stocked F0 and high stocked F2 were small. The DM percentage yield of T.S. was strongly increased by fertilizer, and, most importantly, also by high stocking rates in the presence of fertilizer. Values for F0 treatments remained below 10 per cent, but in the final year values for F1 and F2 at the highest stocking rates were 36 and 27 per cent, respectively. Despite these large changes in T.S., there was overall stability of botanical composition. Phosphorus and nitrogen concentrations in T.S. and H. contortus were increased by superphosphate but there was an overall decline in potassium concentration. Soil phosphorus levels were greatly increased
Nitrogen and phosphorus nutrition of dryland grain sorghum at Katherine, Northern Territory. 3. Effect of nitrogen carrier, time and placement
Authors: Myers RJK
Published: March 2005

Different nitrogen carriers, and placements and strategies of application to dryland grain sorghum growing in a clay loam soil were compared in field experiments at Katherine, Northern Territory. The nitrogen carriers were ammonium sulphate, ammonium nitrate, urea and anhydrous ammonia ; placements were banding, mixing into the topsoil, and broadcasting; and strategies consisted of split application, and varying time of broadcasting. The rate used throughout was 50 kg N ha-1.Responses to the various treatments varied between the two seasons (1970-71, 1971-72) due to differing soil moisture conditions. There was a response to broadcasting nitrogen after emergence, giving higher grain yield and nitrogen yield than earlier broadcasting or application with the seed. Banded nitrogen (both seasons) and split nitrogen (one season) were superior to other methods of applying nitrogen with the seed. The only yield differences between sources of nitrogen were with broadcast application, where ammonium sulphate proved superior in one season, and with respect to apparent recovery of nitrogen by the crop, when the order ammonium nitrate > ammonium sulphate > urea was observed in both seasons. It is suggested that in this environment and on this soil, nitrogen is not particularly susceptible to volatilization, and broadcasting urea and ammonium fertilizer onto dry soil may retain nitrogen within the rooting zone, in comparison with nitrate, which is more susceptible to leaching. Incorporated fertilizer is more susceptible to nitrification and subsequent leaching, while banded nitrogen appears to resist nitrification and leaching.
Genetic variation in meat quality and the incidence of malignant hyperthermia syndrome in Large White and Landrace boars
Authors: McPhee CP , Takken A , D'Arcy KJ
Published: March 2005

Genetic variation in meat quality was investigated in Large White and Landrace boars in the Queensland boar performance testing station. An autosomal recessive gene of frequency 0.2 in Landrace but absent in Large White produced malignant hyperthermia syndrome (MHS) in 10 out of 206 Landrace boars given the halothane test. Muscle acidity was measured in 86 Large White and 92 Landrace carcases 1 hour (pH,) and 24 hours (pH,) after slaughter. In four Landrace litters which contained both normal and MHS boars, muscle pH was significantly lower in MHS than normal carcases. Averaged over loin, middle and neck sites of measurement, pH, values were 5.8 vs 6.3 (P < 0.01), and pH, values were 5.5 vs 6.0 (P < 0.05). The colour of the I. dorsi muscles was also paler in MHS than normal carcases (1.25 score points vs 2.5 points, P < 0.05). Excluding MHS carcases, heritability estimates of 0.33 � 0.31,0.46 � 0.30 and 0.3910.29 were obtained for pH,, pH, and colour score of the I. dorsi. There were no significant differences between the breeds in muscle acidity. Average values were 6.44 0 � 0.01 for pH, and 6.11 � 0.02 for pH,. Landrace had paler I. dorsi than Large White (2.6 points vs 2.8 points, P < 0.05). The use of meat quality measurements and the halothane test in selection programs is discussed.
Distribution in South Australia of Anguina funesta, the nematode associated with annual ryegrass toxicity
Authors: Fisher JM , Dube AJ , Watson CM
Published: March 2005

