scholarly journals Ground Juniperus pinchotii and urea in supplements fed to Rambouillet ewe lambs Part 2: Ewe lamb rumen microbial communities1

2017 ◽  
Vol 95 (10) ◽  
pp. 4587-4599 ◽  
Author(s):  
S. L. Ishaq ◽  
C. J. Yeoman ◽  
T. R. Whitney
Keyword(s):  
Ewe Lambs ◽  
Juniperus Pinchotii ◽  
Ewe Lamb

Single female offspring born to primiparous ewe-lambs are lighter than those born to adult multiparous ewes but their reproduction and milk production are unaffected

2012 ◽  
Vol 52 (7) ◽  
pp. 552 ◽  
Author(s):  
M. F. P. Loureiro ◽  
S. J. Pain ◽  
P. R. Kenyon ◽  
S. W. Peterson ◽  
H. T. Blair
Keyword(s):  
Milk Production ◽  
Reproductive Performance ◽  
Crude Protein ◽  
Female Offspring ◽  
Productive Performance ◽  
Single Female ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Generation Offspring

Little is known about the long-term impacts of selecting progeny born to ewe-lambs (EL) as replacements. This study investigated whether being born to a ewe-lamb affected the liveweight, milk production and reproductive performance of the offspring to 3 years of age in comparison with those born to adult multiparous ewes. Twenty-seven and 28 single-born Romney ewe progeny (G1) were born to either EL or to adult ewes (AE), respectively. Offspring born to ewe-lambs (ELG1) were lighter (P < 0.001) at birth and up to 12 months of age compared with offspring born to adult ewes (AEG1). Reproductive performance of AEG1 and ELG1 did not differ in regards to puberty attainment, pregnancy rate and number of fetuses. First lactation milk production, fat, crude protein, total protein, casein, lactose and total solids yield did not differ (P > 0.05). The second generation offspring born to ELG1 and AEG1 did not differ in birthweight in the first parity, but it did differ in the second parity and those lambs born to ELG1 were heavier from birth to weaning compared with those lambs born to AEG1. Combined, these results indicate, in the animals used in our study that productive performance of ewes born to EL does not differ to 3 years of age to that of ewes born to AE.

Ewe lamb nutrition during pregnancy affects pregnancy outcome

2008 ◽  
Vol 48 (8) ◽  
pp. 1085 ◽  
Author(s):  
F. J. Mulvaney ◽  
P. R. Kenyon ◽  
S. T. Morris ◽  
D. M. West
Keyword(s):  
Treatment Group ◽  
Survival Rates ◽  
Breeding Period ◽  
Treatment Groups ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Pregnant Ewe ◽  
High Level ◽  
The Impact ◽  
High Treatment

This experiment aimed to investigate the impact of pregnancy nutritional treatment on ewe lamb pregnancy rate and pregnancy loss and the liveweight of resulting lambs. Two hundred and forty ewe lambs mated during a 5-day breeding period were randomly allocated to one of three nutritional regimes (‘low’, ‘medium’ and ‘high’). The low (n = 80) treatment group was fed pasture to maintain liveweight during the first 100 days of pregnancy, thereafter feeding was increased to achieve a total liveweight change of 180 g/day. The medium treatment group was fed to ensure a liveweight change equivalent to 100 g/day throughout the entire pregnancy period, while the high treatment group was offered feed ab libitum. The target liveweight changes were achieved in all ewe lamb treatment groups. Fewer (P < 0.05) ewe lambs were scanned pregnant at day 50 of pregnancy and lambed in the high treatment compared with their medium counterparts. In addition, fewer (P < 0.05) low treatment ewe lambs lambed compared with the medium treatment ewe lambs. The lower numbers lambing in the low and high treatment groups were somewhat explained by greater (P < 0.05) pregnancy losses between day 50 and term. Lambs born to low treatment ewe lambs were lighter (P < 0.05) at birth (L0), L53 and L87 and had lower (P < 0.05) survival rates than those born to either medium or high treatment ewe lambs. While the present study was not designed to identify optimal ewe lamb feeding levels in pregnancy, it clearly indicates adverse effects from either a low or high level of pregnancy nutrition beginning in early pregnancy. Therefore, further studies are required to identify the optimal pastoral feeding conditions for the pregnant ewe lamb.

scholarly journals Abortion and Lamb Mortality between Pregnancy Scanning and Lamb Marking for Maiden Ewes in Southern Australia

