Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 2. Reproductive activity, liveweight and wool production of ewe lambs

1995 ◽  
Vol 35 (8) ◽  
pp. 1075 ◽  
Author(s):  
NM Fogarty ◽  
DG Hall ◽  
AR Gilmour
Keyword(s):  
Degrees Of Freedom ◽  
Fibre Diameter ◽  
High Standard ◽  
Reproductive Activity ◽  
Ovulation Rate ◽  
Late Winter ◽  
Production Traits ◽  
Wool Production ◽  
Ewe Lambs ◽  
The Difference

Liveweight, wool production, oestrous expression and ovulation rates of 260 Trangie Fertility Merino x Dorset (TD) and 278 Booroola Merino x Dorset (BD) ewes born in late winter-spring over 4 different years were analysed from post-weaning to first joining at about 19 months of age. The percentage of ewes expressing oestrus reached a peak of 68% in May-June, declined to 7% in September and rose to 93% in January prior to first joining. The proportion of ewes ovulating followed a similar pattern. The proportion of ewes expressing oestrus in March, May and June increased (P<0.001) substantially with increasing age and liveweight, which accounted to some extent for the large differences in oestrous activity between years. There was little difference between the strains in proportion of ewes expressing oestrus or ovulating throughout the year. TD ewes were heavier (P<0.001) than BD ewes, the difference increasing from 2 to 4 kg at 7 and 19 months. They also produced 0.3 kg more clean wool which had 1.2 pm higher fibre diameter (P<0.001). Ovulation rate, measured in each of 2 years at 2-monthly intervals, increased from 7 to 19 months of age. BD ewes had a higher ovulation rate than TD ewes on all occasions, and the difference averaged +0.4 ovulations. The mean ovulation rate in February (19 months) for ewes born over 3 years was 2.1 ova for BD and 1.4 ova for TD ewes (P<0.001). Based on subsequent ovulation rate and litter size records, 42% of the BD ewes were identified as carriers of the FecB gene. Ages at first oestrus and ovulation varied considerably between years (P<0.001). There was no difference between the strains in age at first oestrus, although BD ewes first ovulated at a younger age (P<0.05) than TD ewes. The stud of origin of the dam, dam age, dam parity and birth type were not significant for any reproduction trait. There was significant (P<0.001) variation in liveweight due to the origin of the dam. Half-sib estimates of heritability for ewe liveweight, ovulation rate at various seasons and wool production traits were generally high with relatively high standard errors as they were based on 23-40 degrees of freedom for sire.

Assessing Wiltshire Horn-Merino crosses. 1. Wool shedding, blowfly strike and wool production traits

1994 ◽  
Vol 34 (6) ◽  
pp. 717 ◽  
Author(s):  
KA Rathie ◽  
ML Tierney ◽  
JC Mulder
Keyword(s):  
Fibre Diameter ◽  
The Other ◽  
Wool Fibre ◽  
Production Traits ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Fleece Weight ◽  
Head Neck

Wiltshire Horn-Merino (WH-M) crosses of 1/2, 5/8 and 3/4 Merino content were compared over 10 years for wool shedding, blowfly strike frequency and wool production traits. Merinos and 1/2 Merino WH-M were compared over 4 years. For wool production traits, 1/2 and 5/8 Merino WH-M ewes were compared to Border Leicester-Merino (BL-M) ewes over 2 years. Shedding increased with age for all WH-M genotypes, with 3/4 Merinos showing less shedding than 1/2 Merinos at all ages. At 1 and 2 years of age, 5/8 Merinos were intermediate between the other 2 WH-M genotypes, but at later ages they were similar to 1/2 Merinos. All genotypes showed less shedding at the belly site than the head, neck and breech as lambs, but not at older ages. Phenotypic correlations between sites on the same sheep were high, averaging 0.85. Repeatability estimates for each site ranged from 0.26 to 0.45. Shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Little or no shoulder and back wool was shed by most sheep. All 1/2 and 5/8 Merinos and most 3/4 Merinos had bare legs and points. Blowfly strike incidence was far higher in Merinos than 1/2 Merinos, in all years. Among WH-M, blowfly strike incidence increased as Merino content increased, in all years. All WH-M were far inferior to both Merinos and BL-M in total greasy wool weight and all its components, and also in clean fleece weight, with their level of inferiority increasing as their Merino content declined. Wool fibre diameter for all WH-M was coarser than for Merinos, but was a little finer than for BL-M. Fibre diameter increased in the WH-M as their Merino content declined. All WH-M had lower wool yields than the Merinos or BL-M. In some years the 314 Merinos had lower wool yields than the 1/2 and 5/8 Merinos, which were similar in all years. Shedding caused numerous genotype x age interactions in wool weight and its components, as Merinos and BL-M did not shed, and with the WH-M shedding increased most with age in the 1/2 Merinos, and least in the 3/4 Merinos. Due to preferential shedding from the belly and other low-value areas, the WH-M inferiority in total wool weight was less severe for fleece weight. Winter shearing succeeded in harvesting some wool from WH-M that would be shed before a summer shearing, but not enough to alter rankings among genotypes. All WH-M genotypes have wool too coarse, and not enough of it, to compete as a wool sheep with the Merino at current wool prices under usual Australian pastoral conditions. In areas where mustering is difficult or blowfly strike unusually severe, WH-M genotypes may find a niche.

