تأثير مستوى الطاقة و البروتين في العليقة على معامل هضم العناصر الغذائية و ميزان الأزوت في التعاج العواس الحلوب

الملخص EN

The objective of this paper was to study the effect of protein and energy level on the Nutrient Digestibility and Nitrogen balance of Lactating Awassi Ewes.

This study was conducted at the Agricultural Scientific Research Center (ASRC), Salamieh.

Twenty-four lactating ewes of 2-5 years old , delivered single lambs and similar lambing dates were randomly assigned to four treatments, namely high energy-high protein (HH), high energy-medium protein (HM), medium energy-high protein (MH) and medium energy-medium protein (MM).

The high and medium levels of energy or protein represented 120 and 100 percent of the requirements of lactating ewe based on the British Feeding Standards (ARC,1981) .

Ingredients used for ration formulation were barley grains, wheat bran, cottonseed cake, cottonseed husks, barley straw, salt and a mineral mixture.

Digestibility coefficients of dry matter, organic matter and energy were maximum for the treatment HH, but differences between treatments were not statistically significant.

Ether extract digestibility was highest (P<0.001) for the MH treatment.

On the other hand, MM treatment showed significantly highest ADF digestibility coefficients.

Fecal nitrogen excretion increased as dietary nitrogen decreased, while urinary nitrogen increased as dietary nitrogen increased.

Therefore, nitrogen balance showed best nitrogen retention for the rations of high protein level.