I cant advise on the amount of chicken versus meatloaf because I don't know what kind of crowd it is or what the rest of the menu is. For example, men tend to eat more beef.
These two recipes from the Armed Services Quartermaster sites make 100 portions each (6-7 13 slice loaves). NOTICE that they use 90% lean beef, if you use regular hamburger you must have 40 pounds per recipe and drain fat during cooking.
One hour 15 minutes at 300 in a convection oven is about the same as 1 1/2 hours at 325 in a PREHEATED regular oven. The internal temp on a meat thermometer should read 180.
Meat Loaf
BEEF,GROUND,BULK,RAW,90% LEAN 30 lbs
BREADCRUMBS 3-3/4 lbs 1 gal
SALT 3-3/4 oz 1/4 cup 2-1/3 tbsp
PEPPER,BLACK,GROUND 1/4 oz 1 tbsp
GARLIC POWDER 1/3 oz 1 tbsp
MILK,NONFAT,DRY 2-1/8 oz 1 cup
WATER 2-7/8 lbs 1 qts 1-1/2 cup
CELERY,FRESH,CHOPPED 1 lbs 1 3/4 cup (1-3/8 lbs as purchased)
ONIONS,FRESH,CHOPPED 1 lbs 2-7/8 cup (1-1/8 lbs as purchased)
PEPPERS,GREEN,FRESH,CHOPPED 1 lbs 3 cup (1-1/4 lbs as purchased)
EGGS,WHOLE,FROZEN 2-3/8 lbs 1 qt plus 1/2 cup (2 dozen plus 2)
JUICE,TOMATO,CANNED 3-1/8 lbs 1 qt plus 1-3/4 cup
Method
Combine beef with bread crumbs, salt, pepper and garlic; mix until well blended.
Reconstitute milk.
Add milk, celery, onions, sweet peppers, eggs, and tomato juice. Mix lightly but thoroughly. DO NOT OVERMIX.
Place 11 pounds 6 ounces meat mixture into each steam table pan and divide into 2 loaves per pan.
Using a convection oven, bake 1 hour 15 minutes at 300 F. CCP: Internal temperature must reach 155 F. or higher for 15 seconds. Skim off excess fat and liquid during cooking.
Let stand 20 minutes before slicing. Cut 13 slices per loaf. CCP: Hold for service at 140 F. or higher.
Tomato Meat Loaf
BEEF,GROUND,BULK,RAW,90% LEAN 30 lbs
BREADCRUMBS 3-3/4 lbs 1 gal
SALT 2-1/2 oz1/4 cup 1/3 tbsp
PEPPER,BLACK,GROUND 1/4 oz 1 tbsp
GARLIC POWDER 1/3 oz 1 tbsp
MILK,NONFAT,DRY 2-3/8 oz 1 cup
WATER 2-7/8 lbs 1 qts 1-1/2 cup
CELERY,FRESH,CHOPPED 1 lb 3-3/4 cup (1-3/8 lbs as purchased)
ONIONS,FRESH,CHOPPED 4 oz 1/2 cup 3-1/3 tbsp (4-1/2 oz as purchased)
PEPPERS,GREEN,FRESH,CHOPPED 1 lbs 3 cups (1-1/4 lbs as purchased)
EGGS,WHOLE,FROZEN 2-3/8 lbs 1 qts 1/2 cup
SOUP,CONDENSED,TOMATO 5-1/8 lbs 2 qts 1-1/4 cup
WORCESTERSHIRE SAUCE 1-5/8 oz 3 tbsp
WATER 1-1/3 lbs 2-1/2 cup
SOUP,CONDENSED,TOMATO 5-1/8 lbs 1-1/2 #3cyl
Method
Combine beef with bread crumbs, salt, pepper and garlic; mix until well blended.
Reconstitute milk.
Add milk, celery, onions, sweet peppers, eggs, tomato soup, and Worcestershire sauce. Mix lightly but thoroughly. DO NOT OVERMIX.
Place 11 pounds 6 ounces meat mixture into each steam table pan and divide into 2 loaves per pan.
Using a convection oven, bake 1 hour 15 minutes at 300 F. on high fan, closed vent. CCP: Internal temperature must reach 155 F. or higher for 15 seconds. Skim off excess fat and liquid during cooking period.
Combine tomato soup and water. Bring to a boil. Let meat loaf stand 20 minutes before slicing. Cut 13 slices per loaf. Pour tomato soup mixture evenly over baked meat loaf slices. CCP: Hold for service at 140 F. or higher.