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Thomas Clune ◽  
Amy Lockwood ◽  
Serina Hancock ◽  
Andrew N. Thompson ◽  
Sue Beetson ◽  
...  
Keyword(s):  
Cohort Study ◽  
Reproductive Performance ◽  
Important Contributor ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Overall Mortality

The contribution of abortions to the overall mortality of lambs born to maiden (primiparous) ewes in Australia remains unclear. This cohort study aimed to quantify abortion and lamb mortality for ewe lambs and maiden Merino two-tooth ewes. Lamb mortality from pregnancy scanning to marking were determined for 19 ewe lamb and 11 Merino two-tooth ewe flocks across southern Australia. Average lamb mortality from scanning to marking was 35.8% (range 14.3–71.1%) for the ewe lambs and 29.4% (range 19.7–52.7%) for the two-tooth ewes. Mid-pregnancy abortion was detected in 5.7% of ewes (range 0–50%) in the ewe lamb flocks and 0.9% of ewes (range 0–4.4%) in the two-tooth ewe flocks. Mid-pregnancy abortion affecting ≥2% of ewes was observed in 6/19 ewe lamb flocks and 2/11 two-tooth ewe flocks. Lamb mortality from birth to marking represented the greatest contributor to foetal and lamb mortality after scanning, but mid-pregnancy abortion was an important contributor to lamb mortality in some ewe lamb flocks. Variability between the flocks indicates scope to improve the overall reproductive performance for maiden ewes by reducing foetal and lamb losses. Addressing mid-pregnancy abortion may improve the reproductive performance in some flocks.

scholarly journals Models predict the proportion of bone, muscle, and fat in ewe lamb carcasses from in vivo measurements of the 9th to 11th rib section and of the 12th rib

2016 ◽  
Vol 37 (2) ◽  
pp. 1081 ◽  
Author(s):  
Maria Da Graça Morais ◽  
Bruna Biava de Menezes ◽  
Caroline Bertholini Ribeiro ◽  
Catherine Cecília Walker ◽  
Henrique Jorge Fernandes ◽  
...  
Keyword(s):  
Subcutaneous Fat ◽  
Fat Content ◽  
Accurate Estimation ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Bone Content ◽  
Study Population ◽  
Subcutaneous Fat Thickness ◽  
Breed Crosses

The present work aimed at evaluating models that predict the proportion of bone, muscle, and fat in ewe lamb carcasses using in vivo data obtained from the 9th to 11th rib section and from the 12th rib. A study population of 30 wooled ewe lambs, derived from Texel breed crosses, were fed with different concentrate levels (0%, 20%, 40%, 60%, and 80%) and slaughtered at a weight of 37.70 ± 10.23 kg. Carcass fat content (FC%) and muscle content (MC%) were estimated from models using the proportion of muscle and fat in the 9th to 11th rib section or in the 12th rib, with or without additional data regarding subcutaneous fat thickness (SFT mm) or carcass ribeye area (RA cm2). Carcass bone content (BC%) was predicted based on the proportion of bones in the 9th to 11th rib section or in the 12th rib. Modeling with in vivo data included fasting body weight (FBW), withers height (WH), and ultrasound measurements of SFT and RA. The FC% could be estimated from the carcass SFT and fat content in the 12th rib. The MC% was more accurately predicted from the proportion of muscles in the 9th to 11th rib section and from carcass RA. The 9th to 11th rib section provided the most accurate data for the prediction of BC%. To determine FC% and MC% from in vivo inputs, the model must include FBW and WH. In vivo FBW measurements alone allow for the estimation of BC%. We recommend the use of 12th rib composition for the accurate estimation of carcass fat content, and the use of the 9th and 11th rib section for the prediction of carcass muscle and bone content. Models using in vivo data for the prediction of fat, muscle, and bone in ewe lambs should incorporate FBW and WH.

