Breeding ewe lambs successfully to improve lifetime performance

Small Ruminant Research

Volumn 118, Issue 1-3, 2014, Pages 2-15

  Kenyon, P R ^a   Thompson, A N ^b,c   Morris, S T ^a  

^a MASSEY UNIVERSITY   (New Zealand)

^b DEPARTMENT OF AGRICULTURE AND FOOD WESTERN AUSTRALIA   (Australia)

^c MURDOCH UNIVERSITY   (Australia)

Author keywords

Ewe; Growth; Hogget; Lamb; Lifetime performance; Reproduction

Indexed keywords

OVIS ARIES;

EID: 84897081542     PISSN: 09214488     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.smallrumres.2013.12.022     Document Type: Article

References (168)

1. Afolayan R.A., Fogarty N.M., Gilmour A.R., Ingham V.M., Gaunt G.M., Cummins L.J. Reproductive performance and genetic parameters in first cross ewes from different maternal genotypes. J. Anim. Sci. 2008, 86:804-814.
2. Afolayan R.A., Fogarty N.M., Gilmour A.R., Ingham V.M., Gaunt G.M., Cummins L.J. Genetic correlations between early growth and wool production of crossbred ewes and their subsequent reproduction. Anim. Prod. Sci. 2009, 49:17-23.
3. Akcapinar H., Unal N., Atasoy F. The effects of early age mating on some production traits of Bafra (Chios x Karayaka) sheep. Turk. J. Vet. Anim. Sci. 2005, 29:531-536.
4. Allison A.J. Techniques of modifying reproductive performance. Sheep Production, Volume 1-Breeding and Reproduction 1982, 239-263. New Zealand Institute of Agricultural Science, Ray Richards Publisher. G.A. Wickham, M.F. McDonald (Eds.).
5. Allison A.J., Kelly R.W., Lewis J.S., Binnie D.B. Preliminary studies on the efficiency of mating of ewe hoggets. Proc. N. Z. Soc. Anim. Prod. 1975, 35:83-90.
6. Anonymous, 2013. Ministry for Primary Industries, Livestock Statistics. Accessed 25 March 2013. http://www.mpi.govt.nz/news-resources/statistics-forecasting/livestock-statistics.aspx.
7. Annett R.W., Carson A.F. Effect of plane of nutrition during the first month of pregnancy on conception rate, foetal development and lamb output of mature and adolescent ewes. Anim. Sci. 2006, 82:947-954.
8. Atta M., El Khidir The effect of age and diet on the reproductive performance of Sudan Nilotic ewes. J. Agric. Sci. 2005, 143:421-426.
9. Baker R.L., Clark J.N., Carter A.H., Diprose G.D. Genetic and phenotypic parameters in NZ Romney Sheep I. Body weights, fleece weight and oestrous activity. N. Z. J. Agric. Res. 1979, 22:9-21.
10. Baker R.L., Steine F.A., Vabenoe A.W., Bekken A., Gjedrem T. Effect of mating ewe lambs on lifetime performance. Acta Agric. Scand. 1978, 28:203-217.
11. Baker R.L., Clark R.N., Diprose G.D. Effect of mating Romney ewe hoggets on lifetime production-preliminary results. Proc. N. Z. Soc. Anim. Prod. 1981, 41:198-203.
12. Baker R.L., Clark J.N., Harvey G. Crossbred performance of Border Leicesters and Coopworths and six strains of Romneys. Agricultural Research Division Annual Report 1984 1985, 185:38-39. NZ Ministry of Agriculture & Fisheries.
13. Beck N.F.G., Davies M.C.G. The effect of stage of breeding season or pre-mating oestrogen and progesterone therapy on fertility in ewe lambs. Anim. Prod. 1994, 59:429-434.
14. Beck N.F.G., Davies M.C.G., Davies B. A comparison of ovulation rate and late embryonic mortality in ewe lambs and ewes and the role of late embryo loss in ewe lamb subfertility. Anim. Sci. 1996, 62:79-83.
15. Bichard M., Younis A.A., Forrest P.A., Cumberland P.H. Analysis of production records from a lowland sheep flock. Anim. Prod. 1974, 19:177-191.
16. Cannon D.J., Bath J.G. Effect of age at first joining on lifetime production by Border Leicester×Merino ewes. Aust. J. Exp. Agric. Anim. Husb. 1969, 9:477-491.
17. Cave L.M., Kenyon P.R., Morris S.T. Effect of timing of exposure to vasectomised rams and ewe lamb body condition score on the breeding performance of ewe lambs. Anim. Prod. Sci. 2012, 52(6-7):471-477.
18. Chang T.S., Rae A.L. The genetic basis of growth, reproduction, and maternal environment in Romney ewes I. Genetic variation hogget characters and fertility of the ewe. Aust. J. Agric. Res. 1970, 21:115-129.
