Heterosis in crossbred hill sheep

1963 ◽  
Vol 5 (3) ◽  
pp. 289-299 ◽  
Author(s):  
H. P. Donald ◽  
J. L. Read ◽  
W. S. Russell
Keyword(s):  
Birth Weight ◽  
The Other ◽  
Weaning Weight ◽  
Bone Length ◽  
The Mean ◽  
Fleece Weight ◽  
Reproductive Characters

SUMMARY1. For ten years purebred Blackface and Swaledale ewes have been kept on a small hill grazing together with first crosses and backcrosses to the Swaledale. The total flock of about 120 ewes was mated and lambed on sown pastures where ewes with twins remained from lambing until weaning. Four new rams (two of each breed) were used each year.2. It is concluded that the Swaledales produced fewer lambs than the other ewes, but these were of greater birth weight (5 %) and cannon bone length (2 %); moreoever, they were better mothers than Blackface (4 %) when rearing singles on hill grazing but not if rearing twins on sown grass.3. Blackface sheep showed greater weights at weaning (5%), at mating (5%), and of fleece (15%) than did pure Swaledales.4. First cross sheep were equal to or slightly superior to the parental mean in birth weight, weaning weight and cannon-bone length. They exceeded the better parent in ewe weight, first fleece weight, and weight of weaned lambs.5. Backcross sheep although not always statistically distinguishable from Swaledale in cannon-bone length and fleece weight or from first cross sheep in reproductive characters tend to confirm the interpretations placed on the relations between the purebred and first cross sheep.6. Heterosis estimated as a superiority of first cross sheep over the mean of the two parental breeds varied from 0% for cannon-bone length to 9·5% for prolificacy of 4-year-old ewes.

scholarly journals LAMB AND WOOL PRODUCTION FROM FIVE BREEDS ON RANGE

1966 ◽  
Vol 46 (1) ◽  
pp. 9-18 ◽  
Author(s):  
J. A. Vesely ◽  
H. F. Peters ◽  
S. B. Slen
Keyword(s):  
Body Weight ◽  
The Other ◽  
Production Traits ◽  
Weaning Weight ◽  
Wool Production ◽  
Breed Differences ◽  
Percentage Yield ◽  
Ewe Lamb ◽  
Fleece Weight ◽  
Staple Length

Rambouillet, Romnelet, Columbia, Targhee, and Suffolk sheep were evaluated under range conditions for the production of lamb and wool in the period 1960–1963. The production traits analyzed were: birth and weaning weight; face cover and neck wrinkling; fertility, prolificacy, weaned lamb production, and body weight of ewe; lamb survival to weaning; grease and clean fleece weight, staple length, wool grade, and percentage yield of clean wool by yearling and mature ewes.Lambs of Romnelet were lighter at birth than those of the other breeds. Targhee and Suffolk were the heaviest at birth. Romnelet and Columbia lambs were lighter at weaning than those of Rambouillet, Targhee, and Suffolk.Fertility, prolificacy, and weaned lamb production were essentially the same in the four range breeds. Suffolk produced more weaned lamb than the other four breeds. There were no breed differences in the survival of lambs.Columbia exceeded all other breeds in production of grease and clean fleece weight. Suffolk produced the smallest amount of wool. Staple length of Columbia ewes was 4.3, 7.5, 18.6, 23.7 mm longer than that of Romnelet, Targhee, Suffolk, and Rambouillet ewes.

The role of selection in the improvement of Welsh Mountain sheep

1958 ◽  
Vol 9 (6) ◽  
pp. 819 ◽  
Author(s):  
JM Doney
Keyword(s):  
Birth Weight ◽  
Maternal Environment ◽  
Weaning Weight ◽  
Phenotypic Correlations ◽  
Selection For ◽  
Heritability Estimates ◽  
Fleece Weight ◽  
Staple Length

Means and variances of several economic characters in Welsh Mountain sheep are given. The repeatabilities of, and phenotypic correlations between, these characters are generally within the range of similar estimates given for other breeds. Heritabilities, calculated from parent-offspring correlations, were : birth weight 0.39, weaning weight 0.68, 18-month weight 0.59, greasy fleece weight 0.61, and staple length 0.73. These values are in general higher than similarly derived estimates from other breeds. A method of correcting heritability estimates to remove the error due to correlation between maternal environment, and the character as measured in the dam, is described. This reduces the estimate for weaning weight to 0.48, and that for 18-month weight to 0.16, but does not change that for fleece weight. The use of such estimates in predicting the effect of selection is discussed, and it is concluded that accurate selection for the chosen economic characters will result in improvement at the present genetic stage of the breed.