Genetic and phenotypic parameters for reproduction, production and bodyweight traits in Australian fine-wool Merino sheep

2018 ◽  
Vol 58 (2) ◽  
pp. 207 ◽  
Author(s):  
S. Dominik ◽  
A. A. Swan
Keyword(s):  
Genetic Relationships ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Careful Consideration ◽  
Production Traits ◽  
Merino Sheep ◽  
Wool Production ◽  
Phenotypic Correlations ◽  
Reproduction Traits ◽  
Definition Of

The present study estimated phenotypic and genetic relationships between wool production, reproduction and bodyweight traits in Australian fine-wool Merino sheep. The data for the study originated from the CSIRO Fine Wool Project, Armidale, Australia. Data on wool characteristics, measured at ~10 and 22 months of age, bodyweight and several reproduction traits across consecutive lambing opportunities were analysed. The genetic correlations were moderately negative between fibre diameter measured as yearling and adult, and lamb survival (rg = –0.34 ± 0.15 and rg = –0.28 ± 0.14 respectively) and total number of lambs weaned (rg = –0.32 ± 0.21 and rg = –0.40 ± 0.21 respectively). The genetic correlations of yearling and adult greasy and clean fleece weights with number of lambs weaned and fecundity showed moderately to highly negative relationships and a moderately negative correlation with the number of fetuses at pregnancy scanning. Phenotypic correlations between reproduction and wool production traits were estimated to be zero, with the exception of bodyweight showing low to moderate positive phenotypic correlations with total number of lambs born and weaned. Genetic variances were generally low for the reproduction traits and resulted in low heritability estimates (from h2 = 0.03 ± 0.01 to h2 = 0.12 ± 0.13), with the exception of total number of lambs born (h2 = 0.25 ± 0.03). The study indicated that parameter estimation and trait definition of lifetime reproduction records require careful consideration and more work in this area is required.

Grazing management of native pastures in the New England region of New South Wales. I. Pasture and sheep production with special reference to systems of grazing and internal parasites

1959 ◽  
Vol 10 (4) ◽  
pp. 530 ◽  
Author(s):  
R Roe ◽  
WH Southcott ◽  
HN Turner
Keyword(s):  
New England ◽  
Fibre Diameter ◽  
Wool Fibre ◽  
Maximum Diameter ◽  
Late Winter ◽  
Parasitic Infestation ◽  
Wool Production ◽  
Skeletal Size ◽  
Significant Difference ◽  
Sheep Production

In a 4-year grazing experiment with Merino sheep, on a native pasture dominated by Bothriochloa ambigua S.T. Blake, three rates of stocking and continuous v. rotational grazing were compared. The effects of these treatments on the forage available and the botanical composition of the pasture and on sheep liveweights, size of sheep, wool production, wool fibre diameter, and parasitic infestation, both with and without drenching with phenothiazine, mere studied. The effects of seasonal conditions on the above and on the chemical composition of the pasture were also recorded. No consistently significant differences between grazing treatments in their effects on the pasture or on sheep liveweights or parasitic infestation were recorded, although during the final 3 years the total forage available was less under heavy stocking. Seasonal variations in total forage mere not marked, but, production of green forage increased greatly in the spring and declined to a very low level during winter. Similarly, sheep liveweights increased during spring and summer and declined in the winter. These liveweight changes were significantly correlated with the amount of green forage available. Wool fibre diameter showed similar seasonal fluctuations but the maximum diameter was attained earlier than maximum liveweight. Coincident with a spring rise in the amount of green forage there was also an increase in the percentages of crude protein and phosphorus in the green components of the pasture. Liveweight gains of the drenched sheep were significantly greater from the beginning of each experimental year in the late spring (November) to late winter (August) in all stocking treatments. In the spring, when the quality of the pasture improved and worm egg counts were low, drenching had no effect on liveweight gains in three out of four years. Drenching also significantly improved wool production and resulted in an increase in skeletal size of sheep in three out of four years. Drenching reduced egg counts of the parasites Oesophagostomum spp. and Haemonchus contortus (Rudolphi) Cobb but was less effective against Trichostrongylus-Ostertagia spp. For all grazing treatments there was no significant difference in the amount of wool produced per head, but over the 4-year period 56 per cent. more wool per acre was produced from the heavy than from the light rate of stocking.

