Effect of some non-genetic factors on the productivity and profitability of Holstein Friesian dairy cows

Milk yield (MY) is one of the main factors that affect the economic profitability of dairy farms. Thus, increasing the MY per animal and decreasing the feed cost can lead to economic gains, so the objective of this study was to evaluate the effect of dry period length (DPL), days open (DO), and days in milk (DIM) on the productivity and profitability of dairy cow farms. Data used in this study were taken from 3095 lactation records of Friesian dairy cows of private and governmental sectors. The data were classified into 4 DPL categories: DPL 75 days, 3 DO categories: DO ≤90 days; DO 91-110 days and DO >111 days, and 8 DIM categories: DIM 180-210 days; DIM 211-240 days; DIM 241-270 days; DIM 271-300 days; DIM 301-330 days; DIM 331-360 days; DIM 361-447 days; and DIM >447 days. The average net profit (NP) was significantly different (p