@conference {3678, title = {BRIEF COMMUNICATION: Are fetal programming effects, due to maternal early pregnancy nutrition, evident in adult male offspring in sheep?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {209-211}, address = {Napier}, abstract = {Manipulation of fetal development processes via maternal nutritional intervention can affect the physiology and cellular function of adult offspring through a process known as fetal programming (Harding \& Johnson 1995). Nutritional status of the dam in the first trimester of pregnancy is crucial to fetal development because, although fetal energy requirements in early pregnancy are relatively small, and thus, total nutrient demand is typically low, fetal metabolic activity is very high and organogenesis is occurring (Harding \& Johnson 1995)...}, issn = {1176-5283}, author = {Pain SJ and Asmad K and Fermin LM and Kenyon PR and Blair HT} } @conference {89265, title = {Effect of dam size and nutrition during pregnancy on fetal testicular development in sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {41-44}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

In male sheep, testicular development is almost complete at birth. Testicular cells start to differentiate as early as Day (D) 27 of gestation followed by steroidogenesis and the activation of associated enzyme systems (Rhind 2004). Sertoli cells are present at around D34 and replication continues postnatally (Hochereau-de Reviers et\  al. 1987). Seminiferous cords that will develop into tubules appear between D35 and D40 (Sweeney et al. 1997; Rhind et al. 2001). By D70 the rete testis is organised in the centre of testis (Sweeney et al. 1997) and between D35 and D85 the GnRH neuronal system develops in the hypothalamus (Caldani et al. 1995). Testicular gonocytes are typically observed between birth and 25 days after birth, and then progressively differentiate into spermatogonia up to 70 days after birth (Sharpe et al. 2003).

}, issn = {1176-5283}, author = {Asmad K and Kenyon PR and Parkinson TJ and Pain SJ and Lopez-Villalobos N and Blair HT} } @conference {78985, title = {Effects of maternal nutrition during pregnancy on the growth and reproductive development of male sheep: a meta-analysis}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {51-57}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {

Nutrient supply to the fetus is one of the crucial factors in the regulation of fetal growth and reproductive development. The effect of maternal nutrition can be exerted at all stages of fetal development, from conception until birth. A meta-analysis of maternal nutrition effects on the growth and reproductive development of male sheep offspring was undertaken using sixteen sheep studies. Eleven studies were included for prediction of the growth curves using a logistic growth model, and eleven studies were included for reproductive development and analysed using a mixed model. The meta-analysis suggested that, male sheep offspring undernourished during gestation had a significantly slower growth and lower testosterone levels while there were no statistically significant effects on testis weight, seminiferous tubule diameter or Sertoli cell count. The lack of a statistical effect on seminiferous tubule diameter and Sertoli cell count may be due to the limited number of studies examining the effects of maternal nutrition during pregnancy on male sheep offspring reproductive development. The meta-analysis reported here suggests that additional studies are warranted to more conclusively determine whether maternal nutrition during pregnancy effects male sheep growth and reproductive development.

}, issn = {1176-5283}, author = {Asmad K and Nakagawa S and Lopez-Villalobos N and Kenyon PR and Pain SJ and Blair HT} } @conference {75879, title = {BRIEF COMMUNICATION: 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}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {83-85}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Breeding ewe lambs at eight to nine months of age has gained popularity on New Zealand sheep farms in recent years. This is predominantly because of the many production advantages it offers: greater net profits, increased number and weight of lambs produced per ewe productive lifetime, better use of spring herbage, early recognition of fertility potential, increased rates of genetic gain and... Continued}, issn = {1176-5283}, author = {Loureiro MFP and Paten AM and Asmad K and Pain SJ and Kenyon PR and Pomroy WE and Scott I and Blair HT} } @conference {75873, title = {BRIEF COMMUNICATION: The effects of dam nutrition during pregnancy on the postnatal growth and puberty attainment of ewe progeny}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {56-58}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {In New Zealand{\textquoteright}s pastoral sheep-production systems, feed can become limiting during winter, when breeding ewes are pregnant. Ewes are often restrictively fed during early-gestation (Kenyon \& Webby, 2007) to enable greater levels of nutrition in late-gestation. Many studies have demonstrated that dam nutrition during various stages of pregnancy can program the...}, issn = {1176-5283}, author = {Paten AM and Asmad K and Loureiro MFP and Kenyon PR and Pain SJ and Peterson SW and Pomroy WE and Scott I and Blair HT} } @conference {75874, title = {BRIEF COMMUNICATION: The effects of dam nutrition during pregnancy on the growth of male offspring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {59-61}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {During pregnancy, nutritional status of the ewe is crucial because of its potential effect on fetal development, subsequent lamb survival and reproduction post-birth (Rhind et al., 2001). Manipulation of the progress of fetal development can affect the structure and physiology of adult offspring through the process of fetal programming (Barker et al., 1993). Epidemiological data... Continued }, issn = {1176-5283}, author = {Asmad K and Paten AM and Loureiro MFP and Kenyon PR and Pain SJ and Parkinson TJ and Pomroy WE and Scott I and Blair HT} }