essam elsayed

Introduction Milk yield of a dairy cow depends on four main factors: (a) genetic ability; (b) feeding program; (c) herd management; and (d) health. As cows continue to improve genetically, we must also improve nutrition and management to allow the cow to produce to her inherited potential. A good dairy feeding program must consider the quantity fed, the suitability of the feed and how and when the ...

Artificial insemination is a powerful tool for genetic improvement that enhances the value of bred heifers. A longer duration of estrus and more mounting activity makes the detection of estrus in heifers easier than in lactating cows, thus heifers are generally more sexually active than cows and easier to catch in estrus. For optimum fertility, heifers should have three or more estrous cycles bef ...