Ecomomic Impacts of Undernutrition on Fetal Programming during Early Gestation in the Cow: Effects on Growth, Development and Carcass Characteristics of Steers and Reproductive Efficiency of Heifers

Project Overview

SW02-011
Project Type: Research and Education
Funds awarded in 2002: $23,013.50
Projected End Date: 12/31/2003
Matching Non-Federal Funds: $25,880.00
Region: Western
State: Wyoming
Principal Investigator:
Stephen Ford
Email
University of Wyoming

Commodities

  • Agronomic: sugarbeets
  • Animals: sheep

Practices

  • Animal Production: animal protection and health, feed rations, preventive practices
  • Education and Training: demonstration, on-farm/ranch research
  • Farm Business Management: whole farm planning, risk management
  • Sustainable Communities: sustainability measures

    Abstract:

    The first half of gestation is critical for placental growth, differentiation and vascularization as well as fetal organogenesis. Placentomes are the functional units of placental exchange in the ewe, and are classified as A, B, C or D types (Figure 1), associated with increasing placentomal efficiencies. We compared two groups of multiparous Rambouillet ewes: 1) adapted to a nomadic existence (grazed ~250 miles/year); Baggs ewes and 2) relatively sedentary ewes supplied with more than adequate nutrition (UW ewes). Equal numbers of UW and Baggs ewes were fed to 50% (nutrient restricted, NR) or 100% (control fed, CF) of NRC requirements from day 28 to 78 of gestation. A ~30% reduction of fetal weight was observed in the NR vs. CF UW ewes, but not Baggs ewes on day 78. Further, placentome type was more advanced in NR Baggs ewes (B,C and D) than NR UW ewes (vertially all A). Conversion to more advanced placentomal types resulted in similar placentomal efficiencies (fetal weight/ placentomal weight) for NR and CF Baggs ewes, while placentomal efficiency of NR UW ewes declined markedly. These data suggest that selection of ewes under different production schemes can alter the negative impacts of early maternal undernutrition on fetal growth and development. The impacts of these maternally dependent changes in placentomal and fetal growth and development on the resultant offspring are currently under investigation.

    Project objectives:

    Measurements taken in this study included diet-associated changes in maternal body weight and body condition, fetal size and organ weights, placentomal numbers, weights and morphologies, and fetal blood glucose concentrations.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.