22 December 2009
While sheep and goats have many similarities, their taxonomy (scientific clasification) eventually diverges. Each is a distinct species and genus. Sheep (Ovis Aries) have 54 chromosomes, while goats (Capra Hircus) have 60. While sheep and goats will occasionally mate, fertile sheep-goat hybrids are rare. Hybrids made in the laboratory are called chimeras.
• Look at their tails
The easist way to tell the difference between a sheep and goat is to look at their tails. A goat's tail goes up (unless it is sick, frightened, or in distress). Sheep tails hang down and are often docked (shortened) for health and sanitary reasons.
• Foraging behavior
The biggest difference between sheep and goats is their foraging behavior and diet selection. Goats are natural browsers, preferring to eat leaves, twigs, vines, and shrubs. They are very agile and will stand on their hind legs to reach vegetation. Sheep are grazers, preferring to eat short, tender grasses and clover. Their dietary preference is forbs (broadleaf weeds) and they like to graze close to the soil surface. Goats like to eat the tops of plants.
There are many behavior differences between sheep and goats. Goats are naturally curious and independent, while sheep tend to be more distant and aloof. Sheep have a stronger flocking instinct and become very agitated if they are separated from the rest of the flock.
Goats will seek shelter more readilty than sheep. Neither likes to get their feet wet and both prefer upland grazing to lowland.
In a fight, a ram will back up and charge to butt heads. A goat will rear up on his hind legs and come down forceably to butt heads. This fighting behavior favors the ram.
• Physical differences
Sheep and goats have many physical differences. Most goats have hair coats that do not require shearing or combing. Most sheep grow wool and need to be sheared annually. Lamb tails are usually docked (shortened) whereas goat tails are not.
Sheep have an upper lip that is divided by a distinct philtrum (groove). The goat does not.
Male goats have glands beneath their tail. Sheep have face or tear glands beneath their eyes and foot or scent glands between the toes. Male goats develop a distinct odor as they grow in sextual maturity. The odor is very strong during the rut (mating season). Sexually mature rams have much less of an odor.
Most goats naturally have horns. Some goats have beards. Many breeds of sheep are naturally hornless (polled). Some sheep have manes. Goat horns are more narrow, upright, and less curved than sheep horns. Sheep tend to curl their horns in loops on the sides of their heads.
Sheep and goat production
The estrus cycle of the ewe averages 17 days; 21 days for the doe. Goats are much easier to artificially inseminate (breed) than sheep. Sheep have a complicated cervix which makes passage of an insemination rod very difficult. Sheep show few visible signs of estrus (heat) as compared to goats. Male goats have an offensive odor during the mating season; rams do not.
Though it varies by breed, goats tend to be less seasonal and more prolific than sheep.
Sheep and goats have similar nutrient requirements, though goats have slighter higher maintenance requirements, as they are usually a smaller animal (by weight). Sheep tend to grow much faster than goats, no matter what the diet is. They convert feed more efficiently. Grain-feeding is less likely to be profitable in goat production.
With the exception of hair sheep, sheep and goats fatten very differently. Goats deposit fat around their internal organs before depositing external fat. Sheep deposit external fat before depositing internal fat. Finn sheep and some of the hair breeds deposit fat around their organs similar to goats.
Sheep have a narrow tolerance for excess copper in their diet, though toxic levels depend upon the availability of other minerals (Molybednum and Sulfur) in the diet. It is recommended that sheep be fed grain and mineral mixes that have been specifically formulated for sheep, as products formulated for other livestock or generic livestock feeds will likely have added copper.
It can also be risky to graze sheep on pastures that have been fertilized with poultry or hog manure. It is not advisable to use copper as a deworming agent. Goats have require more copper in their diet than sheep and are not as sensitive to copper toxicity. When co-mingled, sheep products should be fed.
Sheep and goats are generally susceptible to the same diseases, including scrapie, which is transmitted via infected placenta to genetically-susceptible animals. Sheep and goats are infected by the same internal parasites (worms), though coccidia are species-specific.
Goats tend to be more susceptible to worms than sheep, due to their origins and natural browsing behavior. Goats metabolize anthelmintics quicker and require higher doses of the drugs. The clostridial vaccines also seem to be less effective in goats. 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.
• There is no disease similar to "floppy kid syndrome" in lambs.
• Social dominance
Due to their more aggressive behavior, goats will usually dominate sheep, especially if the goats have horns. 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.
21 December 2009
Goat and cow’s milk are nutritionally similar, though definitely not equal. The main difference is that goat's milk has smaller fat globules. This helps to lessen the strain on a child's immature digestive system. Consequently, goat’s milk may reduce the possibility of allergies, asthma and other ailments. Children who are allergic to cows milk often thrive on goat's milk.
