I was hanging out with my nephew today, and we were talking about wizards, Cheez Whiz, and conspiracy theory cults. Naturally, the question came up as to whether there’s any urine content in the cow milk we buy at the supermarket.
So, naturally, I did a search on “% of cow milk that is urine.”
In the results, I stumbled on the following study from the esteemed Journal of Dairy Science:
“When and where do dairy cows defecate and urinate?” by M. Villettaz Robichaud, A.M. de Passillé, D. Pellerin, J. Rushen
Here’s the abstract:
The accumulation of urine and feces can be responsible for many cow and environmental problems. Despite this, little is known about the factors affecting defecation and urination. In the first experiment, the occurrence of defecation and urination behaviors of 48 lactating Holstein cows was observed [days in milk (DIM) = 144.7 ± 38.0 d, body weight (BW) = 667.1 ± 72.0 kg, parity = 2.8 ± 2.3] in freestalls over 48 h. In the second experiment, defecation and urination by 29 lactating Holstein dairy cows were observed (DIM = 62 ± 22.1 d, BW = 590 ± 70.0 kg, parity = 2 ± 1.3) in another freestall barn over a period of 5 d and related to cow activity and feeding behavior. In both experiments, based on total occurrence of eliminative behaviors, cows mainly defecated (experiment 1: 33.4 ± 2.0%; experiment 2: 42.3 ± 3.1%) and urinated (experiment 1: 28.2 ± 2.5%; experiment 2: 42.7 ± 4.0%) in the feed alley and while occupying a stall (defecation: experiment 1: 28.5 ± 1.0%; experiment 2: 26.2 ± 3.0%; urination: experiment 1: 42.2 ± 1.5%; experiment 2: 39.9 ± 3.8%). Occupying a stall included lying, standing in the stall, or standing with 2 feet in the stall and 2 feet in the alley. In both experiments, differences were found between cows in frequency of defecation (experiment 1: 9.8 ± 4.2/d, range = 3 to 20; experiment 2: 15.4 ± 4.3/d, range = 6 to 36) and in frequency of urination (experiment 1: 7.0 ± 3.1/d, range = 2 to 18; experiment 2: 9.3 ± 2.8/d, range = 3 to 19). Large differences between cows were observed in the frequency of defecation and urination, but these were not correlated with parity, milk production, BW, DIM, or dry matter intake.
And here’s my Abstract of the Abstract:
After watching cows pee and poo for seven days, we learned absolutely nothing.
