Estimates of Pre- And Perinatal Mortality in the New Zealand Romney Marsh Ewe

Td, Quinlivan; Ca, Martin; Wb, Taylor; Im, Cairney

doi:10.1530/jrf.0.0110391

Cited by 14 publications

(27 citation statements)

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“…Embryonic loss from fertilization to lambing has been estimated at around 30% (Bolet 1986). In ewes bred during the early breeding season, the majority of loss occurred prior to day 18 of gestation (Quinlivan et al. 1966).…”

Section: Discussionmentioning

confidence: 99%

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Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F₂α

Dixon

Knights

Pate

et al. 2006

Reprod Domestic Animals

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Three experiments were conducted with a total of 1579 ewes to examine reproductive performance in response to synchronization of oestrus during the breeding season, using controlled internal drug releasing (CIDR-G) inserts in regimens designed to provide high concentrations of circulating progesterone. In experiment 1, treatment with two CIDR-G inserts for 12 days produced conception rate (79%) and prolificacy (1.9) to first service equivalent to breeding at natural oestrus (56% and 2.0, respectively). Pregnancy rates to two service periods were 90 and 79%, respectively. In experiments 2 and 3, progesterone was delivered by a single CIDR-G insert for 5 days in combination with prostaglandin F2alpha (PGF2alpha; 5 mg i.m., twice, 3 h apart) the day before (experiment 2), or at insert removal (experiment 3). The combined treatments improved rates of synchronization of oestrus (p<0.01) by 23 and 20% points, respectively, and pregnancy rates to the first service period by 19 (p<0.05) and 13 (p<0.01) percentage points, respectively, compared to treatment with PGF2alpha alone. It is concluded that the combination of treatment for 5 days with a CIDR-G insert and two injections of 5 mg PGF2alpha, the day before, or the day of insert removal, were effective treatments to obtain high fertility at synchronized oestrus in ewes during the breeding season.

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Section: Discussionmentioning

confidence: 99%

“…Losses were estimated to be 9.4% after day 18 of gestation (Hulet et al. 1956) and 1.3 and 5.6% after day 30 in parous and non‐parous ewes, respectively (Quinlivan et al. 1966).…”

Section: Discussionmentioning

confidence: 99%

Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F₂α

Dixon

Knights

Pate

et al. 2006

Reprod Domestic Animals

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“…Thus, approximately 40% of all barren ewes presumably conceive and fail to recycle. It is impossible to relate this figure to that of Quinlivan et al (1966). who demonstrated a 21.0% embryonic mortality in parous 2.5-year-old Romney ewes.…”

Section: Distribution Patterns In Various Reproductive Parametersmentioning

confidence: 87%

Survey observations on the reproductive performance of both romney stud and commercial flocks throughout New Zealand

Quinlivan¹,

Martin²

1971

New Zealand Journal of Agricultural Research

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The results of an intensive survey conducted during 1964-68, which examined the reproductive performance of 184,217 ewes in registered Romney stud flocks throughout New Zealand, are given. The flocks, situated in six geographical localities based on latitude, were not a random sample and represented the upper limits of reproductive performance quoted in an earlier paper. The following are conclusions from the data:-I. There were significant differences between areas in the proportions of 3.5-(P < 0.01), 4.5-(P < 0.01), and 6.5-year and older ewes (P < 0.05).2. The mean incidence of barren ewes was 6.8%, with the following area differences: 1, 9.0%; 2, 5.9%; 3, 7.5%; 4, 6.9%; 5, 5.5%; 6, 5.4% (P < 0.01).3. A mean of 1.8% of ewes died between mating and lambing, and a further 1.0% died during lambing. There were no between-area differences in these losses.4. Highly significant between-area differences were demonstrated in lamb production. These were due to significant decreases from north to south in the proportions of ewes lambing single lambs (P < 0.001), and significant linear increases from north to south in the proportions of ewes lambing multiple births (twins, P < 0.001; triplets, P < 0.01).5. The incidence of ewes which lost lambs and of lamb deaths was lowest in South Island flocks. The following proportions of singles, twins, and triplets were lost through abortion and perinatal death: singles, 12.5%; twins, 8.8%; triplets, 21.0%, with significant differences between areas (P < 0.01 -P < 0.001).6. Analyses of the distribution curves of ewes lambing single and multiple births at 5-day intervals throughout lambing, and of the patterns of live and dead single and twin births, confirmed the large between-area differences.7. There were no significant between-year differences either in the age structure of flocks, the incidence of barrenness, ewe deaths, the proportions of ewes lambing single or multiple births, or of lamb mortality.

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“…Although most embryo deaths occur in the first month after conception, a variable percentage of embryo and foetal deaths can occur later in gestation, especially when an outbreak of vibriosis, toxoplasmosis, or other diseases occurs (Quinlivan et al 1966;Edey 1969). When embryo deaths occur after day 19 of gestation there can be delays of 11-32 days before ewes exhibit oestrus (Edey 1967;Sawyer & Knight 1975).…”

Section: Discussionmentioning

confidence: 99%

Identification of barren ewes by vasectomised rams

Knight

Dalton

Hight

1979

New Zealand Journal of Experimental Agriculture

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The ability of harnessed vasectomised (teaser) rams to identify barren ewes over the 4-6 weeks after joining with entire rams, has been calculated from 4-6 years' data from 2 flocks. Of the total barren ewes, 29.6% (range 18.2%-46.6%) in one flock and 48.0% (range 31.3%-66.9%) in the other flock were marked in the 4 weeks after joining. The percentage of barren ewes marked by the teasers increased with increasing prejoining Ii ve weight of the ewes. There was no effect of breed of ewe on the percentage of barren ewes marked but there were large variations among years. There was only a small increase in the percentage of barren ewes marked when the period of joining with teasers increased from 4 to 6 weeks. The teasers marked 7.1 %-8.1 % of the total ewes in one flock and 9.5%-10.8% in the other in 4 weeks, but the proportion marked varied among years. In both flocks, pregnant ewes were marked by the teasers, but in all except one year these formed only a small percentage (0.6%-1.2%) of the total pregnant ewes. Culling ewes marked by the teaser rams was more effective in reducing the percentage of barren ewes present at lambing than culling a similar proportion of ewes based on low prejoining live weight or culling ewes with no recorded mating by entire rams.

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Estimates of Pre- And Perinatal Mortality in the New Zealand Romney Marsh Ewe

Cited by 14 publications

References 0 publications

Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F₂α

Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F₂α

Survey observations on the reproductive performance of both romney stud and commercial flocks throughout New Zealand

Identification of barren ewes by vasectomised rams

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Estimates of Pre- And Perinatal Mortality in the New Zealand Romney Marsh Ewe

Cited by 14 publications

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Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F2α

Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F2α

Survey observations on the reproductive performance of both romney stud and commercial flocks throughout New Zealand

Identification of barren ewes by vasectomised rams

Contact Info

Product

Resources

About

Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F₂α

Reproductive Performance of Ewes after 5‐Day Treatment with Intravaginal Inserts Containing Progesterone in Combination with Injection of Prostaglandin F₂α