When it comes to fiber digestion, the ruminants are the clear winners! The rumen allows food to be fermented very early in the process; by the time the waste leaves the body, almost all the cellulose fiber has been broken down into usable sugars and starches. Through bacterial and enzymatic action in their rumens, the ruminants are also able to synthesize all of their necessary amino acids from whatever nitrogenous compounds are present in the plants they eat.
The horse’s cecum performs a similar function to a cow’s or sheep’s rumen; however, since the cecum comes fairly late in the digestive process, it is less efficient at both fiber digestion and amino acid synthesis. Even though ruminants and horses are physiologically capable of meeting most of their nutritional needs on a limited (grass) diet, there are times when their diet will need to be beefed up. Any animal that’s at work has higher nutritional requirements; its rations must supply a significant level of both available energy and protein. I will discuss work and diet in more detail later on.
Ruminant Digestion
Ruminant digestion is an interesting process in its own right. A ruminant’s mouth doesn’t contain upper teeth. Instead, the top of the mouth is an extremely hard palate. A ruminant grabs a piece of food — say, a mouthful of grass — between its lower teeth and hard palate, and tears it off. The food is lightly chewed; just enough to moisten it a little and form a ball before it’s swallowed. The ball of food, or bolus, travels down the esophagus and enters the rumen. Heavier food items such as whole grains (or stones, or pieces of hardware) usually bypass the rumen altogether and enter the reticulum, or second stomach, directly. Grain that bypasses the rumen generally remains intact, which is why you’ll see some whole grain kernels in the manure if you’re feeding whole grain. There are two ways to mitigate this: Feed ground or cracked grain, or feed the whole grains with hay or other light fibrous feeds, so it is captured in the rumen (Figure 6.4).
Figure 6.4. The rumen acts as a large digester, where bacteria and other microorganisms break down food. The top of the rumen is filled with gas, the middle contains recently eaten hay, which floats on the bottom slurry of yesterday’s hay, grain, and fluid.
The rumen and reticulum are in fact an interconnected pair of stomachs that work together. They are sometimes referred to as the reticulorumen. The bacteria that are responsible for fermentation in the rumen live and reproduce in the reticulum.
Actually, saying that bacteria are responsible for fermentation is oversimplifying things. The rumen is populated by bacteria, protozoans, yeast, and fungi. For each gallon (3.8 L) of rumen capacity, there’s up to 200 trillion bacteria and 4 billion protozoans. The quantities of yeast and fungi are more variable, but still number in the millions under normal circumstances. Now multiply these figures by the normal 25 to 30 gallons (95 to 114 L) of rumen content in a cow — or 3 to 5 gallons (11.4 to 18.9 L) in a sheep — and you’ll get a good idea of just how large is the workforce that ferments food in the rumen. An important objective of a ruminant feeding program is to maintain an environment that is good for these microorganisms, so they can do their jobs well. A key approach to keeping happy microbes is to make any dietary changes slowly — say, over the course of two weeks — so the microbes can adjust to the change.
The rumen is like a boiling pot of water: There is always movement in it. But the movement takes place within layers. The top layer consists of gases (primarily methane, which is a by-product of the bacteria’s life cycle). The bottom layer consists of a fluid mixture of grains and completely saturated roughage (yesterday’s hay). The middle layer floats on the bottom layer, and is made up of newly eaten roughage. The rumen contracts every 1 to 3 minutes during the day, which helps keep everything in motion. These contractions work the heaviest materials into the reticulum, so they can continue their trip through the digestive tract.
Figure 6.5. Ruminants have to spend a good part of each day chewing cud, or ruminanting. This chart shows the proportions of each hour during a day that cows eat, chew cud, and rest. For example, between 6 A.M. and 7 A.M., a cow grazes for 10% (6 minutes) of the hour, ruminates for about 42% (25 minutes) of the hour, and is “idle” for the remaining time (29 minutes). Idle, in this case, means time spent not eating or chewing cud. When idle, a cow could be sleeping, playing, grooming, or traveling.
(Modified from André Voison, Grass Productivity. Covelo, CA: Island Press, 1988, p. 70.)
Ruminants spend up to 6 hours per day eating, and up to 8 hours per day chewing cud, or ruminating (Figure 6.5). Cud is simply a bolus of food that has been floating in the rumen for some time, and is then forced back up the esophagus and into the mouth to be chewed again. Cud chewing serves two purposes: It provides some additional mechanical breakdown of food, and it provides for the introduction of large quantities of saliva into the rumen. During the course of a day, a mature cow produces up to 50 gallons (18.9 L) of saliva while ruminating, which helps neutralize acid in the rumen and maintain the rumen environment for the microbes that live there.
One side effect of fermentation in a ruminant is that a significant amount of gas is produced. In fact, a mature cow can produce up to 20 cubic feet (0.57 m3) of gas per hour, which is enough gas to fill a balloon the size of a large chest freezer! This gas must be passed through regular belching, or eructation. Occasionally, sudden changes in feed will cause an animal to bloat. This is simply caused by the animal’s inability to get rid of the gas it produces through belching, but it’s far from a simple problem: It is a life-threatening condition. (See more about bloat in chapter 8.)
