Higher weaning weight improves postweaning growth and survival in young Merino sheep

2008 ◽  
Vol 48 (7) ◽  
pp. 966 ◽  
Author(s):  
S. Hatcher ◽  
J. Eppleston ◽  
R. P. Graham ◽  
J. McDonald ◽  
S. Schlunke ◽  
...  
Keyword(s):  
Growth Rates ◽  
Compensatory Growth ◽  
New South ◽  
Late Pregnancy ◽  
Parasite Control ◽  
Weaning Weight ◽  
Growth And Survival ◽  
Merino Sheep ◽  
South Wales ◽  
Pregnancy And Lactation

Two monitoring projects were conducted to investigate weaner mortality in commercial Merino flocks in the Yass and the Central Tablelands Rural Lands Protection Boards located in the Southern Tablelands agricultural region of New South Wales. The projects were conducted in Yass in 2005 and in the Central Tablelands in 2006. A random sample of weaners from four flocks in the Yass board and 11 flocks in the Central Tablelands board were regularly weighed, growth rates were calculated after weaning and survival was determined by the continuing presence of an individual weaner at subsequent weighing activities. Weaning weight was the most important factor in determining postweaning liveweight, growth rates and survival with the significant impact of weaning weight on liveweight persisting for up to 6 months after weaning. Despite the lightest weaners being capable of considerable compensatory growth given sufficient postweaning nutrition, the lightest 25% of weaners were more than twice as likely to die as heavier weaners. A focus on ewe nutrition and parasite control during late pregnancy and lactation will allow Merino producers to achieve higher weaning weights that will set their weaners up for strong postweaning growth with a decreased likelihood of mortality.

Genetic and phenotypic parameters for pre-weaning growth and weaning conformation of Angus cattle

1978 ◽  
Vol 29 (2) ◽  
pp. 373
Author(s):  
R Barlow ◽  
EB Dettmann
Keyword(s):  
Least Squares ◽  
New South ◽  
New South Wales ◽  
Genetic Correlations ◽  
Components Of Variance ◽  
Weaning Weight ◽  
Environmental Correlations ◽  
Angus Cattle ◽  
South Wales

Weaning weight (WW) and conformation score (CS) records on Angus calves from four New South Wales herds were analysed by least-squares procedures. Paternal half-sib components of variance and covariance were used to obtain estimates of heritabilities of various measures of growth and cs, as well as genetic, phenotypic and environmental correlations. Estimates of the heritabilities of measures of growth ranged from 0.20 (all data) to 0.24 when derived from heifer data only. The heritability of cs was 0.24 when the data were adjusted for ww, and 0.19 when no covariate was included in the analysis. All correlations among different measures of growth were positive and close to unity. There were small positive phenotypic and environmental correlations (0.19 to 0.36) and small negative genetic correlations between ww and cs (–0.02 to –0.41).

Effect of fitting sheep covers and injection of a mineral supplement on the brightness, clean colour and photostability of wool grown by grazing Merino sheep

2016 ◽  
Vol 56 (1) ◽  
pp. 18
Author(s):  
S. Hatcher ◽  
J. W. V. Preston
Keyword(s):  
Factorial Design ◽  
Genetic Resource ◽  
New South ◽  
Genetic Selection ◽  
Combined Effect ◽  
Mineral Supplement ◽  
Merino Sheep ◽  
Treatment Groups ◽  
South Wales ◽  
Selection For

Wethers sourced from a Merino genetic resource flock, selected on the basis of their measured wool clean colour at 2 years of age, were stratified on the basis of clean colour and allocated to one of four treatment groups in a 2 × 2 factorial design. The aim was to investigate the effect of coating the fleece and administration of a commercial mineral supplement on brightness, clean colour and photostability over a 12-month period when run on the Central Tablelands of New South Wales. Coating the fleece significantly improved both the brightness and clean colour of the fleece (P<0.001, by 4 and 0.5 T units, respectively), but had no effect on the photostability of the two traits. The mineral supplement had no significant impact on the colour or photostability traits and there was no evidence of an interaction between coating the fleece and the mineral supplement. Although the improvements in brightness and colour arising from coating the fleece complemented the predicted responses to genetic selection for these two traits, the combined effect would not be sufficient to replace the routine use of oxidative bleaching during processing.

