DMancaster Farming Saturday, April 7,1990 David Kradel Herbert Jordan Milton Madison Penn State Poultry Pointers Herbert Siegel Donald Singletai CHICKEN GROWTH HORMONE RESEARCH AT THE DEPARTMENT OF POULTRY SCIENCE Herb Siegel Department of Poultry Science As many of you know, the gene tic makeup of the bird determines its optimum rate of growth. That is, characteristics inherited from its sire and dam determine how fast the bird will grow and how large a size it will attain. Within this genetic background, factors in the bird’s environment such as temperature, light, dis eases and nutrition —interact with each other and with the inherited characteristics to modify this growth. One of the important inter nal mechanisms that is genetically Cow Research Minus The Cow NEWARK, Del. Innovative lab equipment is allowing Univer sity of Delaware scientists to research cow digestion minus the cow. Continuous culture fermenters are the laboratory equivalent of the cow’s rumen, the first of the animal’s four stomachs. Dr. Limin Kung, assistant pro fessor of ruminant nutrition, said the rumen is especially interesting to researchers because it enables cows to use bacterial protein as well as protein from plant sources. ‘The rumen is a fermentation vat that allows cows to use fibrous feeds efficiently,” he said. “The fermentation also increases bac terial production of protein. Cows and other ruminants get protein from the feed that they eat as well as from the bacterial protein pro duced in the rumen.” According to Kung, theoretical ly cows do not need an arpino acid or protein source in the diet to build muscle tissue or produce milk. However, to maximize pro duction, supplemental proteins are fed to today’s ruminants. He said that ruminants do not have to compete with humans or other animals that need protein from grains, because non-protein nitrogen sources, such as urea and ammonia, are used to produce pro tein by the bacteria that live in the rumen. Studying ruminant digestion in the laboratory is not new. But most studies have used batch fer menters, thus limiting the types of experiments. A continuous culture fermenter, such as the one Kung uses, allows for a greater range of experiments. Most importantly, it can simulate the digestion of cows over a period of time. The continuous culture fer menter system is one of only 6 or 7 in the country. Eight 500 ml glass cylinders simulate eight rumens. They are nestled in a bath, a 20-gallon aquarium, held at 40 degrees centigrade, the tempera ture of a rumen. Dr. Ken Lomax and research associate Stephen Gottfried, both of the department of agricultural Turn to Page D 3) Morris Mast determined, but which is signific antly influenced by the environ ment, is the endocrine or hormone system. A vast array of hormones, some times acting alone but mostly interacting with each other, control or modify not only the growth of the bird but the composition and distribution of its muscle and fat This distribution is of great impor tance not only to the growers and processors but also to the consumer. Research in the Department of Poultry Science at Penn State by Dr. Regina Vasilatos-Younken, her associates, and students on chicken growth hormone (cGH), a hormone important for its effect on growth and carcass composition, LORSBAN*SOW The on LORSBAN*SOW wettable powder insecticide is the only broad spectrum product you can use early to mid-season that also sup presses mite populations. So you spend less money on mite sprays, and keep more in your pocket. What’s more, LORSBAN SOW provides: -Excellent control of tufted apple budmoth, leafrollers, scale crawlers, codling moth and aphids. —Easy on beneficials. —Complements your integrated pest management program. Regardless of the insecticide you choose ALWAYS READ THE LABEL BEFORE USE AND ALWAYS CAREFULLY FOLLOW ALL LABEL DIRECTIONS AND PRECAUTIONS for sale use 333-232-190 has revealed some fascinating facts about how cGH works. They found that during the rapid stages of growth in the broiler (1 to 4 weeks of age), the level of cGH in the blood is very episodic about every 90 minutes there is a pulse of cGH, which then subsides. This pulse timing is very consis tent for an individual bird. As the bird passes the most rapid growth stage, (he heights of the pulses become smaller but do not disap pear entirely. What is the purpose of this pul satile output? For most hormones to be effective, there must be a receptor for that hormone in the cells of the tissues that are most affected by the hormone, such as liver or muscle. Dr. Vasilatos-Younken and her students are studying the receptors in livers of growing chickens. Their results suggest that when all receptors are in use (scientists use the term “saturated”), the growth hormone has little or no effect The rise and fall of cGH levels in the blood that flows through the liver allows these cGH receptors to desaturate. Dr. Vasilatos-Younken has shown that cGH is more effec tive in promoting more efficient growth, with less fat in the carcass, if the hormone is given in a pulsa tile manner. vi OJ u C ‘Digging For Data’ Shows Leaner Beef CHICAGO, HI. Sixth grade students who view a new science video are getting the message that today beef is leaner. “Digging for Data” is a 20-mi nute video produced by the educa tion department of the Meat Board to help students understand scien tific problem solving. The new science program is provided free to teachers and includes the video, teacher’s guides, and activity masters. Since sixth-grade students are often con cerned about how tall they will be, the video attracts their attention by talking about height In “Digging for Data,” students research how the food available to the Indians and early settlers affected their average height. Stu dents explore an archeological dig, travel to a mid-nineteenth century immigrant’s home, visit a university beef cattle research center, and finally meet with a food technologist in a supermarket. “Improvements in food tech nology provide us with a greater variety of foods all year long,” said Maureen Lambe, Meat Board d-spectrum insecticide that also suppresses mites. assistant director of education. “Through the video, students learn that this variety and a balanced diet are key to reaching their full height potential.” Pilot testing was conducted to measure the value of the tape as a teaching aid. One question asked, “New methods of breeding and feeding cattle reduces the amount of fat in beef, resulting in a better diet. True or False?” Before see ing the video, only 30 percent of the students correcdy answered true. After seeing the video, 77 percent answered correctly. This message is reinforced with the worksheet, “Cattle Go On A Diet.” This worksheet compares cattle raised in the 19S0s to those raised in the 1990 s to show changes in beef in response to consumer desire for lean meat. Teacher, comments about the video have been very positive. For example, Charlotte Bums, a sixth grade science teacher from Hous ton, Texas, said, “If you have ever searched for an interesting video to reinforce scientific problem sol ving, this is it! Students are encouraged to gather information and actually think like scientists.” DowElanco Tr«d#m«rK of Dowßinco * A
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