Year-round production of ‘supercows’ now possible

The country can now produce "supercows" or quality herds of cattle year round through embryo transfer (ET) and vitrification.

Using these biotechnologies, the Philippine Council for Agriculture, Forestry and Natural Resources Research and Development of the Department of Science and Technology (PCARRD-DOST) and the Dairy Training and Research Institute (DTRI) of the University of the Philippines Los Baños hope to produce superior lines of dairy cattle at the DTRI farm.

DTRI researchers claimed that the daughters of superior cows at the DTRI farm can form the foundation herd of quality milking animals in the future, while their sons can be further tested to produce an elite herd of bulls for semen production.

The researchers also added that bovine ET attempts to produce a number of excellent calves from selected cows with superior genetic makeup, a sturdy body conformation, and outstanding strength. The bovine ET has been used to propagate the superior of the dam or the female parent resulting in the production of "supercows" capable of producing more than 18,000 liters of milk per lactation.

From this PCARRD-funded project alone, the country can have a local production of about 120 embryos from the top 10 percent of the herd. Valued at an average cost of $600 per embryo, the DTRI researchers projected a total savings of about $72,000 or P3.9 million on an import substitution basis.

In bovine ET, the donor animal is treated with follicle stimulating hormone (FSH) to increase the number of ova or eggs released during ovulation. The donor in heat (estrus) is then inseminated with the required doses of high-quality semen obtained from bulls. The embryos are then collected from the reproductive tract of the animal a week after estrus. Collection of embryos is done by using a two-way cathether with a flushing solution. The collected embryos are examined and classified in a laboratory kept at 20 degrees Centigrade to 22 degrees Centigrade. The embryos are classified from poor to excellent. Poor-quality embryos are discarded, while viable embryos are either transferred within the same day to the reproductive tract of the recipient animals by using an insemination gun or cryopreserved in a gene bank through vitrification.

In vitrification, good to excellent embryos are placed in vitrification solution (ethylene glycol solution) and packed in an insemination straw as thin as a hair strand. After packing the embryos into the straw, the straw is sealed and exposed to liquid nitrogen vapor on a styrofoam boat floating in liquid nitrogen before it is plunged into the liquid nitrogen. The straw is kept in a liquid nitrogen tank in the gene bank for future use.

About 17 bovine embryos from each superovulated cow can be collected. The embryos can be transferred to cows of different bred provided that they are healthy. Vitrified embryos can be transported to other places. – Arlene R. Obmerga, S&T Media Service