@conference {3672, title = {BRIEF COMMUNICATION: Does Viagra protect fetal lambs against maternal pregnancy toxaemia?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {172-174}, address = {Adelaide}, abstract = {Poor fetal growth is commonly caused by placental insufficiency. In sheep, multiple fetuses have relatively small placentae with fewer cotyledons than singletons, limiting blood flow to the placenta, especially in late gestation when fetal growth rate is highest. Factors that reduce fetal growth, such as maternal genotype, nutrition, age, parity, fetal number, or environmental temperature, typically reduce placental size and are associated with lower rates of fetal oxygen and nutrient uptakes and placental blood flow (Reynolds \& Redmer 2001). Further, circumstances that influence placental vascular development have a dramatic impact on fetal growth and development, and affect neonatal survival and growth (Borowicz et al. 2007; Satterfield et al, 2010). Sildenafil citrate (SC, trade names Viagra or Avigra) increases vasodilatation of uteroplacental vessels (Wareing et al. 2005) and may represent a novel therapy to improve fetal lamb growth. Sildenafil citrate has successfully increased birth weight in rodent models and singleton bearing ewes (Satterfield et al. 2010; Miller at al. 2009). There is no published information regarding the use of SC in multiple-bearing ewes. The objective of this trial was to determine if SC administration to triplet-bearing ewes in late gestation could increase lamb birth weight. In addition, the influence of SC on the incidence of pregnancy toxaemia is also reported here.}, issn = {1176-5283}, author = {Peterson SW and Pain SJ and McCoard SA and Oliver M and Baker PN and Kenyon PR and Blair HT} } @conference {3672, title = {Reproductive performance of singleton and twin female offspring born to ewe-lamb dams and mature adult dams}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {76}, year = {2016}, month = {07/2016}, pages = {151-154}, address = {Adelaide}, abstract = {This study was undertaken to compare the reproductive and live weight performance of female singleton and twin ewes born to either mature or young dams from 18 months to 2.5 years of age. One hundred and fifteen singleton- and twin-born female offspring born to either ewe-lamb (8 months at breeding) or adult ewe dams were maintained as one cohort under commercial New Zealand grazing conditions. Ewe live weights and body condition scores were recorded, as were ovulation rates at a synchronised breeding and number of fetuses present at pregnancy scanning. The live weight of ewes born to ewe-lambs were lighter (P<0.05) than those born to adult ewes at breeding and during their first pregnancy but not (P>0.05) at the weaning of their lambs. Twin-born ewes were lighter (P<0.05) than their singleton-born counterparts. There was no difference in corpora lutea number (P>0.05) at breeding or number of fetuses at pregnancy scanning. Lambs whose grand dam was a ewe-lamb were heavier at birth (P<0.05) but not at weaning (P>0.05) compared to those lambs whose grand dams was an adult ewe. This data suggests there are few negative impacts from selecting progeny born to ewe lambs as replacement ewes. However, before this hypothesis can be supported, lifetime data of these ewes needs to be collected.}, issn = {1176-5283}, author = {Loureiro MFP and Pain SJ and Kenyon PR and Blair HT} } @conference {3672, title = {The effect of dam age on ewe offspring productive performance and efficiency}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {239-242}, address = {Dunedin}, abstract = { productive performance and efficiency of singleton ewe offspring to four years of age. Live weight was recorded every two months from birth to four years of age for singleton ewe progeny born to either ewe-lamb dams or adult ewes (ewe-lamb progeny: ELP, n = 20; adult-ewe progeny: AEP, n = 25). The number of lambs born and weaned, and weight (kg) of lamb born and weaned were determined for each ewe for each productive year and as a combined total. Ewe production efficiency was calculated