Response of additional ewe lamb liveweight during gestation on birth and weaning weight of offspring and liveweight of the ewe lamb at weaning

2010 ◽  
Vol 50 (6) ◽  
pp. 528 ◽  
Author(s):  
N. M. Schreurs ◽  
P. R. Kenyon ◽  
F. J. Mulvaney ◽  
P. C. H. Morel ◽  
D. M. West ◽  
...  
Keyword(s):  
Management Practices ◽  
Analytic Approach ◽  
Gestation Period ◽  
Third Trimester ◽  
Management Options ◽  
Weaning Weight ◽  
Early Gestation ◽  
Positive Effects ◽  
Ewe Lambs ◽  
Ewe Lamb

Increasing the liveweight of ewe lambs during gestation may have positive effects on lamb birthweight and weaning weight and also on ewe lamb liveweight at weaning. Specific times during the gestation period of the ewe lamb may be more responsive to improved nutrition and increases in liveweight. The objective of this work was to use a meta-analytic approach to investigate the effects of ewe lamb liveweight at mating and during pregnancy on lamb birth and weaning weights, and the ewe lamb’s liveweight at weaning. Increasing ewe lamb liveweight in early gestation and in particular before mating gave the greatest increases in the birth and weaning weight of the lambs, and also of the ewe lamb’s liveweight at weaning compared with increasing liveweight in the second and third trimester of gestation. This indicates that management practices for ewe lambs that generate higher liveweight at mating are likely to result in increased lamb survival, higher weaning percentages, greater lamb weaning weights and create rising 2-year-old ewes with better liveweight for mating in the subsequent season. Compared with ewe lambs that gave birth and reared singletons to weaning, those ewe lambs that gave birth to twins and reared twins had greater increases in lamb birthweights, lamb weaning weights and ewe lamb weights at weaning for each extra kilogram of ewe lamb liveweight during gestation. For ewe lambs, especially those that birth and rear twins, management options that increase the pre-mating weights will have the greatest response in lamb birthweight, weaning weight and liveweight of the ewe lamb itself at weaning.

Effect of timing of exposure to vasectomised rams and ewe lamb body condition score on the breeding performance of ewe lambs

2012 ◽  
Vol 52 (7) ◽  
pp. 471 ◽  
Author(s):  
L. M. Cave ◽  
P. R. Kenyon ◽  
S. T. Morris
Keyword(s):  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Breeding Period ◽  
Breeding Performance ◽  
Ewe Lambs ◽  
Percentage Points ◽  
Condition Score ◽  
Ewe Lamb ◽  
Timing Of Exposure

The aims of this study were to examine the effects of exposing Romney ewe lambs (8–9 months of age) to vasectomised rams across three studies in the February–March period and to determine the influence of body condition score (CS) in two of the studies on their reproductive performance. In all studies, ewe lambs exposed to vasectomised rams had greater (P < 0.05) conception rates to the first 17 days of breeding by 6–12 percentage points. However, Studies 2 and 3 indicated that exposing ewe lambs to vasectomised rams did not increase (P > 0.05) the percentage of ewe lambs conceiving over a 34-day breeding period, nor did it increase the number of fetuses per ewe lamb presented for breeding. The results of Study 1 suggest that there is a limit to how early in the year ewe lambs can be exposed to vasectomised rams. In Study 2, a greater (P < 0.05) percentage of Teased CS 2.0 or 2.5+ ewe lambs conceived during the first 17 days of breeding than those which were Unteased. This effect was not observed (P > 0.05) in CS 1.5 ewe lambs. In Study 3, a greater (P < 0.05) percentage of CS 2.5+ ewe lambs conceived over the 34-day breeding period than ewe lambs of lower CS. In Studies 2 and 3, ewe lambs with a CS of 2.5+ had a greater (P < 0.05) number of fetuses per ewe lamb presented for breeding than CS 1.5 ewe lambs. In conclusion, exposing ewe lambs to vasectomised rams in the late February or March period increased the proportion of ewe lambs successfully bred in the first 17 days of breeding. Further achieving higher CS and heavier liveweights of ewe lambs at breeding should result in improved reproductive performance.

Effect of nutrition pre-breeding and during pregnancy on breeding performance of ewe lambs

2010 ◽  
Vol 50 (10) ◽  
pp. 953 ◽  
Author(s):  
F. J. Mulvaney ◽  
S. T. Morris ◽  
P. R. Kenyon ◽  
P. C. H. Morel ◽  
D. M. West
Keyword(s):  
Pregnancy Rate ◽  
Breeding Period ◽  
Breeding Performance ◽  
Pregnancy Diagnosis ◽  
Breeding Group ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
Breeding Groups ◽  
Pregnant Ewe ◽  
Medium Group

