Cows are livestock that has high species diversity and are found in almost all countries, including Indonesia. Friesian Holstein cattle are milk-producing cows with a very high average milk production, around 25-30 kg/day. Many of the characteristics of high-value animals economically show a wide variety of morphological (phenotypic) variations. Furthermore, variation in the field of the phenotype is influenced by genetic and environmental factors.
Besides showing variations in the field of phenotypes, sometimes genetic and environmental influences can affect the health of livestock, one of which is reproductive health. As we know, reproductive health in livestock is an important factor in the development of livestock populations. Some sources say that several reproductive diseases will arise due to changes in the genetic makeup of livestock.
The development of dairy cattle populations in the future should be based on the genetic identification of candidates for superior cows. Genetic identification of the reproductive health condition of broodstock is expected to increase the acceleration of the Friesian Holstein (FH) dairy cow population. The genetic identifier is needed especially for reproduction control. Thus, the superior female FH dairy cows in the stone area can be accounted for quality because superior females are one of the criteria that must be had when developing mass cattle.
So far, identification to determine the level of fertility of superior female broodstock is only made through rectal examination and ultrasound. Besides, identification of the level of fertility is also seen from physical appearance and trace heritability (lineage). However, this test is less accurate, because characteristics will not necessarily be inherited through marriage and heritability tests take a long time, making it inefficient.
Potential FSH-receptors (RFSH) as a marker indicator
The basic determination of RFSH as a marker indicator principle in determining the fertility of FH dairy cows is based on several previous studies which showed that the amount of RFSH in a female cow is directly proportional to the fertility of a female cow.
Based on previous studies, mutations in the RFSH gene sequence cause changes in the amino acid structure of the RFSH protein, which can cause changes in receptor expression on the cell surface that affect the ability to bind FSH and also to transduce the correct FSH signal. Some examples of mutations that occur in the RFSH sequences are as follows Asp5673 becomes Asn, Thr4493 becomes Ile, Thr4493 becomes Ala, Ile5453 becomes Thr, Asp5673 becomes Gly, Ala1893 becomes Val, Asn1913 becomes Ile, Ile1603 becomes Thr, Arg5733 becomes Cache, Ile2453 becomes Thr, Asp5673 becomes Gly, Ala1893 becomes Val, Asn1913 becomes Ile, Ile1603 becomes Thr, Arg5733 becomes Cache, Asp2243 becomes Val, Asp5673 becomes Gly, Ala1893 becomes Val, Asn1913 becomes Ile, Ile1603 becomes Thr, Arg5733 becomes Cys, Asp2243 becomes Val, Asp5243 becomes Val, Leu6013 becomes Val, Pro3483 becomes Arg, Ala4193Thr, Pro5193 becomes Thr and Phe5913 becomes Ser.
Of all the polymorphisms and allele variants identified in the RFSH gene, they have been shown to increase the presence of several different haplotypes that can affect the effect of FSH on target tissue (for example, affecting ovarian responsiveness to exogenous FSH).
Based on the explanation above, it can be concluded that the use of RFSH as an indicator of genetic markers of reproductive health of superior female Friesian Holstein cattle has good potential as a marker indicator in the selection of good superior female broodstock.
Author: Tantri Dyah Whidi Palupi