Food Requirements
Food needs vary. They change with age; they change according to the amount of work an animal is doing; they change with the changing seasons. One ration isn’t always suitable for all animals, and the true husbandman must develop an eye for the condition of his or her animals. Feeds need to be adjusted according to the ever-changing needs and conditions of the stock.
Maintenance rations represent the food required to support the animal when it is doing no work, and producing no product (milk, meat, or fiber). A maintenance ration basically supports all minimum body functions, such as respiration and cardiovascular function. It maintains the animal’s weight at a steady state: no gain, no loss. An animal kept on a maintenance ration wouldn’t put on growth, reproduce, or do any form of work. Without an adequate maintenance ration, an animal slowly starves to death, eating away its own fat, muscle, and tissue until there isn’t anything left to eat away. For most farm animals, up to one-half of their ration is strictly used to meet their maintenance requirement.
Providing adequate feed for growth, reproduction, and work is the goal of every farmer. And adequate is a key concept in my mind — you want to feed enough to keep your animals healthy and strong, but you don’t want to overfeed them. Overfeeding not only costs too much, but it isn’t good for the animal. An overly fat breeding animal has trouble getting bred, and young animals that are fed too much or too quickly grow so fast that they can develop severe joint and bone problems; this is especially true for young horses.
FARMER PROFILE
Lanie Fondiler
Lanie Fondiler calls her farm in Westfield, Vermont, the Lazy Lady Farm, but her enterprise hardly fits her moniker. Since coming here in 1987, she has created a working farm operation, supporting herself off 35 acres, using goats and sheep.
“There was just a little cabin here when I bought the place,” she says, “and the land was beat. The 12 tillable acres had been in corn for many years.” The rest of Lanie’s land is woods and brush.
Her first year, Lanie worked up 1g acres of garden and sold produce. That year she had to work a job in winter to support herself.
The following year, Lanie purchased her first livestock: seven ewes and their lambs. The second winter she used her wool to weave rugs for sale.
“I lived in France for a couple of years, which gave me the idea for doing goat cheese.” Today Lanie’s operation has both sheep and goats, with rugs, chee
se, and specialty sausages as her main products.
Lanie spends about 60 hours per week milking the goats and making cheese, and another 30 at the farmers’ market. She does all the other work of maintaining her farm, including tending her garden, caring for the animals, and weaving her rugs, in her spare time!
Her sheep are grazed through a series of paddocks. The goats have two paddocks near the barn, but they spend most of their time around the barn. As she says, “They’re barn potatoes, and they’d be couch potatoes if I gave them one.” To give them some exercise and let them eat some free browse, she has a few friends who stop by during the week to take the goats on walks through the woods and along the road ditches. These trips help cut down her feed bills.
Lanie sells most of her products at three farmers’ markets: one in Montpelier, the state capital; one in Waterbury, which is a suburban bedroom community; and one in Stowe, a resort community that sees mainly tourists. She says, “Each market is different, with its own atmosphere and its own style of clients. The Montpelier market has lots of people who are involved with politics — lots of activists — these people have strong opinions and like to talk about issues. The Waterbury people are kind of low key, and small talk is the order of the day. Stowe is hardest for me, because the tourists are sometimes difficult to deal with. They’ll try some cheese, and say things like, ‘Well, it certainly doesn’t taste like the cheese I had in France last year.’ Now I’ve learned to just smile, and try to not let those type of people bother me, but at times it’s real tough. I’m trying to learn how to schmooze with them, and I guess it is getting easier, because I haven’t come home from there as stressed as I used to.
“I’d say the most important thing for really small farmers who hope to make a living at it is that you have to really know yourself. Know what you like, and try to figure out a way you can capitalize on it. Whatever you want to raise on this scale, you’re going to have to sell. The best way to do that is to put a face behind the product. I have a much easier time selling at the farmers’ markets, where my customers get to know me, than I have when I’ve tried selling through stores. And really, try to determine ways to save on your expenses. A ‘penny saved’ really is a ‘penny earned’ on a really small farm.”
Appendix A has tables of feeding standards for various classes of livestock; appendix B lists the composition of common feedstuffs. Use these to calculate rations.
Economy Feeding
Grass is some of the most economical feed that “money can buy,” but chances are it’s not the only feed you’ll ever need. If you keep pigs or poultry, they require a wider variety of feeds. If your plans include milking an animal — or many animals — you will definitely have to supplement them. If you are working horses, they too will require more than just grass and hay.
Your local feed dealer will gladly supply you with premixed, bagged rations for any class of livestock you’re raising. Heck, if you buy through a Purina dealer you can purchase Rat Chow, Pigeon Chow, Trout Chow, or “Chows” for just about any critter you can think of. These prepared feeds are convenient, and if you don’t need a great deal of supplemental feed during the course of the year they are probably worth going with. In quantity, they do get expensive, though.
One easy way to save money on feed purchases is to buy directly from area farmers during the harvest. Whether you’re buying hay or grain, you can often find some good deals if you purchase the crop out of the field. This option requires adequate storage (see chapter 7). We often found a local farmer would allow us to take his grain wagon home, unload it, and return it as part of the deal.