The objective of the present studies was to investigate the effect of differing nutritional levels before breeding and during the pregnancy period on the breeding activity, conception rate (proportion pregnant/ewe lambs bred), pregnancy rate (proportion pregnant/ewe lambs joined with the ram) and the number of fetuses identified at pregnancy diagnosis. In Study 1, ewe lambs were allocated to either ‘medium’ or ‘ad lib’ levels of herbage from 4 days before the start of the breeding period (P –4) to P64. In Study 2, four different pre-breeding nutritional groups (‘maintenance’, ‘medium’, ‘medium/ad lib’ and ‘ad lib’) were utilised from P –17 until P5. The ‘medium/ad lib’ group involved a nutritional switch from the ‘medium’ to the ‘ad lib’ group at P –4 and remained in the ‘ad lib’ until P5. At P5, all ewe lambs that were identified as bred (crayon-marked by ram) were allocated to either ‘medium’ or ‘ad lib’ levels of nutrition until P122. In Study 1, more (P < 0.05) ewe lambs were bred, identified as pregnant at P64 and more fetuses identified at P64 in the ‘ad lib’ group compared with the ‘medium’ group. In Study 2, fewer (P < 0.05) ‘maintenance’ pre-breeding group ewe lambs were bred over the 5-day breeding period compared with the other pre-breeding groups but the proportion of the ewe lambs pregnant at P53 did not differ (P > 0.05). In addition, more (P < 0.05) fetuses were identified at pregnancy diagnosis in the ‘ad lib’ pre-breeding group compared with all other pre-breeding groups. Post-breeding nutrition did not affect (P > 0.05) the proportion of ewe lambs displaying oestrus post-breeding, pregnancy rate or the number of fetuses identified at pregnancy diagnosis per ewe lamb present. This indicates that New Zealand pastoral farmers should aim to allow ad libitum levels of nutrition immediately before the start of the breeding period to pregnancy diagnosis to maximise the number of fetuses at pregnancy diagnosis.

scholarly journals Genetic and nongenetic factors associated with the fate of maiden ewe lambs: slaughtered without ever lambing versus retained for breeding1

2019 ◽  
Vol 4 (1) ◽  
pp. 242-249 ◽  
Author(s):  
Noirin McHugh ◽  
Thierry Pabiou ◽  
Kevin McDermott ◽  
Eamon Wall ◽  
Donagh P Berry
Keyword(s):  
Mixed Models ◽  
Variance Components ◽  
Threshold Model ◽  
Genetic Correlations ◽  
Decision Support Tool ◽  
Data Set ◽  
Support Tool ◽  
Ewe Lambs ◽  
Ewe Lamb ◽  
First Time

Abstract The decision on which ewe lamb to retain versus which to sell is likely to vary by producer based on personal preference. What is not known, however, is if any commonality exists among producers in the characteristics of ewe lambs that influence their eventual fate. The objective of the present study was to determine what genetic and nongenetic factors associate with the fate of maiden ewe lambs. The fate of each ewe lamb born in the present study was defined as either subsequently: 1) having lambed in the flock, or 2) was slaughtered without any recorded lambing event. A total of 9,705 ewe lamb records from 41 crossbred flocks were used. The logit of the odds of the ewe lamb being retained for lambing was modeled using logistic regression. Variance components were then estimated for the binary trait representing the fate of the ewe lamb using animal linear and threshold mixed models. The genetic correlations between fate of the ewe lamb and preweaning, weaning, or postweaning liveweight were also estimated. From the edited data set, 45% of ewe lambs born entered the mature flock as ewes. Ewe lambs reared as singles, with greater levels of heterosis but lower levels of recombination loss, born to dams that lambed for the first time as hoggets, with greater breed proportion of the Belclare, Suffolk, Texel, and Llyen breeds were more likely (P &lt; 0.001) to eventually lamb in the flock than be slaughtered without ever lambing. Irrespective of the age of the animal when weighed, heavier ewe lambs were more likely to eventually lamb (P &lt; 0.001). The genetic SD and direct heritability of fate of the ewe lamb estimated in the univariate linear model was 26.58 percentage units and 0.31 (SE = 0.03), respectively; the heritability was 0.30 when estimated using the threshold model. The corresponding direct heritability of fate of the ewe lamb estimated in the bivariate analyses with liveweight ranged from 0.29 (SE = 0.03; preweaning weight) to 0.35 (SE = 0.04; postweaning weight). The genetic correlations estimated between fate of the ewe lamb and the liveweight traits were weak to moderate but strengthened as the age of the ewe lamb at weighing increased. Results from this study provide an understanding of the factors producers consider when selecting females for retention versus slaughter which may form useful parameters in the development of a decision support tool to identify suitable ewe lambs for retention.

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