The relation of weaning weight to birth weight of lambs

1955 ◽  
Vol 1955 ◽  
pp. 38-44 ◽  
Author(s):  
W. Thomson ◽  
I. McDonald
Keyword(s):  
Birth Weight ◽  
Later Life ◽  
The Other ◽  
Weaning Weight ◽  
The Past ◽  
Other Hand ◽  
Established Fact ◽  
High Level

It is now a well established fact that high-level nutrition of the in-lamb ewe during the later stages of pregnancy results in heavy lambs of high vitality at birth and in good milking ewes. On the other hand, when ewes are poorly fed during the same period, or suffer a check, they produce underweight lambs of low vitality and have poor milk yields. While it is agreed that underweight lambs are undesirable, one is often asked whether the larger and sturdier lambs at birth maintain their superiority in later life, a problem on which relatively few results have been published. A study has therefore been made of a large number of birth and weaning weights collected as a normal routine at the Rowett Institute during the past few years.

scholarly journals THE EFFECTS OF BREED AND CERTAIN ENVIRONMENTAL FACTORS ON BIRTH AND WEANING TRAITS OF RANGE SHEEP

1964 ◽  
Vol 44 (2) ◽  
pp. 215-219 ◽  
Author(s):  
J. A. Vesely ◽  
H. F. Peters
Keyword(s):  
Birth Weight ◽  
Environmental Factors ◽  
Total Variation ◽  
The Other ◽  
Weaning Weight ◽  
Body Conformation ◽  
Condition Score ◽  
The Face ◽  
Total Variability ◽  
Sources Of Variation

Data collected during a 4-year period from 830 lambs of the Rambouillet, Romnelet, Canadian Corriedale, and Romeldale breeds were used to estimate the effects of breed and certain environmental factors on birth weight, weaning weight, face cover, conformation, and condition score.Rambouillets ranked first in birth weight and weaning weight, had most wool on the face, and scored poorest in conformation. Romnelets ranked second in weaning weight, had least wool-covering on the face, and were judged superior to the other breeds in conformation and condition. Canadian Corriedales had heavier lambs at birth than Romeldales; however, the Romeldales were more open in the face and scored better in conformation and condition.Year was one of the major sources of variation in weaning weight and conformation. Breed and sex contributed largely to variation in face-cover score. Effects of birth and rearing type (single, twin, or twin raised singly) on birth weight, weaning weight, conformation, and condition were significant (P < 0.01) and accounted for a large part of the total variation in birth weight, weaning weight, and condition score. Age of dam had significant effects on birth weight (P < 0.01) and weaning weight (P < 0.05) but was relatively unimportant as a source of variation. Birth weight increased with advancing date of birth, and weaning weight, body conformation score, and condition score improved with age at weaning.The percentage of total variability (sum of squares) due to the fitting of constants for the factors studied was: birth weight, 47; weaning weight, 47; face cover, 19; conformation, 37; and condition, 24.

Nutrition in relation to reproduction in sows

1960 ◽  
Vol 54 (2) ◽  
pp. 170-178 ◽  
Author(s):  
E. S. E. Hafez
Keyword(s):  
Birth Weight ◽  
Allantoic Fluid ◽  
Uterine Horn ◽  
The Other ◽  
Fallopian Tubes ◽  
Weaning Weight ◽  
Foetal Mortality ◽  
Placental Membranes ◽  
Successive Generations ◽  
Two Peaks