19. Chang T.S., Rae A.L. The genetic basis of growth, reproduction, and maternal environment in Romney ewes II. Genetic covariation between hogget characters, fertility, and maternal environment of the ewe. Aust. J. Agric. Res. 1972, 23:149-165.
20. Chu T.T., Edey T.N. Reproductive performance of ewe lambs at puberty. Proc. Aus. Soc. Anim. Prod. 1978, 12:251.
21. Corbett J.L., Furnival E.P. Early weaning of grazing sheep, 2. Performance of ewes. Aust. J. Exp. Agric. Anim. Husb. 1976, 16:156-166.
22. Corner R.A., Kenyon P.R., Stafford K.J., West D.M., Morris S.T. The effect of nutrition during pregnancy on the behaviour of adolescent ewes and their lambs within 12h of birth. Proc. N. Z. Soc. Anim. Prod. 2006, 66:439-443.
23. Corner R.A., Kenyon P.R., Stafford K.J., West D.M., Oliver M.H. The effect of different types of stressors during mid- and late-pregnancy on lamb weight and body size at birth. Animal 2010, 4:2065-2070.
24. Corner R.A., Mulvaney F.J., Morris S.T., West D.M., Morel P.C.H., Kenyon P.R. A comparison of the reproductive performance of ewe lambs and mature ewes. Small Rumin. Res. 2013, 114:126-133.
25. Craig R.L. Breeding from Romney ewe hoggets in the Waihora Group Breeding Scheme. N. Z. Agric. Sci. 1982, 16:101-104.
26. Curtis K., Croker K. Wool desk report, September 2005 1985, 17. Department of Agriculture and Food Western Australia.
27. Da Silva P., Aitken R.P., Rhind S.M., Racey P.A., Wallace J.M. Effect of maternal overnutrition during pregnancy on pituitary gonadotrophin gene expression and gonadal morphology in female and male foetal sheep at day 103 of gestation. Placenta 2003, 24:248-257.
28. Dalton D.C., Knight T.W., Johnson D.L. Lamb survival in sheep breeds on NZ hill country. N. Z. J. Agric. Res. 1980, 23:167-173.
29. Davies M.C.G., Beck N.F.G. A comparison of plasma protein LH and progesterone concentrations during oestrus and early pregnancy in ewe lambs and ewes. Anim. Prod. 1993, 57:281-286.
30. De Barbieri I., Montossi F., Vinoles C., Kenyon P.R. Impact of wool stubble depth after mid pregnancy shearing on Corriedale ewe and lamb performance. Small Rumin. Res. 2012, 107:111-116.
31. Donald H.P., Read J.L., Russell W.S. A comparative trial of crossbred ewes by Finnish Landrace and other sires. Anim. Prod. 1968, 10:413-421.
32. Dyrmundsson O.R. Puberty and early reproduction performance in sheep. I. Ewe lambs. Anim. Breed. Abstr. 1973, 41:273-289.
33. Dyrmundsson O.R. Natural factors affecting puberty and reproductive performance in ewe lambs: a review. Livest. Prod. Sci. 1981, 8:55-65.
34. Earl C.R., Dunstan E.A., Stafford J.P., Male R.H., Rowe J.P. Early weaning of crossbred lambs. Proc. Aust. Soc. Anim. Prod. 1990, 18:192-195.
35. Edey T.N., Chu T.T., Kilgour R., Smith J.F., Tervitt H.R. Estrus without ovulation in puberal ewes. Theriogenology 1977, 7:11-15.
36. Edey T.N., Kilgour R., Bremner K. Sexual behaviour and reproductive performance of ewe lambs at and after puberty. J. Agric. Sci. 1978, 90:83-91.
37. Elvidge D.G., Coop I.E. Effect of shearing on feed requirements of sheep. N. Z. J. Exp. Agric. 1974, 2:397-402.
38. Everett-Hincks J.M., Dodds K.G. Management of maternal-behaviour to improve lamb survival in easy care sheep systems. J. Anim. Sci. 2008, 86(ESuppl.):E259-E270.
39. Ferguson M.B., Thompson A.N., Gordon D.J., Hyder M.W., Kearney G.A., Oldham C.M., Paganoni B.L. The wool production and reproduction of Merino ewes can be predicted from changes in liveweight during pregnancy and lactation. Anim. Prod. Sci. 2011, 51:763-775.
40. Fitzgerald J., Butler W.R. Seasonal effects of hormonal patterns related to puberty in ewe lambs. Biol. Reprod. 1982, 27:853-863.
41. Fogarty N.M., Brash L.S., Gilmour A.R. Genetic parameters for reproduction and lamb production and their components and liveweight, fat depth and wool production in Hyfer sheep. Aust. J. Agric. Res. 1994, 45:443-457.
42. Fogarty N.M., Ingham V.M., Gilmour A.R., Afolayan R.A., Cummins L.J., Hocking Edwards J.E., Gaunt G.M. Genetic evaluation of crossbred lamb production 5. Age of puberty and lambing performance of yearling crossbred ewes. Aust. J. Agric. Sci. 2007, 58:928-934.
