I assume they often include milk in the recipes because most farmers had their own milk cow(s) and meat scraps because people often did their own butchering. That all kinda loses the original intent when these days you'd have to go out to the grocery store to purchase these items.
Milk, yes several of them mention using milk that was produced on the farm, and talk about whether it is worth more as poultry feed than what it could be sold for.
But the "meat scraps" or "beef scrap" was typically an ingredient that was purchased, not made on the farm. It was cooked down to a dry form, much more concentrated than fresh meat.
Fresh meat has about 75% water and 20% protein by weight. Source:
Source:
https://www.fsis.usda.gov/food-safe...aration/food-safety-basics/water-meat-poultry
The "meat scraps" and "beef scrap" had protein ranging from 50% to over 60% and was often included in a dry mash mixture.
Checking that in several of the sources provided:
Book page 283 (going by the page number in the corner) says:
"
Beef scrap is probably the best and most convenient substitute for meat that can be used. It is made by the packing houses from scraps of meat that have been cooked and dried. It keeps well and is easily handled. The popular way to feed it is in a dry mash with the other meals, but it may be fed entirely alone."
This 1939 research paper -
Link to research -
page 15, "A 62 percent protein meat scrap was used in this experiment. "
page 29, "All pens received the following all-mash mixture fed dry in hoppers" with ingredients including "Meat scrap (50% protein)"
page 41, "Meat scrap (50% Pro.)"
And, for perspective regarding the above post, one state over in Kansas for a similar time frame (1920 - 1924)
Hens averaged about 80 eggs per year.
Source
Page 11-12, "animal product feeds such as tankage and meat scraps, have a place on many farms. However, an increasing number of farmers are mixing their own feeds, using home - grown grains, and skim milk replaces tankage and other similar feeds."
Michigan State 1927
Source
It covers feeding for eggs
And care and feeding for chicks
Page 7 of the caring for chicks section includes "Meat scrap, 50 per cent protein" as an ingredient in the dry mash mixture.
North Dakota, 1907...This paper only sort of gives recipes. It looks more variable than what I would call a recipe.
Source
North Dakota Agricultural College
Bulletin 78
Page 444, a recipe includes "dried beef scraps"
Page 445, "Many poultrymen recommend letting the fowls have free access to dried beef scraps."
Page 452, "One of the most satisfactory meat foods for poultry is the commercial by-product, dried beef scraps. Concentrated meat foods of this sort can be kept indefinitely, and the poultryman can usually place reliance on the chemical composition of the product. Dried beef scraps can be bought in large bags ready for use from any poultry supply house."
Page 452 does also mention, "Cooked meat scraps from the table can be used to good advantage," but they obviously consider this to be a different product than the "dried beef scraps."