@article {3672,
	title = {Effects of maternal bromocriptine and melatonin treatments during early gestation on fetal lamb growth},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {79},
	year = {2019},
	month = {07/2019},
	pages = {74-79},
	address = {Palmerston North},
	abstract = {Lower birth weights of autumn-born than of spring-born lambs may be due to a seasonal impairment of placental development, established by d84 of gestation, and perhaps mediated by high summer prolactin concentrations. This study attempted to determine whether reducing circulating summer prolactin concentrations in ewes during early gestation, using bromocriptine and melatonin, would improve placental and fetal growth and birth weights of autumn-born lambs. Pregnant mixed-age Romney ewes were randomly allocated to three treatment groups, balanced for age, live weight (LW) and source flocks, on d15 after mating. Ewes in the Bromocriptine group (n=20, LW 58.3{\textpm}6.7 kg) were injected with 50 mg Parlodel{\textregistered}LA, the Melatonin group (n=20, LW 58.6{\textpm}6.6 kg) each received one 18-mg Regulin{\textregistered} implant, while the Control group (n=21, LW 58.5{\textpm}5.8 kg) was injected with saline solution (0.9\% NaCl). At d139 of gestation, ewes were randomly allocated to a {\textquoteleft}Slaughter group{\textquoteright} sacrificed at d140-2 (n=30 LW 61.2{\textpm}5.6 kg) and a {\textquoteleft}Live-birth group{\textquoteright} (n=31, LW 60.0{\textpm}7.1 kg). Maternal plasma prolactin concentrations were significantly reduced by both bromocriptine (Control vs. Bromocriptine): 48.3{\textpm}9.2 vs. 0.7{\textpm}9.9 ng/ml (P<0.001) at d20 of gestation, and 82.6{\textpm}8.5 vs. 4.5{\textpm}9.1 ng/ml (P<0.001) at d40 of gestation, and melatonin treatments (Control vs. Melatonin): 82.6{\textpm}8.5 vs. 18.4{\textpm}9.5 ng/ml (P<0.001) at d40 of gestation, and 16.8{\textpm}3.7 vs. 2.9{\textpm}4.2 ng/ml (P<0.05) at d60 of gestation. Fetal plasma prolactin concentrations were not affected by treatments (Control vs. Bromocriptine vs. Melatonin): 32.4{\textpm}18.3 vs. 32.4{\textpm}19.1 vs. 59.8{\textpm}16.4 ng/ml. At d140 of gestation, there were no treatment effects (adjusted for sex and litter size) on fetal weight, crown-rump length, placental parameters, and maternal and fetal organ weights, except thymus reduced 20\% (P<0.05) by melatonin treatment. Birth weights and subsequent growth rates were similar among groups. Despite treatments reducing plasma prolactin concentrations there was no affect on placental or fetal growth, indicating that high prolactin concentrations early in pregnancy are not responsible for low birth weight in ewes lambing in May.},
	issn = {1176-5283},
	author = {Peterson SW and Wigati S and Jenkinson CMC}
}
@article {3672,
	title = {BRIEF COMMUNICATION: Impact of maternal plane of nutrition, ewe weight and twinning on fetal mammary gland development in sheep},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {78},
	year = {2018},
	month = {07/2018},
	pages = {183-185},
	address = {Lincoln},
	abstract = {This study evaluated the effects of maternal nutrition, weight and gestation rank on fetal mammary gland development. Light
(L) and heavy (H) single- and twin-bearing ewes were fed ad libitum (A) or maintenance (M) nutritional regimens from day
21 to day 140 of gestation and euthanised for tissue collection. Plane of maternal nutrition or maternal weight did not affect
histomorphometry of fetal mammary glands. Singleton fetuses had 43\% greater total duct area (P<0.05), 62\% greater secretory cell
area and 32\% fewer ducts (P<0.05) but similar total lumen area, cell size and total cell number than twins. These results indicate
that twinning reduces area of mammary ducts and secretory cell area while maternal weight and plane of nutrition from day 21
have little impact on mammary morphology at day 140 of gestation.},
	issn = {1176-5283},
	author = {McCoard SA and Adiletta AM and Jenkinson CMC and Peterson SW and Kenyon PR and Blair HT}
}
@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 {79021,
