Document
National Institute of Environmental Health Sciences, NIEHS
Generically Dependent Continuant
RDF description of Shearing during late pregnancy increases size at birth but does not alter placental endocrine responses in sheep - http://orbis.uaslp.mx/vivo/individual/scopus6375
Article
Information Content Entity
birth weight; body mass index; glycoproteins; pregnancy shearing; progesterone fatty acid; glycoprotein; progesterone; animal; birth; birth weight; blood; endocrine system; female; glucose blood level; male; physiology; placenta; pregnancy; sheep; wool; Animals; Birth Weight; Blood Glucose; Endocrine System; Fatty Acids, Nonesterified; Female; Glycoproteins; Male; Parturition; Placenta; Pregnancy; Progesterone; Sheep; Wool
Shearing during the latter half of pregnancy is a common practice to improve flock health and productivity. Previous studies have demonstrated that shearing pregnant ewes at mid or late pregnancy is associated with an increase in lamb birth weight. In the present study, we used singleton Polypay × Dorset pregnant sheep, to investigate the potential roles of placental function and changes in maternal metabolism in underlying this increased birth weight response. Two groups were randomly established and blocked at enrollment by animal BW, body condition score and subcutaneous adipose tissue depth. The groups were shorn (SH; n = 18) or not (C; n = 20) at gestational day (GD) 107 ± 1 (mean ± SEM). Weekly maternal plasma samples were collected between shearing and birth, but only six samples were assayed for progesterone, pregnancy-associated glycoproteins (PAG1), glucose and non-esterified fatty acids (NEFAs). At birth, sex, birth weight, and newborn body mass index (BMI) were recorded. Maternal BW during mid- to late-pregnancy was similar between groups. Shearing resulted in increased lamb birth weight and BMI (P < 0.05) regardless of fetal sex but did not affect the maternal concentration of PAG1 or progesterone from GDs 100 to 142. After shearing (GD100) and up to lambing, shorn females had higher circulating glucose concentrations (P < 0.05), but not NEFA, compared to the control group. Maternal circulating PAG1, progesterone, glucose or NEFA concentration across pregnancy did not differ according to lamb sex. Across pregnancy, birth weight was positively associated with PAG1 (P < 0.001), but not with progesterone concentrations. In conclusion, weight and BMI at birth were higher in both sexes upon shearing in singleton pregnancies. Despite PAG1 being associated with birth weight, late-pregnancy shearing did not alter the placental endocrine response. Whether other placental factors are altered upon shearing and may influence the increase in birth weight and BMI remain to be investigated. © 2019 The Animal Consortium
progesterone, 57-83-0; Blood Glucose; Fatty Acids, Nonesterified; Glycoproteins; Progesterone
Shearing during late pregnancy increases size at birth but does not alter placental endocrine responses in sheep
National Institute of Food and Agriculture, NIFA: MICL02383
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, INIFAP