Monday, January 30, 2017

Bava Basra 8

Considering the Rashi about dogs and ravens

Raven Feeding Young:

Medieval Bestiary
Pliny the Elder [1st century CE] (Natural History, Book 10, 15): When raven chicks are strong enough to fly, their parents drive them far away from the nest, so that in small villages there are never more than two pairs of ravens. Ravens experience 60 days of poor health due primarily to thirst, before the figs ripen in autumn. Some say that ravens mate or lay eggs through the beak, and as a consequence if a pregnant women eats raven eggs or has such eggs in the house, she will experience a difficult birth; but Aristotle says this is not true. Ravens are the only birds that understand the meaning they convey in auspices, and it is a particularly bad sign if a raven gulps down its croak as though it was choking. (Book 10, 60): When Tiberius was emperor, there was a raven in Rome that always greeted him by name. Another raven was seen dropping stones into an urn of water, causing the water to rise high enough for it to drink.
Bartholomaeus Anglicus [13th century CE] (De proprietatibus rerum, book 12): The raven beholdeth the mouths of her birds when they yawn. But she giveth them no meat ere she know and see the likeness of her own blackness, and of her own colour and feathers. And when they begin to wax black, then afterward she feedeth them with all her might and strength. It is said that ravens' birds are fed with dew of heaven all the time that they have no black feathers by benefit of age. Among fowls, only the raven hath four and sixty changings of voice. (Mediaeval Lore from Bartholomew Anglicus (London, 1893/1905) Steele edition of 1905)

Ravens will eat all sorts of food, though, including the feces of the chicks.

Dog Digestion, Source 1:
There is no simple answer though as passage timedepends on several factors. Each dog is an individual. In general, raw dog food takes about 4 to 6 hours to move through your dog. Dry dog food takes a bit longer to digest and spends about 10 to 12 hours inside your dog.

Dog Digestion, Source 2: (Study)

Body weight and GI transit times in dogs

Dogs with the lowest body weight appeared to have longer gastric and small intestinal transit times than did large- and giant-breed dogs

The objective of this study was to assess the relationship between body weight (BW) and gastrointestinal (GI) transit times in healthy dogs, measured by a wireless motility capsule (WMC) system. Food was withheld overnight from 31 healthy dogs. The following morning, each dog received an orally administered WMC, then a test meal that provided a fourth of the daily energy requirements. Measurements were obtained from each dog in its home environment via a vest holding a receiver that collected and stored data from the WMC.
Gastric emptying time (GET) ranged from 405 to 897 minutes, small bowel transit time (SBTT) ranged from 96 to 224 minutes, large bowel transit time (LBTT) ranged from 427 to 2,573 minutes and total transit time (TTT) ranged from 1,294 to 3,443 minutes. There was no positive relationship between BW and GI transit times. A nonlinear inverse relationship between BW and GET and between BW and SBTT best fit the data. The LBTT could not be explained by this model and likely influenced the poor fit for the TTT.
Dogs with the lowest BW appeared to have longer gastric and small intestinal transit times than did large- and giant-breed dogs.
Source : C.S. Boillat et al., 2010. Assessment of the relationship between body weight and gastrointestinal transit times measured by use of a wireless motility capsule system in dogs. AJVR 71: 898-902. doi: 10.2460/ajvr.71.8.898

1 comment:

dov said...

very interesting.

do you know of any one place where all scientific statements by chazal/rishonim which have previously been mentioned by scientists are listed. ?

also do you know where does rabeinu bechai speak about nesher shedding its wings as it goes to gilgal haeish ?


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