Haemoglobin Type and Reproductive Performance in Australian Merino Sheep

Nature ◽  
1965 ◽  
Vol 207 (5004) ◽  
pp. 1396-1397 ◽  
Author(s):  
J. V. EVANS ◽  
HELEN NEWTON TURNER
Keyword(s):  
Reproductive Performance ◽  
Merino Sheep ◽  
Haemoglobin Type ◽  
Australian Merino

Effect of pre-mating nutrition on reproductive performance of Booroola Merino × South Australian Merino ewes

1991 ◽  
Vol 26 (3-4) ◽  
pp. 269-279 ◽  
Author(s):  
D.O. Kleemann ◽  
S.K. Walker ◽  
J.R.W. Walkley ◽  
R.W. Ponzoni ◽  
D.H. Smith ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Australian Merino

Effects of inbreeding on four families of Peppin Merinos

1957 ◽  
Vol 8 (3) ◽  
pp. 299 ◽  
Author(s):  
JM Doney
Keyword(s):  
Fibre Diameter ◽  
Genetic Effect ◽  
Direct Consequence ◽  
Specific Gene ◽  
Single Strain ◽  
Merino Sheep ◽  
Fibre Number ◽  
Per Se ◽  
Fleece Weight ◽  
Australian Merino

The influence of inbreeding on several fleece and body characters in a strain of Australian Merino sheep is reported. The four families from which data were taken were derived from a single strain of Peppin Merinos. Inbreeding without selection has been carried on since the foundation of the families between 1939 and 1944. Inbreeding is responsible for a reduction in body size, fertility, greasy and clean fleece weight, and wrinkle score, but has relatively little influence on the fleece components (yield, staple length, fibre diameter, and density of fibre population). It follows that the reduction in fleece weight is a direct consequence of a decrease in total fibre number. Since the reduction in fibre number is likely to be a correlated effect of low pre-natal and early post-natal growth rates, it is suggested that the inbreeding has had no genetic effect on the several independent systems involved in adult wool production but has affected only those associated with fitness and vigour. The depression due to inbreeding therefore may not be caused by specific gene fixation but by increased homozygosity per se.

Genetic studies of South Australian Merino sheep. 2. Environmental effects on wool and body traits at 15-16 months of age

1981 ◽  
Vol 32 (4) ◽  
pp. 657 ◽  
Author(s):  
IP Gregory ◽  
RW Ponzoni
Keyword(s):  
Body Weight ◽  
Surface Area ◽  
Multiple Birth ◽  
Production Traits ◽  
Merino Sheep ◽  
Main Production ◽  
The Difference ◽  
Fleece Weight ◽  
Main Components ◽  
Australian Merino

The effects of years, sex, type of birth (i.e. whether or not multiple birth) and age of dam on 26 wool and body traits of South Australian Merino sheep were estimated by least-squares analysis. Years and sex had highly significant effects on all traits. Of the main production traits, type of birth had a significant effect on body weight, greasy and clean fleece weight and total wool follicle number, while age of dam only had a significant effect on body weight and greasy fleece weight. The possible consequences of failing to correct body weight and greasy and clean fleece weights for type of birth and age of dam were considered and it was concluded that, although in some years correction of these traits may not be warranted, in other years correction may be necessary to prevent selection against fecundity and an increase in the generation interval. The main components contributing to the 6.0 % difference between fleece weights of singles and twins were surface area, total follicle number and wrinkle score. The difference between fleece weights of animals from older ewes and animals from maidens was only 1.5 %; surface area was the main contributor to this deviation.

The Agouti gene: a positional candidate for recessive self-colour pigmentation in Australian Merino sheep

1999 ◽  
Vol 50 (6) ◽  
pp. 1099 ◽  
Author(s):  
Y. M. Parsons ◽  
M. R. Fleet ◽  
D. W. Cooper
Keyword(s):  
Comparative Mapping ◽  
Economic Importance ◽  
The Self ◽  
Positional Candidate ◽  
Chromosome 13 ◽  
Merino Sheep ◽  
Merino Wool ◽  
Agouti Gene ◽  
Mapping Information ◽  
Australian Merino

The occurrence of self-colour pigmentation in the Australian Merino wool flock is of considerable economic importance. The Agouti gene is believed to be responsible for the recessive expression of pigmented fleece. Using comparative mapping information we have investigated the putative homologous ovine map positon of the Agouti gene for linkage to the recessive self-colour phenotype of Australian Merino sheep. Significant results were observed with microsatellites previously mapped to ovine chromosome 13. Comparative data suggest that the ovine Agouti gene would map to the same chromosome, making the Agouti gene a positional candidate for the self-colour phenotype.