Rapid techniques, based on grinding ryegrass seedheads and extracting nematodes with a Baermann funnel, were developed to isolate Anguina funesta the nematode involved in annual ryegrass toxicity. From data on more than 500 samples, the distribution was found to be more widespread than the distribution of toxic pastures.
Growth rate effects on the chemical composition of the carcase and muscle tissue of sheep
Authors: Murray DM , Slezacek O
Published: March 2005

A study was conducted of the effects of a high (H), low (L), or high growth rate with an intermittent period of liveweight maintenance (HMH) on the chemical composition of both the whole half carcase and the standard muscle groups (SMG's) (Butterfield 1963). Animals in the three treatments were killed at common liveweights of 25, 30, 35 and 40 kg and compositional data compared by regression using analysis of covariance and the logarithmic transformation of the allometric equation. Significant differences were found in the regression slopes relating carcase water (HMH > H), protein (L > H, HMH) and chemical fat (H > HMH, L) to carcase weight indicating differential treatment effects on composition with increasing carcase weight. These differences could not be explained by corresponding differences in carcase muscle composition, which was similar in the three treatments except for protein (H > HMH). Chemical analyses of the SMG's showed that muscle group protein was greater in the H than in the HMH treatment for all groups, although significantly so only for SMG's 3, 4, 6, 8 and 9. Except for this difference in protein content, relatively minor treatment differences were found in muscle group composition. The similarity of muscle group composition in the H and L treatments provides a theoretical basis for the prediction of total muscular composition from that of a single muscle group in carcases from continuously grown animals.
Lucerne survival in south-east Queensland in relation to grazing management systems
Authors: Leach GJ
Published: March 2005

Survival of lucerne plants and changes in the row cover of lucerne in relation to grazing management were studied in an experiment at Lawes, south-east Queensland, from 1971 to 1977. There were six grazed treatments (resting for 32 or 44 days combined with grazing for 4 or 16 days, resting for 56 days with grazing for 4 days, and resting for 40 days with grazing for 8 days) and three mown treatments (mown every 36,48 or 60 days). All grazing was with sheep, at a stocking rate equivalent to 20 ha-1 on a year round basis. The experiment was irrigated when necessary to ensure that moisture at least equivalent to the long-term average monthly rainfall was received. There were about 42 lucerne plants m-2 in November 1971 and about 13 plants m-2 in October 1977; thus lucerne survival was good in all treatments, with stands losing about five plants m-2 annum-1. Management effects were small, with survival and row cover becoming slightly better as the interval between grazings or mowings increased from 32 to 60 days. Grazing for four days gave poorer survival than either grazing for 8 or 16 days or mowing. Perennial grass cover was much greater with four-day grazing than in the other treatments. Inspection at the end of the experiment showed nearly all crowns to have moderate symptoms of crown rot caused by Colletotrichum trifolii. The need for critical attention to the interaction between moisture supply, grass invasion and disease accumulation in maintaining lucerne stands in sub-tropical environments is discussed.
Clover and crop production under 13- to 15-year-old Pinus radiata
Authors: Anderson GW , Batini FE
Published: March 2005

A thirteen-year-old Pinus radiata plantation was thinned to 143 or 261 stems ha-1 and pruned to 6 m at Mundaring, Western Australia. The production of the Daliak, Seaton Park and Woogenellup cultivars of subterranean clover sown under the trees and on an adjacent area under pasture only was measured for two years. The yields of oats and lupins sown for two successive years following one year of clover pasture were also measured. No seedling establishment problems were encountered and healthy, productive pastures resulted. In the first year, Daliak was inferior to the other cultivars for both herbage and seed production. Seed yields were highest under the low tree density. By the third growing season herbage yields had fallen under the trees to 84% of the control pastures (4800 kg ha-1) at 143 stems ha-1 and 68% at 261 stems ha-1. The yields of oats were usually higher on the control plots but those of lupins seldom so.
Water-soluble polysaccharide in nine commercial sweet corn cultivars and its suitability for estimating kernel maturity
Authors: Darbyshire B , Muirhead WA , Henry RJ
Published: March 2005

