How to effectively prevent vices in pheasant farming
Pheasant vices, also known as pecking vice, pica, depraved appetite, and mutual pecking vice, are a syndrome of abnormal taste caused by a deficiency of various nutrients and their metabolic disorders. It can occur in chickens of all ages and breeds, especially in chicks and growing chickens, and the incidence is even higher under intensive rearing and cage rearing. Once vice-prone chickens appear, it quickly spreads through the entire flock; in severe cases the incidence reaches over 80% and the mortality rate reaches 50%. Even if the triggering factors disappear, the vice often persists in the flock, causing injury, disability, and death of chickens, resulting in certain economic losses.
1 Causes of chicken vices
The occurrence of vices in a chicken flock has internal causes and triggering factors. The internal causes are mainly congenital genetic factors, and the triggering factors are mainly the triggering effect of human factors on the internal causes. Some believe that chicken vices are caused by improper feeding and management, narrow chicken pens, and insufficient sulfide in the feed; others believe they are caused by insufficient alkali and calcium in the feed, deficiency of protein and vitamins, intensive rearing, and lack of outdoor exercise. From the perspective of modern veterinary medicine, chicken vices are a stress syndrome in which imperfect artificial conditions trigger the congenital genetic factors of chickens. The main triggering factors of chicken vices are as follows.
Insufficient nutrient content in the diet, or improper proportions of various nutrients
For example, if the diet is not nutritionally complete, the content of animal protein or certain amino acids is somewhat low, amino acids are unbalanced, crude fiber content is too low, vitamins and minerals are deficient, green feed or roughage is lacking, salt is insufficient, or corn content is too high, etc. Complete pelleted feed is more likely to cause chicken vices than mash feed, and cage rearing more likely than floor rearing.
(1) Protein and amino acids are nutrients essential for the life activities of the chicken body. Taking laying hens as an example, 8 g of protein is needed daily for maintenance, and 15 g of protein is needed for each egg produced. If the laying rate remains at 70%, then the protein required per hen per day cannot be less than 18.5 g. It is generally believed that vices are easily induced when the crude protein in the diet of laying hens is below 15%, that of growing chickens below 14%, and that of chicks below 19%; or when methionine in the diet of laying hens is below 0.27%, that of growing chickens below 0.25%, and that of chicks below 0.3%. In addition, a diet containing only plant protein without animal protein, or having sufficient methionine but neglecting the balance of various amino acids, also easily induces vices.
(2) A deficiency or insufficiency of a certain vitamin can cause physiological dysfunction and metabolic disorder in chickens. Normal chicken feed must contain at least 14 essential vitamins, and in appropriate proportions, otherwise disease will occur. For example, a lack of VB1, VB2, or VB12 in chicken feed can affect the normal absorption of protein by the chicken body; a lack of VB6 can cause disordered information transmission in the chicken body, and even obvious neurological symptoms.
(3) Macro elements such as Ca and P and trace elements such as Fe and Se are indispensable substances for the chicken body to form cells, build bones, and maintain muscle and nerve physiological activities. For example, the absorption rate of Ca in the diet by chickens is 50%-60%, and each egg contains about 2.2 g of calcium. Therefore, for each egg laid by a laying hen, at least 4 g of Ca must be supplied. It is generally believed that vices can be induced when the Ca content in the diet is below 3% for laying hens, below 0.6% for growing chickens, and below 0.9% for chicks; or when the calcium-to-phosphorus ratio in the diet is below 5:1 for laying hens, below 1.2:1 for growing chickens, and below 1.3:1 for chicks. In addition, vices can also be induced when salt in the diet is below 0.3%; when one of the various trace elements is insufficient; or when the proportions among various trace elements are improper.
(4) Crude fiber in the diet can promote intestinal peristalsis and digestion and absorption. It is generally believed that the crude fiber content in the diet should not be lower than 2.5% or higher than 4.5% for laying hens, not lower than 3% or higher than 5% for growing chickens, and not lower than 3% or higher than 4% for chicks.
Poor chicken-raising environment and improper feeding and management
(1) Slightly high temperature, poor ventilation; high concentration of harmful gases, with ammonia pungent to the nose and irritating to the eyes; damp floor, making the flock feel stuffy and uncomfortable; too strong sunlight or too strong lighting, unreasonable lighting schedule; restricted feeding, etc., can all make chickens restless, induce vices, and affect the laying rate. (2) Chickens have limited ability to recognize companions. If the group is too large, or the density in cages or floor rearing is too high, it will increase the chance of mutual pecking due to unfamiliarity, and violent pecking fights often occur. (3) Mixing strong and weak birds, mixing large and small birds, or mixing chickens of different breeds, different ages, and different feather colors together when regrouping. (4) Strong light inside the nest boxes, or insufficient nest boxes, with many hens fighting for a nest, increases the chance of vent pecking. If eggs are not collected in time, especially thin-shelled eggs and soft-shelled eggs, once they are stepped on and broken by chickens and pecked and eaten, egg-eating vice is quickly induced. (5) Improper feeding. For example, feeding time is not fixed, feeding amount is insufficient, feeding time is irregular, feed quality is poor, feed is moldy and deteriorated, and drinking water supply is insufficient. In addition, insufficient troughs, or arbitrarily changing the number and time of feedings, will cause chickens to bully the weak in the process of competing for food and to form vices during pecking fights.
