Effect of Non-Genetic Factors and Temperature-Humidity Index (THI) on Daily Milk Yield of Crossbred Jersey and Holstein Friesian Cows in Chitwan, Nepal

• DOI: 10.3126/jafu.v6i1.79194
• Publication Date: 2025-05-27T09:32:47Z
• Authors: Sagar Paudel; Nirajan Bhattarai; Hom Bahadur Basnet; Neena Amatya Gork...; Saroj Sapkota; Pratik Hamal
• Keywords: Heat index

The effect of non-genetic factors on daily milk yield helps optimize production, improve economic efficiency, make informed management decisions, advance breeding programs, and adapt to changing climatic impacts. present study had the main objective assess temperature-humidity index (THI) other including year, season calving, parity, milking, stage lactation (DMY) Jersey Holstein-Friesian dairy herd reared under sub-tropical region at National Cattle Research Center (NCRP), Chitwan, Nepal. A total number 88,268 individual records maintained pedigree performance recording scheme (PPRS) during year 2016 2022 involving 50 75 lactating cows (depending upon studied) were used for this study. Data analyzed using General Linear Model procedure (GLM) R Program version 4.4.1. Least Squares Maximum Likelihood Estimation methods with unbalanced subclass numbers analysis data. overall mean was 8.09 kg 7.79 breed 8.40 Holstein Friesian (HF) cattle breeds Chitwan. Primiparous (first parity) have highest DMY 8.55 significantly lower production (7.49 kg/day) secundiparous (second cows. An improvement in observed across recent years, likely due although a slight decline noted COVID-19 years (2019 2020). Highest early (10.23 kg) month December May. Milk decreases increasing THI levels (i.e., as heat stress increases), both breeds. This revealed that Chitwan NCRP farm is influenced by thermal stress, crosses producing more but being heat-sensitive, while optimal stage, cooler seasons enhanced productivity.