Prediction of lifetime reproductive performance of Australian Merino ewes from reproductive performance in early life

1996 ◽  
Vol 36 (2) ◽  
pp. 123 ◽  
Author(s):  
GJ Lee ◽  
KD Atkins
Keyword(s):  
Reproductive Performance ◽  
Early Life ◽  
Later Life ◽  
Low Fertility ◽  
Annual Cycles ◽  
Reproductive Cycles ◽  
Relationship Of ◽  
The Relationship ◽  
Australian Merino

The lifetime reproductive performances (5 annual cycles) of 2105 Merino ewes from a multiple bloodline flock (15 separate bloodlines) were used to determine the association between reproductive performance in early life (either at 2 or 3 years of age, or the combined information from both years) and later performance. Early life fertility was indicative of both the fertility and the rearing ability of ewes in later life. The relationship of the combined weaning performance at the first and second annual reproductive cycles with reproductive performance in later life suggested gains were possible in the current flock from culling with emphasis on low fertility and rearing ability. Ewes that were dry at 2 and 3 years of age subsequently reared only half as many lambs as ewes that had reared lambs at 2 and 3 years of age.

Association of steroid 17-alpha-hydroxylase/17,20 lyase (CYP17) single nucleotide polymorphism (SNP) 628 and dopamine receptor D2 (DRD2) SNP939 genotypes with sheep reproductive performance

2019 ◽  
Vol 31 (4) ◽  
pp. 743
Author(s):  
Xiaoyan Qiu ◽  
Xiong Xiao ◽  
Nan Li ◽  
Wenhui Ling ◽  
Mingyu Wang ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Dopamine Receptor ◽  
Reproductive Performance ◽  
Maternal Behaviour ◽  
Multiple Gestation ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Merino Sheep ◽  
Dopamine Receptor D2 ◽  
Potential Marker

In a previous study we investigated the association between two single nucleotide polymorphism (SNP) genotypes, namely steroid 17-alpha-hydroxylase/17,20 lyase (CYP17) SNP628 and dopamine receptor D2 (DRD2) SNP939, with two temperaments (calm and nervous) in Australian Merino sheep and concluded that the DRD2 SNP939 T/T genotype combined with the CYP17 SNP628 G/G genotype is associated with a calm temperament and could be used as a potential marker for calm sheep, whereas the DRD2 SNP939C allele combined with the CYP17 SNP628 A/A genotype is associated with a nervous temperament and could be used as a potential marker for nervous sheep. In sheep, the association between temperament and reproductive performance has been determined, but the association of these two SNP genotypes with sheep reproduction has not been investigated. Therefore, using Chinese Sinkiang Merino sheep, the present study investigated the association of the two CYP17 SNP628 and DRD2 SNP939 genotypes with sheep reproductive performance. Sheep with the DRD2 SNP939 T/T genotype combined with the CYP17 SNP628 G/G genotype had a higher ovulation rate, multiple gestation rate, better maternal behaviour and lower lamb mortality. Thus, the results of this study contribute to our knowledge of the association between genotypes and reproduction in sheep, which is beneficial for sheep genetics and breeding.

Neuronal ceroid lipofuscinosis in Australian Merino sheep: a new animal model

2001 ◽  
Vol 5 ◽  
pp. 37-41 ◽  
Author(s):  
Imke Tammen ◽  
Roger W. Cook ◽  
Frank W. Nicholas ◽  
Herman W. Raadsma
Keyword(s):  
Animal Model ◽  
Neuronal Ceroid Lipofuscinosis ◽  
Merino Sheep ◽  
Ceroid Lipofuscinosis ◽  
Australian Merino

Microsatellite-based genetic variation and differentiation of selected Australian Merino sheep flocks

2016 ◽  
Vol 136 ◽  
pp. 137-144 ◽  
Author(s):  
R. Al-Atiyat ◽  
W. Flood ◽  
I. Franklin ◽  
B. Kinghorn ◽  
A. Ruvinsky
Keyword(s):  
Genetic Variation ◽  
Merino Sheep ◽  
Australian Merino
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