43. Forrest P.A., Bichard M. Analysis of production records from a lowland sheep flock 2, Flock statistics and reproductive performance. Anim. Prod. 1974, 19:25-32.
44. Foster D.L., Yellon S.M., Olster D.H. Internal and external determinants of the timing of puberty in the female. J. Reprod. Fertil. 1985, 75:327-344.
45. Gaskin C.T., Snowder G.D., Westman M.K., Evans M. Influence of body weight, age and weight gain on fertility and prolificacy in four breeds of ewe lambs. J. Anim. Sci. 2005, 83:1680-1689.
46. 100 more-a guide to hogget mating. Meat and Wool Innovation, Wellington, New Zealand 2002, R. Gavigan, P.V. Rattray (Eds.).
47. Gordon I. Breeding sheep at younger ages. Controlled Reproduction in Sheep and Goats, vol. 2 1999, 341-344. CABI Publishing, New York, USA.
48. Hare L., Bryant M.J. Ovulation rate and embryo survival in young ewes mated either at puberty or at the second or third oestrus. Anim. Reprod. Sci. 1985, 8:41-52.
49. Hegarty R.S., Alcock D., Robinson D.L., Goopy J.P., Vercoe P.E. Nutritional and flock management options to reduce methane output and methane per unit product from sheep enterprises. Anim. Prod. Sci. 2010, 50:1026-1033.
50. Hight G.K. Sheep Production, Volume 1-Breeding and Reproduction 1982, 169-198. New Zealand Institute of Agricultural Science, Auckland, New Zealand. G.A. Wickham, M.F. McDonald (Eds.).
51. Hight G.K., Jury K.E. Hill country sheep production II. Lamb mortality and birth weights in Romney and Border Leicester×Romney flocks. N. Z. J. Agric. Res. 1970, 13:735-752.
52. Hight G.K., Jury K.E. Hill country sheep production VIII. Relationship of hogget and two-year old oestrus and ovulation rate to subsequent fertility in Romeny and Border Leicester×Romney ewes. N. Z. J. Agric. Res. 1976, 19:281-288.
53. Howe L., West D.M., Collet M.G., Tattersfield G., Pattison R.S., Pomroy W.E., Kenyon P.R., Morris S.T., Williamson N.B. The role of Neospora caninum in three cases of unexplained ewe abortions in the southern North Island of New Zealand. Small Rumin. Res. 2008, 75:115-122.
54. Hulet C.V., Wiggins E.L., Ercanbrack S.K. Estrus in range lambs and its relationship to lifetime reproductive performance. J. Anim. Sci. 1969, 28:246-252.
55. Jefferies B.C. Body condition scoring and its use in management. Tas. J. Agric. 1961, 32:19-21.
56. Johnston J.B., Morris S.T., Purchas R.W., McCutcheon S.N., Parker W.J. A comparison of unbred and once-bred lamb production. Proc. N.Z. Soc. Anim. Prod. 1996, 56:307-309.
57. Keane M.G. Effect of previous lambing on body weight and reproductive performance of hoggets. Ir. J. Agric. Res. 1974, 13:191-196.
58. Keane M.G. Breeding from ewe lambs. Farm Food Res. 1976, 7:10-12.
59. Kenyon P.R. Hogget performance-unlocking the potential 2012, 1-50. Beef+Lamb New Zealand, Wellington, New Zealand.
60. Kenyon P.R., Morel P.C.H., Morris S.T., West D.M. The effect of individual liveweight and use of teaser rams prior to mating on the reproductive performance of ewe hoggets. N. Z. Vet. J. 2005, 53:340-343.
61. Kenyon P.R., Morel P.C.H., West D.M., Morris S.T. Effect of liveweight and teasing of ewe hoggets prior to breeding on lambing pattern and weight of singleton lambs. N. Z. J. Agric. Res. 2006, 49:341-347.
62. Kenyon P.R., Morel P.C.H., Morris S.T., Burnham D.L., West D.M. The effect of length of use of teaser rams prior to mating and individual liveweight on the reproductive performance of ewe hoggets. N. Z. Vet. J. 2006, 54:91-95.
63. Kenyon P.R., Morel P.C.H., Morris S.T., Burnham D.L., West D.M. The effect of teaser ratio prior to breeding on the reproductive performance of ewe hoggets. N. Z. Vet. J. 2007, 55:342-345.
64. Kenyon P.R., Morel P.C.H., West D.M., Morris S.T. Effect of age of ram on the reproductive performance of ewe hoggets. N. Z. Vet. J. 2007, 55:184-187.
65. Kenyon P.R., Morel P.C.H., West D.M., Morris S.T. A note on the effect of vasectomised rams and short-term exposure to entire rams prior to the breeding period on the reproductive performance of ewe lambs. Appl. Anim. Behav. Sci. 2008, 110:397-403.