	title = {Effect of the maternal environment on fetal growth at mid-gestation in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {72},
	year = {2012},
	month = {Jan},
	pages = {205-209},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {Our group has previously shown that maternal size can affect embryonic development by Day 19 of gestation and lamb birth weight. This study set out to investigate the effect of the maternal uterine environment on fetal growth at mid-gestation. Pure-breed single embryos were transferred within and reciprocally between large (Suffolk: S) and small (Cheviot: C) breeds of ewes to establish four maternal environments; SinS, SinC, CinS and CinC. On Day 90 of gestation, 37 single-bearing recipient ewes (10 CinC, 7 SinC, 10 CinS and 10 SinS) were euthanased. Fetal body weight, fetal body dimensions and fetal organ weights, and placentome number and total weight were measured. Body weight was significantly (P < 0.001) smaller in Cheviot compared to Suffolk fetuses. However, Cheviot fetuses had heavier (P < 0.05) kidneys and liver than Suffolk fetuses. SinC fetuses had heavier (P < 0.05) pancreas than those from all other pregnancy groups. CinS fetuses tended to have longer (P < 0.10) fore- and hind-leg lengths than CinC fetuses. There were no differences (P > 0.05) in placental parameters between the pregnancy groups. The maternal uterine environment had no major effect on fetal weight, fetal dimensions and fetal organ mass at mid-gestation.},
	issn = {1176-5283},
	author = {Jenkinson CMC and Sharma RK and Kenyon PR and Blair HT}
}
@conference {69503,
	title = {Preliminary investigation of milk production in Angus heifers exposed to different nutrition in utero},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {70},
	year = {2010},
	month = {Jun},
	pages = {194-198},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Palmerston North},
	abstract = {Milk yield (MY) and composition were measured on one day in Weeks 7, 9 and 11 in 17 offspring of Angus cows fed for high (1.2 kg/d; HB) or medium (0.5 kg/d; MB) liveweight gain (LWG) for 10 days before insemination and medium (0.5 kg/d; MA) or low (0.01 kg/d; LA) LWG during gestation. Mean MYs in the progeny were; Week 7: 5790 {\textpm} 420 g/d, Week 9: 7418 {\textpm} 447 g/d, Week 11: 6244 {\textpm} 392 g/d. Better feeding before mating had little effect on MY or milk crude protein (CP\%) in the progeny but tended to reduce the milkfat\% (Week 9; HB (n = 8) 3.50 {\textpm} 0.17\% versus MB (n = 8) 3.74 {\textpm} 0.22\%) (P <0.19), casein (Week 11; HB 2.59 {\textpm} 0.03\% versus MB 2.68 {\textpm} 0.04\%) (P = 0.11) and lactose (Week 11; HB 5.18 {\textpm} 0.13\% versus MB 5.42 {\textpm} 0.05\%) (P = 0.075). Better feeding of the dam after artificial insemination did not significantly increase MY of the progeny (Week 9; MA (n = 9) 7972 {\textpm} 378 g/d versus LA (n = 8) 6794 {\textpm} 826 g/d) (P = 0.23), or milkfat\%, decreased CP (Week 9; MA 3.22 {\textpm} 0.07\% versus LA 3.41 {\textpm} 0.08\%) (P <0.09) and casein\% (at Weeks 7 and 9 identical values of MA 2.52 {\textpm} 0.06\% versus LA 2.69 {\textpm} 0.07\%), but increased lactose\% after the peak of lactation (Week 11 MA 5.42 {\textpm} 0.06\% versus LA 5.15 {\textpm} 0.14\%) (P <0.08). Feeding before and after conception may affect the nutrition of the grand generation},
	issn = {1176-5283},
	author = {Peterson SW and Jenkinson CMC and Hickson RE and Morris ST and Blair HT and Kenyon PR}
}
@conference {60931,
	title = {Maternal environment as a regulator of birth weight and body dimensions of newborn lambs},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {69},
	year = {2009},
	month = {Jun},