for each year and as a combined total. Results show that AEP were heavier at birth and remained heavier until one year of age (P<0.05). Live weight was again greater (P<0.05) for AEP in mid-pregnancy in 2010 and at weaning in 2011. The number of lambs born and weaned and the weight of lamb born and weaned per ewe did not differ in any of the three productive years or for the combined total. Ewe production efficiency was not affected by dam age, with similar efficiencies reported for ELP and AEP. The results from this study show that despite experiencing a weight penalty, the productive performance and efficiency of singleton ewe progeny born to ewe-lamb dams, if conventionally bred themselves as 18 months of age, appears to be similar to that of singleton ewe progeny born to mature adult ewes.}, issn = {1176-5283}, author = {Pain SJ and Loureiro MFP and Kenyon PR and Blair HT} } @conference {3672, title = {Effect of dam age on the growth and body composition of singleton ram offspring to 11 months of age}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {75}, year = {2015}, month = {07/2015}, pages = {231-234}, address = {Dunedin}, abstract = { Studies in sheep suggest that ewe-lamb dams produce smaller offspring compared to mature adult ewes. This study was designed to examine the growth trajectory, body composition and carcass characteristics of 48 singleton Romney male progeny born to either ewe-lambs (ELP; n = 17) or adult ewes (AEP; n = 21). Both dam groups were maintained together under commercial grazing conditions during breeding, pregnancy and lactation. After, weaning the ram lambs continued to be managed together under commercial conditions. Ram offspring were weighed and measured at birth. They were subsequently weighed every two months until 11 months of age (d322). At d322, nine ELP and 10 AEP were euthanised and several body-size and composition measurements were taken. The ELP were lighter and smaller (P<0.05) at birth compared with AEP and they remained significantly (P<0.05) lighter until d218. After d218 this difference in live weight became a tendency (P<0.1). Slaughter data revealed that ELP tended (P<0.1) to have more visceral fat than AEP (P<0.05). Similarly, dual-energy X-ray absorptiometry (DXA) was performed on the left hind-leg and showed that AEP tended to have greater (P<0.1) lean mass compared with ELP. Despite the liveweight differences and the tendency towards differences in adiposity observed at slaughter, ram lamb carcass weight and dressing-out percentage were unaffected indicating that ram offspring meat production from ewe-lamb dams is similar to that from mature adult ewes.}, issn = {1176-5283}, author = {Loureiro MFP and Pain SJ and Kenyon PR and Firth EC and Rogers CW and Blair HT} } @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 {3678, title = {BRIEF COMMUNICATION: Comparison of early embryo development in Cheviot and Suffolk breeds of sheep}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {202-204}, address = {Napier}, abstract = {Maternal constraint is the major non-genetic factor determining the size of the fetus at term (Gluckman \& Hanson 2004). Previous studies in various animal models have reported the effect of maternal size on birth size and postnatal growth, (Allen et al. 2002; Gardner et al. 2007) whereby fetal development and birth weight are reduced in a restricted maternal uterine environment, while enhanced in a luxurious uterine environment...}, issn = {1176-5283}, author = {Fermin LM and Pain SJ and Blair HT and Kenyon PR} } @conference {3728, title = {BRIEF COMMUNICATION: Developmental programming in sheep due to early pregnancy nutrition alters milk yields of adult female offspring but not of grand-offspring}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {212-214}, address = {Napier}, abstract = {Two long-term studies by our group have shown that nutrition of the pregnant dam altered the growth and development of the ewe offspring, and their subsequent lactational performance (van der Linden et al. 2009; Paten et al. 2013a). These effects were attributed to developmental programming possibly via epigenetic changes. Epigenetic regulation, such as histone modifications and chromatin condensation, has been implicated in the short- and long-term control of transcription in mammary epithelial cells (Kress et al. 2010)...