66. Kenyon P.R., Morris S.T., Perkins N.R., West D.M. Hogget mating in New Zealand-a survey. Proc. N. Z. Soc. Anim. Prod. 2004, 64:217-222.
67. Kenyon P.R., Morris S.T., Revell D.K., McCutcheon S.N. Shearing during pregnancy-review of a policy to increase birthweight and survival of lambs in New Zealand pastoral farming systems. N. Z. Vet. J. 2003, 51:200-207.
68. Kenyon P.R., Morris S.T., West D.M. Effects of nutrition during pregnancy on hogget pregnancy outcome and birthweight and liveweights of lambs. N. Z. J. Agric. Res. 2008, 51:77-83.
69. Kenyon P.R., Morris S.T., West D.M. The proportion of rams and the condition of ewe lambs at joining influences their breeding performance. Anim. Prod. Sci. 2010, 50:454-459.
70. Kenyon P.R., Pinchcheck G.L., Perkins N.R., Morris S.T., West D.M. Identifying factors which maximise the lambing performance of hoggets, a cross-sectional experiment. N. Z. Vet. J. 2004, 52:371-377.
71. Kenyon P.R., Proctor L., Morel P.C.H., Morris S.T., West D.M. The effect of breeding ewe lambs on subsequent two-year-old ewe performance. Livest. Sci. 2008, 115:206-210.
72. Kenyon P.R., Revell D.K., Morris S.T. Mid-pregnancy shearing can increase birth weight and survival to weaning of multiple-born lambs under commercial conditions. Aust. J. Exp. Agric. 2006, 46:821-825.
73. Kenyon P.R., Sherlock R.G., Morris S.T., Moral P.C.H. The effect on mid- and late-pregnancy shearing of hoggets on lamb birth weight, weaning weight, survival rate, and wool follicle and fibre characteristics. Aust. J. Agric. Res. 2006, 57:877-882.
74. Kenyon P.R., Smith S.L., Morel P.C.H., Morris S.T., West D.M. 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. N. Z. Vet. J. 2009, 57:290-294.
75. Kenyon P.R., van der Linden D.S., West D.M., Morris S.T. The effect of breeding hoggets on lifetime performance. N. Z. J. Agric. Res. 2011, 54:321-330.
76. Knight T.W., Lynch P.R., Hall D.R.H., Hockey H-U.P. Identification of factors contributing to increased lamb survival in Marshall Romney sheep. N. Z. J. Agric. Res. 1988, 31:259-271.
77. Laster D.B., Glimp H.A., Dickerson G.E. Factors affecting reproduction in ewe lambs. J. Anim. Sci. 1972, 35:79-83.
78. Loureiro M.F.P., Pain S.J., Kenyon P.R., Blair H.T. Do fetuses from primiparous one-year-old ewes differ from those of multiparous mature ewes?. Proc. N. Z. Soc. Anim. Prod. 2010, 70:118-120.
79. Loureiro M.F.P., Pain S.J., Kenyon P.R., Peterson S.W., Blair H.T. Single female offspring born to primiparous ewe-lambs are lighter than those born to adult multiparous ewes but their reproduction and milk production are unaffected. Anim. Prod. Sci. 2012, 52:552-556.
80. Loureiro M.F.P., Paten A.M., Asmad K., Pain S.J., Kenyon P.R., Pomroy W.E., Scott I., Blair H.T. The effect of dam age and lamb birth rank on the growth rate, faecal egg count and onset of puberty of single and twin female offspring to 12 month of age. Proc. N. Z. Soc. Anim. Prod. 2011, 71:83-85.
81. McCall D.G. Factors affecting hogget lambing performance. Annual Report 1977 1978, 178:3-4. Whatawhata Hill Country Research Station.
82. McCall D.G., Hight G.K. Environmental influences on hogget lambing performance and the relationship between hogget and two-tooth lambing performance. N. Z. J. Agric. Res. 1981, 24:145-152.
83. McMillan W.H. Hogget lamb mortality. Proc. N. Z. Soc. Anim. Prod. 1983, 43:33-36.
84. McMillan W.H., Knight T.W. Shearing and time of joining effects on reproduction in two-tooth ewes. Proc. N. Z. Soc. Anim. Prod. 1982, 42:45-46.
85. McMillan W.H., McDonald M.F. Reproduction in ewe lambs and its effects on two-year old performance. N. Z. J. Agric. Res. 1983, 26:437-442.
86. McMillan W.H., McDonald M.F. Survival of fertilised ova from ewe lambs and adult ewes in the uteri of ewe lambs. Anim. Reprod. Sci. 1985, 8:235-240.
87. McMillan W.H., Moore R.W. Capitalising on hogget oestrus. Proceedings of Sheep & Beef cattle Society of the NZ Veterinary Association, vol. 13 1983, 47-52.