The water-soluble polysaccharide content of nine sweet corn cultivars planted at three different times was determined. The use of water-soluble polysaccharide to estimate maturity of sweet corn cobs for freezing was substantiated by comparing water-soluble polysaccharide with moisture content of the nine cultivars. When cobs matured under the relatively higher temperatures of the earlier sowing dates, there was a more rapid increase in water-soluble polysaccharide in relation to loss in moisture.
Induction of early cropping of guava seedlings in a closely planted orchard using urea as a defoliant
Authors: Chapman KR , Saranah J , Paxton B
Published: March 2005

A problem with young guava trees is that they carry light and variable crops, and both young and old trees flower and fruit over protracted periods. A 25 % urea spray plus wetting agent applied to 15-month-old guava seedlings of the variety GA9-EX39, produced a three-fold increase in yield over untreated trees at 22 months of age. In addition, the harvesting period was shortened from 15 weeks for control trees to four weeks for sprayed trees. Mean yields for sprayed trees were 34.69 kg, equal to 27.93 t ha-1 at a plant density of 805 trees ha-1; yields for unsprayed trees were 10.85 kg, or 8.73 t ha-1. Such yields exceed those attained in other countries at a similar age. Fruit size was not affected by the urea spray compared with controls, and the second crop 12 months later, also induced with urea sprays, was 40% more than the first. The use of urea as a defoliant spray permits early cropping of young, densely planted orchards and thus faster economic returns. In addition, shortening of the harvest period reduces labour costs and allows better economic control of fruit fly, a major pest of guava.
Effect of duration and pattern of underfeeding in early lactation on milk production and reproduction of dairy cows
Authors: Grainger C , Wilhelms G
Published: March 2005

Eighty cows of mixed breeds were fed so that they calved in moderate condition, and were then strip-grazed at different rates over the first ten weeks of lactation. Two levels of feeding were used factorially ; either ad libitum pasture intake (H) or an allowance of pasture which resulted in an intake of 7 kg of pasture dry matter cow-1 day-1 (L), for the first or second five-week period. After ten weeks, all cows were grazed as one group as well as seasonal conditions permitted. The effects of five-week periods of underfeeding on milk, milk fat and protein yield were equal and additive over the first ten weeks of lactation, HL and LH groups producing 11 kg and LL group 22 kg less milk fat than the HH group. Residual effects, however, from week 11 to the end of lactation differed markedly between treatments, the LH group producing the same as, but HL and LL groups producing 9 and 21 kg less than, the HH group. Residual effects of only 0.7 and 1.0 times the immediate effect were recorded for underfeeding in the first five and ten weeks of lactation, respectively. Cows underfed in early lactation gained more liveweight in later lactation at the expense of milk yield. An extra 10 kg pasture dry matter was required in early lactation to give an extra kilogram of milk fat over the lactation. The calving to conception interval in the LL group was 18 days longer than in the HH group (P < 0.05). The delay was associated with both a longer post-partum anoestrus and a higher number of services per conception. There was no effect of stage of underfeeding (HL vs LH) on reproductive performance. The poor understanding of factors affecting residual effects from underfeeding in early lactation is highlighted. As pattern of underfeeding has little effect on lactation performance, this gives the farmer considerable flexibility in allocating feed supplies in early lactation.
Hybrid Bermudagrass compared with Kikuyu and common couch in coastal New South Wales. 1. Establishment, dry matter production and persistence
Authors: Andrews AC , Crofts FC
Published: March 2005