}, issn = {1176-5283}, author = {Peterson SW and Pain SJ and Jenkinson CMC and Kenyon PR and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: Grand-dam age has no effect on ram lamb live weight and carcass characteristics}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {196-198}, address = {Napier}, abstract = {Breeding ewe lambs at 7 to 9 months of age can increase their lifetime productivity and profitability (Young et al. 2010; Kenyon et al. 2011, 2014). Further, in theory, increased genetic gain can be made from selecting progeny born to ewe lambs as replacement ewes. However, little is actually known about the long-term phenotypic impacts of such a management option. Loureiro et al. (2012) examined the reproductive and lactational performance of 18-month-old ewes born to either ewe lambs or mature ewes and reported little difference. They did, however, report that in one of two years, lambs born to dams who themselves were born from ewe lambs (i.e., the grand-offspring) were slightly heavier at weaning than grand-offspring from mature ewes. If this apparent effect was found to be consistent after weaning, and also to affect carcass characteristics, it might indicate a potential advantage of selecting replacement ewes born to ewe lambs. To date, these relationships have not been examined. Therefore, the present study examined the live weight and carcass characteristics of two cohorts of male lambs born to ewes that themselves were born to either mature ewes or ewe lambs...}, issn = {1176-5283}, author = {Burnham DL and Kenyon PR and Pain SJ and Hickson RE and Blair HT} } @conference {3678, title = {BRIEF COMMUNICATION: Inter-generational effects on male offspring born to ewes whose dams were offered varying feeding levels in pregnancy}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {74}, year = {2014}, month = {06/2014}, pages = {199-201}, address = {Napier}, abstract = {There is a growing body of evidence to indicate that pregnancy nutrition can affect the productive performance of the offspring in sheep (Kenyon \& Blair 2014). Recently we demonstrated that pastoral-based feeding of the ewe (G0) can affect the milk production of the ewe offspring (G1) and the growth and live weight of the grand-offspring (G2) to weaning (van der Linden et al. 2009; Paten et al. 2013). An effect of feeding on grand-offspring is termed an inter-generational effect, and while these effects have been reported in species such as mice and rats, their occurrence in the sheep literature is rare. There is some evidence to suggest feeding of the ewe in pregnancy can alter the growth and carcass characteristics of her offspring (see review Greenwood et al. 2010) but there is no data available on potential inter-generational effects. The aim of the present study was to determine if feeding of the ewe (G0) in either early- or mid- to late-pregnancy could alter the live weight and slaughter characteristics of male grand (G2) offspring...}, issn = {1176-5283}, author = {Burnham DL and Kenyon PR and Pain SJ and Hickson RE and Peterson SW 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 {89227, title = {Uterine expression of oestrogen receptor alpha in Suffolk and Cheviot ewes at Day 19 of pregnancy, following embryo transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {73}, year = {2013}, month = {Jan}, pages = {86-89}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Hamilton}, abstract = {

Whilst it is recognised that maternal uterine capacity has a marked influence on offspring birth weight and size (Walton \& Hammond 1938; Allen et al. 2002; Jenkinson et al. 2007, 2012; Sharma et al. 2012), Sharma et al. (2010) demonstrated in reciprocal embryo transfer experiments that the maternal uterine environment exerts an effect on embryonic growth by Day 19 in early gestation, when maternal uterine capacity is not a limiting factor.

