The effect of nutrition in mid pregnancy and ewe liveweight change on birth weight and management for lamb survival in highly fecund ewes

1992 ◽  
Vol 32 (1) ◽  
pp. 1 ◽  
Author(s):  
NM Fogarty ◽  
DG Hall ◽  
PJ Holst
Keyword(s):  
Birth Weight ◽  
Treatment Period ◽  
Litter Size ◽  
Late Pregnancy ◽  
Weather Conditions ◽  
Gestation Length ◽  
Nutritional Treatment ◽  
Lamb Survival ◽  
Staple Strength ◽  
Fleece Weight

The effect of moderate undernutrition in mid pregnancy on lamb birth weight and survival of single- and multiple-bearing ewes is reported. A total of 1220 ewes of 3 crossbred types with different fecundity, Booroola Merino x Dorset (BD), Trangie Fertility Merino x Dorset (TD) and Border Leicester x Merino (BLM), were examined over 2 years. The treatments were low (L) and high (H) nutrition at pasture for 4 weeks from about day 75 of pregnancy. Ewe liveweight of the L group at the end of the treatments was 5 kg lower in 1984 and 8 kg lower in 1985 (P<0.01) than the H group. The differences were smaller by late pregnancy and post-lambing. The L treatment increased (P<0.01) birth weight by 0.16 kg in 1984 but had little effect in 1985. Litter size had the greatest effect on birth weight (P<0.01). Ewe crossbred type and lamb sex effects were also significant (P<0.01), although they tended to be reduced for higher order births. Nutritional treatment had no effect on gestation length. Ewe liveweight at joining and weight gains before and after the treatment period significantly affected birth weight and accounted for the large difference in birth weight between years (0.7 kg). Ewe weight gain during the treatment period in mid pregnancy had no significant effect on lamb birth weight. Nutritional treatment in mid pregnancy had no effect on lamb survival. Litter size significantly affected lamb survival, although inclusion of birth weight in the model reduced the effect. Weather conditions, as measured by chill index, significantly (P<0.01) affected lamb survival in 1984 but accounted for less variation in 1985 (P<0.05). Lamb survival for ewes was ranked BLM > TD > BD. Maximum survival was achieved at birth weights of 4-5 kg from BD and TD ewes and 5-6 kg from BLM ewes. The L treatment reduced (P<0.01) ewe greasy fleece weight by 0.15 kg but did not affect staple strength. Plasma glucose concentration at the end of treatment was lower (P<0.01) for L ewes, but there was no difference between L and H ewes in late pregnancy. Glucose declined with increasing fetal number. Plasma B-hydroxybutyrate concentration was lower for the H group than for L, and also for BLM than TD and BD ewes (P<0.01).

Supplementation of high fecundity Border Leicester x Merino ewes with a high protein feed: its effect on lamb survival

1996 ◽  
Vol 36 (2) ◽  
pp. 129 ◽  
Author(s):  
GN Hinch ◽  
JJ Lynch ◽  
JV Nolan ◽  
RA Leng ◽  
BM Bindon ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Protein Supplement ◽  
High Fecundity ◽  
Lamb Survival ◽  
Staple Strength ◽  
Protein Feed ◽  
Lamb Growth ◽  
Positive Effect ◽  
Sire Breed

Two hundred and fifty Border Leicester x Merino ewes (40% heterozygous for the Booroola Fec B gene) were used in an experiment, replicated over 2 years, to examine the effects of cottonseed meal-based supplementation on lamb survival, birth, marking and weaning weight, as well as, liveweight and fleece characteristics of ewes. From 50 to 100 days of pregnancy, half of the ewes were supplemented with 80 g/head.day. The supplemented group was then split according to litter size and, until 30 days after lambing, were offered pellets at 80, 160 and 220 g/head .day, respectively, for ewes bearing single, twin and triplet (or more) lambs. Over the 2 years, ewes averaged 2.11 lambs per parturition and supplementation significantly increased lamb survival to weaning (73 v. 58%) with no interaction with litter size. Although supplementation had a positive effect on birth weight of all but twins, the effects of supplementation on survival were independent of birth weight effects. Significant effects of year, sire breed and litter size on lamb survival and birth weight were also noted. No effects of supplementation were apparent on lamb growth while ewe age, sire breed, sex and rearing rank all significantly influenced growth rates. Ewe weights, fleece weights and staple strength were significantly influenced by year, ewe age and litter size but not by supplementation. These findings indicate the benefits to lamb survival of providing a 'bypass' protein supplement to high fecundity flocks even when ewes are grazing good quality pastures.

Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 3. Reproduction, liveweight and wool production of adult ewes

1995 ◽  
Vol 35 (8) ◽  
pp. 1083 ◽  
Author(s):  
NM Fogarty ◽  
DG Hall
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Significant Variation ◽  
Ovulation Rate ◽  
Average Birth Weight ◽  
Wool Production ◽  
Component Traits ◽  
Lamb Survival ◽  
Fleece Weight ◽  
Almost All

Reproduction, liveweight and wool production are reported for 4 cohorts of 377 Trangie Fertility x Dorset (TD) and 261 Booroola x Dorset (BD) ewes over 6 years. The BD ewes were 3-4 kg lighter (P<0.001) and had a higher ovulation rate prior to joining in February-March (2.37 � 0.03 v. 1.65 � 0.03) than TD ewes. This resulted in a higher litter size (2.07 � 0.03 v. 1.66 � 0.04) and number of lambs born per ewe joined (1.92 � 0.04 v. 1.56 � 0.04) for the BD ewes. Lamb survival was lower from BD than TD ewes (0.71 � 0.02 v. 0.85 � 0.02), so that the 2 ewe strains weaned the same number of lambs. The growth rate of lambs was lower from the BD ewes and overall they weaned 3.8 kg less (P<0.001) weight of lamb than TD ewes. Chill (index of environmental conditions at lambing), litter size and average birth weight of lambs in the litter (linear and quadratic) affected (P<0.001) lamb survival. At moderate levels of chill there was little difference in survival of single and twin lambs from BD and TD dams when birth weight was 4-5 kg, but survival declined more rapidly for progeny of BD ewes at lower birth weight. Under severe lambing conditions survival was depressed more for lambs born from BD ewes than TD ewes. Almost all ewes expressed oestrus over the 3, 6-week periods, December-January, January-February and March (joining). There was significant variation (P<0.001) in incidence of oestrus due to year and age (linear and non-linear), but not liveweight at joining, and there was little difference between ewe strains. Similarly, for post-lambing oestrus (to fit 8-monthly joining) and post-lambing anoestrous interval, there was little difference between strains, but year and age were highly significant (P<0.001). BD ewes had a lower (P<0.001) greasy fleece weight (3.76 v. 3.86 kg), than TD ewes. BD ewes were classified as either carriers (F+) or non-carriers (++) of the FecB gene, which was significant (P<0.001) for ovulation rate (+1.14 ovulations), litter size (+0.8 lambs), lamb survival (-18%), lambs born per ewe joined (+0.64 lambs) and total weight of lamb born per ewe joined (0.5 kg, P<0.01). The effect of the FecB gene was non-significant for lamb survival when litter size and lamb birth weight (P<0.001) were included in the model. Repeatability estimates based on over 3 records per ewe were about 0.2 for lambs born, weight of lamb born, lambs weaned and weight of lamb weaned per ewe joined. Component traits ranged from 0.27 for litter size to 0.10 for lamb survival, with fertility intermediate (0.15). Greasy fleece weight (0.72) and ovulation rate (0.41) had high repeatabilities with post-lambing anoestrous interval being low (0.11). Repeatability for ovulation rate was reduced to 0.34 when F+ ewes were excluded.

scholarly journals The impact of maternal genetic merit and country of origin on ewe reproductive performance, lambing performance and ewe survival

2021 ◽  
Author(s):  
N Fetherstone ◽  
N McHugh ◽  
T M Boland ◽  
F M McGovern
Keyword(s):  
New Zealand ◽  
Birth Weight ◽  
Litter Size ◽  
Country Of Origin ◽  
Reproductive Traits ◽  
Gestation Length ◽  
Genetic Merit ◽  
Genetic Groups ◽  
One Year ◽  
The Impact