Merino ewe and lamb performance in the Central Tablelands of New South Wales following joining in March-April or June-July

1988 ◽  
Vol 28 (5) ◽  
pp. 561 ◽  
Author(s):  
HL Davies ◽  
E Devaud
Keyword(s):  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Late Pregnancy ◽  
Stocking Rate ◽  
South Wales ◽  
Group Number ◽  
Nutritional Advantage ◽  
June July ◽  
Group 1

A March-April joining of Merino ewes was compared with a June-July joining in central New South Wales at a low stocking rate on subterranean clover based pastures over 3 years. In all years, ewes joined in June were heavier (P < 0.05) than ewes joined in March (55 v. 52 kg). Liveweights at the start of lambing and liveweight change from joining to lambing were also high and favoured the later lambing group. The proportion of ewes lambing (97% March v. 93% June) and proportion of ewes twinning (29% March v. 20% June) were not significantly different between the 2 groups, but consistently favoured the March-April joining. Perinatal mortality was low (9.4% March v. 7.1% June) and not significantly different between the 2 groups, but was consistently lower in the June joined group. Number of lambs weaned per 100 ewes joined was also not significantly different, but was higher each year in the March joined group (1 13% March v. 105% June). The growth rate of the lambs (both singles [24% greater, 248 v. 200 g/day] and twins [37% greater, 2 13 v. 155 g/day]) was consistently in favour of March joined ewes. Mean greasy fleece weights of the ewes were not significantly different between the 2 groups, but were in favour of the late joined group (4.83 v. 4.50 kg). Time of joining significantly affected liveweights and greasy and clean fleece weights of the progeny at the shearing in the year following their birth in favour of March joining. These data suggest that, despite a nutritional advantage to the ewes in late pregnancy and milder weather at lambing with a June-July joining, a March- April joining is the preferred option on the Central Tablelands of New South Wales.

The growth rates of weaned lambs grazing three legume-based pastures during summer

1980 ◽  
Vol 20 (102) ◽  
pp. 9
Author(s):  
ID Sanderson ◽  
JD McFarlane ◽  
WR McManus
Keyword(s):  
Growth Rates ◽  
New South ◽  
New South Wales ◽  
Red Clover ◽  
Experimental Period ◽  
Poor Growth ◽  
Average Growth ◽  
The Poor ◽  
South Wales ◽  
Lamb Growth

An experiment was conducted on the Central Western Slopes of New South Wales with Dorset Horn x Merino lambs to assess their liveweight gains during summer when weaned on to a lucernebased pasture under dryland conditions, and when weaned on to irrigated lucerne and red clover pastures. Lambs grazing irrigated lucerne, irrigated red clover and dryland lucerne had average growth rates of 155, 178 and 124 g day-1/head, respectively, throughout the 106 day experimental period. The poor growth rates of lambs on the dryland lucerne were apparently due mainly to the low digestibility of the dry feed on offer as a result of low rainfall, which also caused feed supply to be limiting during part of the experimental period. Lamb growth and intake data suggest that the diets selected from the red clover were of higher digestibility than those selected from the irrigated lucerne. It was concluded that irrigated red clover and irrigated lucerne provided useful diets for young lambs in this environment, although the growth rates achieved were less than reported elsewhere for these species in cooler climates. Growth rates achieved by lambs grazing dryland lucerne were less satisfactory for prime lamb production.

Hybrid Bermudagrass compared with Kikuyu and common couch in coastal New South Wales. 1. Establishment, dry matter production and persistence

1979 ◽  
Vol 19 (99) ◽  
pp. 437 ◽  
Author(s):  
AC Andrews ◽  
FC Crofts
Keyword(s):  
Growth Rates ◽  
Dry Matter ◽  
Cynodon Dactylon ◽  
New South ◽  
New South Wales ◽  
Sandy Soils ◽  
The Other ◽  
Potential Value ◽  
South Wales ◽  
Matter Production

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.