}, issn = {1176-5283}, author = {Sequeira M and Pain SJ and Sartore I and Meikle A and Kenyon PR 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 {78981, title = {Expression of uterine progesterone receptor in Suffolk and Cheviot ewes at Day 19 of pregnancy, following embryo transfer}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {72}, year = {2012}, month = {Jan}, pages = {35-37}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Many animal studies have shown that uterine capacity has a marked influence on birth weight and size (Walton \& Hammond 1938; Allen et al. 2002; Jenkinson et al. 2007; Sharma et al. 2012). However, in reciprocal embryo transfer experiments ... }, issn = {1176-5283}, author = {Sequeira M and Pain SJ and Sartore I and Meikle A and Kenyon PR and Blair HT} } @conference {75922, title = {BRIEF COMMUNICATION: Effect of gender and prior exposure on the intake and preference of sheep for plantain post-weaning}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {71}, year = {2011}, month = {Jan}, pages = {278-280}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Invercargill}, abstract = {Animals are exposed to a sensory learning environment both pre- and post-birth birth (Nicolaidis, 2008). Numerous experiments with rats (Smotherman, 1982), chickens (Porter \& Picard, 1998; Sneddon et al., 1998) and sheep (Nolte et al., 1992; Schaal et al., 1995; Simitzis et al., 2008) have demonstrated prenatal... Continued}, issn = {1176-5283}, author = {Pain SJ and Kenyon PR and Morris ST and Kemp PD} } @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} } @conference {69484, title = {Do fetuses from primiparous one-year-old ewes differ from those of multiparous mature ewes?}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {118-120}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {The number of ewe-lambs (8 to 9 months of age) mated in New Zealand has increased to approximately 33\% over the last 15 years (Anon, 2009). There are many potential advantages to ewelamb breeding including higher net profits, more lambs produced per ewe productive lifetime, better use of spring herbage, increased efficiency, early recognition of fertility potential and increased rates of genetic gain (Hight, 1982). However, little is known about the long term impacts of selecting progeny born to these young ewes as replacement animals. There is some evidence from human studies to suggest that there may be negative impacts for both the offspring and to the first parity young mother (Lucas et al., 1999).}, issn = {1176-5283}, author = {Loureiro MFP and Pain SJ and Kenyon PR and Blair HT} } @conference {69525, title = {Preference of lambs for novel pasture herbs}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {285-287}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {There is strong evidence that sheep show a preference for some plant species over others (Parsons et al.,1994; Concha \& Nicol, 2000; Foster et al., 2002; Rutter, 2006; Corkran, 2009). Differences among ruminant species in forage selectivity, offers a unique opportunity to manipulate utilization of pastures. Recently, increased milk yields and higher weaning weights of lambs have been shown to occur, when grazing a mixed herb sward containing chicory (Cichorium intybus), red and white clover (Trifolium pratenseand T. repens) and plantain (Plantago lanceolata) (Golding, 2008).}, issn = {1176-5283}, author = {Pain SJ and Hutton PG and Kenyon PR and Morris ST and Kemp PD} } @conference {69475, title = {Use of novel pasture species to reduce methane emissions from New Zealand grazing ruminants}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {70}, year = {2010}, month = {Jun}, pages = {77-79}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Palmerston North}, abstract = {In New Zealand, methane (CH4) accounts for approximately 38\% of greenhouse gas emissions. The majority of this methane, approximately 98\%, is from ruminants (Waghorn \& Woodward, 2006). New Zealand{\textquoteright}s ruminant production industry relies heavily on a pasture-based system and depends on efficient utilisation of pasture. Variation between plant species in their nutritional and chemical composition provides an opportunity to manipulate rumen fermentation patterns and increase the utilization of pastures, while potentially reducing ruminant livestock CH4emissions. Preliminary findings are reported from a pilot study which investigated the effects of nutritional composition of a range of forage species on the short-term in vitro production of CH4.}, issn = {1176-5283}, author = {Roca FJ and Hutton PG and Pain SJ and Kenyon PR and Morris ST} } @conference {60960, title = {Dairy cows and horses do not select oaten hay based on its greenness : Brief Communication}, booktitle = {Proceedings of the New Zealand Society of Animal Production}, volume = {69}, year = {2009}, month = {Jun}, pages = {132-134}, publisher = {New Zealand Society of Animal Production}, organization = {New Zealand Society of Animal Production}, address = {Christchurch}, abstract = {Domestic and export markets for oaten hay are driven largely by estimates of the quality of hay produced. This assessment is commonly based on the plant of origin and subjective criteria, such as colour, or {\textquoteright}greenness{\textquoteright}, and general appearance as judged by an observer. However, subjective measures such as these are not always reliable indicators of an animal{\textquoteright}s response to a hay when offered, in terms of its intake and ultimate performance. Understanding the role of specific plant characteristics that... Continued }, issn = {1176-5283}, author = {Pain SJ and Revell DK} }