Impact of using nigella sativa meal as a protein source on performance of growing Barki lambs under semi-arid conditions of Egypt

الملخص EN

the study aimed to investigate the effect of partial substitution of 5 and 10% of cotton seed meal (CSM) in the commercial concentrate feed mixture by Nigella sativa meal (NSM) on productive performance and carcass traits of Barki lambs.

Twenty one growing Barki Lambs with an average live body weight of 22.7 kg and about 3 months old were used from weaning until sexual maturity (300 days).

Animals were assigned into three similar groups (7 lambs each).

Animals in group 1 (R1) was fed of a formulated concentrate feed mixture (CFM) consists of 35% undecorticated cotton seed meal, 33% wheat bran, 22% yellow corn grain, 4% rice bran, 3% molasses, 2%limeston and 1.0% salt, while the other two groups were fed the same CFM where CSM was replaced by NSM either by 5% in group 2 (R2) or 10% in group 3 (R3).

Animals in all groups were fed on berseem hay (BH) as a sole roughage.

All rations were offered to cover the nutritional requirements of 100 g gain / day at concentrate: roughage ratio of 60: 40.

Three digestibility trials using three lambs of each group were carried out to evaluate the experimental rations.

At the end of the experiment, 3 animals from each group were slaughtered to study some physical and chemical carcass traits.

Results showed that NSM had higher content of CP and EE than Those of CSM, while the CF and NFE content were lower.

No significant difference among means of DM and CP intake were detected.

Adding NSM in R2 and R3 minimized drinking water (ml/kg BW) by 18.2 and 25.8%, respectively, than R1.

Tested R3 showed significant (p<0.05) improvement in TDN and DCP% than those of R1 being 5.92 and 10.14% respectively.

The digestion coefficient of all nutrients except EE were significantly (P<0.05) improved by adding NSM to R3 compared with R1.

The improvement recorded was found to be 6.62, 5.95, 7.52 and 14.26% for DM, OM, CP and CF, respectively.

All animals received tested rations were in positive nitrogen balance.

Lambs fed on R3 tended to retain higher (p<0.05) nitrogen (0.245 g/kg BW) than those fed R1 (0.187 g/kg BW).

The obtained values of pH, NH3 - N and VFA's were within the normal ranges for normally function rumen with all tested rations.

Blood constituents data showed that total proteins, albumine, globuline and urea concentration increased significantly (P<0.05) by adding NSM in R3, while creatinine, cholesterol, total lipids and triglycerids concentration decreased.

R3 and R2 (with NSM) scored the highest final margine (LE/head) being 41.9 and 35.6% higher than R1 (free NSM).

Also the same trend was observed for dressing percentage, which was higher (P<0.05) in R 3 and R 2 compared with R 1.

It could be concluded that Nigella sativa meal could be used safely, economically and successfully as a partial replacer to CSM by 10% of formulating commercial concentrate feed mixture.