Hybrid vigour and lamb production. 2. Effects on survival and growth of first-cross lambs, and on wool and body measurements of hogget ewes

1978 ◽  
Vol 18 (95) ◽  
pp. 753 ◽  
Author(s):  
BJ McGuirk ◽  
ME Bourke ◽  
JM Manwaring
Keyword(s):  
Agricultural Research ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Research Station ◽  
Hybrid Vigour ◽  
Body Measurements ◽  
South Wales ◽  
Survival And Growth ◽  
Lamb Survival ◽  
Fleece Weight

In an experiment at Cowra Agricultural Research Station, New South Wales, five drops of Border Leicester (BB), Merino (MM), Border Leicester x Merino (BM) and Merino x Border Leicester (MB) lambs have been compared to estimate hybrid vigour effects on lamb survival and growth, and on the wool and body measurements of ewe hoggets. Hybrid vigour has been estimated as the percentage superiority of the crossbreds 1/2(MB + BM) over the average of the purebred 1/2(BB + MM) flocks. Hybrid vigour was observed for lamb survival, with the crossbreds superior by 10 per cent in lambs weaned per lamb born (P < 0.05). The crossbred lambs were also heavier at birth (4 per cent) and weaning (6 per cent) and crossbred wether lambs were 11 per cent heavier at slaughter (all P < 0.05). The crossbred ewes were significantly superior to the average of the purebred flocks in both greasy (8 per cent) and clean fleece weight (12 per cent), liveweight (12 per cent) and chest depth (5 per cent) (all P < 0.05). There was no evidence that the crossbreds were superior in any component of wool production per unit area of the skin ; fibre length, fibre diameter or follicle density. Other evidence from this experiment indicates that the breeds and crosses differ in their susceptibility to pneumonia and that there may be heterosis for resistance. This situation could give rise to heterosis for production characters and the heterosis estimates obtained may only be applicable to first-cross flocks derived from Border Leicester studs which are susceptible to pneumonia. Lamb survival to weaning was higher for purebred Merinos (88 per cent) than for purebred Border Leicesters (73 per cent, P < 0.05). The Border Leicester lambs were heavier at all ages and in all years, although the magnitude of their superiority varied significantly between years (P < 0.05). This breed x year interaction was also significant for clean fleeca weight, but the average production of the two groups was similar over the five years. Variation, measured as the coefficient of variation, was generally lower within the crossbred flocks for those characters for which hybrid vigour effects were observed, but these differences were not statistically significant.

The importance of close hocks in Merino breeding

1966 ◽  
Vol 6 (21) ◽  
pp. 134
Author(s):  
RB Dun ◽  
BA Hamilton
Keyword(s):  
Agricultural Research ◽  
Research Station ◽  
Body Measurements ◽  
Phenotypic Correlations ◽  
Agricultural Research Station ◽  
Fleece Weight

Ewes born between 1956 and 1959 in a number of Merino selection flocks maintained at Trangie Agricultural Research Station were scored for distance between the hocks : 1 wide to 6 close. The heritability of hock score was high (0.49 � 0.10). The phenotypic correlations between hock score and fleece and body measurements were all small although the following were significant and positive : with greasy fleece weight, 0.11 ; with clean fleece weight, 0.06 ; with fold score, 0.09. Hock score had no influence on the total number of lambs weaned per ewe-lifetime. Ewes with close hocks (scores 5 and 6) did not lag in the rear third of a travelling flock relative to ewes with score 4 or score 1 hocks.

Selection for clean fleece weight in Merino sheep. I. Direct response to selection

1974 ◽  
Vol 25 (4) ◽  
pp. 643 ◽  
Author(s):  
WA Pattie ◽  
R Barlow
Keyword(s):  
Agricultural Research ◽  
Fibre Diameter ◽  
Initial Increase ◽  
Research Station ◽  
Environment Interaction ◽  
Response Patterns ◽  
Cross Sectional ◽  
Merino Sheep ◽  
Two Generations ◽  
Fleece Weight