Four ecotypes of hybrid Bermudagrass (Cynodon dactylon) were compared with common couch (C. dactylon) and kikuyu (Pennisetum clandestinum) at five sites in coastal districts of New South Wales. The sites were Grafton and Coaldale (Lat. 30�S), Mitchells Island (Lat. 32�S) and Richmond and Badgerys Creek (Lat. 34�S). Hybrid Bermudagrass ecotypes 6389 and 692 were established quickly at all sites while ecotypes 71 9 and 632 were satsifactory. Kikuyu was strong at all sites except Grafton but the rate of establishment of common couch was poor. At the frost-free sandy site of Mitchells Island, Bermudagrass ecotypes 719, 692, 6389, and 632 outyielded kikuyu by 75, 65, 65 and 35%, respectively. However, at Grafton and Coaldale, the highest yielding Bermudagrass ecotype, 719, had only 35% higher production than kikuyu. At the frost prone southern sites of Richmond and Badgerys Creek, the annual production of kikuyu was equal to that of ecotypes 719, 6389, 692 and 632. Common couch yields were equal to kikuyu at all sites except at Richmond. At Mitchells Island, the hybrid Bermudagrasses outyielded kikuyu in spring, summer and early autumn but in the late autumn kikuyu had equal and sometimes higher growth rates than the best Bermudagrasses. In winter, the growth of both species was negligible, although kikuyu, unlike the Bermudagrasses, did produce some new shoots at the base of the sward. Data on persistence under grazing were collected from only three of the sites but trends were similar to establishment. Ecotype 6389 had the highest persistence rating of the Bermudagrasses. Kikuyu failed at the poorly drained sandy site of Grafton but remained strong at the other sites. It was concluded that hybrid Bermudagrasses were of potential value for pastures in New South Wales, especially for sites with sandy soils and low frost incidence.
Hybrid Bermudagrass compared with Kikuyu and common couch in coastal New South Wales. 2. Crude protein content, and estimated in vivo digestibility
Authors: Andrews AC , Crofts FC
Published: March 2005

In a previous study it was found that four ecotypes of hybrid Bermudagrass (Cynodon dactylon) (ecotypes 632, 692, 6389 and 719) outyielded kikuyu (Pennisetum clandestinum) and common couch (C. dactylon) at three sites in New South Wales. The relative feeding value of these grasses was compared in terms of their crude protein content and organic matter digestibility when grown for two years at Mitchells Island, New South Wales (Lat. 32�S). Over the two years, kikuyu had the highest crude protein content, averaging 124 g kg-1 compared with 11 6,115,ll 1, 103 and 108, respectively, for the ecotypes 632, 692, 6389, 719 and common couch. Mean digestibilities of ecotypes 632, 692, 6389 and 719 were 63, 60, 61 and 58% respectively, compared with 60% for kikuyu and 57% for common couch. The crude protein content and digestibility of all ecotypes tended to be highest in early spring and late autumn and lower in summer, trends which were opposite to dry matter production rates. It was concluded that the quality of hybrid Bermudagrass forage was comparable with that of other sub-tropical grasses now being used in subcoastal New South Wales. However, careful pasture management would be required to maintain herbage quality during summer.
Replacing a nitrophilous weed association with Phalaris aquatica and Medicago sativa on non-arable land
Authors: Campbell MH , McDonald WJ
Published: March 2005

In an experiment (1974 to 1978) carried out on the Central Tablelands of New South Wales, the effects of nine herbicide treatments, two intervals between spraying and sowing, and sowing in late autumn, on the ability of Medicago sativa, Phalaris aquatica and Vicia dasycarpa to establish, develop and replace a nitrophilous weed association (broadleafed plants, annual grasses and native perennial grasses) were measured. Herbicide treatment of the resident species was necessary for the establishment and development of M. sativa and P. aquatica but not for the establishment of V. dasycarpa. Successful treatments were: 2,2-DPA + amitrole, 2,2-DPA + 2,4-D, paraquat + diquat and glyphosate. Intervals of 7 and 28 days between spraying and sowing had no differential effect on establishment. Sowing in late autumn resulted in successful establishment of all species. Over four years the percentage ground cover of sown species on the herbicide treatments increased from 0% in early 1974 to 49% in late 1978; the control treatment rose from 0% to 12%. The percentage ground cover of the nitrophilous weed association on the herbicide treatments decreased from 76% in 1974 to 27% in 1978; the control fell from 76% to 68%. The experiment demonstrated that a nitrophilous weed association can be replaced with perennial pasture species on non-arable land on the Central Tablelands by using aerial techniques. Further research is needed to determine the optimum time of spraying and sowing.
Effect of time and rate of application of herbicides on serrated tussock (Nassella trichotoma) and improved pasture species. 1. Glyphosate and 2,2-DPA
Authors: Campbell MH , Gilmour AR
Published: March 2005