Abstract The objective of this study was to investigate the impact of the ewe’s maternal genetic merit and country of origin (New Zealand or Ireland) on ewe reproductive, lambing and productivity traits. The study was performed over a four year period (2016 to 2019) and consisted of three genetic groups: high maternal genetic merit New Zealand (NZ), high maternal genetic merit Irish (High Irish) and low maternal genetic merit Irish (Low Irish) ewes. Each group contained 30 Suffolk and 30 Texel ewes, selected based on the respective national maternal genetic indexes; i.e. either the New Zealand Maternal Worth (New Zealand group) or the €uro-star Replacement index (Irish groups). The impact of maternal genetic merit on reproductive traits such as litter size; lambing traits such as gestation length, birth weight, lambing difficulty, mothering ability, and productivity traits such as the number of lambs born and weaned were analyzed using linear mixed models. For binary traits, the impact of maternal genetic merit on reproductive traits such as conception to first AI service; lambing traits such as dystocia, perinatal lamb mortality and productivity traits such as ewe survival were analyzed using logistic regression. New Zealand ewes outperformed Low Irish ewes for conception to first AI (P&lt;0.05) and litter size (P=0.05). Irish ewes were more likely to suffer from dystocia (6.84 (High Irish) and 8.25 (Low Irish) times) compared to NZ ewes (P&lt;0.001); birth weight and perinatal mortality did not differ between groups (P&gt;0.05). Lambs born from NZ ewes were 4.67 (95% CI: 1.89 to 11.55; P&lt;0.001) and 6.54 (95% CI: 2.56 to 16.71; P&lt;0.001) times more likely to stand up and suckle unassisted relative to lambs born from High or Low Irish ewes, respectively. New Zealand and High Irish ewes had a greater number of lambs born and weaned throughout the duration of the study compared to their Low Irish counterparts (P&lt;0.001). New Zealand ewes tended to be more likely to survive from one year to the next compared to Low Irish ewes (P=0.07). Irish ewes of high maternal genetic merit outperformed their Low counterparts in total number of lambs born and weaned per ewe, but performance did not differ across other traits investigated. This highlights the importance of continuous development of the Irish maternal sheep index to ensure favourable improvements in reproductive, lambing and productivity traits at farm level. Overall, results demonstrate the suitability of NZ genetics in an Irish production system.

scholarly journals Influence of birth weight and litter size on lamb survival in high fecundity Booroola-Merino crossbred flocks

1985 ◽  
Vol 28 (1) ◽  
pp. 31-38 ◽  
Author(s):  
G. N. Hinch ◽  
S. F. Crosbie ◽  
R. W. Kelly ◽  
J. L. Owens ◽  
G. H. Davis
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
High Fecundity ◽  
Lamb Survival

Some consequences of high flock prolificacy in an intensive grassland sheep production system

1975 ◽  
Vol 20 (2) ◽  
pp. 219-232 ◽  
Author(s):  
T. G. Boaz ◽  
W. M. Tempest
Keyword(s):  
Perinatal Mortality ◽  
Breeding Season ◽  
Litter Size ◽  
Growth Rates ◽  
Production System ◽  
Late Pregnancy ◽  
Optimal Level ◽  
Fleece Weight ◽  
Sheep Production ◽  
Lamb Growth

SummaryAn intensive sheep production system using flocks of 100 Scottish Halfbred (SHB), 100 Welsh Speckleface (WSF) and 100 Finn Blackface (FBF) ewes maintained by 8, 4 and 6 ha grassland respectively for a 5-year period, was investigated to establish the consequences of high flock prolificacy and the measures taken to achieve it, including PMS administration. Mating occurred in late October/November at ewe: ram ratios of 25 or 33: 1. Ewes were housed in winter and fed silage, with supplementary cereals in late pregnancy. Lambs in excess of 2 (SHB) and 1 (WSF and FBF) per ewe were artificially reared and fattened indoors; ewes and lambs at grass were rotationally grazed (with forward creep grazing by the lambs). Prolificacy in the SHB breed was 225 lambs born per 100 ewes mated for untreated ewes and 237 for hormone-treated ewes; 119 and 155 respectively for WSF ewes; and 255 for FBF ewes (all untreated). Lambs sold per 100 ewes mated were: for SHB, 200 and 177; WSF, 102 and 107; FBF, 201.Good ewe condition and heavy live weights at mating were associated with appetite problems on silage in late pregnancy; PMS injection with a failure to secure conception rates above 80% at the critical oestrus and a markedly lower prolificacy for ewes conceiving at later oestruses; mating in the middle of the breeding season and March/April lambing with slow lamb growth rates on grass in July and August. Hormone-induced high prolificacy was associated with a greater proportion of large multiple litters than natural high prolificacy, and consequent smaller lamb birth weights and more perinatal mortality. There was a significant negative regression relating fleece weight with litter size. The results suggest the existence of an optimal level of prolificacy for the system employed.

