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.

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.

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.

Proportion of rams and the condition of ewe lambs at joining influences their breeding performance

2010 ◽  
Vol 50 (6) ◽  
pp. 454 ◽  
Author(s):  
P. R. Kenyon ◽  
S. T. Morris ◽  
D. M. West
Keyword(s):  
Reproductive Performance ◽  
Pregnancy Rates ◽  
Breeding Period ◽  
Breeding Performance ◽  
Ewe Lambs ◽  
Condition Score ◽  
Ewe Lamb ◽  
In Pregnancy

The aim of the present study was to examine the effects of ram : ewe lamb ratio and condition score on the reproductive performance of ewe lambs. In the 2007 study, ewe lambs were bred with rams, at ram : ewe lamb ratios of 1 : 30, 1 : 50, 1 : 75 or 1 : 100. In the 2008 study, ewe lambs were bred at ratios of 1 : 31, 1 : 50, 1 : 75 or 1 : 100. Ewe lambs were bred over two 17-day periods. In both studies, ewe lambs bred in the first 17 days of breeding only were heavier (P < 0.05) than those bred in the second 17-day period only, and those ewe lambs diagnosed as twin-bearing were heavier (P < 0.05) than their single-bearing counterparts. Ewe lambs with a condition score of 2.5 or greater were more likely (P < 0.05) to be bred, and be pregnant, in the first 17 days of breeding than those of condition score 1.5 or 2.0. Over the entire 34-day breeding period, ewe lambs with a condition score of 2.5 or greater had higher (P < 0.05) pregnancy rates than those with a condition score of 2.0, which in turn had higher rates than those of 1.5. In the 2007 study, after 34 days of breeding, there were no differences (P > 0.05) in pregnancy rates among the different ram : ewe lamb ratios. While in the 2008 study, pregnancy rates after 34 days were greater (P < 0.05) in the 1 : 50 compared with both the 1 : 75 and 1 : 100 treatments. Pregnancy rates of 1 : 31 ewe lambs were greater (P < 0.05) than those of 1 : 75 ewe lambs. In the 2007 study, pregnancy rates of ewe lambs to the first 17 days of breeding were greater (P < 0.05) for those bred at a ratio of 1 : 75 than for those bred at 1 : 50, and tended to be greater (P = 0.08) than for those bred at 1 : 100. In addition, those bred at a ratio of 1 : 30 tended to have higher pregnancy rates (P = 0.07) than those bred at 1 : 50. While in the 2008 study, pregnancy rates to the first 17 days of breeding were greatest (P < 0.05) in the 1 : 31 and 1 : 50 treatments groups. In conclusion, the results of the present study indicate that achieving greater liveweights and higher condition scores of ewe lambs at breeding will increase the proportion pregnant, especially early in the breeding period. The data also suggest, in combination with the results of previous research, that farmers should consider utilising ram : ewe lamb ratios lower than 1 : 100, although further studies are warranted.

Plane of nutrition of Corriedale ewe lambs from foetal life to the onset of breeding affects weight at service and reproductive outcome

2015 ◽  
Vol 55 (8) ◽  
pp. 1011
Author(s):  
L. Piaggio ◽  
H. Deschenaux ◽  
F. Baldi ◽  
S. Fierro ◽  
G. Quintans ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Soybean Meal ◽  
Phase 1 ◽  
Breeding Period ◽  
Phase 2 ◽  
Phase 3 ◽  
Ewe Lambs ◽  
Native Pastures ◽  
New Treatments ◽  
First Year Of Life

