NUITRIENT REQUIREMENTS FOR MAINTENANCE AND PRODUCTION IN BROILERS&VARIOUS FACTORS AFFECTING NUTRIENT REQUIREMENTS AND PRODUCTION IN BROILERS
SUBMITTED BY • HAROON RASHID (557) • ZEESHAN HAIDER (558) • MUHAMMAD USMAN (559) • RAMEEZ SARWAR (560) • MUHAMMAD SAJJAD HUSSAIN (562) • MUHAMMAD SALEEM (563)
BROILER Poultry birds kept for meat purposes. They attain 1.5 kg body weight by consuming 3-4 kg feed within 6 weeks.
. NUTRIENT REQUIREMENTS • Broilers diets must be formulated to provide all of the bird’s nutrient requirements if optimum growth and production is to be achieved.
Classes of Nutrients • Carbohydrates – the major source of energy for broiler. Most of the carbohydrate in Broilers diets is provided by cereal grains. • Fats – provide energy and essential fatty acids that are required for some body processes. • Proteins – required for the synthesis of body tissue (particularly muscle), physiological molecules (such as enzymes and hormones), feathers and for egg production. Proteins also provide a small amount of energy.
Classes of Nutrients • Vitamins – organic chemicals (chemicals containing carbon) which help control body processes and are required in small amounts for normal health and growth. • Minerals - inorganic chemicals (chemicals not containing carbon) which help control body processes and are required for normal health and growth. • Water: Required for the survival of life.
Water Water is of vital importance and is considered an essential nutrient. Water deprivation for ≥12 hr has an adverse effect on growth of young poultry; water deprivation for ≥36 hr results in a marked increase in mortality of both young and mature poultry. Cool, clean water must be available at all times.
Protein and Amino acids • Poultry can synthesize glycine but often not in sufficient amounts. Cystine and tyrosine are considered essential even though they can be synthesized from methionine and phenylalanine, respectively. • In practical feed formulation, Methionine can spare choline as a methyl donor, and tryptophan can be used to synthesize niacin. These relationships are important because the 2 vitamins can be supplied in diets more economically than the 2 amino acids.
Vitamins • One IU of Vitamin A activity is equivalent to 1.3 µg of pure retinol. However, young chicks are not efficient in using β-carotene. • Requirements for Vitamin D are expressed in IU. Birds use vitamin D3 from fish oils and irradiated animal sterols quite effectively but cannot use vitamin D2 . Metabolic forms of vitamin D have been isolated and synthesized; these are 25-hydroxy vitamin D3, which is synthesized in the liver, and 1,25-dihydroxy vitamin D3, which is synthesized in the kidneys.
Vitamin • Choline is required as an integral part of the body phospholipid, as a part of acetylcholine, and as a source of methyl groups. Growing chickens can use betaine as a methylating agent, but betaine cannot replace choline in preventing perosis. Betaine is widely distributed in practical feedstuffs and may be important in sparing choline. Adequate dietary vitamin B12 helps pullets develop the ability to biosynthesize choline. The choline requirement values apply to diets containing the specified levels of vitamin B12.
Minerals • The calcium requirement of laying hens is difficult to define. Too much dietary calcium interferes with the use of several other minerals, as well as fat, and tends to reduce palatability.
FACTORS AFFECTING THE NUTRIENT REQUIREMENTS OF BROILERS • Genetics • Age • Sex • Productive state • Ambient temperature • Housing systems • Health status • Production aims.
Factors Affecting Nutrient Requirements Genetics • Different species, breeds or strains of bird have different average body sizes, growth rates and production levels and will also absorb and utilise nutrients from feed with different levels of efficiency, leading to different nutrient requirements. As the genetics of commercial poultry is constantly changing so are their nutrient requirements. Consequently, breeders of commercial poultry provide information on the specific nutrient requirements for the birds they sell. Age • Nutrient requirements are related to both body weight and the stage of maturity.
Factors Affecting Nutrient Requirements Sex • Prior to sexual maturity the sexes have only small differences in their nutrient requirements and males and females can usually be fed the same “compromise” diet to achieve acceptable growth rates. Differences in nutrient requirements are larger following the onset of sexual maturity and significantly different diet formulations are then required for each sex. Reproductive state • The level of reproductivity in broiler breeders and sexual activity in males will affect nutrient requirements.
