Sheep and goat production
Reproduction
There are a few differences in the reproduction systems of sheep and goats. The estrus (heat ) cycle of the ewe averages 17 days while the doe's estrus cycle averages 21 days. Goats are much easier to artificially inseminate (AI) than sheep. There are several reasons why.
Ewes have a more complicated cervix which makes passage of an insemination rod very difficult. Frozen semen is usually delivered laparoscopically into the uterine horns. Sheep show few visible signs of estrus as compared to goats. A teaser ram is required to detect estrus or timed inseminations are done after hormonal manipulation.
Though it varies by breed, goats tend to be less seasonal and more prolific than sheep. Male goats have an offensive odor during the mating season; rams do not. The mating rituals of the two species vary, with goats being more "bizarre" in their behavior.
Nutrition
Sheep and goats have similar nutrient requirements, though goats have higher maintenance requirements because they are not able to digest the cellulose of plant cell walls as well as sheep. Lambs tend to grow much faster than kids, no matter what the diet is. Sheep convert feed more efficiently. Grain-feeding is less likely to be profitable in goat production.
With the exception of a few breeds, sheep and goats fatten very differently. Goats deposit fat around their internal organs before depositing external fat over their back, ribs, and loin. Sheep deposit external fat before depositing internal fat. Finn sheep and hair sheep of tropical orgins deposit fat around their organs similarly to goats.
Sheep have a narrow tolerance for excess copper in their diet, though toxic levels depend upon the level of other minerals in their diets. Breeds also vary in their sensitivity to copper toxicity. For this reason, it is generally recommended that sheep not be fed grain and mineral mixes that have been formulated for other livestock (including goats), as these feeds likely have copper added to them.
It can also be risky to graze sheep on pastures that have been fertilized with poultry or hog manure. Caution should be exercised when using any form of copper as a deworming agent. Additional copper should not be added to the diet of sheep unless a deficiency is confirmed by laboratory tests.
Goats require more copper in their diets than sheep and are not as sensitive to copper toxicity. Their maximum level of copper is considered to be similar to cattle. When co-mingled, sheep products should be fed. It may be necessary to give copper supplements to goats that are co-raised with sheep.
Diseases
Sheep and goats are generally susceptible to the same diseases, including scrapie, which is transmitted via infected placenta to genetically-susceptible offspring. U.S. law requires both species to carry official USDA identification when entering commerce or moving from the farm of origin.
Sheep and goats are infected by the same internal parasites (worms), though coccidia (Eimeria spp.) tend to be host-specific. Both sheep and goats can serve as a abnormal host for meningeal worm, a parasite of white tail deer.
Goats tend to be more susceptible to worms than sheep, due to their origins (in a dry climate) and natural browsing behavior. Goats also metabolize anthelmintics quicker and require higher doses of the drugs. The clostridial vaccines also seem to be less effective in goats than sheep. Tissue reactions (to vaccinations) tend to be more common in goats than sheep. Fewer drugs are FDA-approved for use in goats.
OPP (ovine progressive pneumonia) and CAE (caprine arthritic encephalitis), are similar diseases, caused by a slow virus (like HIV), that affect sheep and goats, respectively. The primary mode of transmission is through the colostrum. Cross infection is possible.
No disease similar to "floppy kid syndrome" has been diagnosed in sheep.
Social dominance
Due to their more aggressive behavior, goats will usually dominate sheep, especially if the goats have horns and the sheep are polled (hornless). However, when young bucks and rams are maintained together, rams will dominate because the ram will preemptively strike the buck in the abdomen while the buck is still in the act of rearing up.