An evaluation of genetic variation in gestation length, birthweight and early growth in Scottish Blackface sheep

1996 ◽  
Vol 1996 ◽  
pp. 108-108
Author(s):  
P Johnston ◽  
J A Roden ◽  
A Murray ◽  
B Merrell ◽  
W Haresign
Keyword(s):  
Genetic Variation ◽  
Birth Weight ◽  
Litter Size ◽  
Early Growth ◽  
Genetic Effects ◽  
Early Mortality ◽  
Gestation Length ◽  
Early Vigour ◽  
Breeding Programmes

Birth weight (BW) and gestation length (GL) have important implications for the survival and early vigour of the lamb, in turn affecting the early growth. In hill sheep BW and early growth have low heritabilities, when considered as a trait of the lamb. They are highly influenced by maternal genetic effects and non genetic effects such as litter size, date of birth and the environment. When studying hill sheep there are also problems obtaining accurate records of birth weights and early growth and it is normally impossible to obtain accurate measures of GL. Exploitation of the genetic variation in the traits BW, GL and early growth could be useful in breeding programmes to reduce early mortality and improve vigour in lambs.

Genetic evaluation of crossbred lamb production. 1. Breed and fixed effects for birth and weaning weight of first-cross lambs, gestation length, and reproduction of base ewes

2005 ◽  
Vol 56 (5) ◽  
pp. 443 ◽  
Author(s):  
N. M. Fogarty ◽  
V. M. Ingham ◽  
A. R. Gilmour ◽  
L. J. Cummins ◽  
G. M. Gaunt ◽  
...  
Keyword(s):  
Litter Size ◽  
Fixed Effects ◽  
Mixed Model ◽  
Genetic Evaluation ◽  
Gestation Length ◽  
Production Traits ◽  
Weaning Weight ◽  
Frozen Semen ◽  
Lamb Survival ◽  
Sire Breed

This is the first paper in a series that reports on a national maternal sire central progeny test program (MCPT) to evaluate the genetic variation for economically important production traits in first- and second-cross progeny of maternal and dual purpose (meat and wool) sires and the scope for genetic improvement. The MCPT program also provides direct linkages between breeds that will contribute information for across-breed genetic evaluation. Crossbred progeny by 91 sires from more than 7 maternal breeds (including Border Leicester, East Friesian, Finnsheep, Coopworth, White Suffolk, Corriedale, and Booroola Leicester) at 3 sites over 3 years with 3 link sires in common at each site and year were evaluated in this study. National estimated breeding values for the sires that were entered by industry breeders indicated that there was some selection for weight, but not other traits and the sires were generally representative of the maternal genetics available to the industry. There were 8377 base Merino and Corriedale ewes artificially inseminated with thawed-frozen semen from the 91 sires and 8193 crossbred lambs born and 6117 lambs weaned. Mixed model analyses of birth and weaning weight, lamb survival, and gestation length as well as fertility, litter size, and lamb weaning rate of the base ewes are reported. Sire breed was significant for birth weight (with a range of 4.0–4.4 kg at an average litter size of 1.8) and weaning weight (19.6–22.5 kg), as well as lamb survival (70–79%) and gestation length (147.1–150.3 days). Birth/rearing type was significant for all traits. Males were significantly heavier than females at birth and weaning, although there was no sex difference for lamb survival or gestation length when birthweight was included in the model. Pregnancy rate from the artificially inseminated base ewes varied from 40 to 84% at the 3 locations in the various years. Sire breed was significant for the number of lambs weaned per ewe lambing, but not for fetal number or litter size born. There were also significant differences in performance due to the source of the base ewes at each site.

