I used a translator.

The number of cattle will continue to be zero when coded below.
What should I do?

%{;;s}% is #

Code (Skript):

1. options:
2.     prefix: &eAnimal&f>
3.    
4. command /animal [<text>]:
5.     permission: lom.op
6.     trigger:
7.         if arg-1 is not set:
8.             send "{@prefix} /animal wand &c-> &fGive a wand."
9.             send "{@prefix} /animal check &c-> &fcheck number of animal"
10.         else if arg-1 is "wand":
11.             set {_wand} to feather named "&cAnimal Check Wand" with lore "Left click: select pos %{;;s}%1||Right click: select pos %{;;s}%2"
12.            
13.             give 1 of {_wand} to player
14.            
15.             send "{@prefix} Left click: select pos %{;;s}%1"
16.             send "{@prefix} Right click: select pos %{;;s}%2"
17.         else if arg-1 is "check":
18.             if {animalcheck.pos1} is not set:
19.                 send "{@prefix} please select pos %{;;s}%1"
20.             else if {animalcheck.pos2} is not set:
21.                 send "{@prefix} please select pos %{;;s}%2"
22.             else:
23.                 set {_animals} to 0
24.                 loop all entities:
25.                     set {_loc} to loop-entity's location
26.  
27.                     set {_animals} to number of cows in {animalcheck.pos1} and {animalcheck.pos2}
28.                 send "Number of animals : %{_animals}%"
29.                
30.                 delete {animalcheck.pos1}
31.                 delete {animalcheck.pos2}
32.                
33. on leftclick:
34.     if player has permission "lom.op":
35.         set {_wand} to feather named "&cAnimal Check Wand" with lore "Left click: select pos %{;;s}%1||Right click: select pos %{;;s}%2"
36.         if player's tool is {_wand}:
37.             cancel event
38.             set {_click} to event-location
39.             if {_click} is not set:
40.                 stop
41.             else:
42.                 cancel event
43.                 set {animalcheck.pos1} to event-location
44.                 send "{@prefix} First position set to %event-location%"
45.                
46. on rightclick:
47.     if player has permission "lom.op":
48.         set {_wand} to feather named "&cAnimal Check Wand" with lore "Left click: select pos %{;;s}%1||Right click: select pos %{;;s}%2"
49.         if player's tool is {_wand}:
50.             cancel event
51.             set {_click} to event-location
52.             if {_click} is not set:
53.                 stop
54.             else:
55.                 cancel event
56.                 set {animalcheck.pos2} to event-location
57.                 send "{@prefix} Second position set to %event-location%"