Water consumption and water turnover of sheep grazing semiarid pasture communities in New South Wales

1974 ◽  
Vol 25 (2) ◽  
pp. 339 ◽  
Author(s):  
AD Wilson
Keyword(s):  
Water Consumption ◽  
Mineral Content ◽  
New South ◽  
New South Wales ◽  
Supplementary Data ◽  
Sheep Grazing ◽  
Water Turnover ◽  
Merino Sheep ◽  
South Wales ◽  
Reduced Water

The water consumption and water turnover of Merino sheep grazing on three natural pastures of south-western New South Wales were recorded throughout 1 year, and supplementary data on the water consumption of sheep on some pastures were collected for a further 2–4 years. On Danthonia caespitosa grassland, water was consumed for up to 7 months each year over the summer months. Maximum intakes were 3–3.5 litres per sheep per day, but this was reduced for 1–2 weeks after falls of rain of less than 25 mm and for longer periods after heavier falls. The provision of shade reduced water turnover by a maximum of 0.3–0.5 litre per day on some occasions only, which indicates that shade is of little importance to woolled sheep. On the saltbush (Atriplex vesicaria) and belah-rosewood (Casuarina cristata-Heterodendrum oleifolium) communities, water intakes were up to 6–7 litres per day in summer. In the particularly dry summer of 1972–73, water intakes of the sheep on saltbush rose to 12 litres per day for several months. The higher water intakes of these sheep were attributed mainly to the high mineral content of the Atriplex and Bassia spp. eaten by them, although the sheep on the belah-rosewood community were also in a hotter environment. In contrast to the sheep on Danthonia, those on the bush communities consumed significant amounts of water throughout the winter in years of low rainfall.

Sizes and ages in commercial landings with estimates of growth, mortality and yield per recruit of yellowtail kingfish (Seriola lalandi) from New South Wales, Australia

2004 ◽  
Vol 55 (5) ◽  
pp. 489 ◽  
Author(s):  
John Stewart ◽  
Douglas J. Ferrell ◽  
Bryan van der Walt
Keyword(s):  
Growth Rates ◽  
New South ◽  
New South Wales ◽  
Fork Length ◽  
South Wales ◽  
Current Minimum ◽  
Yellowtail Kingfish ◽  
Seriola Lalandi ◽  
Size At Age ◽  
Yield Per Recruit

The size and age compositions of yellowtail kingfish (Seriola lalandi) were studied in commercial landings in New South Wales, Australia between 1998 and 2000. The fishery was dominated by fish smaller than 65 cm fork length and these fish were estimated to be 2 and 3 year olds. Estimates of growth rates were made using size-at-age data from sectioned otoliths. The oldest yellowtail kingfish found was 21 years and measured 136 cm fork length. There were no differences in the growth rates between regions or between sexes. Yellowtail kingfish grow rapidly and reach their minimum legal length of 60 cm total length at around 2 years of age. These estimates showed that previous studies, which estimated ages using whole otoliths, may have underestimated the ages of older yellowtail kingfish. Total instantaneous mortality rates generated from catch curves ranged between 0.43 and 0.79. Yield per recruit models suggest that the population is currently growth overfished. The information provided is used to discuss the suitability of the current minimum legal length for yellowtail kingfish in New South Wales.

Growth and age validation of Rainbow Trout, Oncorhynchus mykiss (Walbaum)' in Lake Eucumbene, NSW

1992 ◽  
Vol 43 (5) ◽  
pp. 1033 ◽  
Author(s):  
RA Faragher
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Growth Rates ◽  
Age Estimation ◽  
New South ◽  
Age Validation ◽  
Scale Reading ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
South Wales ◽  
Second Year

Growth rates of finclipped rainbow trout (Oncorhynchus mykiss) released into Lake Eucumbene, New South Wales, at an age of 0+ years were examined for each year between 1986 and 1988. Traps and nets yielded significant numbers of marked fish for validation of age estimation and length backcalculation from scale reading. Poor recognition of the marks by anglers was confirmed, indicating that survival of the fish was higher than was implied by angling returns. The diffuse nature of the second annulus in scales provided initial difficulty in ageing, particularly because of a similarly diffuse false check formed during the second year. Care was required in separating the annuli after asymptotic growth was reached (3 years), Growth rates in Lake Eucumbene were comparable with those found in studies in Tasmania and Victoria. Back-calculated lengths were in agreement with those from fish of known ages. The presence of finclipped fish aged 2 + and 3 + years in a spawning population confirmed that stocked fish contributed to the spawning stocks. The study reconfirms the importance of validation of ageing techniques in fisheries investigations.

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