Abstract
Six heifers each of $F_1$, $F_2$, $F_3$, $F_4$ H. Friesian $\times$ Sahjwal halfbreds and pure Sahiwal with overall average initial age and live weight of $315.6{\pm}134.8 days$ and $143.8{\pm}48.5kg$, respectively were used for this study. The under trial animals were fed according to N.R.C. (1978). The overall average age at maturity, first conception and first calving was $563.8{\pm}116.8$, $675.8{\pm}135.6$ and $956.8{\pm}149.8days$ with live weights as $302.2{\pm}58.6$, $342.6{\pm}41.5$ and $433.9{\pm}38.1kg$, respectively. The overall 305 days and total milk yield for 1st lactation was $2,729.0{\pm}669.3$ and $2,992.7{\pm}377.5litre$ while the FCM (at 4%) was $2,934.2{\pm}410.8litre$. The lactation length was $336.6{\pm}69.6days$. The fat and solids not fat contents were $4.5{\pm}0.2$ and $8.2{\pm}0.3percent$, respectively. The milk production in Sahiwal cows was significantly lower than crossbred cows. The services per conception were $2.5{\pm}1.3$. The overall per head per day consumption of DM, TCP and ME was $10.9{\pm}1.2kg$, $1,399{\pm}199gm$ and $22.6{\pm}2.4 M.Cal.$, respectively. The overall milk producing efficiency for the production of one litre of FCM was $1.12{\pm}0.15kg$ of DM, $142.2{\pm}17.76gm$ of TCP and $2.31{\pm}0.27M.Cal.$ of energy while the feeding cost was Rs. $1.46{\pm}0.22$ per litre of FCM produced. The feeding cost per litre FCM was significantly higher in Sahiwal and $F_2$ than in other genetic groups.