88. McMillan W.H., Parker W.J. Mating of Ewe Hoggets-An Appraisal for a Wairarapa Farm 1981, 35-45. Massey University Riverside Farm Publication No. 5.
89. McMillan W.H., Wilson L.D. Autumn shearing and level of rearing effects on hogget reproduction. Agricultural Research Division Annual Report 1981 1982, 182:114. Ministry of Agriculture & Fisheries.
90. McMillan W.H., Wilson L.D. Hogget reproduction responses to shearing and rearing level. Agricultural Research Division Annual Report 1982 1983, 183:142. Ministry of Agriculture & Fisheries.
91. Meyer A.M., Reed J.J., Neville T.L., Taylor J.B., Hammer C.J., Reynolds L.P., Redmer D.A., Vonnahme K.A., Caton J.S. Effects of plane of nutrition and selenium supply during gestation on ewe and neonatal offspring performance, body composition, and serum selenium. J. Anim. Sci. 2010, 88:1786-1800.
92. Meyer A.M., Reed J.J., Neville T.L., Thorson J.F., Maddock-Carlin K.R., Taylor J.B., Reynolds L.P., Redmer D.A., Luther J.S., Hammer C.J., Vonnahme K.A., Caton J.S. Nutritional plane and selenium supply during gestation affect yield and nutrient composition of colostrums and milk in primiparous ewes. J. Anim. Sci. 2011, 89:1627-1639.
93. Meyer H.H. Early predictors of ewe fertility. Proc. N. Z. Soc. Anim. Prod. 1981, 41:204-208.
94. Meyer H.H., French R.L. Hogget liveweight-oestrus relationship among sheep breeds. Proc. N. Z. Soc. Anim. Prod. 1979, 39:56-62.
95. Moore R.W., Knight T.W., Whyman D. Influence of hogget oestrus on subsequent ewe fertility. Proc. N. Z. Soc. Anim. Prod. 1978, 38:90-96.
96. Moore R.W., McMillan W.H., Dockrill G., Dow B.W. Lambing of Romney and Booroola cross hoggets with and without the F gene under different pasture allowances. Proc. N. Z. Soc. Anim. Prod. 1989, 49:281-283.
97. Moore R.W., Smeaton D.C. Effects of different growth paths from 4 to 11 months of age on Romney hogget oestrus and subsequent reproduction. Proc. N. Z. Soc. Anim. Prod. 1980, 40:27-33.
98. Moore R.W., Sumner R.M.W., Bass J.J., Hockey H.-U.P. Hogget lambing and its effect on the subsequent two-tooth performance of three breeds. Proc. N. Z. Soc. Anim. Prod. 1983, 43:21-24.
99. Moore R.W., Sumner R.M.W., Miller C.M. The effect of hogget lambing on subsequent performance of three breeds. Agricultural Research Division Annual Report 1983 1984, 184:137. NZ Ministry of Agriculture & Fisheries.
100. Morel P.C.H., Morris S.T., Kenyon P.R. Effects of birth weight on survival in twin born lambs. Proc. N. Z. Soc. Anim. Prod. 2009, 69:75-79.
101. Morel P.C.H., Wickham J.L., Morel J.P., Wickham G.A. Effect of birth rank and yearling lambing on long-term ewe reproductive performance. Proc. N. Z. Soc. Anim. Prod. 2010, 70:88-90.
102. Morris S.T., Kenyon P.R., West D.M. Effect of hogget nutrition in pregnancy on lamb birth weight and survival to weaning. N. Z. J. Agric. Res. 2005, 48:165-175.
103. Muir, P., 2001. Finding out more about hogget oestrus. Meat NZ R & D Brief 92 March 2001, 2 pp.
104. Mulvaney, F.J., 2011. Investigating methods to improve the reproductive performance of hoggets. PhD Thesis. Massey University, New Zealand.
105. Mulvaney F.J., Kenyon P.R., Morris S.T., West D.M. Ewe lamb nutrition during pregnancy affects pregnancy outcome. Aust. J. Exp. Agric. 2008, 48:1085-1089.
106. Mulvaney F.J., Morris S.T., Kenyon P.R., Morel P.C.H., West D.M. Effect of nutrition from mid-pregnancy to parturition on the live weight of twin bearing hoggets and the live weight and survival of their lambs. N. Z. J. Agric. Res. 2012, 55:385-392.
107. Mulvaney F.J., Morris S.T., Kenyon P.R., West D.M., Morel P.C.H. The effect of weaning at 10 or 14 weeks of age on liveweight changes in the hogget and her lambs. Proc. N. Z. Soc. Anim. Prod. 2009, 69:68-70.
108. Mulvaney F.J., Morris S.T., Kenyon P.R., West D.M., Morel P.C.H. Effect of live weight at the start of the breeding period and live weight gain during the breeding period and pregnancy on reproductive performance of hoggets and the live weight of their lambs. N. Z. J. Agric. Res. 2010, 53:355-364.