The objective of this study was to identify periods in the life (foetal and postnatal) of Corriedale ewe lambs where different nutrition levels can affect bodyweight at breeding and pregnancy rate in their first year of life. The effect of three different phases of nutrition on the growth and pregnancy rate (n = 133) of Corriedale ewe lambs of 7 months of age were evaluated. Phase 1 included the last phase of gestation of their mothers (30 last days of gestation, Day –30; partum = Day 0) until marking (Day 24). Phase 2 was between marking and weaning (Day 114) and phase 3 between weaning to the onset of breeding (Day 207). For phase 1, 350 adult ewes had access to improved pastures (phase 1, H) or native pastures (phase 1, L). After lambing, all ewes and their lambs were offered native pastures. After marking only ewes bearing females lambs were kept. In phase 2, 67 lambs born to H and 66 lambs born to L ewes were sorted in two new treatments: access to native pastures supplemented with ~1% of their bodyweight with soybean meal (phase 2, H) or access to native pastures alone (phase 2, L). In phase 3, each of the lambs of the four treatments applied during phase 2 were sorted in two new treatments: access to improved pastures (phase 3, H) or native pastures supplemented with 0.7% of liveweight with soybean meal (phase 3, L). Breeding period lasted 41 days and pregnancy diagnosis was performed 86 days after the onset of breeding. The pregnancy rate varied from 0% to 47%. Phase 3 of nutrition was the only phase that affected pregnancy rate (28% vs. 10% for female lambs offered H and L plane of nutrition respectively; P = 0.005). A discriminative analysis demonstrated that the liveweight at breeding was the only variable that affected the success of pregnancy in ewe lambs (P = 0.0025). Moreover, the ewe lambs that were heavier at the onset of breeding (more than 35 kg or in average 38 kg) were the most successful to get pregnant (35% of pregnancy for lambs over 35 kg and 13% for lambs under 35 kg, P = 0.0044). In conclusion, under the conditions of this experiment, the most important parameters to explain successful pregnancy of ewe lambs were the growth rate after weaning, and the liveweight at the onset of breeding.

Does dam parity affect the performance of ewe progeny born to 2-year-old ewes?

2008 ◽  
Vol 48 (7) ◽  
pp. 979 ◽  
Author(s):  
P. R. Kenyon ◽  
S. T. Morris ◽  
H. T. Blair ◽  
K. J. Stafford
Keyword(s):  
Production Systems ◽  
First Year ◽  
Productive Performance ◽  
Breeding Performance ◽  
Female Progeny ◽  
Ewe Lambs ◽  
Birth Rank ◽  
Condition Score ◽  
Ewe Lamb ◽  
Puberty Onset

An increasing number of ewe lambs are being presented for breeding in New Zealand, resulting in more two-tooth ewes of second parity compared with the more normal first parity. The effect of this on the resulting ewe progeny is unknown but is of interest as they are potential replacement ewes. This study was designed to determine if parity of Romney two-tooth ewes had any effect on their ewe lamb progeny to 20 months of age. Two-hundred and fifty female progeny born to two-tooth dams, which had lambed as a ewe lamb (n = 97), failed to conceive at ewe lamb breeding (n = 79), or had not been presented for breeding as a ewe lamb (n = 74), were weighed at regular intervals. The progeny also had onset of puberty and two-tooth breeding and pregnancy scanning performance measured. There were no effects of dam group on liveweight, condition score, 18-month breeding performance or pregnancy diagnosis. However, ewe lambs born to dams which failed to conceive as ewe lambs themselves were less likely (P < 0.05) to achieve puberty. In comparison with single-born lambs, twin-born ewes were lighter (P < 0.05) during their first year of age only. Birth rank had no effect on puberty onset or 18-month breeding performance. These findings indicate that ewe progeny born to second parity two-tooths or two-tooths, which were not presented for breeding as a ewe lamb, do not differ in their productive performance and that either group are suitable as replacement ewes. However, progeny born to two-tooth dams, which failed to conceive as a ewe lamb, would be less suitable as replacement ewes in production systems where ewe lamb breeding is an integral component of the system. Further studies are required to determine if similar relationships would be observed under differing environmental conditions and with different breeds.

scholarly journals 184 Utilizing Breeding Indictors for an Effective AI Program in Brahman Cows

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 2-2
Author(s):  
Emily K DeShazo ◽  
Sydney T Reese ◽  
Gessica A Franco ◽  
Don A Neuendorff ◽  
Ron Randel ◽  
...  
Keyword(s):  
Pregnancy Rate ◽  
Roc Curve ◽  
Curve Analysis ◽  
Homosexual Behavior ◽  
Roc Curve Analysis ◽  
Trial Duration ◽  
Pregnancy Diagnosis ◽  
Estrus Detection