Two closed selection flocks of Merino sheep consisting of 100 ewes mated to five rams each were established at the Agricultural Research Station, Trangie, N.S.W., in 1951. One flock was selected for high clean fleece weight (Fleece plus) and the other for low clean fleece weight (Fleece minus). Responses to selection in these flocks over approximately five generations were measured against a randomly selected control flock (100 ewes mated to 10–25 rams). All flocks were selected from the same base population (1700 ewes and 150 rams) and were maintained in the same environment. The response patterns were asymmetrical. In the Fleece plus flock there was an initial increase of approximately one standard deviation in the first two generations but no consistent response was observed in the following three generations. This is shown by realized heritabilities of 0.53 and 0.11 for ewes in the first two, and subsequent generations respectively, the corresponding figures for rams being 0.65 and 0.02. In contrast to this pattern, response in the Fleece minus flock was approximately linear with overall realized heritabilities of 0.44 and 0.38 for ewes and rams respectively. The average level of inbreeding increased between 4 and 5% during selection, and the pooled partial regression of inbreeding coefficient on clean fleece weight independent of the effects of selection was –0.033 kg per 1% inbreeding. This would not have been sufficient to cause a cessation of response after the first two generations. Sampling variation and genotype x environment interaction are possible causes of this response pattern. An additional explanation is suggested which is based on the fact that clean fleece weight is a complex character in which two components, fibre density and cross-sectional area, have a negative genetic correlation between them which may become stronger under selection. It is shown that this could account for a large proportion of the reduction in realized heritability. Thus it is suggested that breeding plans should aim to control fibre diameter while selecting for high clean fleece weight if continued response is to be obtained.

Hybrid vigour and lamb production. 1. Reproductive performance of the purebred and crossbred matings

1978 ◽  
Vol 18 (95) ◽  
pp. 745 ◽  
Author(s):  
BJ McGuirk ◽  
ME Bourke
Keyword(s):  
Reproductive Performance ◽  
Agricultural Research ◽  
New South ◽  
Research Station ◽  
Hybrid Vigour ◽  
Mating Activity ◽  
South Wales ◽  
Breed Difference ◽  
The Difference ◽  
Mixed Flock

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.

The influence of selection and plane of nutrition on the components of fleece weight in Merino sheep

1958 ◽  
Vol 9 (6) ◽  
pp. 802 ◽  
Author(s):  
RB Dun
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Small Contribution ◽  
Cross Sectional ◽  
Single Character ◽  
The Mean ◽  
Low Levels ◽  
The Difference ◽  
Fleece Weight ◽  
High Level

The components of clean fleece weight were examined in five experimental flocks of medium-wool Peppin Merinos. Four single-character selection groups – clean fleece weight plus, clean fleece weight minus, crimps per inch plus, and crimps per inch minus – were examined by measuring fleece production in 18-month-old ewe progeny. Measurements were also made on progeny from the "nucleus" flock, which was selected for clean fleece weight with subsidiary selection for crimps per inch and against fold score. Data were collected in 1952 and 1954. The 1954 figures were obtained from a nutrition experiment in which sheep mere grown from weaning to 18 months on a high and on a low plane of nutrition. The mean measurements of the components of clean fleece weight (W) were compared between flocks using the "percentage deviation" technique. Four comparisons were made: (1) Nucleus/Fleece minus; (2) Fleece plus/Fleece minus; (3) Crimps minus/Crimps plus; (4) high nutritional plane/low nutritional plane. In comparisons (1) , (2), and (3), difference in weight of wool per unit area of skin (w) accounted for nearly all the difference in W. Body weight (S) made a small contribution while difference in fold score (R) was negligible. Fibre density (N) accounted for +86 per cent., and fibre cross-sectional area (A) for –28 per cent., of the difference in W in comparison (1). In comparison (2) the figures were N +47 per cent., A +21 per cent., while the figures for comparison (3) were N –26 per cent., A +121 per cent. The increase in fleece weight was invariably accompanied by a decrease in crimps per inch. In all three comparisons primary density (P) was the major cause of change in N. Fibre length (L) made a uniform contribution of approximately +15 per cent. in the three comparisons.The relative importance of the components of fleece weight was similar at both high and low levels of nutrition.The effect of a high level of nutrition was to produce large increases in A, L, and S. The increase in S was compensated by an equal decrease in P. The increase in fibre diameter was not associated with any change in crimps per inch.

The effects of breed, crossbreeding and other factors on variation in fleece and skin traits

1980 ◽  
Vol 30 (3) ◽  
pp. 417-429 ◽  
Author(s):  
J. A. Woolliams ◽  
G. Wiener
Keyword(s):  
Unit Area ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Live Weight ◽  
Strong Relationship ◽  
Average Fibre Diameter ◽  
Wide Range ◽  
Average Fibre ◽  
Fleece Weight ◽  
The Relationship

ABSTRACTBreed and crossbreeding significantly affected variation in 10 fleece, follicle density and fibre diameter traits in 12-week-old lambs. The breeds involved were the Scottish Blackface, South Country Cheviot, Welsh Mountain, Lincoln Longwool, Southdown and Tasmanian Merino, but the last only by rams.The Southdown came closest to the Merino in affecting density and diameter traits although the Merino crosses remained clearly distinguishable by their high follicle density. The Lincoln and Blackface crosses were notable for their long fibres and the Blackface crosses also had the least dense follicle and coarsest primary fibres. The coarsest secondary fibres were from Lincoln and Cheviot crosses. Heterosis estimates were obtained for crosses involving the Blackface, Cheviot, Welsh and Lincoln breeds. Significant heterosis was present in a wide range of traits but was not apparent in all crosses. Maternal differences were evident for many of the traits but with density these differences were apparently related to maternal effects on live weight of the lamb. The sex of the lamb, its birth type and rearing and its 12-week live weight significantly affected many of the traits.Among breeds and crosses a strong relationship was found between fibre density and average fibre diameter. The relationship suggested that breed variation in total fibre area per unit area of skin was small compared with the breed variation in its components. Fleece weight per unit area was most closely related to mean fibre length.

