Compositional characterisation of colostrum and proline rich polypeptides of indigenous cattle (Bos indicus family) and Holstein Friesian (Bos taurus) and their crossbred Karan Fries cattle [Mass Spectrometry Facility]

Proline-rich polypeptides (PRPs) are polypeptides characterized by a high proportion of hydrophobic amino acids (∼ 45%) and over 20% proline, with molecular weights ranging from 0.5 to 17 kDa. Colostrum is the only source of PRPs; therefore, excess colostrum could be utilized for PRPs production. These PRPs mostly originate from caseins, such as β-casein and α-casein. The role of PRPs in preventing pathological processes in the central nervous system is well established and many formulations included PRPs or colostrum in their medications. Present study envisages composition of colostrum and quantify PRPs content across select indigenous breeds with exotic breed (Holstein Friesian, HF) and one cross breed of HF and Tharparkar (Karan Fries, KF), with time period after parturition. Furthermore, PRPs were characterized using SDS-PAGE, HPLC, amino acid composition, and LC-ESI-MS/MS to understand molecular weight distribution and sequential changes. The HF and Sahiwal breed consistently exhibited the higher PRPs yields at 12, 24 and 36 h postpartum. HF (114.10±19.41 mg/L of colostrum) and Sahiwal (102.20±2.35 mg/L of colostrum) showed the highest PRPs concentrations at 12 h, followed by a decline, highlighting colostrum collected within 24 h of parturition as the optimal PRPs source. Indigenous breeds such as Sahiwal (24.50%), Gir (21.91%), and Tharparkar (22.30%) has shown higher concentrations of proline compared to the crossbred KF (17.49%) and the exotic HF (18.25%).