Yellowhammer put up a link a while back that I've bookmarked:
http://www.sheepusa.org/index.phtml?page...ume=Volume%2019,%202004%20-Special%20Edition:%20Predation
There's easily a couple of days reading on that one site, but relevant to this discussion are some excerpts below.
In short, coyotes
do kill livestock, goats, sheep, then cattle, in descending order. The
amount of predation varies greatly depending on the area, and the livestock and predation management methods used.
Free roaming dogs, feral or not, can be as large a problem (or larger) as wild animal predation depending on the area.
Free roaming cats, feral or not, can be a huge problem for game bird populations too.
During the 1970s, a series of studies were conducted to evaluate and document coyote damage to sheep in the absence of management in western states (Huben, Shwiff and Bodenchuk, this issue). With adult sheep, losses range from 1.4 to 8.4 percent and lamb losses range from 6.3 to 29.3 percent. In a similar study conducted with Angora goats in South Texas, Guthrey and Beasom (1978) reported 49% losses of adult does and 64% losses of kid goats due to predators (primarily coyotes).
http://www.sheepusa.org/index.phtml?page...ume=Volume%2019,%202004%20-Special%20Edition:%20Predation
Direct effects of predation (i.e., killing of animals) can result in significant economic losses to livestock producers. A recent publication by the USDA, Wildlife Services (2002) identified the following losses: (1) livestock losses attributed to predators, predominantly coyotes (Canis latrans), reach about $71 million annually; (2) cattle and calf losses to predators in the United States totaled 147,000 head during 2000. A National Agricultural Statistics Service (NASS) study valued these losses at $51.6 million; (3) sheep and lamb losses to predators in the United States totaled 273,000 in 1999. A NASS study valued these losses at $16.5 million; (4) In Arizona, New Mexico, and Texas, the three major goat-producing states, 61,000 goats and kids were lost to predators in 1999. A NASS study valued these losses at $3.4 million. Although direct losses of livestock due to depredation are often conspicuous and economically significant, they likely underestimate the total loss to producers because they do not consider indirect effects of carnivores as a result of livestock being exposed to the threat of predation without being killed.
http://www.sheepusa.org/index.phtml?page...ume=Volume%2019,%202004%20-Special%20Edition:%20Predation