A study was carried out in a mango orchard on reclaimed land for two seasons in 2019 and 2020. The experiment was implemented on fifteen years old mango trees “Fagri Kalan” budded on seedling mango rootstock and planted at 4 × 4 m. This experiment involved two soil growth stimulants (K humate, magnetite) and foliar application with cobalt. The experiment involved two factors, the first one was soil application with K humate by two levels (50 and 100 g/tree/year) and magnetite by two levels (250 and 500 g/tree /year) plus control, whereas the second factor was a foliar application with Co as cobalt sulfate by three levels (0, 15, and 30 ppm Co). The experiment was carried out in a factorial experiment in split plot design with three replicates whereas each replicate was represented by two trees. Result indicated that soil application with K humate at 100 g/tree followed by magnetite at 250 g/tree or foliar application with Co at 15 ppm alone or the combination between (K humate at 100 g/tree and cobalt at 15 ppm) gave the highest values of yield/tree, fruit weight, TSS, reducing sugars, leaf N, P, K, and Fe content of “Fagri Kalan” mango trees grown under salinity conditions.

Twelve local Zaraiby goats with average live body weight of 10.71±0.23 kg (5-6 months). Animals were divided into three comparable groups. Goats in first group were fed without supplement (control group) or sup-plemented with 25% ordinary cobalt and 25% nanocobalt from cobalt requirements (NRC, 1985). The results showed that no significant difference (P>0.05) among experimental groups for DMI and CPI values. However, there was a highest significant difference (P<0.05) in average daily gain, total gain, and feed efficiency (kg gain/ kg DMI) for nanoco-balt group. Nutrients digestibility values as DM, CP, CF, NFC, ADF, NDF, cellulose and hemicellulose in addition to percentage of TDN in nanocobalt treatment were higher sig-nificantly than those others groups. But the ra-tio of nitrogen balance in goats' diet with nano-cobalt group was less than that using ordinary cobalt and control group. While the DE (Mcal/Kg DMI) ratio was no significant differ-ences observed among groups. Rumen pH and TVFA’s values after 3 and 6 hours of feeding, the control and the ordinary cobalt groups in-creased (P<0.05) more than the nanocobalt group. After 3hrs, adding nanocobalt has lower significant values for NH3-N than those others. Where, the control group recorded the lowest value. No significant (P>0.05) differences were observed at 0, 3and 6 hrs. after feeding for all blood parameters. There was a slight in-crease for most of body measurements with nanocobalt supplement. It could be concluded that adding nanocobalt for goats' rations en-hanced growth performance, digestibility coef-ficients, rumen parameters and slightly body measurements without any diverse effect on animals' health.