Factors Affecting Nutrient Requirements Ambient temperature • Poultry have increased energy requirements to maintain normal body temperature in cold ambient temperatures and the opposite in hot ambient temperatures. The process of digestion of food produces body heat and the amount of heat produced will vary according to the nutrient composition of the diet. This is called the heat increment of the diet. In cold temperatures it may be desirable to formulate a diet with a higher heat increment and the opposite in hot temperatures. Housing system • The type of housing system will influence the level of activity of the birds and therefore their energy requirements.
Factors Affecting Nutrient Requirements Health status • Birds experiencing a disease challenge may benefit from an increase in the intake of some nutrients, most commonly vitamins. Production aims • Optimal nutrient composition of the diet will vary according to production aims, such as optimising weight gain or carcass composition, egg numbers or egg size. Poultry that are raised for breeding purposes may need to have their energy intake restricted to ensure that they do not become obese.
BROILER HOUSING • Site selection • Barn construction • Manure System • Heating System • Ventilation System • Feeding and Watering System
Site Selection • Regardless of the type of commercial poultry production being considered, a relatively large building site is a key requirement. Future expansion should always be considered. • The proposed building site should be reasonably level to accommodate manure handling, and load out. Good drainge away from the building is also required. Depending on the number of barns and the desired layout, space must be provided in the poultry yard for manure storage and between the barns for proper ventilation, fire safety and snow and wind control. A distance of 15 to 30 m (50 to 100 ft) is usually adequate and still practicle. • A good water source that has both asequate quantity and quality is another criticle factor to consider in selecting a building site. A well should have a capacity of 1 to 1 ½ gallons per minute per 10,000 birds and have total dissolved solids of less than 2500 ppm. Nitrate and nitrites should be less than 100 ppm and alkalininty should be less than 1000 ppm.
BARN CONSTRUCTION • Broiler barns are single or multi-storey barns constructed by either the pole-frame or stud wall method. Today the most common types being constructed are two storey frame and single storey stud frame. Both balloon and platform framing methods are used for two storey construction. • Two or three storey barns are popular because of lower construction costs and heat savings. Barn construction costs can be reduced by about 15% per floor if a multi-storey barn is built, and energy costs can be reduced as much as 20% to 50% depending on the age of the broilers. Most barns are 10.9 to 12.2 m (36 to 40 ft.) in width but some are 17 to 18.3 m (56 to 60 ft.) wide.
HEATING SYSTEMS • Heat in the broiler house comes from three different sources: from the birds themselves; from the heating sytem; and from lights, motors and solar heat. Broilers produce a significant amount of their own heat in the form of sensible heat that is useful in helping to maintain barn temperature in cooler weather. • The heating system used in most broiler barns is a hot water broiler and 50 mm (2 in.) black iron pipes which serve as the heat radiators. Water temeperatures of 93 to 98 C (200 to 208 F) produce approximately 200 watts/m of pipe. The pipes are usually hung on one wall, running the length of the barn at about 200 to 300 mm oc.
VENTILATION SYSTEMS • Ventilation confinement rearing places the responsibility on the operator of providing his birds with a satisfactory air environment, ideally within their “comfort zone”. This zone is dependant on the age and weight of the birds and is achieved by the proper temperature, relative humidity, better moisture and air speeds for that group of birds.
FEEDING AND WATERING SYSTEMS • The usual feeding system used for broilers is the suspended automatic chain and trough feeder or the suspended automatic chain and pan feeder system. These systems normally make a complete circuit within the broiler barn, ensuring that enough feeder space is available if the birds are on ftAl feed. If a restricted feeding program is used, additional feeder space has to be provided. • Waterers are usually the hanging automatic bell type or the newer nipple style drinkers. The automatic trough type and the hanging water cups are also available for floor or cage reared broilers. An ample, clean source of water is required. Birds have no stomach so their water retaining capacity is very low. They must drink freely and often as they require 0.9 to 1.4 kilograms (2 to 3 Ibs) of water to efficiently utilize 0.45 kilograms (1 lb) of feed. The water source should be low in minerals and particularly low in salt as excess salt leads to watery droppings and consequently wet litter.