Diversity of milk quality and butter based on the genotype of GH gene from Saanen and Etawah Grade goats

Abstract

The Growth hormone (GH) secreted by the pituitary gland plays an important role in lactation. The objectives of this study were to observe the quality of raw milk (fat, protein, density, and dry matter) and characteristics of butter from Saanen and Etawah-Grade (EG) goat and to analyse the effect of GH gene type in milk quality. The DNA of 89 goats (Saanen and EG) was evaluated. Single-strand conformation polymorphisms (SSCP) was utilized to identify goat growth hormone (gGH) gene. The results showed that there were exist five types of GH gene in exon 4 consist of type CE, BC, CD, BB and CC. The CE, BC and BB types were found in all population (Saanen and EG). The CD and CC type only found in Saanen and EG goats respectively, but this diversity did not affect milk quality of the raw milk of Saanen and EG goats. Diversity of genotypes of GH gene also did not affect the characteristics of goat's milk butter.

Hormon Pertumbuhan (Growth Hormone/GH) merupakan hormon yang disekresikan oleh kelenjar hipofisis serta memainkan peranan penting dalam laktasi. Tujuan penelitian ini adalah untuk menganalisis kualitas susu segar (lemak, protein, BJ dan bahan kering), mempelajari karakteristik mentega dari kambing Saanen dan Peranakan Etawah (PE) serta menganalisis pengaruh keragaman gen GH terhadap kualitas susu. Evaluasi DNA dari 89 kambing (Saanen dan PE) menggunakan metoda Single-strand Conformation Polimorphysm (SSCP) untuk mengidentifikasi polimorfisme pada gen hormon pertumbuhan kambing (gGH). Amplifikasi gen GH exon 4 pada kambing perah (Saanen dan PE) menghasilkan ruas DNA sepanjang 200 bp. Berdasarkan hasil SSCP pada gen GH mendapatkan lima pita DNA yang menunjukkan pola migrasi yang berbeda, disebut tipe gen CE, BC, CD, BB dan CC. Gen CD hanya dijumpai pada bangsa kambing Saanen sedangkan tipe gen CC hanya terdapat pada kambing PE. Keragaman genotipe ini tidak berpengaruh terhadap kualitas susu kedua bangsa kambing Saanen dan PE. Keragaman genotipe gen GH juga tidak berpengaruh terhadap karakteristik mentega susu kambing Saanen.