The effect of three rates of glyphosate (1, 3 and 5 kg a.i. ha-1) and two of 2,2-DPA (21 and 33 kg a.i. ha-1), each applied in October 1972, January 1973, April 1973 and July 1973, on serrated tussock and associated improved species (Phalaris aquatics, Trifolium repens, T. subterraneum) was ascertained in an experiment near Bathurst, New South Wales. The effect of the herbicide treatments on the improved species was measured in October 1973 and the percentage kill of serrated tussock recorded in May 1974. Increasing the rate of glyphosate increased the percentage kill of serrated tussock (up to a mean of 77% with 5 kg a.i. ha-1) ; time of application had no significant effect on percentage kill. No glyphosate treatment resulted in a commercially acceptable kill of serrated tussock (above 90%). Thus the herbicide was inferior to 2,2-DPA which produced a 95% kill when applied in summer. P. tuberosa was more tolerant of glyphosate and 2,2-DPA than serrated tussock and recovered from all treatments. T. repens and T. subterraneum recovered from glyphosate and 2,2-DPA applied in summer. Thus it proved possible to selectively remove a large proportion of a serrated tussock infestation with 2,2-DPA or glyphosate, applied in summer, without permanent damage to the associated improved species.
Nitrogen and phosphorus requirements of wheat sown by minimum tillage into rice stubble and the effects of rice stubble treatment
Authors: Dear BS , McDonald DJ , Falconer G
Published: March 2005

Egret wheat was sown into rice stubble using a minimum cultivation technique called seedavation. Nitrogen was surface applied as sulphate of ammonia in 1974 and ammonium nitrate in 1975 at 0,60 and 120 kg N ha-1. Phosphorus as single superphosphate was drilled with the seed at 0 and 17.5 kg P ha-1. The effects of burning, incorporating and removing rice stubble were compared. Large grain yield responses to nitrogen were achieved with yields up to 5 t ha-1 despite the use of minimum tillage. Tiller numbers were highly correlated with yield. No yield response to phosphorus was obtained. Low protein levels (less than 10%) suitable for biscuit wheat were obtained even at the high nitrogen fertilizer rates. The effect of stubble treatment varied between years; in 1974 it had no effect on yield; however, in 1975 removing or incorporating stubble reduced yields compared with burning the stubble. These results indicate that in rice growing areas a significant rise in wheat yields can be achieved through the use of higher nitrogen fertilizer rates.
Feeding whole or cracked wheat or lupins to beef cattle, and a comparison between whole wheat and oats
Authors: Axelsen A , Nadin JB , Crouch M , Edwards CBH
Published: March 2005