Gilts of the ‘Palouse’ breed were divided into two groups; one group was full fed from weaning to 1501b. and the other group was fed 70% of full feeding. After six generations, one-half of the pigs in each group were shifted to the other plane of nutrition, thus forming four groups: high-high (HH), low-high (LH), low-low (LL) and high-low (HL). F10 gilts were slaughtered 38 or 100 days post-coitum to study reproductive and prenatal phenomena.1. Ten successive generations of controlled feeding had no significant effect on: length of Fallopian tubes, weight of corpus luteum, percentage of implantation, number of viable foetuses, foetus weight, weight of placental membranes, volume of placental fluids or embryonic mortality.2. There were significant differences between the high and low planes of nutrition in: weight of pituitary, thyroid and adrenals, weaning weight, puberty weight, puberty weight to birth weight, puberty weight to weaning weight and puberty age. The effect of six generations of controlled feeding was not maintained when the plane of nutrition was changed from high to low or low to high.3. The frequency of silent heat and the number of services per conception was lower in the low planes than in the high planes.4. Ova migration occurred in both directions in 41% of the gilts; one to four ova migrated. The foetal sex ratio ranged from 4:0 to 1:7 with an average of 1:1. The sexes were unevenly distributed in the horns.5. Foetus weight at 38 or 100 days post-coitum was not affected by plane of nutrition or sequence in the uterine horn.6. Within-litter variations were highest in the volume of allantoic fluid followed in order by variations in weight of placental membranes and then the amniotic fluid and foetus.7. Foetal mortality was not related to sequence in the uterine horn or the number of implantations.8. There seemed to be two peaks of early prenatal mortality, one at implantation and another at the onset of organo-genesis.

Effect of age at first joining on lifetime production by Border Leicester × Merino ewes

1969 ◽  
Vol 9 (40) ◽  
pp. 477 ◽  
Author(s):  
DJ Cannon ◽  
JC Bath
Keyword(s):  
Birth Weight ◽  
Early Summer ◽  
The Other ◽  
Meat Production ◽  
Early Autumn ◽  
Other Hand ◽  
The Mean ◽  
Effect Of Age

Three hundred and fifty Border Leicester X Merino ewes, born March-April 1961, were drafted to two flocks, A and B. Flock A only was joined with rams on February 14, 1962. Subsequently both flocks were joined in November or December each year from 1962 to 1965. The flocks were depastured together on all occasions except for joining and lambing of flock A in 1962. There were negligible differences, between the flocks, in ewe deaths, wool cut, lambs born and reared, lamb birth weight and lamb carcase weight for the mean for the four years or in each of the years 1963 to 1966. Meat production in flock A was increased by 12 kg per ewe as a result of the extra lambing. On the other hand, 3 per cent of the ewes of flock A died in 1962 but no deaths occurred in flock B. Joining when 10-11 months old in early autumn did not disrupt the practice of joining when 20-21 months old in early summer, and, in the experiment, was the most profitable procedure.

scholarly journals Teat order affects postweaning behaviour in piglets

2015 ◽  
Vol 45 (9) ◽  
pp. 1660-1666 ◽  
Author(s):  
Roberta Sommavilla ◽  
Osmar Antonio Dalla Costa ◽  
Luciana Aparecida Honorato ◽  
Clarissa Silva Cardoso ◽  
Maria José Hötzel
Keyword(s):  
Growth Rate ◽  
Weight Gain ◽  
Birth Weight ◽  
Solid Food ◽  
The Other ◽  
Agonistic Interaction ◽  
Weaning Weight ◽  
Solid Diet ◽  
Suckling Piglets ◽  
Time Eating

<p>The objective of this study was to investigate if piglets that suck anterior teats differ from the others in the litter in birth weight, if they have higher growth rate during lactation, and if this affects behaviour and post-weaning weight gain, when piglets change to a solid diet. For this, the teat order of 24 litters was determined during suckling. Piglets were weaned on the 28<sup>th</sup>day of age, and 24 groups were formed, composed of one piglet that sucked on the first two pairs of teats (AT) and three piglets that sucked on the other teats (OT). Even though weight at birth did not vary according to teat order, weight gain at weaning differed between the groups (AT: 6.64, S.E. 0.20kg, OT: 5.73, S.E. 0.13kg; P<0.001). After weaning, AT piglets spent more time lying (P<0.01) and less time eating (P<0.01) and vocalizing (P<0.01), than the other piglets. Other behaviours (agonistic interaction, escape attempt and drinking) did not differ between the groups. Piglets that sucked anterior teats gained more weight until weaning, suggesting they took in more milk; this fact might have lead them to have less contact with solid food before weaning, influencing their post-weaning alimentary behaviour.</p>