109. Mulvaney F.J., Morris S.T., Kenyon P.R., West D.M., Morel P.C.H. Effect of nutrition around the time of breeding and during pregnancy on yearling live weight change, pregnancy loss and live weight and survival of their offspring. Proc. N. Z. Soc. Anim. Prod. 2010, 70:91-95.
110. Mulvaney F.J., Morris S.T., Kenyon P.R., Morel P.C.H., West D.M. Effect of nutrition pre-breeding and during pregnancy on breeding performance of ewe lambs. Anim. Prod. Sci. 2010, 50:953-960.
111. Mulvaney F.J., Morris S.T., Kenyon P.R., Morel P.C.H., West D.M. Is there any advantage of early weaning of twin lambs born to hoggets?. Proc. N. Z. Soc. Anim. Prod. 2011, 71:79-82.
112. Munoz C., Carson A.F., McCoy M.A., Dawson L.E.R., O'Connell N.E., Gordon A.W. Effect of plane of nutrition of 1- and 2- year old ewes in early and mid-pregnancy on ewe reproduction and offspring performance up to weaning. Animal 2009, 3:657-669.
113. Nicol A.M., Brookes I.M. The metabolisable energy requirments of grazing livestock, Pasture and Supplements for Grazing Animals. Occasional Publication No. 14 2007, 151-172. New Zealand Society of Animal Production, Christchurch, New Zealand. P.V. Rattray, I.M. Brookes, A.M. Nicol (Eds.).
114. Oldham C.M., Thompson A.N., Ferguson M.B., Gordon D.J., Kearney G.A., Paganoni B.L. The birth weight and survival of Merino lambs can be predicted from the profile of liveweight change of their mothers during pregnancy. Anim. Prod. Sci. 2011, 51:776-783.
115. Palmer R.M., Thompson M.G., Meallet C., Thom A., Aitken R.P., Wallace J.M. Growth and metabolism of fetal and maternal muscles of adolescent sheep on adequate or high feed intakes:possible role of protein kinase C-α in fetal muscle growth. Brit. J. Nutr. 1998, 79:351-357.
116. Parr R.A. Nutrition-Progesterone interactions during early pregnancy in sheep. Reprod. Fertil. Dev. 1992, 4:297-300.
117. Peel R.K., Eckerle G.J., Anthony R.V. Effects of overfeeding naturally-mated adolescent ewes on maternal, fetal and postnatal lamb growth. J. Anim. Sci. 2012, 90:3698-3708.
118. Ponzoni R.W., Azzarini M., Walker S.K. Production in mature corriedale ewes first mated at 7 to 11 or 18 months of age. Anim. Prod. 1979, 29:385-391.
119. Ptak G., Tischner M., Bernabo N., Loi P. Donor dependent developmental competence of ooctyes from lambs subjected to repeated hormonal stimulation. Biol. Reprod. 2003, 69:258-278.
120. Quirke J.F. Control of reproduction in adult ewes and ewe lambs, and estimation on reproductive wastage in ewe lambs following treatment with progestagen impregnated sponges and PMSG. Livest. Prod. Sci. 1979, 6:295-305.
121. Quirke J.F. Oestrus, ovulation, fertilisation and early embryo mortality in progestagen-PMSG treated Galway ewe lambs. Ir. J. Agric. Res. 1979, 18:1-11.
122. Quirke J.F. Regulation of puberty and reproduction in female lambs, a review. Livest. Prod. Sci. 1981, 8:37-53.
123. Quirke J.F., Hanrahan J.P. Comparison of the survival in the uteri of adult ewes of cleaved ova from adult ewes and ewe lambs. J. Reprod. Fertil. 1977, 51:487-489.
124. Rattray P.V., Morrison M.C.L., Farquhar P.A. Performance of early-weaned lambs on lucerne and pasture. Proc. N. Z. Soc. Anim. Prod. 1976, 36:179-183.
125. Rosales Nieto C.A., Ferguson M.B., Macleay C.A., Briegel J.R., Martin G.B., Thompson A.N. Selection for superior growth advances the onset of puberty and increases reproductive performance in ewe lambs. Animal 2013, 7:990-997.
126. Rosales Nieto C.A., Ferguson M.B., Macleay C.A., Briegel J.R., Wood D.A., Martin G.B., Thompson A.N. Ewe lambs with higher breeding values for growth achieve higher reproductive performance when mated at age 8 months. Theriogenology 2013, 80:427-435.
127. Russel A.J.F., Doney J.M., Gunn R.G. Subjective assessment of body fat in live sheep. J. Agric. Sci. (Cambridge) 1969, 72:451-454.
128. Safari E., Fogarty N.M., Gilmour A.R. A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep. Livest. Prod. Sci. 2005, 92:271-289.
129. Safari E., Fogarty N.M., Gilmour A.R., Atkins K.D., Mortimer S.I., Swan A.A., Brien F.D., Greeff J.C., van der Werf J.H.J. Genetic correlations among and between wool, growth and reproduction traits in Merino sheep. J. Anim. Breed. Genet. 2007, 124:65-72.
