الفهرس 
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Abstract
This study was carried out at South Sinai Research Station (Ras Sedr), Desert Research Center. This work aimed to assess and evaluate the impact of salinity in both drinking water and feeding salt-tolerant plants (alfalfa) on the leather physical properties, some skin histological parameters and some physiological responses of growing Shami male goats under semi-arid conditions in Sinai, Egypt.
Twenty eight growing male Shami goats (2.0 – 2.5 months old and 13.02 ± 0.34 kg average body weight) were assigned randomly into four equal groups (7 each). The first group (G1; BH&TW) was fed on berseem (Trifolium alexandrnum) hay (BH) and drank tap water (TW, 274 ppm) and served as control. The second group (G2; BH&SW) was fed on BH and drank saline water (SW, 6000 ppm). The third group (G3; STP&TW) was fed on salt-tolerant plants (alfalfa) and drank TW and the fourth group (G4; STP&SW) was fed on STP and drank SW. All groups were offered concentrate feed mixture (CFM) and roughages (60:40%) to cover their maintenance and productive requirements according to Kearl (1982).
The experimental animals were kept continuously in semi-open pens under the same managerial, hygienic conditions and diagnosed as clinically free from internal and external parasites.
Determination of blood minerals and hormonal assays were conducted in the Central Lab of DRC. Whereas, skin histological features was executed at Wool Production and Tech. Lab of DRC.
At the end of the experiment three animals from each group were chosen randomly to be slaughtered and prepared for tanning processes.
Results obtained from this study could be summarized as follows:
1. Analysis of tap water (TW) and saline water (SW) indicated that SW had higher values of all minerals than those in TW.
2. The total dissolved solids, electric conductivity and hardness were higher in SW than those in TW while pH values was almost equal in both types of water.
3. The minerals concentrations increased in alfalfa (1.4, 1.72 0.962 and 0.666%) compared to berseem hay (0.7, 1.24, 0.682 and 0.233%) for Na, K, Ca and P, respectively.
4. Initial live body weights were nearly the same in the four groups, being 13.16, 12.85, 13.14 and 12.92 kg for BH&TW, BH&SW, STP&TW and STP&SW, respectively while the final body weight was higher for STP&TW (G3) followed by H&SW (G2) and the lowest value recorded by BH&TW (G1).
5. Daily gain varied significantly among groups. Increasing daily gain were reflected on total gain, being the highest for STP&TW (32.07 kg) followed by BH&SW (31.07 kg) and then STP&SW (30.64 kg) and BH&TW (30.08).
6. The average value of fresh skin weight were found to be 2.16, 2.19, 2.26 and 2.17 (kg) for BH&TW, BH&SW, STP&TW and STP&SW, respectively.
7. For dry skin weight, the average value were found to be 1.87, 1.88, 1.94 and 1.87 (kg) for BH&TW, BH&SW, STP&TW and STP&SW, respectively.
8. The highest concentration of sodium (Na) was found in STP&SW while, the lowest one was found in BH&TW. While, potassium (K) concentration was higher in the two groups which drank SW.
9. STP had a significant (P<0.05) effect of the mean values of plasma calcium (Ca) concentration. The mean value of STP groups was 9.77 vs 7.73 for BH groups. Also, SW had a significant (P<0.05) effect on (Ca) concentration. The mean value of SW groups was 9.92 vs 7.58 for TW groups.
10. Phosphorus (P) concentration showed the same trend as found in Ca concentration. Both of STP and SW had a significant (P<0.05) effect on (P) concentration.
11. Salinity in both feeding and water affected significantly (P<0.05) Mg concentration. group 4 (STP&SW) had higher value (3.08±0.073 mg/dl) of Mg concentration while, the lowest one (1.79±0.073 mg/dl) was recorded for G1 (BH&TW) group.
12. Cl concentration tended to increase with increasing salinity level; STP and SW groups had higher (P<0.05) values than control group.
13. The higher value of zinc concentration was recorded in (STP&SW) group (5.40±0.239 mg/dl) while the lowest one was recorded in (BH&TW) group (4.67±0.239 mg/dl).
14. Triiodothyronine (T3) was higher (P<0.05) in the two groups of TW than that found in SW. The highest (P<0.05) value was observed in (BH&TW) group while the lowest was observed in (STP&SW) group.
15. Thyroxine (T4) levels was affected significantly (P<0.05) by salinity in both feeding and drank saline water. Whereas both of them (STP and SW) decrease T4 level.
16. Result of aldosterone (Ald) level indicated that drinking SW and feeding STP both of them tended to decrease Ald secretion in blood. Which means that, the effect of SW and STP were significant (P<0.05) on Ald. level.
17. Cortisol (Cort.) level tended to increase with increasing salinity level so we see that SW groups had higher (P<0.05) values than that of TW groups and STP groups had higher (P<0.05) values than that of H groups.
18. Present study showed a significant (P<0.05) effect of salinity on epidermis layer thickness. SW increased significantly (P<0.05) the thickness of epidermis while, STP decreased its thickness.
19. Salinity had a non-significant effect on papillary layer thickness. The thickness of papillary seemed decreased with SW or/ STP. The higher value was obtained at (BH&TW) followed by (BH&SW), (STP&TW) and (STP&SW) with values 674.18, 641.99, 624.37 and 562.25 µm, respectively.
20. Water salinity had a significant (P<0.05) effect on reticular layer thickness while, the effect of STP was non-significant. the highest value was 1429.36 µm and lowest one was 963.50 µm for (STP&TW) and (STP&SW), respectively.
21. The skin thickness was affected significantly (P<0.05) by water salinity. While, the follicle depth was affected significantly (P<0.05) by STP feeding.
22. Salinity have non-significant effect on primary or secondary populations. Also, follicles density were not affected significantly by salinity.
23. STP had a significant (P<0.05) effect on each of Primary, secondary and total follicles areas. While, it’s non-significant for SW.
24. Tensile strength showed a non-significant effect by feeding (BH or/ STP) and also by water salinity. While, the higher value of Ts was obtained in (BH&SW) group with value 131.43 kg/cm2 and the lower one was obtained with (STP&SW) with value 93.65 kg/cm2.
25. The present results showed a non-significant effect of STP /or SW on elongation and tear strength. Whereas, the higher value of elongation and tear strength was obtained in group (BH&SW) and the lowest one was obtained in group (STP&SW). Which induce hyper salinity.
Generally, better results were obtained when tap water (TW) or hay (BH) were included in feeding in both G2 (BH&SW) or G3 (STP&TW) due to mild salinity. On the other hand, control group (G1) or the fourth group (G4) gave lower results, due to low salinity or hyper salinity.