Evaluation of Hereford and first-cross cows on three pasture systems. II. Growth of Hereford and Brahman sired calves out of mature cows

1994 ◽  
Vol 122 (1) ◽  
pp. 131-138 ◽  
Author(s):  
H. Hearnshaw ◽  
P. F. Arthur ◽  
P. J. Kohun ◽  
R. Barlow
Keyword(s):  
Average Daily Gain ◽  
The Other ◽  
Weaning Weight ◽  
South Wales ◽  
Medium Quality ◽  
The Mean ◽  
Main Effects ◽  
Calving Difficulty ◽  
Daily Gain ◽  
Sire Breed

SUMMARYThe preweaning growth of the progeny of mature cows grazing high, medium or low quality pasture was evaluated. The cows were 5–9 years of age at the beginning of the study and were either purebred Hereford (H x H), first-cross Brahman x Hereford (B x H), Simmental x Hereford (S x H) or Friesian x Hereford (F x H). Hereford and Brahman bulls were mated to these cows for three mating seasons commencing in 1982, at Grafton, New South Wales, Australia. Records on 634 calves born over three consecutive years were used.Most traits were subject to significant sire breed or dam breed effects or their interactions with one or more of the other main effects (pasture, year of birth of calf, cow age and sex of calf). The incidences of calving difficulty and stillbirths were exceptions. Stillbirths (mean of 3·8%) were not affected by any of the effects studied, while calving difficulty was affected only by sex of calf effect (males, 3·9%; females, 0·8%). The mean calving date of Brahman-sired calves was 11·4 days later (P < 0·05) than that of Hereford-sired calves. Differences between Brahman-sired and Hereford-sired calves for weaning weight were not significant for S x H (Brahman, 237 kg; Hereford, 232 kg) and FxH (Brahman, 238kg; Hereford, 238kg) dams. For HxH dams however, calves sired by Brahman were heavier at weaning (205 kg) than those sired by Hereford (193 kg) bulls, while for B x H dams the reverse was true (Brahman, 222 kg; Hereford, 231 kg). For calves with B x H dams average daily gain (ADG) was the same (957 g/day) for each sire breed, while for the other dam breeds, Brahman-sired calves had a higher ADG than Hereford-sired calves (862 v. 779, 1014 v. 946 and 1022 v. 950 g/day for H x H, S x H and FxH, respectively). Calves sired by Brahman bulls had > 90% eyelid pigmentation while Hereford-sired calves had 44–74%. On high quality pasture, the weaning weights and ADG of calves of F x H and S x H dams were higher than those of B x H and HxH dams. On medium quality pasture, weaning weight of calves of crossbred dams (B x H, S x H and FxH) were similar but higher than those of H x H dams. On low quality pasture, mean weaning weight of calves of B x H was higher than those of S x H and F x H dams, which in turn, were higher than that of H x H dams.

Effect of selection for leanness on overall reproductive performance in Large White sows

1995 ◽  
Vol 61 (3) ◽  
pp. 561-564 ◽  
Author(s):  
J. B. Gaughan ◽  
R. D. A. Cameron ◽  
G. McL. Dryden ◽  
M. J. Josey
Keyword(s):  
Birth Weight ◽  
Reproductive Performance ◽  
Live Weight ◽  
The Other ◽  
Large White ◽  
Weaning Weight ◽  
Weaned Piglet ◽  
Selection For ◽  
Weight Number ◽  
M 14

AbstractReproductive records from 1072 Large White sows (3589 litters) were used to examine the effect ofbackfat depth (Bd) and live weight (Lw) at selection on first litter and lifetime reproductive performance. The variables investigated included mating age, total piglets born, total born alive, piglet birth weight, number weaned, piglet weaning weight, weaning to remating period and number of litters produced. Using backfat depth, sows were categorized into three groups: L, 9 to 13 mm; M, 14 to 16 mm; and F, ≥17 mm. Bd had no significant effect (P > 0·05) on the measured traits for the sows grouped by fat at first parity. When lifetime reproductive data were analysed, the L group had fewer litters (P < 0·05), and weaned fewer pigs (P < 0·01) than either the M or F group. The birth weight for piglets from L sows were significantly higher (P < 0·05) than for piglets from the other groups. The data suggest that the reproductive performance of L sows is not as good as that of M or F sows.

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