scholarly journals The Effect of Age of Dam and Birth Rank on the Reproductive Performance of Ewes as One- and Two-Year-Olds

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 770
Author(s):  
Emma Pettigrew ◽  
Rebecca Hickson ◽  
Steve Morris ◽  
Paul Kenyon ◽  
Rene Corner-Thomas ◽  
...  
Keyword(s):  
New Zealand ◽  
Reproductive Performance ◽  
Litter Weight ◽  
Ewe Lambs ◽  
Birth Rank ◽  
Mature Weight ◽  
L1 And L2 ◽  
Effect Of Age

Currently, 30–43% of New Zealand sheep farmers breed their ewe lambs, but few retain the offspring as replacements for their flock. No difference in lamb production as a yearling among singletons and twins born to ewe lambs and twins born to mature ewes has been reported, provided the ewe lambs had reached the 60–65% of their likely mature weight prior to breeding at seven to eight months of age. The aim of this experiment was to determine the lamb production from singletons and twins born to ewe lambs and twins born to mature ewes during their first two years of lambing. The experiment included 8-month-old ewes born as twins to mature ewes (M2, n = 135), singletons born to ewe lambs (L1, n = 135), and twins born to ewe lambs (L2, n = 88), bred during the same period to the same rams, over two years. The efficiency of lamb production (total litter weight at weaning divided by the pre-breeding weight of the ewe, for all ewes presented for breeding) after two years of production was not significantly different (p > 0.05) among the groups (0.40 ± 0.02, 0.39 ± 0.02, and 0.39 ± 0.03, for M2, L1, and L2, respectively).

Reproductive performance of New Zealand Romney sheep grazed on red clover (Trifolium pratense) pastures

1961 ◽  
Vol 57 (1) ◽  
pp. 123-127 ◽  
Author(s):  
T. S. Ch'ang
Keyword(s):  
New Zealand ◽  
Corpus Luteum ◽  
Breeding Season ◽  
Reproductive Performance ◽  
White Clover ◽  
Trifolium Pratense ◽  
Red Clover ◽  
Ewe Lambs ◽  
Per Se ◽  
Endometrial Cyst

The reproductive performance of 253 female Romney sheep of different ages has been studied from 1958 to 1960. Comparisons of the reproductive performance were made between ewes grazed on red clover pastures and ewes grazed on perennial rye-grass and white clover swards. The red clovers were oestrogenic during all periods of utilization.The ingestion of oestrogenic red clovers caused the ewe lambs to accept the male before the start of the normal breeding season. No corpus luteum was found in the ovary of these lambs thus induced into oestrus. The subsequent reproductive performance of these ewe lambs at 2 years of age was not affected. The oestrus per se or the regularity of oestrus of the young (1½-year-old) or the aged (5½-year-old) ewes was not affected by the diet of oestrogenic red clover.The ingestion of oestrogenic red clover did not affect the reproductive performance of the young ewes at 2 years of age, but did cause a protracted lambing season and a reduced level of lambing performance in the aged ewes at 6 years of age. No endometrial cyst was found in the aged ewes. It was suggested that the reduced level of reproductive performance of the aged ewes could have resulted from an unfavourable environment within the ewe, for the process of fertilization or implantation of the fertilized ova during the breeding season.

scholarly journals Reproductive Performance of New Zealand White, Dutch and Their Crosses Raised in Rivers State, Niger Delta of Nigeria

2019 ◽  
pp. 121-123
Author(s):  
Ologbose F. I. ◽  
Benneth H. N.
Keyword(s):  
Social Sciences ◽  
Body Weight ◽  
New Zealand ◽  
Negative Correlation ◽  
Reproductive Performance ◽  
Niger Delta ◽  
Litter Weight ◽  
The Social ◽  
Significant Difference ◽  
Rivers State

A total of twenty- four breeding rabbits of New Zealand White (NZW), Dutch (DUT) and their crosses (NZW x DUT) i.e. Eight (8) female rabbits (doe) for each genotype were used to determine the effects of breeds on the reproductive performance of rabbits in Rivers State, Niger Delta, Nigeria, as well as to investigate the correlation between the genotypes and the reproductive performance. The following reproductive performance were considered: Body weight before mating ( BWBM ), Body weight after mating ( BWAM ), Body weight before kindling (BWBK), Body weight after kindling (BWAK ), Litter size (LS), Litter weight (LW) and Average litter weight (ALW). Body weight was measured using weighing balance. Data generated were analyzed using Statistical Package for the Social Sciences (SPSS). The result showed significant different (p< 0.05) in BWBM and BWAM between DUT and NZW x DUT breeds of rabbits, DUT recorded the highest value of BWBM and BWAM while NZW x DUT had the least performance. However, there was no significant different (p>0.05) in reproductive performance between NZW and DUT. Furthermore, NZW recorded the highest value in BWBK, BWAK and ALW. There was no significant different (p> 0.05) among the genotypes for BWBK, L S, L W and ALW. BWAK showed a significant difference between DUT and NZW x DUT. More so, NZW x DUT recorded the highest values for L S and LW. The results also showed that genotypes effect had negative correlation with BWBW, BWAM, BWAK, BWBK and ALW with correlation values of -0.64, -0.64, -0.207, 0.385 and 0.045 respectively. The genotypes of rabbits also revealed a high correlation between BWBM and BWAM. BWAK showed a high correlation between BWAM and BWBK.

scholarly journals Effect of re-mating intervals on growth and reproductive performance of rabbits