Goat’s milk also has a closer protein composition to human milk. This also helps to explain the low allergy rate. Beta caseins are found in both human and goat’s milk. These have a softer curd and easier digestibility than the alfa caseins that are so prevalent in cow's milk. Goat's milk also does not contain Agglutamin. This is the reason fat globules do not cluster, assisting digestion. On average, goats milk contains more calcium, vitamin B6, vitamin A, potassium, niacin, chloride, copper, phosphorous, manganese and selenium. It is slightly lower in folic acid (1), has less arginine and less sulphur-containing amino acids (particularly methionine) but more glycine than cow's milk (2). Goats also are more finicky eaters than cows – meaning they eat a more varied diet, usually richer in minerals. While switching from cow’s milk to goat’s milk, it is recommended you mix a littleof the cow’s milk with the goats milk to help adjust to the new taste.
Goat's milk enriches intestinal flora and can be used to relieve constipation. Cow's milk conversely may result in constipation in children with a sensitive digestion. Laura Morales from the Even Star Goat Dairy in Lowood (near Toowoomba) says that Goat’s milk is also considered to be less phlegm producing.
If the milk is pasteurised, boiling it will assist in the digestion. Pasteurisation partially dismantles the protein structure. This makes the milk more difficult to digest. Boiling the milk finishes the process and decreases the chance of allergic reaction (1).
Ideally however, purchase 'raw' or unpasteurised milk. This has many advantages. Goat's milk is one of the best sources of dietary fluorine, nearly ten times higher than cow's milk. Fluorine helps build immunity and strengthen teeth and bones. Fluorine is depleted during the cooking process so is only present in unpasteurised milk. The chemical "fluoride" does not have the same healing properties (3) and is best avoided wherever possible.
Pasteurisation also destroys the beneficial bacteria that assist in digestion. These can only be replaced by culturing the milk and is why yoghurt is easier to digest than milk. The proteins are pre-digested by the bacterial action of the souring process.
If goat's milk is not available (or the taste is disagreeable), one ways to increase the digestibility of the milk from the cow is to soften the curds by adding gelatin. This will bring it closer to resembling the soft curds of Goat’s milk and mother's milk . Adding gelatin also emulsifies fat and by stabilising the casein (protein), improves the digestibility of the fat, which would otherwise be carried down with the casein in a lump mass. Vomiting, upper respiratory infections, constipation and diarrhea may also be reduced by the addition of gelatin (9). Use one teaspoon per four cups of milk. Prepare the gelatin as per the usual instructions by dissolving it in half a cup of water (or more). Mix with the milk and drink or refrigerate.
In Ayurveda (Indian medicine), fresh cow’s milk is thought to be excellent for those with a strong digestion who want to increase their weight. They believe it is a sattvic food, meaning that it can help develop Spiritual awareness. On the other hand, they also believe that homogenization makes the fat in the milk nearly indigestible and causes toxic residues (ama) to form in the body (5).
Homogenisation allows the enzyme xanthine oxidase to penetrate the intestinal wall, move into the lymphatic system and then to enter the bloodstream, instead of being excreted as would normally occur. When this enzyme enters the heart and arteries, it scratches and corrodes the membranes, creating primary lesions or scar tissue. The body then releases cholesterol into the bloodstream in an attempt to lay protective fatty material on the scarred areas. This can result in clogging the arteries (5) (1). Homogenisation also makes the fat and cholesterol more susceptible to rancidity and oxidation (7) and creates trans fats in the milk - these are rigid molecules that are so altered that the body doesn't recognise them as natural. (8) Fortunately goat's milk is never homogenised - another plus for it.
In summary, the deciding factors are - does cow's milk agree with the person consuming it? If not, try goat's milk , if this still doesn't agree, life will be no poorer without dairy. If dairy does agree, ensure a quality product is consumed - ideally organic and non-homogenised. The best dairy products of all, are non-pasteurised! More on this in the next issue.
(1) Echo Mountain dairy - information obtained through the University of Delaware and Texas (2) Proc. Soc. Exp. Biol med (1962): M. Lee, M.Rohitkumar & S. Lucia. (3) Diet and Nutrition: R Ballentine. (4) Healing with Whole Foods: Paul Pitchford (5) Prakruti: RSvoboda (6) Homogenized!: N. Sampsidis (7) Nourishing Traditions: Sally Fallon (8) Eat Fat, Lose Weight, The Right Fats: Ann Louise Gittleman (9) Gelatine in Nutrition and Medicine: N.R. Gotthoffer.