Management of highly fecund ewe types and their lambs for 8-monthly lambing. 1. Effect of lamb weaning age on ewe reproductive activity in spring

1992 ◽  
Vol 32 (4) ◽  
pp. 421 ◽  
Author(s):  
NM Fogarty ◽  
DG Hall ◽  
ST Dawe ◽  
W Atkinson ◽  
C Allan
Keyword(s):  
Post Partum ◽  
Reproductive Activity ◽  
Ovulation Rate ◽  
Late Winter ◽  
First Year ◽  
Weaning Age ◽  
Second Year

The spring reproductive activity of ewes following a late winter lambing, and varying duration of suckling or lamb weaning age of 6-13 weeks, was investigated in 321 Booroola Merino x Dorset (BD) and 543 Trangie Fertility Merino x Dorset (TD) ewe records over 2 years and 238 Border Leicester x Merino (BLM) ewes in the second year. The ewes were joined about 12 weeks post-partum in November for 6 weeks, following lambing in July-August to conform to an %-monthly lambing regime. In the first year, ewes were run with vasectomised rams and oestrus, ovulation rate, and interval to first observed oestrus were determined under a simulated joining regime. In the second year entire rams were joined in spring following July-August lambing and oestrus, pregnancy, fetal number, lambs born per ewe joined and lambing interval were analysed. Amongst ewes rearing lambs, longer suckling significantly increased the interval to first oestrus and the lambing interval (P<0.01), but had no effect on the percentage of ewes expressing oestrus, percentage of pregnant ewes or lambs born. Significantly fewer ewes that lambed but failed to rear any lambs (LL), than ewes rearing lambs expressed oestrus, ovulated and became pregnant. This resulted in considerably lower lambing rates for LL ewes (95.8 v 137.2% lambs born, P<0.01). Reproductive activity was not greatly affected by ewe liveweight or liveweight gain during joining. BD and TD ewes had hgher pregnancy and lambing rates and a shorter lambing interval than BLM ewes. Ovulation rate and fetal number increased with the number of lambs being reared (0.20 � 0.08 and 0.11 � 0.04 per lamb, P<0.05). The results show that high pregnancy and lambing rates can be achieved from natural joining in the spring following late winter lambings within an 8-monthly lambing regime, when lambs are weaned prior to joining.

Genetic parameters for visually assessed traits and their relationships to wool production and liveweight in Australian Merino sheep

2009 ◽  
Vol 49 (1) ◽  
pp. 32 ◽  
Author(s):  
S. I. Mortimer ◽  
D. L. Robinson ◽  
K. D. Atkins ◽  
F. D. Brien ◽  
A. A. Swan ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Quality Traits ◽  
Production Traits ◽  
Merino Sheep ◽  
Wool Production ◽  
Breeding Objectives ◽  
Wool Quality ◽  
Staple Length