Young cattle were fed whole or cracked wheat with 20% lucerne hay, either ad lib or at a medium level, restricted to approximately 2.3% of fasted liveweight. Over 70 days, animals fed ad lib consumed 3.2 and 2.7% of their mean fasted liveweight on whole and cracked wheat respectively, and weight gains on the ad lib diet were higher than those on the medium feeding level. Cracked wheat gave 32% higher liveweight gains than whole wheat when feeding was restricted to 2.3% of fasted liveweight. However, animals offered whole wheat ad lib consumed 24% more feed, and attained the same rate of gain as those on cracked wheat. Feed conversion ratios were 7.0 and 8.8 for cracked and whole wheat, respectively. It would be economical to crack wheat only if the cost of double handling and processing 6.6 t of wheat was less than the cost of an extra 2.0 t of whole wheat. Animals fed lupins for 42 days did not consume as much as those fed wheat, but gains were only slightly lower. Lupins may be better suited to increasing the protein content of mixed rations. Only when animals were fed ad lib was there some slight advantage in adding urea to wheat rations. When whole wheat and whole oats were fed at the same restricted level, liveweight gains were higher on oats and feed conversion ratio was lower.
Response of three strains of egg-type pullets to three feed restriction regimes imposed during rearing
Authors: Abu-Serewa S
Published: March 2005

The productivity of heavy-, medium- and light-weight White Leghorn x Australorp pullets (216 of each strain) was established on three feed restriction regimes. The pullets were either restricted from 6 to 21 weeks of age to 80% of feed intake of pullets fed ad libitum, restricted in feeding time to 6 hours in every 48 from 6 to 21 weeks, or fed a diet containing 10% protein from day-old to 16 weeks of age. All restricted pullets ate between 19 and 37% less feed during rearing, were between 11 and 34% lighter at 21 weeks of age, and attained 50% production by 10 to 32 days later than pullets fed ad libitum. Strains differed in their responses to feed restriction as measured by mean body weight at 21 weeks, feed intake during lay, and feed per dozen eggs. Strain x rearing interactions were not observed for rate of lay, mean egg weight, total egg mass or rate of mortality. The biological responses were analyzed in economic terms using a computer simulation model. Restricting the feed intake of the heavy strain by any of these methods was more profitable, at ruling 1976 prices, than ad libitum feeding, because of the saving in feed cost and marked improvement in productivity. Performances were not improved by restriction in the light strain pullets, but feed cost was reduced by all three methods. With the medium strain, limiting the quantity of feed was more profitable than the other two methods.
Influence of plant population on yield and yield components of irrigated sunflower in southern New South Wales
Authors: Thompson JA , Fenton IG
Published: March 2005

Three experiments conducted in the Murrumbidgee Irrigation Area of southern New South Wales examined the influence of plant population on the yield and yield components of irrigated sunflowers. Populations ranged from 25,000 plants ha-1 to 140,000 plants ha-1. Furrow irrigation was employed with rows spaced 76 cm apart. In two of the experiments the wide range of plant populations examined had little effect on seed yield. Individual seed weight (g 1000-1) and seed number per head interacted with plant population so that seed yield was only marginally affected. In the remaining experiment, insufficient total dry matter production without improved harvest index prevented the attainment of an acceptable seed yield. There was a consistent trend for harvest index to fall with increasing plant population. Values recorded ranged from 0.36 to 0.23. Plant population had little effect on oil percentage. A plant population of 50,000 plants ha-1 is suggested as a minimum recommendation for irrigated sunflowers in southern New South Wales.
Comparison of trellises and pruning levels for Sultana vines in the Murray Valley
Authors: Baldwin JG , Bleasdale GE , Cadman RS , Keens IL
Published: March 2005

Five trellising systems for irrigated sultana vines under conventional district spacing have been compared in a field trial at Mildura, Victoria. They were 'narrow T', 'narrow T, one foliage wire', 'narrow T, two foliage wires', 'narrow double T' and 'wide T'. For the first two years of the trial, pruning was to six 14-node canes for each vine, then for the next four years three levels of pruning were imposed on the trial as split-plot treatments-'severe'' (as before), 'medium' (averaging about eight 14-node canes) and 'light' (averaging about ten 14-node canes). There were no differences in yield due to the trellising treatments until differential pruning was introduced. Then there were significant differences in dried fruit yield due to trellising, regardless of pruning, in the two good harvests, and due to pruning in all four seasons. Overall the two best treatments were 'light' pruning with 'narrow T, two foliage wires' or with 'wide T', both yielding a quarter more than the conventional 'severe' pruning with 'narrow T'. The differences are seen as due to more bunches per vine with 'light' pruning, and to the ability of 'narrow T, two foliage wires' and of 'wide T' to support without crowding the greater number of bunches put down.
Effects of active immunization against androstenedione or oestrone on oestrus, ovulation and lambing in Merino ewes
Authors: Martin GB , Scaramuzzi RJ , Cox RI , Gherardi PB
Published: March 2005

