ANSC 318 1st EditionExam # 3 Study Guide Lectures: 19 - 25Lecture 19 (November 11)Where does Texas rank in total feedlot cattle inventory?1st.What are the different management options for weaned beef cattle?Option 1: weaned calves  steers and heifers about 7-8 months old are sent to thefeedyard and finished on high grain dietsOption 2: calf (wintered) stockers  put into pasture on high roughage diet with limitedgrain and then finished on high grain in the feedyardOption 3: yearling (summer) stockers  put on pasture with high roughage diet andthen finished on high grain in the feedyardOut of the Beef Growing Programs, which forage has the poorest quality?Stockpiled forages.What are the key advantages to feeding a forage-based diet first and then a high grain diet?Feeding a forage-based diet in the earlier stages of life and then switching to a highgrain diet will allow faster gain from the grain and compensatory growth (leanermuscle/less fat) meaning the feed:gain ratio is lowered and the cattle are more efficient. How do you find dairy NE requirements? Bos Indicus?Dairy  .077(BW.75) x 1.2Bos Indicus  .077(BW.75) x 0.9List 4 factors that effect NEg requirements in beef cattle.Gender  heifer > steers > bullsBody weight  800 > 600 > 400Analbolic implants  non-implanted steers > implanted steersCompensatory growth  calf feds > short yearlings > long yearlingsCan cattle be implanted more than one time?Yes. What is the relationship between lean tissue deposition and protein requirements?Positive. As lean tissue deposition increases, protein requirements do as well.What is the formula for finding N content of urea? Why?Urea x 6.25 = NUrea is 45% N, meaning 1 lb of urea can be converted into 2.81 lb of microbial protein.What are the 3 ways to best utilize NPN sources in beef cattle?•urea is added to high grain diets  less effectively used when high-roughage diets arefed•urea included in diets for short- or long-yearling cattle compared to diets for calf feds•urea included in diets with high concentration of protein feeds high in UIPHow do you prevent urea toxicity?•mix diets well•adapt cattle to urea based diets slowly•limit urea to 1/3 of total dietary proteinWhich cattle may require more UIP than others?Ex. Newly weaned cattle > yearling cattleLarge-frame > small-frameRevalor-implanted > nonimplantedWhat is the proper Ca:P ratio? What does it prevent?1.5:1. Prevents urinary calculi (water belly)List the 6 main macrominerals that are important in growing beef diets.Calcium, phosphorous, sulfur, magnesium, potassium, and sodium/chloride.List the microminerals that are important in growing beef diets.Cobalt, iron, selenium, copper, manganese, and zinc.What vitamins need to be supplemented to cattle?Vitamin A (2,200 IU/kg), Vitamin D (275 IU/kg; if no access to sunlight), Vitamin E (60IU/kg).What are the goals of a receiving cattle feeding program?Restore feed consumption, restore rumen function, regain body tissue loss fromshipping stress, and minimize morbidity and mortality rates.List the key grain sources fed to cattle in order from most rapidly fermented to least.Wheat > barley > sorghum = cornWhat happens to the speed of digestion as processing of grain increases?The rate of digestion increases as well. What are the key protein sources for feedlot cattle and their UIP content?Soybean meal (low UIP), cottonseed meal (intermediate UIP), blood meal (high UIP), andfish meal (high UIP)What are the key carbonaceous and proteinaceous silages for feedlot cattle?•Carbonabeous  corn and milo silage, grass silage, and stover silage•Proteinaceous  alfalfa silage and clover silageList 3 examples of feed additives and their purposes.•Monensin  ionophore; improves feed efficiency•Bambermycin  improves ADG and feed efficiency•Lactobacillus acidophilus  probioticLecture 20 (November 13)What has happened in the dairy cow industry over the past 20 years?•decreased number of operations•same number of cows•increase milk production/cow and total milk productionList the order in which fiber, starch, and fat effect heat increment.Fiber > starch > fatHow do we meet nutrient demands for high-producing dairy cows?Increase DMI and nutrient density of dietList the stages of lactation, their purpose, and physiological priorities.•Early Lactation  0 – 10 weeks; peak milk production occurs within 3 to 6 weeks;lactation > reproduction > growth > maintenance•Mid-Lactation  10 – 24 weeks; milk yield begins to decrease, peak DMI occurs within11 to 13 weeks; reproduction > lactation > growth > maintenance•Late Lactation  > 24 weeks; milk yield continues to decrease, cows regain body tissue reserves; reproduction > growth > maintenance > lactation•Dry period  5 – 8 weeks; dry period, late pregnancy (rapid fetal growth)•Transition period  2 – 3 weeks; dry period, late pregnancy, prepare for lactationWhat are milk producers paid for?Milk volume, milk composition, and milk qualityWhat is the impact of diet of VFA production?•acetate  increased with fiber; increase fat production in mammary glands; precursorto milk production•propionate  increased with starch in dietHow do we maintain adequate fiber levels in lactating dairy cow diets?•formulate diet to contain a minimum forage:concentrate ratio of 40:60•formulate diet to contain minimum of 17% crude fiber or 21% ADF•feed minimum 1 to 1.5% of body weight as forageHow can we increase digestion time?•increase particle size•increase amount of fiber•type of fiber (increase lignin)What are the short and long term benefits of including adequate levels of effective fiber?•short-term  cow will chew more, providing more salivary buffers and increasingrumen pH with more favorable environment for fiber-loving microbes; this will increase acetic acid production, a precursor for milk fat synthesis. •long-term  help maintain the integrity of the rumen epithelial tissue, preventingrumen parakeratosis (rumen burnout)List 4 additional factors that will effect milk composition.•type of grain  faster rates of rumen starch fermentation may depress milk fatWheat > barley > corn = sorghum (i.e. corn is safer than wheat because it takeslonger)•Grain processing  increased processing = increased rate of fermentationSteam-flaked > cracked = dry-rolled > whole•Dietary buffers  buffers will increase rumen pH and help minimize milk