Wool yield and characteristics of Dorset, Leicester and Sunffolk breeds and their ‘DLS’ cross

1977 ◽  
Vol 88 (3) ◽  
pp. 651-653 ◽  
Author(s):  
M. H. Fahmy ◽  
J. A. Vasely
Keyword(s):  
First Generation ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Wool Production ◽  
Average Fibre Diameter ◽  
Average Fibre ◽  
Wool Yield ◽  
Fleece Weight

SUMMARYGreasy fleece weight (12 months growth) and wool samples from hip and shoulder regions were taken on 15 Dorset, 20 Leicester, 20 Suffolk and 17 DLS ewes (a cross of ½ Dorset, ¼ Leicester, ¼ Suffolk obtained by mating DL rams to DS ewes and DS rams to DL ewes). The purpose of the study was to compare wool production and characteristics of the first generation of DLS with that of the three breeds of origin. Wool production of DLS was 3·58 kg, 8·8 and 14% higher than that of Suffolk and Dorset, but 11% lower than that of Leicester (P< 0·01). The percentage of clean wool was highest in Leicester (78·3%), followed by DLS, Dorset and Suffolk (76·1, 74·3 and 70·5%, respectively). The average fibre diameter of the DLS and Leicester was 38 /m, 4 /m thicker than that for Suffolk and Dorset (P < 0·01). Average fibre length was 15 cm in DLS and Dorset, 6 cm shorter than in Leicester, and 3 cm longer than in Suffolk (P < 0·01). The variability in fibre diameter and length was highest in Leicester, followed closely by DLS.

The effects of crossing Merino with Ossimi and Barki sheep on some productive traits

1972 ◽  
Vol 78 (2) ◽  
pp. 275-280 ◽  
Author(s):  
A. Aboul-Naga ◽  
E. E. Eltawil ◽  
E. Salah E. Galal ◽  
F. Labban ◽  
S. S. Khishest
Keyword(s):  
Research Station ◽  
Hybrid Vigour ◽  
Breed Group ◽  
Body Weights ◽  
Males And Females ◽  
The Cross ◽  
Productive Traits ◽  
Fleece Weight ◽  
Breeding Groups ◽  
Birth Records

SUMMARYA total number of 5949 birth records collected over a period of 9 years from a crossbreeding experiment at Sakha Animal Research Station were used in this study. The following breeding groups were included: Fleisch Merino (M), native Ossimi (0) and Barki (B) breeds, MO, MB, ¾M ¼ O, ¾ M ¾ B and the inter se mating groups of the backcrosses (’¾ M ¼O’ and ‘¾ M ¼B’). Productive traits studied were birth, 4-month and yearling weight, lamb liveability at 4 months of age; and first fleece weight (at 10 months of age).Generally, the cross-bred lambs were heavier in body weights and sheared more wool than the pure breds, with the differences being almost significant. In liveability, native breeds showed significantly higher estimates than the cross-breds where the Merino breed was the poorest in this respect.Merino × Ossimi first cross was the best breed group showing a high heterosis estimate of 0·9, 5·2, 10·3, 7·6, 0·9 and 0·7 kg in birth, 4-month, yearling males and females body weights and first fleece weight, respectively. They were followed by ¾ M ¼ O with a corresponding heterosis value of 0·8, 3·9, 7·4, 4·2, 0·5 and 0·5 kg respectively. Merino x Barki and their backcrosses to Merino are ranked second to the Ossimi crosses. Heterosis in the Barki backcross was 0·8, 2·9, 4·8, 2·1, 0·4 and 0·4 kg compared with 0·5, 2·5, 3·1, 2·7, 0·5, 0·4 kg for MB, on different traits, respectively. The interbreeding of the backcrosses caused a diminishing in hybrid vigour. Heterosis estimates in ‘¾ M ¼ O’ were 0·3, 0·9, 4·6, 2·3, 0·3 and 0·3 kg, whereas it was 0·1, 0·3, –0·1, –0·3, 0·0 and 0·1 kg for ‘¾ M ¼B’, in different traits respectively. All cross-breds showed negligible or/and negative heterosis in lamb liveability up to 4 months.The effects of breed group, year of birth, age of dam, sex and type of birth were found to be highly significant on all traits except the effect of type of birth on lamb liveability.