Heritability was estimated for a range of visually assessed traits recorded on Merino sheep, together with the phenotypic and genetic correlations among the visually assessed traits and correlations of the visually assessed traits with measured wool production traits and liveweight. Data were derived from four research resource flocks, with a range of 12 958 to 57 128 records from animals with 478 to 1491 sires for the various traits. The estimates of heritability were high for the wool quality traits of handle, wool character and wool colour (0.33–0.34) and the conformation traits of face cover, neck wrinkle and body wrinkle (0.42–0.45), moderate for front leg structure (0.18) and low for back leg structure (0.13). Fleece rot score had low heritability (0.14), while classer grade was moderately heritable (0.20). Estimates of genetic correlations among the visually assessed wool quality traits were low to moderate in size and positive (0.17–0.47). Genetic correlation estimates among the assessed conformation traits were generally very low, except for the genetic correlations between scores for neck and body wrinkle (0.92 ± 0.01) and front and back leg structure (0.31 ± 0.09). Fleece rot score had low positive genetic correlations with neck and body wrinkle scores (0.18 ± 0.05 and 0.15 ± 0.05, respectively) and classer grade (0.26 ± 0.06). Classer grade was slightly positively correlated with the wool quality traits (0.17–0.45) and leg structure traits (0.21–0.25). The genetic correlations among the visually assessed traits were generally neutral to favourable. The visually assessed wool quality traits had low to moderate favourable genetic correlations with mean and coefficient of variation of fibre diameter (0.19 –0.47), but negative correlations with clean wool yield (–0.26 to –0.37). Face cover was unfavourably correlated with staple length (–0.27 ± 0.04) and liveweight (–0.23 ± 0.02). Neck and body wrinkle scores were genetically associated with higher greasy (0.33–0.39) and clean fleece weights (0.19–0.22), greater coefficient of variation of fibre diameter (0.24–0.26) and fibre curvature (0.27–0.28), but with reduced yield (–0.26 to –0.28) and staple length (–0.34 to –0.41). Fleece rot score was genetically correlated with clean fleece weight (0.26 ± 0.05) and coefficient of variation of fibre diameter (0.27 ± 0.04). Classer grade was favourably correlated with greasy and clean fleece weights (–0.41 to –0.43), staple length (–0.29 ± 0.04), liveweight (–0.36 ± 0.03) and coefficient of variation of fibre diameter (0.27 ± 0.03). Most genetic correlations between the visually assessed traits and the measured production traits and liveweight were close to zero and less than 0.2 in magnitude. This study provides accurate values for the parameter matrix required to incorporate visually assessed traits into breeding objectives and the genetic evaluation programs used in the Australian sheep industry, allowing the development of breeding objectives and indexes that optimally combine visually assessed performance and measured production in Merino sheep.

Studies on the supplementary feeding of sheep consuming mulga (Acacia aneura). 4. Effect of sulphur on intake and digestibility, and growth and sulphur content of wool

1978 ◽  
Vol 18 (95) ◽  
pp. 768
Author(s):  
RJW Gartner ◽  
DR Niven
Keyword(s):  
Feed Intake ◽  
Dry Matter ◽  
Fibre Diameter ◽  
Calcium Sulphate ◽  
Sodium Sulphate ◽  
Sulphur Content ◽  
Dry Matter Intake ◽  
Wool Production ◽  
The Difference ◽  
Acacia Aneura

The effect of supplementing sheep fed mulga with sulphur in the form either of molasses, or calcium or sodium sulphate, was examined. Sulphur supplementation increased dry matter intake by 38 per cent without significant differences in digestibility. Liveweight changes were related to intake. Clean wool production was increased by 45 per cent with sulphur supplements (0.48 vs. 0.33 mg cm-2 day-1) but the fibre diameter and the sulphur content of the wool (mean 2.66 per cent) were not influenced by sulphur intake. The cations calcium and sodium had no effect on any responses. Molasses increased feed intake more than calcium sulphate or sodium sulphate did, but the difference was not statistically significant. The extra response in intake to molasses could be due to its contribution of cobalt, as mulga is marginal in this element (0.07 p.p.m.).

Studies in the wool production of grazing sheep. 2. Variation in wool characteristics with season and stocking rate

1964 ◽  
Vol 4 (15) ◽  
pp. 404 ◽  
Author(s):  
WR McManus ◽  
GW Arnold ◽  
JR Paynter
Keyword(s):  
Fibre Diameter ◽  
Late Summer ◽  
Annual Growth ◽  
Late Winter ◽  
Stocking Rate ◽  
Wool Production ◽  
Grazing Sheep ◽  
Stocking Rates ◽  
Staple Length

A four-year study of the variation in wool characteristics of both periodic midside fleece samples and whole fleeces is reported. The wools are derived from an experiment (Arnold, McManus and Bush 1964) in which Merino wethers were continuously grazed on improved pastures at four widely different stocking rates. Despite very large differences in pasture availability and nutritional patterns between treatments the fleeces were essentially similar in staple length, fibre diameter, clean scoured yield, wax and suint content, in quality count and subjective characteristics of soundness, handle, colour, and character. The value of the fleeces was similar for all treatments. Staple length and fibre diameter were lowest in late summer and late winter, when feed quantity and quality, respectively, were also lowest. On all treatments over half the fleeces exhibited 'trade tenderness' attributable to undernutrition in summer. Winter shearing minimises the effects of undernutrition in winter on the soundness of the fleeces. The staple length on the tattoo midside was 21 per cent greater than annual growth on the alternate midside region. Possible reasons for this increase are discussed.

Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 1. Wool production and quality, lamb growth rate, and size and liveweight of ewes

1984 ◽  
Vol 24 (124) ◽  
pp. 34 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
DR Paull
Keyword(s):  
Fibre Diameter ◽  
Adult Life ◽  
Stocking Rate ◽  
Wool Production ◽  
Ewe Lambs ◽  
Subjective Assessments ◽  
Early Adult Life ◽  
Treatment Trends ◽  
Stocking Rates ◽  
Lamb Growth

Ewe lambs born to Merino ewes grazed at 10 or 20 sheep/ha were weaned at three months (L-, H-) and randomized to low or high stocking rate treatments (-L, -H) until 15 months old. Ewes from each of the four groups (LL, LH, HL and HH) then grazed at 10 or 20 sheep/ha until nine years old. Liveweight in early adult life and some body dimensions were reduced by a low plane of nutrition during rearing. The differences in liveweight declined with time and were not significant after 2% years in ewes stocked as adults at 10/ha or after 5% years in ewes stocked at 20/ha. Wool production and growth rates of lambs were reduced when ewes were stocked at the high stocking rate, but were not affected by rearing treatment. Wool production per sheep was about 30% greater at the lower stocking rate but about 33% less when expressed on a unit area basis. Fibre diameter and fleece length were reduced by a high stocking rate in adult life but were not affected by rearing treatment. Yield was not affected by stocking rate at any time. A number of subjective assessments of wool quality were also recorded; quality declined at a high stocking rate but was not affected by rearing treatment. Trends in wool production and quality with age of ewe are reported.

Effect of nutrition and dose level of PMS on oestrous response and ovulation rate in progestagen-treated non-cyclic Suffolk × Galway ewe lambs

1975 ◽  
Vol 84 (3) ◽  
pp. 507-511 ◽  
Author(s):  
M. G. Keane
Keyword(s):  
Dose Level ◽  
Feed Intake ◽  
Ovulation Rate ◽  
Restricted Feeding ◽  
Nutritional Treatment ◽  
Delayed Onset ◽  
Ewe Lambs ◽  
Ad Libitum ◽  
Fresh Cut ◽  
The Difference

SUMMARYMarch-born non-cyclic Suffolk × Galway ewe lambs were treated with progestagen pessaries while being either fed fresh-cut grass ad libitum, or restricted to 50% of appetite and at pessary removal half of the animals on each nutritional treatment received either 600 i.u. or 300 i.u. PMS. Averaged over both levels of PMS, 97·5% of the lambs showed oestrus when fed ad libitum but only 67·5% of those on restricted feeding responded. When feed intake was not restricted there were no differences due to PMS level but when feed intake was restricted the higher dose level of PMS resulted in a greater percentage showing oestrus and a significantly higher ovulation rate. The dose level of PMS had no effect on the time of oestrous onset but restricted feeding resulted in delayed onset and poor synchronization of oestrus. Duration of oestrus was greatest for lambs fed ad libitum given 600 i.u. PMS and least for those on restricted feeding given 300 i.u. PMS but the difference was not significant. A minority of lambs showed broken oestrous periods.

On the Use of Quantum Thermal Bath in Unimolecular Fragmentation Simulations

2019 ◽  
Author(s):  
Riccardo Spezia ◽  
Hichem Dammak
Keyword(s):  
Degrees Of Freedom ◽  
Molecular Simulations ◽  
Zero Point ◽  
Thermal Bath ◽  
Unimolecular Dissociation ◽  
Point Energy ◽  
Rotational Degrees Of Freedom ◽  
The Difference ◽  
Nuclear Effects

<div> <div> <div> <p>In the present work we have investigated the possibility of using the Quantum Thermal Bath (QTB) method in molecular simulations of unimolecular dissociation processes. Notably, QTB is aimed in introducing quantum nuclear effects with a com- putational time which is basically the same as in newtonian simulations. At this end we have considered the model fragmentation of CH4 for which an analytical function is present in the literature. Moreover, based on the same model a microcanonical algorithm which monitor zero-point energy of products, and eventually modifies tra- jectories, was recently proposed. We have thus compared classical and quantum rate constant with these different models. QTB seems to correctly reproduce some quantum features, in particular the difference between classical and quantum activation energies, making it a promising method to study unimolecular fragmentation of much complex systems with molecular simulations. The role of QTB thermostat on rotational degrees of freedom is also analyzed and discussed. </p> </div> </div> </div>

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