Suffering from parasitic diseases
Chickens with internal parasitic diseases often have worms remaining inside and outside the vent after defecation. At this time, the chicken pecks itself because of itching, or other chickens see the worms and hurriedly come to compete for food and peck the vent until it breaks. Chickens with external parasitic diseases often peck themselves to relieve itching, and once bleeding occurs, it quickly attracts chickens of the same flock to compete in pecking.
Other factors (1) Molting factor. When chickens molt, and when chicks grow new feather buds, the skin itches. When pecking themselves to relieve itching, they occasionally peck and cause bleeding, which can also attract chickens of the same flock to compete in pecking. (2) Hormonal factors. The increase of estrogen and progesterone in the blood of chickens about to start laying, and the increase of androgen in roosters, are both factors that strengthen the tendency toward vices. (3) Disease not treated, and sick chickens not isolated for rearing. For example: suffering from parasites, enteritis, itching skin during molting, and failure to promptly isolate and raise sick chickens with trauma, pecking wounds, anal fissure, and prolapse of the cloaca. In particular, failure to isolate the chickens that often specifically wait for the opportunity to peck the vent, wounds, etc. of other chickens. (4) Adjusting the flock and establishing the pecking order. When adjusting the flock of growing chickens and laying hens, introducing new chickens disrupts the original stable pattern, and fights often occur to re-establish the pecking order; mutual pecking appears before the subordinate relationships are determined.
2 Common types of chicken vices
Flesh-pecking vice This is the most common kind of vice. Chickens of the same flock attack each other, and after injury or even death occurs, part of the corpse is eaten by the attackers. It can occur in flocks of different breeds, and chicks of all ages can be affected. If prevented in chicks, it rarely occurs before adulthood.
Vent-pecking vice Pecking the vent and the lower abdomen is the most serious type of vice. It is seen in high-yielding caged flocks or flocks starting to lay, and those lost are mostly high-yielding laying hens. The trigger is prolonged straining when passing too large an egg, causing prolapse or tearing. Once the vent is pecked open, the flock competes in pecking until the intestine prolapses and drags on the ground, causing death. In laying hens after mating and in pullorum disease, when the feathers around the vent are stuck with white chalky fecal masses, vent pecking is easily caused.
Feather-pecking vice It mostly occurs during the molting period of developing young chicks and during the molting period and peak laying period of laying hens, especially in high-yielding new hens of the current year, and is mostly related to a deficiency of sulfur-containing amino acids, sulfur, and B vitamins. It is manifested as pecking feathers, pecking wings, pecking tails, or self-pecking, being pecked, and mutual pecking. It often leaves the feathers incomplete and the skin and flesh exposed, and the laying rate declines. Sometimes after pecking until the skin and flesh are exposed and bleeding occurs, it develops into flesh-pecking vice.
Toe-pecking vice Chickens peck each other's toes, causing bleeding or lameness; in severe cases the toes can be pecked off. Young chickens are most susceptible. In addition, comb-pecking and wattle-pecking are mostly seen in fights among roosters, and scale-pecking vice is mostly seen in chickens whose feet have lesions due to invasion by external parasites, etc.
Egg-eating vice As soon as a laying hen lays an egg, the flock rushes over to peck and eat it. Sometimes laying hens also peck and eat the eggs they themselves lay. It mainly occurs in laying flocks, especially in spring when laying is vigorous. It is mostly due to calcium deficiency or insufficient protein content in the feed, and is often accompanied by thin-shelled or soft-shelled eggs. It often begins with a soft-shelled egg being stepped on, or an egg occasionally being broken in the nest or on the ground.
Pica Pecking and eating old white lime residue, bricks, tiles, ceramic fragments, and swallowing feathers, sawdust, etc. contaminated by feces and urine, mostly seen in growing chickens or adult chickens. Sick chickens commonly show indigestion, dull feathers, and emaciation.
3 Preventive measures for chicken vices
Timely beak trimming and beak repair Timely beak trimming and beak repair are relatively effective methods for preventing and stopping the occurrence of chicken vices. Beak trimming means using specialized instruments to cut off the tip of the chicken's beak; after trimming, the upper beak is slightly shorter and the lower beak slightly longer, depriving the chicken of the ability to peck and injure skin and flesh and to peck and eat eggs, thereby avoiding the formation of vices. Although beak trimming cannot completely prevent vices, it can reduce the incidence of vices and lessen their damage, and can also save feed.
(1) Beak-trimming instruments: beak trimmers have already been mass-produced in China. If there is no beak trimmer, scissors and an electric soldering iron can be used instead. In addition, use a thin iron plate and drill several elliptical holes of different diameters according to the thickness of the chicken's beak, to serve as a protective plate.
(2) Timing of beak trimming: for early beak trimming, the first beak trimming is better performed at 5-9 days of age (or 7-10 days of age), and at 10-12 weeks of age (or before the start of laying) the laying hens are trimmed again. For late beak trimming, it is performed at 10-12 weeks of age. At the latest, no later than 18 weeks of age, because beak trimming during the laying period will cause a decline in the laying rate. If you do not wish to trim the beaks of the whole flock, at least the vice-prone chickens in the flock should be caught and beak-trimmed.