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RESEARCH ARTICLE

Effect of timing of exposure to vasectomised rams and ewe lamb body condition score on the breeding performance of ewe lambs

L. M. Cave A B , P. R. Kenyon A and S. T. Morris A
+ Author Affiliations
- Author Affiliations

A Sheep Research Centre, Institute of Veterinary, Animal and Biomedical Sciences, Private Bag 11-222, Massey University, Palmerston North, New Zealand.

B Corresponding author. Email: l.cave@massey.ac.nz

Animal Production Science 52(7) 471-477 https://doi.org/10.1071/AN11210
Submitted: 3 October 2011  Accepted: 27 February 2012   Published: 10 April 2012

Abstract

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.


References

Anon. (2010) Statistics New Zealand. Available at http://www.stats.govt.nz [Verified 15 August 2011]

Baker R, Clarke J, Diprose G (1981) Effect of mating Romney ewe hoggets on lifetime production – preliminary results. Proceedings of the New Zealand Society of Animal Production 41, 198–203.

Bastiman B (1972) The effect of ewe condition at tupping on lambing performance. Experimental Husbandry 22, 22–24.

Craig R (1982) Breeding from Romney ewe hoggets in the Waihora group breeding scheme. New Zealand Agricultural Science 16, 101–104.

Dyrmundsson OR (1973) Puberty and early reproductive performance in sheep. 1. Ewe lambs. Animal Breeding Abstracts 41, 273–289.

Ferguson M, Thompson A, Gordon D, Hyder M, Kearney G, Oldham C, Paganoni B (2011) The wool production and reproduction of Merino ewes can be predicted from changes in liveweight during pregnancy and lactation. Animal Production Science 51, 763–775.
The wool production and reproduction of Merino ewes can be predicted from changes in liveweight during pregnancy and lactation.Crossref | GoogleScholarGoogle Scholar |

Forcada F, Abecia J, Sierra I (1992) Seasonal changes in oestrus activity and ovulation rate in Rasa Aragonesa ewes maintained at two different body condition levels. Small Ruminant Research 8, 313–324.
Seasonal changes in oestrus activity and ovulation rate in Rasa Aragonesa ewes maintained at two different body condition levels.Crossref | GoogleScholarGoogle Scholar |

Gunn R, Doney J, Russel A (1969) Fertility in Scottish Blackface ewes as influenced by nutrition and body condition at mating. The Journal of Agricultural Science, Cambridge 73, 289–294.
Fertility in Scottish Blackface ewes as influenced by nutrition and body condition at mating.Crossref | GoogleScholarGoogle Scholar |

Gunn R, Doney J, Russel A (1972) Embryo mortality in Scottish Blackface ewes as influenced by body condition at mating and by post-mating nutrition. Journal of Agricultural Science, Cambridge 79, 19–25.
Embryo mortality in Scottish Blackface ewes as influenced by body condition at mating and by post-mating nutrition.Crossref | GoogleScholarGoogle Scholar |

Jefferies BC (1961) Body condition scoring and its use in management. Tasmanian Journal of Agriculture 32, 19–21.

Keane M (1974) Effect of previous lambing on bodyweight and reproductive performance of hoggets. Israel Journal of Agricultural Research 13, 191–196.

Kenyon P, Morris ST, Perkins NR, West DM (2004a) Hogget mating in New Zealand – a survey. Proceedings of the New Zealand Society of Animal Production 64, 217–222.

Kenyon PR, Morel PCH, Morris ST (2004b) The effect of individual liveweight and condition scores of ewes at mating on reproductive and scanning performance. New Zealand Veterinary Journal 52, 230–235.
The effect of individual liveweight and condition scores of ewes at mating on reproductive and scanning performance.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2M7js1ahtA%3D%3D&md5=766ed91b5d377ccc85c55a21ea319a34CAS |

Kenyon PR, Pinchbeck GL, Perkins NR, Morris ST, West DM (2004c) Identifying factors which maximise the lambing performance of hoggets: a cross sectional study. New Zealand Veterinary Journal 52, 371–377.
Identifying factors which maximise the lambing performance of hoggets: a cross sectional study.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2M7js1antQ%3D%3D&md5=b9bd3109132f7e19ce080d2bb55e0e5eCAS |

Kenyon PR, Morel PCH, Morris ST, West DM (2005) The effect of individual liveweight and use of teaser rams prior to mating on the reproductive performance of ewe hoggets. New Zealand Veterinary Journal 53, 340–343.
The effect of individual liveweight and use of teaser rams prior to mating on the reproductive performance of ewe hoggets.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2Mrktl2itw%3D%3D&md5=6cfd777ac3733e87556999a122662309CAS |

Kenyon PR, Morel PCH, Morris ST, Burnham DL, West DM (2006a) The effect of length of use of teaser rams prior to mating and individual liveweight on the reproductive performance of ewe hoggets. New Zealand Veterinary Journal 54, 91–95.
The effect of length of use of teaser rams prior to mating and individual liveweight on the reproductive performance of ewe hoggets.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD287ptVymtA%3D%3D&md5=c0eee2c72b8302279e0e423039e1b33cCAS |