	pages = {10-14},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {The present research study was undertaken to investigate the effect of maternal uterine environment on birth weight of lambs. Embryos were transferred within, and reciprocally between, Suffolk and Cheviot sheep to establish four groups of pregnancies: Suffolk in Suffolk (SinS; Large control), Suffolk in Cheviot (SinC; Restricted uterine environment) Cheviot in Suffolk (CinS; Luxurious uterine environment) and Cheviot in Cheviot (CinC; Small control). Birth weight and other morphological characteristics of lambs such as head width, head length, crown-rump length, heart girth, fore leg length, hind leg length and femur length were recorded within 24 h of birth. Various placental parameters were also recorded at lambing. Birth weight of SinC lambs (5.04 {\textpm} 0.20 kg) was significantly (P <0.05) lower than SinS lambs (5.93 {\textpm} 0.19 kg). All of the body dimensions were also significantly (P <0.05) reduced in SinC compared with SinS lambs. However, neither birth weight nor other morphological parameters were significantly different (P >0.05) between CinC and CinS lambs. Among placental parameters, cotyledon number was significantly (P <0.05) lower in CinS (57.48 {\textpm} 6.27) than SinS group (74.17 {\textpm} 5.88). These results indicate that a restricted maternal uterine environment affects birth weight probably via alteration to placental characteristics. },
	issn = {1176-5283},
	author = {Sharma RK and Jenkinson CMC and Blair HT and Kenyon PR and Parkinson TJ}
}
@conference {41965,
	title = {The effects of ewe size and nutrition during pregnancy on growth and onset of puberty in female progeny},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {126-129},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {In 2005, {\textquoteleft}heavy{\textquoteright} and {\textquoteleft}light{\textquoteright} Romney ewes were selected, synchronized and artificially inseminated. Half of the ewes in each weight group were fed ad libitumand the other half were restricted to maintenance from days 21-140 of pregnancy, resulting in fourgroups: {\textquoteleft}heavy{\textquoteright}-maintenance (HM), {\textquoteleft}heavy{\textquoteright}-ad libitum(HA), {\textquoteleft}light{\textquoteright}-maintenance (LM) and {\textquoteleft}light{\textquoteright}-ad libitum(LA). The aim of the present study was to investigate the effects of ewe size and nutrition during pregnancy on growth and onset of puberty in female progeny. Lamb birth weights were recorded. After weaning, the progeny were managed as one flock and weighed monthly. Crayon-harnessed teaser rams were joined with the lambs to investigate the onset of puberty. Maternal nutrition during pregnancy affected live weight of lambs from 22 days of age till weaning (100 days of age) (P<0.05). During the first 22 days of life, the growth rate of lambs born to LM was lower (P<0.05) compared with the other groups (215 {\textpm} 8.2, 261 {\textpm} 8.0, 250 {\textpm} 7.9, 275 {\textpm} 7.3 grams/day, for lambs born to LM, LA, HM and HA ewes respectively). From weaning until one year of age lambs born to LM dams were lighter than lambs born to HM dams (P<0.05). No differences in the age of onset of puberty were found among the four groups. Singletons reached puberty earlier than twins (P<0.01). At 13 months of age, no long-term effect of maternal nutrition on the live weight of resulting ewe offspring was found, although dam size had a significant effect on live weight and growth rate. However, neither dam nutrition nor size had any effect on the age of onset of puberty.},
	issn = {1176-5283},
	author = {van der Linden DS and Kenyon PR and Jenkinson CMC and Peterson SW and Lopez-Villalobos N and Blair HT}
}
@conference {41977,
	title = {Maternal constraint in sheep breeds with diverse birth weight},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {67},
	year = {2007},
	month = {Jan},
	pages = {187-191},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Wanaka},