Abstract Estrus detection is crucial to an effective AI program. The objective of this study was to assess whether Estrotect Breeding Indicators were comparable to vasectomized gomer bulls wearing chin ball markers to accurately and efficiently identify estrus. It was hypothesized that Estrotect Breeding Indicators will accurately and more efficiently detect estrus than gomer bulls. On day 0, an Estrotect Breeding Indicator was placed on Brahman cows (n = 204) that were kept with four vasectomized bulls for the following 45-day study period. Once estrus was detected via activated heat patch, cows were artificially inseminated 14 hr later and the bull score was recorded on a scale from 1–3 (1- no bull marks; 3- solid bull marks). Cows were continually monitored for return to estrus and a pregnancy diagnosis was conducted on day 110. All cows displaying estrus (n = 137) had fully activated patches, while 67 cows were anestrous for the trial duration. A ROC curve analysis indicated that the sensitivity of the bulls detecting estrus was 77.4% compared with the Estrotect Breeding Indicators. Out of the cows with a fully activated patch, 62.77% (86/137) became pregnant to AI. Of these, 17.4% (15/86) of pregnant cows received a bull score of 1 or 2, meaning there were little to no marks left from the bulls. Failure of bulls to identify estrus can be attributed to bulls’ loss of energy, cows displaying homosexual behavior, bulls staying with a chosen cow, or even calves preventing the bull access to the cows in estrus. In conclusion, the patches detected estrus in a greater number of cows than the action of vasectomized bulls wearing chin ball markers leading to an increased pregnancy rate.

Exceptional variation in the appearance of Common Murre eggs reveals their potential as identity signals

The Auk ◽  
2021 ◽  
Author(s):  
Tim R Birkhead ◽  
Jamie E Thompson ◽  
Amelia R Cox ◽  
Robert D Montgomerie
Keyword(s):  
Uria Aalge ◽  
Quantitative Evidence ◽  
Breeding Group ◽  
Common Murre ◽  
Trimodal Distribution ◽  
Common Murres ◽  
Egg Traits ◽  
Breeding Groups ◽  
Different Parts

Abstract We studied the ground colors and maculations of 161 Common Murre (Uria aalge) eggs laid by 43 females in 3 small breeding groups on the cliffs of Skomer Island, Wales, in 2016–2018. Both the colors and maculations varied much more among than within females, providing quantitative evidence for the egg traits that might facilitate the parents’ ability to identify their own eggs on the crowded breeding ledges where the density is typically ~20 eggs m–2. Ground colors had a trimodal distribution of hue values (whitish to pale brown, pale blue, or vivid blue-green) and maculations ranged from none to complex squiggles and blotches. The eggs laid by each female in different years were similar to one another, and replacement eggs laid by females within years were also more similar to their first egg than to other eggs in the same breeding group. Egg appearance did not differ among the 3 breeding groups that we studied. Our findings thus support anecdotal observations that, within and between years, female Common Murres lay eggs that have similar ground colors and maculations. We do not, however, find evidence that there is much difference among the eggs laid in different parts of a colony.

Alternative Tactics in the Breeding Behaviour of Male Coho Salmon

Behaviour ◽  
1998 ◽  
Vol 135 (8) ◽  
pp. 1099-1124 ◽  
Author(s):  
◽  
Angela Prince
Keyword(s):  
Coho Salmon ◽  
Large Male ◽  
Aggressive Interaction ◽  
Alpha Male ◽  
Aggressive Interactions ◽  
Small Section ◽  
Breeding Behaviour ◽  
Breeding Group ◽  
Breeding Groups ◽  
Satellite Males

