Lecture 19Outline of Previous LectureOutline of Current LectureI. Environmental physiologyII. Factors affecting critical temperatureIII. Effects of light on animal performancea. Ventilationb. Animal waste managementCurrent LectureANSC 107 1nd Edition Lecture 19Outline of Previous Lecture I. Estrous synchronization a. Ram effectb. Flehman II. Methods a. CIDRb. MGA III. AI a. Advantages b. Disadvantages IV. Extenders Outline of Current Lecture I. Environmental physiology II. Factors affecting critical temperature III. Effects of light on animal performance a. Ventilation b. Animal waste management Current Lecture 1. Adaptation: long term changes in animals in response to their environment that are genetically based 2. Acclimatization: adaptation of an animals to environmental factors over a period of days or week (increase in red cells) 3. Conduction: exchange of heat from warm too cold between objects that are touching 4. Convection: flow of heat from warm too cold through air or water5. Critical temperature: the temperature below (lower critical temperature) which the animal must make physiological adjustments to maintain its body temperature. Upper critical temperature is that temperature at which the animal makes adjustments to try and cool its body a. Ex: sweat glands and shivering These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.b. Reptiles can’t do this but mammals can6. Effective temperature: total heating or cooling power of the environment. Ambient temperature is affected by wind, humidity and solar radiationa. Affected by wind, humidity, and solar poweri. Shade and windbreakb. Feedlots always have a wind break7. Homoeothermic: animals that maintain a relatively constant body temperature regardless of external temperatures. Normal temperatures for farm animals are: a. Horse: 100b. Cattle: 101.5c. Sheep: 102 d. Goats 102e. Swine:102.5f. Chickens: 1078. Radiation: exchange of heat between two objects that are not touching a. Can results in the loss or gain of heat9. Thermo neutral zone: Range of temperature where heat loss and heat production are about the same. Animals is in comfort zone: no physiological response to temperaturea. Comfort zoneb. Heat loss= heat production10.Factor affecting critical temperature a. Hair coat:b. Subcutaneous fat: c. Nutritional level: d. Is the animal wet or dry 11.Relationship of maintenance energy, energy consumed and energy for gain with TNZ (thermo neutral zone)a. Maintenance how much to eat to maintain friend “easy Keeper”12.Hormonal response to temperature stressa. Thyroxin: produced by the thyroid gland, thyroxin secretion increases during cold stress and decreases during heat stress b. Corticoids: produced by the adrenal gland, corticoid secretion increased during the cold sorters and decreased during heat stress 13.Methods of reducing stress during hot periods includea. Shade: cheapest and simplest methods of reducing heat stress due to solar radiation i. Properly shade should be: 10-12 inch high, placed on a hill if possible the top should be white or shinny and the underside dull and dark can be made of a variety of thingsb. Evaporative coolingi. One of the most effective ways to control heat stress, particularly in swineii. Sprinklers, foggers, and wallows are most effective. Evaporative coolers are used in many poultry housesiii. Must be in west Texas to be extremely affected iv. Decrease milk production if feed weren’t shaded c. Refrigeration: refrigerated air conditioning is prohibitive in terms of cost i. Same are pulling air through underground ducts into a barn which may cool the air down into the mid-60s ii. Expensived. Zone cooling: blowing air onto the head has been effective in sows in farrowing housing who have shown increased milk productione. Feed and water needs during stress: i. Water intake during heavy stress increases 50-100%ii. Feed intake is depressed during heat stress. To combat this and keep production levels high, poultry producers often “top dress” rations with B vitamins to increase appetite trace minerals and high energy feed like animal fat 1. B vitamin will stimulate feed intakef. Wind Chill, Wind breaks and shelters: wind breaks and shelters are used north of a line from southern Colorado to Ohio to reduce the effects of wind chilli. the wind breaks are generally built on the north side of the pen to block the cold northerly wind14.Kansas state research a. Fogged increased ADG, daily intake, feed/gain15.Ration adjustments during temperature stressa. Increase in energy required to maintain body temperature result in decreased in feed efficiency b. Energy density of the diet can be increased during periods of temperature stressc. Heat increments of the diet can be decreased during heat stress by reducing the fiber of the diet while the heat increment of the diet can be increased by feeding more fiber during cold stressd. During heat stress laying hens eat less feed i. Producers will increase protein in the diete. During cold stress greater portion of the energy is being used for maintenance less energy is available for gain therefore less protein is needed for gain and the % protein in the diet can be reduced16.Effects of light on animal performancea. Day length is associated with reproductive performance in a number ofspecies i. Control light in hen house ii. ewes being to cycle when the days get shorter iii. mares cycle when days get longeriv. day length is also associated with hair growth and shedding in cattle and horses17.Ventilation a. Producers who are raising livestock in enclosed, confinement building must be particularly conscious of proper air movement (ventilation)b. Moisture must be removed from the air along with ammonia c. Proper air exchange is also important for temperature control18.Animal waste management: one of the major problems facing livestock producers today is management of wastea. Environmental regulation are forcing producers to be more concerned with managing waste property and rightly so b. Confinement swine facilities often have lagoon systems that utilized biological decomposition of waste that is handled in a liquid formc. Manure utilization d. Methane productione. Fiber- refeeding i. Manure can be an excellent source of income for feedlots that manage cattle and lambs ii. Kothmann lamb feedlot in menard Texas was program that utilizes manure
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