Correlation of subclinical gastrointestinal nematode parasitism with growth and reproductive performance in ewe lambs in Ontario

2020 ◽  
Vol 185 ◽  
pp. 105175
Author(s):  
Emma A. Borkowski ◽  
Jacob Avula ◽  
Elizabeth M. Redman ◽  
William Sears ◽  
Brandon N. Lillie ◽  
...  
Author(s):  
Imēne Ben Salem ◽  
Mourad Rekik ◽  
Mohammed Ben Hamouda ◽  
Narjess Lassoued

The current study assessed the effect of the pattern of live weight change on the ovarian function of maiden Barbarine ewes at approximately 1 year of age. For this purpose, a total of 171 weaned ewe lambs (mean live weight  ± s.d. 34.7±3.07 kg and mean age ± SD 196±10 days at weaning) were selected for the experiment. Adjustment of live weight variation  was used. Based on the slope of the curve, animals were grouped into three classes LWCI (n=46),  LWCII (n=91) and LWCIII (n=34) with live weight loss being highest in LWCI and lowest in LWCIII.  Following laparoscopy at 13 months of age, the proportion of ewe lambs found cycling in LWCIII  (85.3%) was higher in comparison to animals in LWCI (43.4%; P<0.001) and tended to be superior to those in LWCII (61.5%; P<0.05). Following synchronisation with progestagen of the females found cycling, levels of plasma IGF-I concentrations between 6 and 42 hrs after removal of sponges were not significantly different between the three classes of live weight, and respectively averaged 94.2, 90.8 and 89.8 µg/l for LWCI, LWCII and LWCIII females. Levels of estradiol were also not significantly different between the three groups (0.73, 0.70 and 0.67 pg/ml for LWCI, LWCII and LWCIII ewe lambs, respectively). It was concluded that, in low input systems of semi-arid and arid Tunisia, mating ewe lambs at the approximate age of 1 year is likely to lead to depressed reproductive performance particularly when the summer live weight-loss is elevated. 


2019 ◽  
Vol 179 ◽  
pp. 1-6
Author(s):  
Andrew Thompson ◽  
Chloe Bairstow ◽  
Mark Ferguson ◽  
Gavin Kearney ◽  
Claire Macleay ◽  
...  

2012 ◽  
Vol 52 (7) ◽  
pp. 552 ◽  
Author(s):  
M. F. P. Loureiro ◽  
S. J. Pain ◽  
P. R. Kenyon ◽  
S. W. Peterson ◽  
H. T. Blair

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.


1972 ◽  
Vol 58 (6) ◽  
pp. 1216 ◽  
Author(s):  
Robert A. Knight ◽  
Halsey H. Vegors ◽  
Ivan L. Lindahl

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Thomas Clune ◽  
Amy Lockwood ◽  
Serina Hancock ◽  
Andrew N. Thompson ◽  
Sue Beetson ◽  
...  

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.


1998 ◽  
Vol 1998 ◽  
pp. 184-184
Author(s):  
T.H. Khan ◽  
N.F.G. Beck ◽  
M. Khalid

Reproductive performance of ewe lambs is lower than that of adult ewes (Quirke. 1979). This is mainly the result of preimplantation losses which can exceed 50% in ewe lambs as compared with 20-30% in ewes (Quirke et al.,1981). Previous evidence from this laboratory suggests that these losses may be associated with inadequate luteal function in ewe lambs (Davies and Beck, 1993). Inadequate luteal function may not only delay the embryo development but also impair the ability of the embryo to communicate its presence to the maternal system. There is also a possibility that inadequate corpora lutea may be refractory to luteotrophic factors produced by the developing embryo. The present study was designed to investigate whether the luteal function varies between ewe lambs and ewes. Another objective of this study was to compare the luteal response to hCG challenge between ewe lambs and ewes and its variation with season.


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