Bos taurus, cattle

Embryology & development

Life Cycle Stages

• Prenatal
  • Oocyte MeSH
  • Embryo Average gestation time in cattle is about 285 days; there are, however, documented breed differences; inter-calving periods are a little more than one year. MeSH
    • Early gestation embryo
      • Pre-implantation embryo
        • Zygote MeSH Fertilized egg,
          1-cell embryo,
          0 days post-conception (d.p.c.)
        • Cleavage MeSH Dividing egg, 2-16 cell embryo;
          2-5 days p.c.
          • 2-cell embryo 1 d.p.c.
          • 4-cell embryo 2 d.p.c.
          • 8-cell embryo 3 d.p.c.
          • 16-cell embryo 4 d.p.c.
        • Morula MeSH 32-64 cell embryo; 4-5 d.p.c.
        • Blastocyst MeSH Also blastula; 6-9 d.p.c.
          • Early blastocyst 6 d.p.c., ~128 cells
          • blastocyst 6-7 d.p.c.; ~250 cells
          • expanded blastocyst 6.5-7.5 d.p.c.
          • hatched blastocyst 7-8 d.p.c.
          • expanding
            hatched blastocyst 8-9 d.p.c.
        • Gastrula MeSH Cattle embryos implant after
          gastrulation (unlike rodent
          embryos).
          • Spherical embryo Up to ~14 d.p.c.
          • Ovoid embryo 14-16 d.p.c.
          • Elongated embryo 16-18 d.p.c.
      • Peri-implantation
        embryo Implantation begins in ~22
        days p.c. and completes
        in ~40 d.p.c.
    • Post implantation embryo
      • Mid-gestation
        embryo 40-180 days p.c.
      • Late gestation embryo
        • Fetus MeSH
• Post natal
  • Neonate Zero-3 days of age; newborn is able to stand and walk soon after birth; at birth, the abomasum is the dominant structure (accounts for about 70% of the volume of the entire stomach) while the rumen is basically non functional and the calf is non-ruminant.
  • Calf Juvenile; until age of reproductive maturity.
    • Pre-ruminant calf Calf with under-developed rumen (until 2-3 weeks of age); during the first two weeks of life, the calf relies almost entirely on mother's milk and consumes negligible amounts of dry matter.
    • Transitional calf The calf starts to consume some starter dry feed; this period lasts until the calf is weaned; during this time, the initial fermentation of dry food begins in reticulorumen that leads to production of first batches of volatile fatty acids (VFA); it leads to rapid expansion of volume and differentiation of the rumen epithelium so that VFA can be absorbed and used.
    • Ruminant calf Abomasum accounts for less than 25% of the total volume; calfs are usually moved from transitional pens at approximately 10 to 14 weeks of age; ruminant phase lasts the rest of animal's life; the ruminant depends on fermentation of dietary carbohydrates for most of its energy in the form of VFA.
  • Adult Abomasum accounts for less than 10% of the total volume; sexual maturity is attained at about 1-1.5 years of age and 250-300 kg body weight; standing to be mounted is the useful sign used by dairy herdsmen for determining the female cow receptivity (estrus); copious quantities of clear elastic mucus flow from the vulva that becomes swollen and reddened at estrus; first calving occurs at about 2 years of age; the young cows having calved for the first time are called heifers; maximum lifespan in domestic cows may exceed 20 years.

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More about cattle at GeoChemBio

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Prints, posters, mugs and other drinkware as well as various bags and even throw pillows with portraits of beautiful cows are available at GeoChemBio shop

Mix and match to create your drinkware sets, to decorate your room or to make an original gift!

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