	abstract = {Reciprocal crosses of Shire and Shetland ponies and transferring embryos between small and large breeds of horses and pigs have shown that maternal size, ratherthan foetal genotype, is the primary determinant of birth size. In the present study, 40 Cheviot (C) ewes and 40 Suffolk (S) ewes were split into two groups. Each group was mated to either two Suffolk rams or two Cheviot rams to generate CC, CS, SC and SS lambs. Birth weights differed significantly (P<0.01) between the four lamb genotypes (CC 4.12 {\textpm} 0.21; CS 4.43 {\textpm} 0.23; SC 5.08 {\textpm} 0.19; SS 5.17 {\textpm} 0.19, kg). Furthermore, lower birth weight was significantly (P<0.01) associated with lower maternal circulating plasma placental lactogen (oPL) concentrations in the Cheviot dams at days 90 (C 25.8 {\textpm} 10.0 vs. S 71.8 {\textpm} 11.6, ng/ml) and 110 (C 84.5 {\textpm} 16.8 vs. S 175.9 {\textpm} 19.0, ng/ml) but not at day 130 of gestation. These results indicate that the size of the ewe affects the intrauterine development of her lamb. Moreover, the lower concentrations of oPL in the Cheviot dams may have contributed to the constraint observed in foetal growth.},
	issn = {1176-5283},
	author = {Jenkinson CMC and Kenyon PR and Blair HT and Breier BH and Gluckman PD}
}
@conference {40839,
	title = {Seasonal effects on fetal growth in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {56},
	year = {1996},
	month = {Jan},
	pages = {297-300},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Previous studies have shown that autumn-born lambs are lighter (by  0.4 to 1.0 kg) at birth than spring-born lambs, an effect which is associated  with impaired placental development in ewes mated to lamb in the autumn.  As previous studies have focused on near-term fetal weights and birth  weights, the objective of this study was to determine the pattern of growth  throughout gestation in lambs destined to be born in the autumn or spring,  and to examine associated changes in placental development. Mature N.Z.  Romney ewes were randomly assigned to groups mated in December (n=23)  or March (n=28) and managed on pasture in both seasons for similar live- weight profiles from mating to day 140 of gestation. Ewes were slaughtered  at day 56, 84, 112 or 140 of gestation, and measures of fetal and placental  weight were determined. Fetal weights (kg) of December- versus March- mated ewes were: d56 (0.040 },
	issn = {1176-5283},
	author = {McCoard SA and Peterson SW and Jenkinson CMC and Campbell JW and McCutcheon SN}
}
@conference {40605,
	title = {The effects of season on placental development and fetal growth in sheep},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {54},
	year = {1994},
	month = {Jan},
	pages = {227-230},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Autumn-born lambs have been reported to have lower birth weights  
than spring-born lambs by 0.4 to 1.0 kg, but the physiological basis of this  
difference is unknown.  This study examined the effects of season on fetal  
growth and placental development independent of the confounding effects of  
maternal nutrition.  Romney ewes (aged 5 and 6 years) were randomly  
allocated to groups mated in December (n=13) or March (n=13 with a similar  
live weight at mating (55.6{\textpm}1.8 vs 55.7{\textpm}1.9 kg, mean{\textpm}SE, P>0.10) and  
managed for a similar live weight at day 140 of gestation (62.5{\textpm}1.8 vs 62.9{\textpm}1.9  
kg, P>0.10).  At day 140 of gestation, measures of fetal growth and placental  
development, adjusted for litter size, were (December- vs March-mated):  
individual fetal weight (4.15{\textpm}0.16 vs 5.07{\textpm}0.16 kg, P<0.001); total fetal weight  
per ewe (6.42{\textpm}0.18 vs 7.14{\textpm}0.22 kg, P<0.01); caruncle number (114.5{\textpm}4.1 vs  
121.0{\textpm}4.2, P>0.10); placentome number (89.4{\textpm}4.2 vs 106.9{\textpm}4.3, P<0.01);  
caruncle occupancy, i.e. number of placentomes/number of caruncles  
(0.79{\textpm}0.03 vs 0.88{\textpm}0.03, P<0.05); and total placentome weight (564.7{\textpm}34.0 vs  
679.0{\textpm}34.9 g, P<0.05).  These results suggest that seasonal differences in birth  
weight of lambs are mediated not by differences in maternal nutrition but rather  
by a direct seasonal effect on placental size (specifically the formation of  
placentomes and hence total placental weight). 
 },
	issn = {1176-5283},
	author = {Jenkinson CMC and Peterson SW and MacKenzie DDS and McCutcheon SN}
}