Influence of season, litter size, parity, gestation length, birth weight, sex and farrowing pen on frequency of congenital splayleg in piglets

1989 ◽  
Vol 21 (2) ◽  
pp. 143-155 ◽  
Author(s):  
H. Van Der Heyde ◽  
J.P. De Mets ◽  
L. Porreye ◽  
H. Henderickx ◽  
A. Calus ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Gestation Length

A comparison of chopped/un-chopped big bale silage, pit silage and hay when offered with concentrates to twin bearing ewes

1999 ◽  
Vol 1999 ◽  
pp. 129-129
Author(s):  
T.F. Crosby ◽  
P.J. Quinn ◽  
J.J. Callan ◽  
B. Flynn ◽  
J.V. O'Doherty ◽  
...  
Keyword(s):  
Birth Weight ◽  
Sugar Beet ◽  
Body Condition ◽  
Body Condition Score ◽  
Late Pregnancy ◽  
Gestation Length ◽  
Limited Information ◽  
Condition Score ◽  
Beet Pulp ◽  
Terminal Sire

Big bale silage has become increasingly popular on many livestock farms in Ireland yet there is limited information on its use for sheep. The objective of this experiment was to compare the effects of feeding chopped or unchopped big bale silage, pit silage and hay when supplemented with either a barley or a molassed sugar beet pulp based concentrate when fed to ewes in late pregnancy on feed intake, ewe weight and body condition score changes, gestation length, lamb birth weight and colostrum yield.Sixty four mature lowland cross ewes (8/treatment) were oestrus synchronised in October and mated to terminal sire breeds (Suffolk, Texel or Charollais). The ewes were housed, winter shorn and pregnancy scanned in December, following which twin bearing animals were allocated to a 4 x 2 factorial experiment and individually fed either un-chopped or chopped big bale silage which had been wilted for 36-48 hours as is usual for this type of forage, pit silage, which had been wilted for 18-24 hours or hay.

Variation in reproduction and production of Poll Dorset ewes

1994 ◽  
Vol 45 (2) ◽  
pp. 415 ◽  
Author(s):  
DG Hall ◽  
AR Gilmour ◽  
NM Fogarty
Keyword(s):  
Litter Size ◽  
Environmental Effects ◽  
Reproductive Performance ◽  
Reproductive Traits ◽  
Late Summer ◽  
Reproductive History ◽  
Reproduction Traits ◽  
Lamb Survival ◽  
Fleece Weight ◽  
One Year

Poll Dorset ewes were joined to Booroola Merino (n = 22) or Trangie Fertility Merino (n = 26) rams in single sire joinings during late summer/autumn of 1978, 1979, 1980 and 1981. Rams were changed each year and there were 1678 individual ewe joinings. A maximum of 527 ewes were used in any one year, and they represented 14 studs and varied in age, reproductive history and liveweight. The traits, litter size, maternal lamb survival, lambs weaned per ewe lambing and weight of lamb weaned per ewe lambing (kg at 100 days) were analysed for the effect of year, stud, age, lambs born and ewe liveweight. Litter size averaged 1-37, maternal lamb survival 0.70, and number of lambs weaned per ewe was 0.94. There were large variations in the reproductive traits due to year and stud and lesser effects due to age. Each extra kilogram of ewe liveweight at joining increased litter size by 0.012 and weight of lamb weaned by 0.39 kg, but had no significant effect on maternal lamb survival or number of lambs weaned. Multiple-bearing ewes weaned 0.72 more lambs and 16 - 2 kg more lamb weight than single-bearing ewes. Lamb survival was similar for singleand multiple-bearing ewes. Greasy fleece weight averaged 2.2 kg ewe-' and single bearing ewes produced 0.19 kg/ewe more than multiple-bearing ewes. Dystocia caused 53% and starvation/mismothering/exposure caused 23% of lamb deaths; the proportion of deaths due to starvation/mismothering/exposure increased with increasing ewe joining liveweight. The large variation between studs in reproductive performance partly reflected genetic differences between Poll Dorset flocks which could be exploited. Estimates of heritabilities ranged from 0.06 to 0.14 � 0.10 for the reproductive traits and were 0.10 � 0.12 for ewe liveweight and 0.16 � 0.20 for greasy fleece weight. However much of the between stud variation may also have arisen from early environmental effects. Estimates of repeatability ranged from 0.06 to 0.l5 � 0 05 for reproduction traits and were 0.44 � 0.06 for ewe liveweight at joining and 0.56 � 0.08 for greasy fleece weight.

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