Abstract1. The movements and breeding behaviour of male coho salmon in Kanaka Creek, British Columbia, Canada, were studied by means of radio-telemetry and detailed observations of males in breeding groups. 2. Males were of three morphological types, large, three year old males (which we term alpha males), small, three year old males (which we term satellite males) and small, two year old 'jack' males (which we term sneak males). All three types of male were common in the population. 3. Males associated with females in breeding groups that included one alpha male and one or more of the two smaller male types. Alpha males dominated in breeding groups. Their movements tended to be restricted to a small section of the spawning stream where they had primary access to redd building females. 4. The majority of aggressive interactions were between resident alpha males and intruding large males, which the resident attempted to drive away. Alpha males would not tolerate another large male nearby and would attack until the intruder left the area. Aggressive interactions between alpha and satellite males or between alpha and sneak males were much less frequent. The alpha males moved from female to female within their section of stream, often returning several times to the same female over the space of a few days. 5. Satellite males adopted positions downstream from a breeding pair. Satellite males were highly mobile within the stream and were observed to join breeding groups at widely spaced locations without significant aggressive interaction with the alpha male. An established satellite male would oppose but not drive away other satellite males attempting to join the breeding group, allowing them to adopt subordinate positions further downstream. The first satellite male in a breeding group would also defend and court the female during periods when the alpha male was absent. 6. Sneak males were most often observed in the spawning redd with the alpha male and female. Sneak males were also found hiding outside the redd early in redd construction, when the cavity of the redd was still shallow, or if the sneak was larger than 30 cm. Sneak males were subject to little aggression from the alpha male or satellite males and displayed the lowest frequency of aggressive interactions of the three types of male. Sneak males would defend their position against other sneak males. Like alpha males, sneak males restricted their movements to a small section of the spawning stream. 7. Overall levels of aggression were lowest in breeding groups consisting of two or three males and much higher in groups consisting of just the alpha male or of four or more males. Intrusion by a large male that challenged the alpha increased the rate of aggressive interaction among all members of the group. 8. Our results suggest three unique breeding tactics among coho males, here termed alpha, satellite and sneak. On the basis of the information currently available, it cannot be determined whether the choice of tactic by a particular male is genetically determined, environmentally determined, or both.

16 False-positive rate after anticipation of early pregnancy diagnosis for resynchronization of ovulation in Bos indicus heifers

2019 ◽  
Vol 31 (1) ◽  
pp. 134
Author(s):  
L. M. S. Simões ◽  
E. A. Lima ◽  
A. P. C. Santos ◽  
R. E. Orlandi ◽  
M. P. Bottino ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pregnancy Rate ◽  
Doppler Ultrasound ◽  
False Positive ◽  
Doppler Ultrasonography ◽  
Bos Indicus ◽  
False Positives ◽  
Colour Doppler ◽  
Pregnancy Diagnosis ◽  
Colour Doppler Ultrasonography

The objective was to determine the incidence of false-positive pregnancy diagnosis following the use of colour Doppler ultrasonography 20 and 22 days after fixed-time AI (FTAI) in Bos indicus heifers submitted to resynchronization 14 days after first FTAI. In the study, 512 Nellore heifers at 24.5±0.8 months of age and body condition score of 3.4±0.1 were used beginning 14 days after FTAI. On Day 14, heifers received 50mg of short-acting progesterone (Afisterone®, CEVA, São Paulo, Brazil) and a progesterone device (Prociclar®, CEVA). Eight days later (Day 22), the progesterone device was removed. A duplex B-mode (grayscale) and pulse-wave colour Doppler ultrasound instrument (M5, Mindray, Shenzhen, China) equipped with a multifrequency linear transducer was used for the examination of luteal blood flow on Days 20 and 22. The percentage of luteal area with colour Doppler signals of blood flow at each examination was determined as previously described (Ginther 2007) and was classified as low [corpus luteum (CL) with less than 25% vascularized area], intermediate (CL with 25-75% vascularized area), or high (CL with more than 75% vascularized area). Heifers with intermediate and high luteal blood flow were diagnosed as pregnant by Doppler ultrasonography, and heifers with low luteal blood flow were diagnosed as nonpregnant. Heifers diagnosed as pregnant by Doppler ultrasonography were examined 30 days after FTAI by B-mode ultrasound examination for pregnancy diagnosis and to determine the number of false positives (heifers pregnant by Doppler ultrasonography and nonpregnant by B-mode ultrasonography). Statistical analysis was performed by the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC, USA). Pregnancy rate by Doppler ultrasonography [Day 20=60.5% (310/512), Day 22=55.3% (283/512); P=0.10] and false-positive percentage [Day 20=29.7% (92/310), Day 22=23.0% (65/2830); P=0.06] were similar on pregnancy diagnoses by Doppler ultrasonography performed 20 and 22 days after FTAI. Furthermore, in the period from 20 to 22 days after FTAI, luteolysis was verified in 5.8% (30/512) of heifers. In conclusion, anticipation of pregnancy diagnosis in 2 days by evaluation of luteal blood flow with colour Doppler ultrasonography (20 days after FTAI) does not interfere with pregnancy rate by Doppler ultrasound and percentage of false positives in Bos indicus heifers.

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.

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