Early pregnancy detection is vital in the cattle industry and improves animal welfare, whilst reducing consumer costs. A simpler, cheaper and safer early pregnancy test, has successfully advanced cattle farming over the last six years, with sales now exceeding $10 million per annum. The development of this test was borne from the discovery of a protein critical for pregnancy success, over 30 years ago.
Farmers depend upon their animals getting pregnant. Why some animals fail to become pregnant in one oestrous cycle but may become pregnant in the next, while others never get pregnant is a constant frustration, and a cause of economic loss. The protein, interferon tau (INFT), was shown to be crucial for successful embryo implantation and the prevention of miscarriage in ruminants, including sheep and cows. Research based on this finding led Prof R. Michael Roberts and colleagues to develop an early pregnancy detection test for cattle based on placental proteins, called pregnancy-associated glycoproteins (PAGs), which enable pregnancy to be determined after just 25 days. This is much more efficient than using ultrasound detection and has contributed to reduced animal costs, more efficient food production, improved animal welfare and ultimately good human health. Although this key function of IFNT in pregnancy was made over 30 years ago, it continues to influence reproductive research and farming practice today.
In a special issue of Reproduction, celebrating the 30th anniversary of the discovery of IFNT in fertility is chronicled and the future research directions it may drive are highlighted. Such as pregnancy tests with even earlier detection capabilities or methods of assessing peak fertility windows in cattle. Guest Editor of the special issue, Prof Roberts says, "I am optimistic that our better understanding of maternal recognition of pregnancy will ultimately allow us to determine the fertility of cows through a gene chip procedure that can identify animals with the optimum gene combination. Identifying the right genetic make-up may indicate that their pregnancies are more likely to be successful. Approaches like this are just coming on board in the livestock industry."
In 2002, Prof Roberts, with colleague Prof Fuller Bazer, were awarded the Wolf Prize in Agriculture "for their discoveries of IFNT, and other pregnancy-associated proteins, which clarified the biological mystery of signaling between embryo and mother to maintain pregnancy, with profound effects on the efficiency of animal production systems, as well as human health and well-being."
Prof Roberts comments, "Pregnancy success underpins the efficiency of the dairy, meat, and natural fibre industries, so the discovery of the key roles of IFNT and other early pregnancy markers was of great practical and economic importance. The discovery of INFT provided some insight into the physiological mechanisms linked to fertility."