Lawns, gardens, and orchards are great sources of feed. Use portable electric fencing to graze the lawn, or if you’re worried about what the neighbors think, put a bagger on your mower and toss the fresh, chopped grass clippings over the fence. Garden waste can also be tossed over the fence, and windfall apples are like the finest imported chocolates to your animals! Limit the serving size of these delicacies at any one time, or digestive upsets may occur.
Pigs and birds, with their omnivorous diets, can eat many of the same items that we do, so table scraps don’t go to waste. Thrown into the pig or poultry pens, these little treats disappear quickly.
Sometimes, “waste” feeds can come very cheaply, or free. Mary, who owned a natural foods store and deli near us, would save us goodies. Cheese or lunch meat that wasn’t quite fit to sell anymore (the odds and ends, or the slightly dried-out stuff) would go into the freezer for my next visit. Freezing prevents the food from going rancid, since the idea is to feed waste — not spoiled garbage! Other businesses that might provide usable food waste include processors, bakeries, groceries, and restaurants. The one caveat: Pick up your freebies on a very regular basis, so your supplier isn’t inconvenienced.
Poisonous Plants and Feeds
It is tragic to lose an animal, or many animals, to food poisoning, but each year it happens to farmers around the country. Unfortunately, many poisoning agents have no antidotes, so prevention is truly the best medicine.
The first step to take so that this doesn’t become a personal tragedy is to learn what poisonous plants grow in your area. This is another time your County Extension Agent should be able to help you; he or she will know what offensive plants grow locally, what they look like, if their toxicity is strictly seasonal or continuous, and to which classes of stock the plant is toxic.
Some crop plants are also poisonous at certain periods in their growth; for example, Sudan grass and sorghums can cause prussic acid poisoning if consumed while the plant is immature, or immediately following a frost. Grazing of these plants at a stage when prussic acid levels are high can result in very quick death (Table 6.2).
Animals often become ill due to spoiled feed, and it isn’t always easy to tell that the feed is spoiled. Mold is the most common cause of spoiling in feed. Cattle tend to be less sensitive to mold than horses, sheep, or pigs, but all species can develop health problems. Though mold itself isn’t generally fatal, some molds produce mycotoxins as a by-product of their life cycle, and these can be fatal. In other cases, the plant that has mold growing on it produces a toxin (called a phytotoxin) in response to the mold.
Table 6.2
SEASONAL TOXICITY OF PLANTS
Mold develops on moist feed. If hay is baled damp, or if it’s rained on after it’s baled, it becomes moldy. Grains that were stored before they dried down sufficiently can also become moldy. Feeding moldy feeds should be avoided; however, if you have some that isn’t badly molded and you need to use it up, feed little bits along with some good feed. For mold, “dilution is the solution.”
Either molds or fungi can produce mycotoxins and phytotoxin responses. They are common throughout the world, and can be found on both stored feeds, and feeds in the field. Fescue poisoning, a common problem in many southern and western states, is the result of a phytotoxin. Again, talk to your County Extension Agent or your veterinarian to learn if mycotoxins or phytotoxins are a possible problem for your operation.
Feeding Babies
The best feed for baby animals comes right from their mothers. But at times, farmers need to step in and hand-feed little ones. In commercial dairy production, almost all calves (or kids) are bottle babies.
When bottle-feeding, the rule of thumb is to provide 10 percent of the baby animal’s body weight per day in whole milk, preferably from their own species, but for most babies goat’s milk works well, and cow’s milk will get you by in a pinch.
If milk is unavailable, there is always commercial milk replacer. These products are made for most classes of livestock (and even for dogs and cats). Calf milk replacer is readily available from feed stores, but replacers for other species may have to be special-ordered. Look for unmedicated milk replacer. As Dr. C. E. Spaulding says in A Veterinary Guide for Animal Owners, “There [are] not enough antibiotics in a pound of feed [medicated milk replacers] to prevent scours or other diseases, and the antibiotic fed daily can dam
age enough of the natural and necessary bacteria in the gut to cause scours.” Also, look for milk replacer that lists milk as the first ingredient; the cheap brands are often made with no milk at all.
Don’t feed babies more than they are supposed to have just because they act crazy when their milk is gone. If possible, feed them smaller milk rations often throughout the day, rather than in one or two big feedings. Don’t feed out of a bucket, because they inhale the milk too quickly — use a nipple appropriate to the animal’s size. Some nipples are designed to be used on a bucket or barrel and require a suction hose (Figure 6.6); these are convenient (especially for feeding groups of babies) and offer some advantages, but they aren’t available everywhere (see appendix E, Resources). Most nipples are designed for use with individual bottles, and you can purchase these in almost any farm supply store.
Figure 6.6. Nipple barrels allow you to feed many calves at one time. The nipple design is actually superior to bottle feeding for calf health, as the calves suck milk up through a tube, which is closer to a calf ’s natural sucking behavior. Calves need to be trained to the barrel, which usually takes about 3 days, but once they get the hang of it, you can’t pry them off! Keep similar-sized animals grouped together on one barrel.
Small-Scale Livestock Farming Page 12