130. Schick G. Hogget mating-will you follow the trend?. Wool Grower Summer 2001, 2001:25-26.
131. Scaramuzzi R., Campbell B., Downing J., Kendall N., Khalid M., Munoz-Gutierrez M., Somchit A. A review of the effects of supplementary nutrition in the ewe on the concentrations of reproductive and metabolic hormones and the mechanisms that regulate folliculogenesis and ovulation rate. Reprod. Nutr. Dev. 2006, 46:339-354.
132. Schreurs N.M., Kenyon P.R., Mulvaney F.J., Morel P.C.H., West D.M., Morris S.T. Response of additional ewe lamb liveweight during gestation on birth and weaning weight of offspring and liveweight of the ewe lamb at weaning. Anim. Prod. Sci. 2010, 50:528-532.
133. Smeaton D.C., Knight T.W., Sumner R.M.W. Effect of early weaning on ewe liveweight and ovulation rate at mating. Agricultural Research Division Annual report 1979/1980 1979, Ministry of Agriculture and Fisheries, Wellington, New Zealand.
134. Smith J.F. A Review of recent developments on the effect of nutrition on ovulation rate the flushing effect with particular reference to research at Ruakura. Proc. N. Z. Soc. Anim. Prod. 1991, 51:15-23.
135. Smith M.E., Bigham M.L., Knight T.W., Sumner R.M.W. A review of effects of shearing on sheep production. Proc. N. Z. Soc. Anim. Prod. 1980, 40:215-220.
136. Smith M.E., Knight T.W. Reproductive management of sheep, Reproductive management of grazing ruminants in New Zealand. Occasional Publication No. 12 1998, 113-144. New Zealand Society of Animal Production. E.D. Fielden, J.F. Smith (Eds.).
137. Smith J.F., Parr J., Murray G., Harris C., Duganzich D.M. Effect of selection for early lambing on the expression of hogget oestrus activity. Proc. N. Z. Soc. Anim. Prod. 1995, 55:154-156.
138. Snowder G.D., Kinght A.D., Van Vleck L.D., Bromley C.M., Kellom T.R. Usefulness of subjective ovine milk scores, 1. Associations with range ewe characteristics and lamb production. J. Anim. Sci. 2001, 79:811-818.
139. Stephenson S.K., Dalton D.C., Kirton A.H. The relationships between growth, body shape and body composition to the initiation of oestrus activity in different sheep breeds. Proc. N. Z. Soc. Anim. Prod. 1980, 40:258-267.
140. Stevens, D., McIntyre, S., 1999. Hogget mating survey. AgResearch Wool Pro Internal Report, 24 pp.
141. Stevens, D.R., 2001a. Best management practices for hogget lambing. Otago Southland Hogget Survey Group. Final Report Autumn 2001, 12 pp. plus appendix.
142. Stevens, D.R., 2001b. Best management practices for hogget mating. Report of premating feeding Autumn 2000. Otago Southland Hogget Survey Group. A FITT Funded Meat NZ and Wool Pro Project, 6 pp.
143. Suiter R.J., Croker K.P. Mating weaners does not affect future ewe performance. J. Agric. S. Perth 1970, 11:92.
144. Sumner R.M.W., Bigham M.L., Knight T.W., McMillan W.H., Wiggins L.K. Shearing-its effects on production. Proceedings of the Ruakura Farmers Conference 1982, 31-34.
145. Swanson T.J., Hammer C.J., Luther J.S., Carlson D.B., Taylor J.B., Redmer D.A., Neville T.L., Reed J.J., Reynolds L.P., Caton J.S., Vonnahme K.A. Effects of gestation plane of nutrition and selenium supplementation on mammary gland development and colostrums quality in pregnant ewes. J. Anim. Sci. 2008, 86:2415-2423.
146. Thomas L., Wallace J.M., Aitken R.P., Mercer J.G., Trayhurn P., Hoggard N. Circulating leptin during ovine pregnancy in relation to maternal nutrition, body composition and pregnancy outcome. J. Endocrinol. 2001, 169:465-476.
147. Thompson B.C., Muir P.D., Smith N.B. Litter size, lamb survival, birthand twelve week weight in lambs born to cross-bred ewes. Proc. N. Z. Grassl. Assoc. 2004, 66:233-237.
148. Tyrell R.N. Some effects of pregnancy in eight-month old Merino ewes. Aust. J. Exp. Agric Anim. Husb. 1976, 16:458-461.
149. Vonnahme K.A., Luther J.S., Reynolds L.P., Hammer C.J., Carlson D.B., Redmer D.A., Caton J.S. Impacts of maternal selenium and nutritional level on growth, adiposity, and glucose tolerance in female offspring in sheep. Domest. Anim. Endocrinol. 2010, 39:240-248.