Merino ewes were immunized against bovine serum albumin (BSA), or oestrone or androstenedione, conjugated to BSA. Immunization against oestrone and androstenedione elevated the mean number of ovulations per ewe ovulating (ovulation rate) from 1.2 to 1.5 and 2.3, respectively. The higher ovulation rate was not reflected in more lambs born per ewe lambing (1.12-1 .I 6 for all groups). The frequency of ovulation and oestrus was depressed in ewes immune to oestrone, and there was a high frequency of abnormalities in the reproductive tract. These effects of immunization were not as frequent in ewes immune to androstenedione. There was no relation between titre and any measure of reproductive performance. The use of immunization against ovarian steroids to improve the reproductive efficiency of commercial flocks is not justified without further investigation.
The effect of adding a feed flavour to the diets of young pigs before and after weaning
Authors: King RH
Published: March 2005

Sixteen sows and their progeny were allotted to treatments in a 23 factorial experiment involving two levels of feed flavour (0 and 50 ppm of Firanor No. 24) in each of the sow, creep and starter diets. Weaning occurred at a mean piglet age of 26.9 days and observations continued for 31 days after weaning. The feed flavour, when added to the sow diet, was incorporated in sow's milk; milk from one sow fed the flavoured diet contained 9 ppm of Firanor No. 24. The addition of the feed flavour to the creep diet failed to improve creep feed consumption or weaning weight; the average daily creep feed intake and daily growth rate prior to weaning being 47.8 g/head and 207 g/head, respectively. During the postweaning period, pigs that were weaned from sows receiving the flavour and then given the flavoured starter diet ate more feed (P<0.05) and tended to grow faster (839 and 400 g day-1, respectively) than pigs given the unflavoured starter diet, or those weaned from sows given no flavour; their average feed intake and growth rate being 764 and 362 g day-1, respectively.
Deficiencies of sodium and sulphur in sorghum forage for animal production in eastern Australia
Authors: Wheeler JL , Hedges DA
Published: March 2005

The response to supplements of sodium and sulphur by beef and dairy cattle and sheep grazing sorghum is briefly reviewed. Analysis of 95 samples of sorghum forage obtained from 30 locations in eastern Australia indicated that a high proportion contained insufficient sodium or sulphur, or both, for maximum animal production : 78% contained <0.03% sodium, 24% contained <0.1% sulphur and 43% had nitrogen/sulphur ratios greater than 15 : 1
Populations of honeybees pollinating sunflower crops on the central Darling Downs, Queensland
Authors: Radford BJ , Rhodes JW , Nielsen RGH
Published: March 2005

Populations of honeybees pollinating flowering sunflower heads in 42 fields on the central Darling Downs were recorded. Mean populations ranged from 21.9 to 171.2 bees per 100 flowering heads. A calculated maximum requirement for the region during fine weather amounted to 24 bees per 100 flowering heads. Populations were positively correlated with number of hives within 3 km of fields. In 18 fields with no hives within 3 km, mean populations (apparently from feral colonies) ranged from 21.9 to 130.9 bees per 100 flowering heads. These populations showed no significant correlation with area of crop in the range 2-95 ha. In another study on the central Darling Downs, seed set was not significantly correlated with number of hives within 3 km, indicating that feral bee populations were adequate for sunflower pollination.