Reproduction Abstracts

Introduction: Large within-litter variation in pig foetal weight may be associated with placental efficiency. Integrin receptors, including AVB6, are present at the attachment site between the foetal and uterine epithelium and may affect the efficiency of attachment. It is hypothesised that the expression of integrin receptors would differ between tissues supplying small foetuses compared to normal-sized littermates. This study compared the distribution and quantity of integri...

Many studies demonstrating that the environment a pregnant female experiences can have profound and sometimes persistent effects on offspring development use extreme experimental perturbations which do not reflect the range of environments a pregnant female is actually likely to experience. We have assessed offspring reproductive development following treatments designed to reflect husbandry and management conditions that pregnant sheep or pigs encounter. Female offspring of s...

Introduction: Low piglet birth weight has severe consequences for neonatal and adult development that cannot be remedied post-natally. It is hypothesised that impaired foetal growth occurs due to inadequate placental vascularisation.Methods: Endometrial and placental tissues supplying small and normal-sized foetuses were collected from Large White x Landrace gilts at gestational days (GD) 30 (n=5), 60 (n=7) and 90 (n=5) for imm...

Introduction: This study determined whether the way in which pregnant ewes were handled affected gonad development in their offspring.Methods: Twin-bearing Scottish Blackface × Border Leicester ewes were either handled minimally (control, C, n=20), positively (predictable timings, soft vocal tones etc. P, n=20) or negatively (random timings, shouting and whistling etc. N, n=20) between day 65 and 100 of pregnancy. Followin...

Introduction: Following IVF, blastocysts produced from oocytes recovered from gilts fed a high fibre diet for the preceding 19 days contained more cells than blastocysts from oocytes of control-fed gilts. Oocytes were collected on day 19 of the gilts’ third oestrous cycle and matured in 10% of their own follicular fluid (FF), suggesting that FF may confer the reproductive benefits. The current study compared the protein composition of pooled FF from six high fibre-fed pig...

Introduction: This study compared uterine and placental expression of genes implicated in placental attachment and angiogenesis in two prolific (hLW and MS) and one control (LW-LD) pig breeds.Methods: Placental and endometrial tissues supplying the smallest and a normal-sized foetus within the same litter were collected from five LW-LD, five hLW and four MS gilts on days 40–45 of pregnancy. RNA was isolated and qPCR for SPP1, VEGFA...

This study determined whether variation (representative of normal UK farm conditions) in pregnant ewe management is sufficient to alter the programing of the male reproductive axis. Between days 85 and 138 of pregnancy, twin-bearing ewes were managed to either mimic ‘poor husbandry’ (PH) with a high stocking density, reduced feeding space and repeated social mixing or according to ‘best practice’ (BP) with a lower stocking density, longer feed troughs, and ...

Low birth weight observed in the ‘runt’ piglet of the litter compared to its siblings has severe consequences for neonatal and adult development that cannot be remedied post-natally. This study compared the expression of a number of candidates hypothesised to be involved in angiogenesis and placental attachment in porcine endometrial samples.Endometrial tissues supplying the smallest and normal-sized foetuses were collected from large white lan...

In a previous study, following IVF, oocytes from gilts fed a high fibre diet for the first 19 days of their third oestrous cycle, produced blastocysts with more cells than oocytes from control-fed gilts. We hypothesise that FF protein composition is altered by the diet and that this confers the reproductive benefits.The current study compared the protein composition of pooled Day 19 FF from 12 high fibre-fed pigs and 12 control-fed pigs in search of biom...

Introduction: CSF1 is the primary growth factor required for macrophage proliferation and differentiation. In adults, the receptor is expressed only in macrophages and their precursors. In mice, mutation of the CSF1 gene produces both male and female infertility due to diminished gonadal steroid production. We tested the effect of increased availability of CSF1 on gonadal development in pigs using CSF1-Fc, a CSF1 fusion protein with increased circulating half-life.<p class...