Monitoring Milk Yield and Composition Traits in Holstein Friesian Crosses: Influence of Blood Level, Location, Lactation Stage, and Parity

Abstract

TThis study evaluated the effects of genotype (G), parity (P), lactation stage (LS), and location (L) on milk yield and 
composition traits of Holstein Friesian crossbred dairy cows in the Shashemene-Dilla milkshed. A total of 117 
lactating cows, 39 per location (Shashemene, Hawassa, and Dilla), with 13 cows from each genotype group (50%, 
75%, and 87.5% HF) were assessed. Milk yield traits, including peak yield (PY), total yield (TY), lactation length 
(LL), peak day (PD), and average daily Milk yield (ADMY), were analysed. Milk composition traits fat (F), protein 
(P), lactose (L), milk density (MD), salt (S), pH, freezing point (Fpt.), and total solids (TS) were analyzed using the 
Milkoscan FT2. Data on milk yield and composition were processed using a linear mixed-effect model in R 4.3.3. 
GraphPad Prism 10.4.0 was used to visualize overall milk production trends, while Origin software was used to plot changes in ADMY across the lactation stages for each genotype. The results revealed that the 87.5% HF crosses outperformed 75% and 50% HF groups in ADMY, TY, PY, LL, and PD. Conversely, 50% HF crosses showed 
higher MD, TS, P, Fpt., and S., while 75% HF cows had superior fat content over both 50% and 87.5%HF. Location 
significantly influenced MD, Fpt., and S (P < 0.05), and genotype × location interactions were significant for MD, 
TS, P, and SNF. Lactation stage significantly (P < 0.001) affected F, MD, TS, P, and S, while parity influenced all 
yield traits except PD.  ADMY showed a significant negative correlation with fat percentage (r = –0.22) and total 
solids (r = –0.22). Among the compositional traits, protein was strongly correlated with density (r = 0.86) and lactose (r = 0.63), while solids-not-fat also demonstrated a strong association with density (r = 0.76). Overall, the findings indicate that higher Holstein-Friesian inheritance enhances milk yield, it is also strongly influenced by location effect. Therefore, raising awareness on milk production potential evaluation to use strategic selection based on recorded performance and gradual improvement of management practices is recommended to maximize the productivity of crossbred dairy cows under smallholder production system.