Seasonal variation in the fertility and fecundity of Bungaree and Peppin Merinos in central-western New South Wales

1969 ◽  
Vol 9 (37) ◽  
pp. 151 ◽  
Author(s):  
JR Giles ◽  
JP Drinan
Keyword(s):  
Seasonal Variation ◽  
Agricultural Research ◽  
New South ◽  
New South Wales ◽  
Ovulation Rate ◽  
Research Station ◽  
Agricultural Research Station ◽  
South Wales

The seasonal variation in fertility and fecundity of Bungaree and Peppin Merinos was compared at the Agricultural Research Station, Trangie, New South Wales. Ewes of both strains were joined to rams of both strains for 32 days on nine occasions ; each joining being separated from adjacent periods by an interval of 10 days. For six weeks after joining the ewes were run with vasectomized rams and were then slaughtered over the following six weeks. Incidence of oestrus and ovulation rate of the two strains were similar at all times. More Bungaree than Peppin ewes returned to service, particularly during the autumn, irrespective of the strain of rams to which they were joined. There was no difference between ram strains in percentage of ewes returning to service or percentage of ewes pregnant, but a significantly higher proportion of ova were lost in pregnant ewes with multiple ovulations after joining to Bungaree rams in winter and spring.

Skin folds and Merino breeding. 8. Fertility of individual rams in flocks selected for high and low skin fold

1969 ◽  
Vol 9 (37) ◽  
pp. 147 ◽  
Author(s):  
BJ McGuirk
Keyword(s):  
Artificial Insemination ◽  
Agricultural Research ◽  
New South ◽  
New South Wales ◽  
Research Station ◽  
South Wales ◽  
Skin Fold ◽  
Single Character ◽  
Lower Fertility ◽  
Selection For

Single character selection flocks-Folds Plus (selection for high fold score) and Folds Minus (selection for low fold score) were established in 1951 from a Peppin Merino flock at Trangie Agricultural Research Station, New South Wales. For the period 1951 to 1966, 25 per cent of rams selected for the Folds Plus flock were rejected following semen examination before joining, compared to only three per cent of Folds Minus rams (P<0.05). The fertility of individual rams in the two flocks has been estimated from the lambing performance of the ewes to which they were mated in the period 1951 to 1963. Averaged over the twelve joinings, a higher proportion of ewes mated to Folds Minus rams lambed following both artificial insemination (53 v. 45 per cent) and paddock joinings (57 v. 47 per cent). The lower fertility of the Folds Plus rams was not due to a higher proportion of completely infertile rams.

Genetic evaluation of production traits between and within flocks of Merino sheep. II. Component traits of the Hogget fleece

1993 ◽  
Vol 44 (7) ◽  
pp. 1523 ◽  
Author(s):  
SI Mortimer ◽  
KD Atkins
Keyword(s):  
Agricultural Research ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Matter Content ◽  
Research Centre ◽  
Production Traits ◽  
Merino Sheep ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Fleece Weight

Components of the fleece and wool quality traits were measured or assessed on Merino hogget ewes in an unselected multiple-bloodline flock over a 7-year period at Trangie Agricultural Research Centre, N.S.W. The traits recorded were face cover score (FC), leg cover score (LC), neck fold score (NF), body fold score (BF), wax content (W), suint content (S), vegetable matter content (VM), dust penetration (D), follicle density (N) and follicle ratio (RA). Genetic differences within and between flocks of Merino sheep were examined for the traits, and estimates of heritability and within-flock genetic and phenotypic correlations and between-flock genetic correlations among the traits were obtained. Genetic and phenotypic correlations were also estimated between these traits and the major wool production traits: greasy fleece weight (GFW), clean fleece weight (CFW), fibre diameter (FD), body weight (BWT) and staple length (SL). Significant strain. flock within strain and flock effects were wresent for all traits. The influence of environmental effects (birth-rearing type, age at measurement and age of dam) on the traits was estimated, with the birth-rearing type being significant and the largest effect for most traits. Paternal half-sib heritability estimates were 0.44� 0.06 for FC, 0.35� 0.06 for LC, 0.24�0.05 for NF, 0.23�0.05 for BF, 0.38�0.07 for W, 0.42�0.07 for S, 0.06�0.04 for VM, 0.22�0.06 for D, 0.20� 0.07 for N and 0.21�0.07 for RA. Estimates of within-flock phenotypic and genetic correlations were in broad agreement with available published estimates. The implications of the results for Merino breeding programs are discussed.

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