Kenyon PR, Morel PCH, West DM, Morris ST (2006b) Effect of liveweight and teasing of ewe hoggets prior to breeding on lambing pattern and weight of singleton lambs. New Zealand Journal of Agricultural Research 49, 341–347.
Effect of liveweight and teasing of ewe hoggets prior to breeding on lambing pattern and weight of singleton lambs.Crossref | GoogleScholarGoogle Scholar |

Kenyon PR, Morel PCH, Morris ST, Burnham DL, West DM (2007) Effect of the ratio of teaser rams used prior to breeding on the reproductive performance of ewe hoggets. New Zealand Veterinary Journal 55, 342–345.
Effect of the ratio of teaser rams used prior to breeding on the reproductive performance of ewe hoggets.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2sjislGhtg%3D%3D&md5=48a331b67ed2f9841a8a42cfa2cd98bdCAS |

Kenyon PR, Morel PCH, Morris ST, West DM (2008a) A note on the effect of vasectomised rams and short-term exposures to entire rams prior to the breeding period on the reproductive performance of ewe lambs. Applied Animal Behaviour Science 110, 397–403.
A note on the effect of vasectomised rams and short-term exposures to entire rams prior to the breeding period on the reproductive performance of ewe lambs.Crossref | GoogleScholarGoogle Scholar |

Kenyon PR, Morris ST, West DM (2008b) Can Romney ram lambs whose scrotums had been shortened by the use of a rubber ring be used as an alternative to vasectomised Perendale rams for inducing early breeding activity in Romney ewe lambs? New Zealand Veterinary Journal 56, 326–329.
Can Romney ram lambs whose scrotums had been shortened by the use of a rubber ring be used as an alternative to vasectomised Perendale rams for inducing early breeding activity in Romney ewe lambs?Crossref | GoogleScholarGoogle Scholar |

Kenyon PR, Proctor L, Morel PCH, Morris ST, West DM (2008c) The effect of breeding ewe lambs on subsequent two-year-old ewe performance. Livestock Science 115, 206–210.
The effect of breeding ewe lambs on subsequent two-year-old ewe performance.Crossref | GoogleScholarGoogle Scholar |

Kenyon PR, Smith SL, Morel PCH, Morris ST, West DM (2009) The effect of the maturity and prior breeding activity of rams and body condition score of ewe hoggets on the reproductive performance of ewe hoggets. New Zealand Veterinary Journal 57, 290–294.
The effect of the maturity and prior breeding activity of rams and body condition score of ewe hoggets on the reproductive performance of ewe hoggets.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1MnmslKmtQ%3D%3D&md5=d3a5137b0318d7337c3814e54d412538CAS |

Kenyon P, Morris S, West D (2010) Proportion of rams and the condition of ewe lambs at joining influences their breeding performance. Animal Production Science 50, 454–459.
Proportion of rams and the condition of ewe lambs at joining influences their breeding performance.Crossref | GoogleScholarGoogle Scholar |

McMillan W, McDonald M (1983) Reproduction in ewe lambs and its effect on 2-year-old performance. New Zealand Journal of Agricultural Research 26, 437–442.
Reproduction in ewe lambs and its effect on 2-year-old performance.Crossref | GoogleScholarGoogle Scholar |

McMillan W, Moore R (1983) Capitalizing on hogget oestrus. Proceedings of the 13th Seminar of the Society of Sheep and Beef Cattle Veterinarians 13, 47–52.

McNeilly A, Jonassen J, Rhind S (1987) Reduced ovarian follicular development as a consequence of low body condition in ewes. Acta Endocrinologica 115, 75–83.

Meyer H, French R (1979) Hogget liveweight-oestrus relationship among sheep breeds. Proceedings of the New Zealand Society of Animal Production 39, 56–62.

Newton J, Betts J, Wilde R (1980) The effect of body condition and time of mating on the reproductive performance of Masham ewes. Animal Production 30, 253–260.
The effect of body condition and time of mating on the reproductive performance of Masham ewes.Crossref | GoogleScholarGoogle Scholar |

Rhind S, Doney J, Gunn R, Leslie I (1984) Effects of body condition and environmental stress on ovulation rate, embryo survival and associated plasma follicle stimulating hormone, luteinizing hormone, prolactin and progesterone profiles in Scottish Blackface ewes. Animal Production 38, 201–209.
Effects of body condition and environmental stress on ovulation rate, embryo survival and associated plasma follicle stimulating hormone, luteinizing hormone, prolactin and progesterone profiles in Scottish Blackface ewes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL2cXktFOkur8%3D&md5=8fc17645ae6a83634e20a19bbdb51c9bCAS |

Rondon Z, Forcada F, Zarazaga L, Abecia J, Lozano J (1996) Oestrous activity, ovulation rate and plasma melatonin concentrations in Rasa Aragonesa ewes maintained at two different and constant body condition score levels and implanted or reimplanted with melatonin. Animal Reproduction Science 41, 225–236.
Oestrous activity, ovulation rate and plasma melatonin concentrations in Rasa Aragonesa ewes maintained at two different and constant body condition score levels and implanted or reimplanted with melatonin.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XjtVGgur4%3D&md5=64192979b4795278013df8837c28928aCAS |

Sanson D, West T, Tatman W, Riley M, Judkins M, Moss G (1993) Relationship of body composition of mature ewes with condition score and body weight. Journal of Animal Science 71, 1112–1116.