150. Wallace J.M. Adaptive maternal, placental and fetal responses to nutritional extremes in the pregnant adolescent, lessons from sheep. Reproduction and Adaptation, Chapter 6 1996, 112-126. Cambridge University Press, England. C.G.S. Mascie-Taylor, L. Rosetta (Eds.).
151. Wallace J.M., Aitken R.P., Cheyne M.A. Nutrient partitioning and fetal growth in rapidly growing adolescent ewes. J. Reprod. Fertil. 1996, 107:183-190.
152. Wallace J.M., Aitken R.P., Cheyne M.A., Humblot P. Pregnancy-specific protein B and progesterone concentrations in relation to nutritional regimen, placental mass and pregnancy outcome in growing adolescent ewes carrying singleton fetuses. J. Reprod. Fertil. 1997, 109:53-58.
153. Wallace J.M., Bourke D.A., Aitken R.P., Cruickshank M.A. Switching maternal dietary intake at the end of the first trimester has profound effects on placental development and fetal growth in adolescent ewes carrying singleton foetuses. Biol. Reprod. 1999, 6:101-110.
154. Wallace J.M., Bourke D.A., Aitken R.P., Palmer R.M., Da Silva P., Cruickshank M.A. Relationship between nutritionally-mediated placental growth restriction and fetal growth, body composition and endocrine status during late gestation in adolescent sheep. Placenta 2000, 21:100-108.
155. Wallace J.M., Bourke D.A., Aitken R.P., Milne J.S., Hay W.W. Placental glucose transport in growth-restricted pregnancies induced by overnourishing adolescent sheep. J. Physiol. 2002, 547:85-94.
156. Wallace J.M., Bourke D.A., Aitken R.P., Leitch N., Hay W.W. Blood flows and nutrient uptakes in growth-restricted pregnancies induced by overnourishing adolescent sheep. Am. J. Physiol. Reg. I 2002, 282:R1027-R1036.
157. Wallace J.M., Bourke D.A., Da Silva P., Aitken R.P. Influence of progesterone supplementation during the first third of pregnancy on fetal and placental growth in overnourished adolescent ewes. Reproduction 2003, 126:481-487.
158. Wallace J.M., Da Silva P., Aitken R.P., Cruickshank M.A. Maternal endocrine status in relation to pregnancy outcome in rapidly growing adolescent sheep. J. Endrocrinol. 1997, 155:359-368.
159. Wallace J.M., Matsuzaki M., Milne J., Aitken R. Late but not early gestational maternal growth hormone treatment increases fetal adiposity in overnourished adolescent sheep. Biol. Reprod. 2006, 75:231-239.
160. Wallace J.M., Milne J.S., Redmer D.A., Aitken R.P. Effect of diet composition on pregnancy outcome in over nourished rapidly growing adolescent sheep. Br. J. Nutr. 2006, 96:1060-1068.
161. Wallace J.M., Milne J.S., Aitken R.P., Hay W.W. Sensitivity to metabolic signals in late-gestation growth-restricted foetuses from rapidly growing adolescent sheep. Am. J. Physiol. Endocrinol. M 2007, 293:E1233-E1241.
162. Wallace J.M., Milne J.S., Matsuzaki M., Aitken R.P. Serial measurement of uterine blood flow from mid to late gestation in growth restricted pregnancies induced by overnourishing adolescent sheep dams. Placenta 2008, 29:718-724.
163. Wallace J.M., Milne J.S., Aitken R.P. Effect of weight and adiposity at conception and wide variations in gestational dietary intake on pregnancy outcome and early postnatal performance in young adolescent sheep. Biol. Reprod. 2010, 82:320-330.
164. West D.M., Pomroy W.E., Collet M.G., Hill F.I., Ridler A., Kenyon P.R., Morris S.T., Pattision R.S. A possible role for Neospora caninum in ovine abortion in New Zealand. Small Rumin. Res. 2006, 62:135-138.
165. Weston J.F., Howe L., Collett M.G., Pattison R.S., Williamson N.B., West D.M., Pomroy W.E., Syed-Hussain S.S., Morris S.T., Kenyon P.R. Dose-titration challenge of young pregnant sheep with Neospora caninum tachyzoites. Vet. Parasitol. 2009, 164:183-191.
166. Winn C.W., Cumberland G.L.P. Relationships of various parameters with lambing performance of hoggets. Proc. N. Z. Soc. Anim. Prod. 1974, 35:100-101.
167. Young J.M., Thompson A.N., Kennedy A.J. Bioeconomic modelling to identify the relative importance of a range of critical control points for prime lamb production systems in south-west Victoria. Anim. Prod. Sci. 2010, 50:748-756.
168. Zain A.E.D., Mousa M. The effect of stage of breeding season and administration of fertirelin acetate GnRH analogue post-mating on ovarian activity and fertility in ewe lambs. Assieut. Vet. Med. J. 1999, 42:353-370.