2013 ◽  
Vol 42 (2) ◽  
pp. 143-147
Author(s):  
BK Saha ◽  
MB Sarker ◽  
MH Alam ◽  
ME Kabir ◽  
MR Amin ◽  
...  
Keyword(s):  
Growth Rate ◽  
New Zealand ◽  
Litter Size ◽  
Milk Yield ◽  
Reproductive Performance ◽  
Gestation Length ◽  
Natural Lighting ◽  
Litter Weight ◽  
Nest Boxes ◽  
Size At Birth

The aim of this study was to know the effects of postpartum re-mating intervals on reproductive performances of does and growth of kits. Fifteen female New Zealand White crossbred rabbits were divided into three groups of equal numbers. They were re-mated within 24 hours, at 10 days and 28 days postpartum. Animals were individually caged in cells measuring 2'×2'×2'. Does were kept under natural lighting. Plastic nest boxes were supplied to does 3-4 days before parturition. They were reared up to four generation. Litter weight at birth was significantly (p<0.05) higher at 10 days postpartum than within 24 hours and at 28 days postpartum intervals. Higher growth rate was observed in 10 days postpartum group comparing to other re-mating groups. Milk yield of the dams were significantly (p<0.05) higher when dam re-mated at 10 days postpartum than those re-mated within 24 hours after parturition. Conception rate, gestation length of does, litter size at birth and weaning, litter weight at weaning, doe weight at mating, kidding, weaning and kid mortality did not differ significantly among the groups. Rabbit does re-mated at 10 days postpartum show maximum litter weight at birth, growth rate of kits and milk yield of dam.DOI: http://dx.doi.org/10.3329/bjas.v42i2.18497 Bang. J. Anim. Sci. 2013. 42 (2): 143-147

Cumulative reproductive performance effect on overall lifetime productivity in Merino sheep

2018 ◽  
Vol 58 (8) ◽  
pp. 1470
Author(s):  
J. S. Richards ◽  
M. A. Sladek ◽  
G. J. Lee
Keyword(s):  
Reproductive Performance ◽  
New South ◽  
Dental Health ◽  
Age Groups ◽  
The South ◽  
Performance Effect ◽  
South West ◽  
South Wales ◽  
The Impact ◽  
Effect Of Age

Reproduction is an important driver of profitability in commercial sheep flocks. Historically, Merino flocks have been run with a fixed age structure, ignoring individual merit and casting for age at a specific age. More recently, research has focussed on utilising the variation within age groups by keeping productive older ewes longer and culling less productive ewes earlier. Previous studies have also examined the effect of age on reproduction and the impact of reproduction status on productivity, but little research has been conducted on cumulative effects of reproductive performance on later productivity, reproduction and health. The present study examined the impact of higher lifetime reproduction on other key production and fitness traits in older ewes run under commercial conditions. Data were collected from two commercial wool-producing properties in the South West Slopes and the Central West Plains of New South Wales during 2009–2011. Reproduction, fleece measurements, bodyweight and condition and dental health were recorded during the study. The results showed that age had a bigger effect on productivity and dental health than did cumulative lifetime reproduction. Environment and genetics determined the level of impact, with minimal loss in productivity from increased age of animals occurring in the South West Slopes flock, whereas the Central West Plains flock would appear to require closer monitoring of productivity as ewes aged. The data collected did not allow separation of the genetic and environmental influences within the study. Retaining animals with a higher reproductive performance past normal culling age does not necessarily result in reduction of productivity or ewe health, but this must be monitored.

scholarly journals Live Weight Changes and Their Relationship with the Ovarian Status of Maiden Fat-Tailed Barbarine Ewes

2010 ◽  
Vol 15 ◽  
pp. 41
Author(s):  
Imēne Ben Salem ◽  
Mourad Rekik ◽  
Mohammed Ben Hamouda ◽  
Narjess Lassoued
Keyword(s):  
Weight Loss ◽  
Reproductive Performance ◽  
Ovarian Function ◽  
Live Weight ◽  
Weight Changes ◽  
Ewe Lambs ◽  
Ovarian Status ◽  
Weight Variation ◽  
Igf I ◽  
Semi Arid

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. 

scholarly journals Effect of age and backfat thickness on reproductive performance of 100 kg Large White sows

1985 ◽  
Vol 34 (3) ◽  
pp. 365-365
Author(s):  
R. GUEBLEZ ◽  
J. M. GESTIN ◽  
Geneviève LE HENAFF
Keyword(s):  
Reproductive Performance ◽  
Backfat Thickness ◽  
Large White ◽  
Effect Of Age

scholarly journals Effect of parity on reproductive performance sows of different breeds

2020 ◽  
Vol 50 (3) ◽  
pp. 434-441
Author(s):  
R. Klimas ◽  
A. Klimienė ◽  
W. Sobotka ◽  
W. Kozera ◽  
P. Matusevičius
Keyword(s):  
Survival Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Weaned Piglets ◽  
Large White ◽  
Litter Weight ◽  
Piglet Survival

The aim of this study was to determine the effect of parity on reproductive performance by sows of different breeds. The sows were raised on three farms, and had seven or more litters of not fewer than seven piglets. A total of 1511 litters from various parities of Lithuanian White (N =721), Large White (N = 162) and Landrace (N = 628) sows were contained in the data that were used in this study. Multiparous sows had larger litters than primiparous sows. Piglet survival rate declined from parity 7. An increase in litter size was observed until parity 5 in Large White and until parity 6 in improved Lithuanian White (P <0.05). In comparison with parity 1, Landrace sows up to parity 5 showed not only increased prolificacy, but also increased number and litter weight of piglets at 21 days old, and the number and litter weight of weaned piglets (P <0.01). The current findings indicate that sows of these breeds can be used effectively in breeding herds until parity 5 and parity 6.Keywords: Landrace, Large White, Lithuanian White, litter size

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