Survey observations on the reproductive performance of both romney stud and commercial flocks throughout new zealand

Quinlivan, T. D.; Martin, C.A.

doi:10.1080/00288233.1971.10421680

Cited by 2 publications

(6 citation statements)

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“…I shows the distribution curves for the percentage total lambs born to the ewes which lambed and the levels of significance within each area. Apart from Areas 2 and 4, participating flocks showed levels of total lamb production at the higher end of the distributions quoted by Quinlivan and Martin (1971a). These differences were consistent for the other measures of lamb production.…”

Section: Comparison Of Samplessupporting

confidence: 73%

“…Selection of flocks was based on a breeder's willingness to participate in a continuing survey. Thus, the distribution of flocks based on flock size showed highly significant differences from that presented by Quinlivan and Martin (1971a) in their national survey, which did nut differ from stud flocks as a whole. However, the numbers of flocks under survey in each area were proportionate to the numbers of stud flocks in the six areas as a whole.…”

Section: Distribution Patterns In Various Reproductive Parametersmentioning

confidence: 65%

“…Either this annual culling is not taking place, or the culling of barren ewes has little influence on their subsequent incidence. Further, the levels quoted for stud flocks are almost twice as high as those for commercial flocks (6.8% v 3.8%, Quinlivan and Martin 1971c). Over a large population of animals this proportion of unproductive sheep is considerable.…”

Section: Distribution Patterns In Various Reproductive Parametersmentioning

confidence: 94%

“…The stud flocks in this survey were not selected at random, and it was important to compare their levels of reproductive performance with those of registered Romney studs as a whole. The data presented by Quinlivan and Martin (1971a) were considered to be a reliable estimate of national performance. For comparison, the data on flock size and lamb production from both surveys were analysed for differences between areas.…”

Section: Comparison Of Samplesmentioning

confidence: 99%

“…Table 1 shows the numbers of flocks and ewes in the survey by geographical areas (1)(2)(3)(4)(5)(6). A description of this arbitrary division has already been presented (Quinlivan and Martin 1971a). The survey began in Areas 3, 5, and 6 in 1964.…”

Section: Introductionmentioning

confidence: 99%

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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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Section: Comparison Of Samplessupporting

confidence: 73%

Section: Distribution Patterns In Various Reproductive Parametersmentioning

confidence: 65%

Section: Distribution Patterns In Various Reproductive Parametersmentioning

confidence: 94%

Section: Comparison Of Samplesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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