690 likes | 1.01k Views
Beef Cattle Nutrition. Beef Cattle Nutrition. diagram of ruminant-handout Esophageal groove – immature ruminants Rumen, omasum, abomasum and reticulum Small Intestine-duodenum, illeum, jejunem Large Intestine-colon, cecum, rectum. Digestive System.
E N D
Beef Cattle Nutrition • diagram of ruminant-handout • Esophageal groove – immature ruminants • Rumen, omasum, abomasum and reticulum • Small Intestine-duodenum, illeum, jejunem • Large Intestine-colon, cecum, rectum
Digestive System • stomach in ruminants comprises 25 % of body • rumen comprises 75 % of stomach • fermentation: digest cellulose, plant tissue, urea, NPN, B & K vitamins • consist of bacteria and protozoa (200 billion/teaspoon)
Characteristics of Ruminants • Mouth • no upper incisor or wolf teeth • use lips and tongue to grab food • four compartments to the ruminant • Consist of microorganisms • Produce Volatile Fatty Acids/ acetic, propionic, butyric
Volatile fatty acids (VFA) • Produced in large amounts through ruminal fermentation and are of paramount importance in that they provide greater than 70% of the ruminant's energy supply. Virtually all of the acetic, proprionic and butyric acids formed in the rumen are absorbed across the ruminal
VFA’s cont. • epithelium, from which they are carried by ruminal veins to the portal vein and hence through the liver. Continuous removal of VFA from the rumen is important not only for distribution, but to prevent excessive and damaging drops in pH of rumen fluid.
Ruminants • Prehension- the process of gathering food to the mouth • Mastication - the process of chewing • Eructation (belching of gas) • Carbon DiOxide and Methane • Enzymes- organic catalyst which speed up a biochemical reaction without being used up
Rumination • Rumination-fermentation • rechewing usually > 8 hours/day dependent on diet (increase fiber, increase rumination time) • CO2 and Methane are the primary gases given off during rumen fermentation
FUNCTION OF FEEDS • Maintenance- a ration which is adequate to prevent any loss or gain of tissue in the body when there is no production • the difference in energy needs are related to the amount of activity • Growth- increase in size of muscles, bones, internal and external parts of the body (the foundation of animal production) • Finishing- the laying on or deposition of fat • Production – lactation, conception, etc.
FEEDS • Definition- any ingredients or material fed to animals for purposes of sustaining them • Classes of Feeds • roughages • concentrates • by-products • protein supplements • minerals, vitamins, and additives
Classes of Feeds-Roughages • Definition: >18% fiber and lower in energy & low digestibility compared to concentrates • Generally; TDN=40-60% and is high in Ca & K • Forage/Pasture, hay, crop-residue (corn, milo), silage (fermented, high-moisture forage), haylage (low-moisture type silage), green chop
Classes of Feeds cont. • Concentrates- high in energy, low in fiber and < 20% protein – Corn, milo, oats, etc. • By-product feeds (from plant and animal processing) carrots, turnip tops, fodder beets • Protein supplements- high in nitrogen • Oilseed Plant by-products (SBM, CSM)
Classes of Feeds cont. • NPN= non-protein nitrogen • urea, ammoniated molasses or chloride, biruet, etc • Urea=45% Nitrogen X 6.25 = 281% protein equivalent • Minerals - NaCl, limestone, dical, etc. • major -Ca, P, Mg, S • trace - Cu, Fe, I, Mn, Zn, Se, etc.
Classes of Feeds • Vitamins • Natural versus synthetics • water vs fat soluble classification • A,D,& E are most common in ruminants • Special Feeds • Fats and oils (increase calories without bulk) • molasses (increase energy and palatability)
Classes of Feeds • Feed additives and implants • increase efficiency of gain, prevent diseases, preserve the feed • antibiotics, hormones, growth promotants, repartitioning agents, etc.
Evaluation of Feedstuffs • Measuring Energy • TDN= sum total of the digestible protein, fiber, and nitrogen free extract, and fat X 2.25 • 40% is low for forages while 60% is high • Most concentrates are 80-90%
Calorie or California Net Energy System • Net Energy= gross energy-fecal energy-gaseous energy-urinary energy-heat increment • gross energy = combustion heat • digestible energy = portion of gross energy that is not excreted in feces • Metabolic energy = portion of gross energy that is not lost in feces, urine and gas • heat increment = difference between ME & NE • heat unavoidably produced by an animal in digestion and metabolism
Evaluation of Feedstuffs • Analyzing Feedstuffs • Proximate analysis • 1) H2O (DM vs As Fed), • 2)CP 3) Ash 4) Fat • Fiber (ADF, NDF) • Energy (Net or TDN) – bomb calorimeter • Minerals & Vitamins
Ration Formulation • Consideration points • availability and cost of feedstuffs • moisture content • composition of feedstuffs • soil analysis • nutrient allowances and requirements • composition of ration and ingredients
Beef Cow Nutrition Objective • feed little as possible as long as we don’t damage reproduction, milk, or longevity • overfeeding causes decreased longevity, dystocia, reprod. rate, and milk prod. • underfeeding causes delayed estrus, puberty, lowers conception rate and milk prod.
Phase Feeding for the Beef Female • feeding accounts for approx. 2/3 of total costs after real estate acquisition • feeding has the greatest influence on growth and performance • Yet, reproduction is the most important economic important trait • feeding influences growth, reproduction (most critical), lactation, etc.
Phases of Feeding • Birth to weaning • Weaning to first breeding • First breeding to first calving • First two productive years (1st two calves) • Third and subsequent years of production
Phase Feeding • Plane of nutrition is dependent upon energy and protein requirements along with forage quality and availability • Can be somewhat breed dependent • European cattle are later maturing and will utilize more forage
Phase Feeding • First phase- Birth to Weaning • objective is to develop replacement females to weaning with maximum subsequent productivity at minimum costs
Phase Feeding • Growthier females at weaning will usually reach puberty earlier, calve on time and return to rebreeding earlier than slower growing heifers • Weaning is usually around 205 days or 7 months of age
Phase Feeding • Second phase - Weaning to First Breeding • objective is to promote adequate growth to insure sexual maturity • first breeding should be done at 60-65 % of the estimated mature weight • ADG of 1-1.5 lbs. per day is recommended
Phase Feeding • Third phase - First Breeding to First Calving • objective is to promote sufficient growth and body development to allow heifers to deliver a calf, and to prepare the heifers physiologically to be able to withstand the rigors of first lactation and rebreeding.
Phase Feeding • Females should gain 70-75% of their weaning weight or be 70-75% of their mature weight at their first calving time.
Phase Feeding • Fourth phase - First two productive years • Objective is to provide a sufficient plane of nutrition to allow the young cows to lactate, rebreed and continue to grow • cows should not lose more than 15% of their weight during the winter
Phase Feeding • Fifth phase - Third and subsequent productive years • Objective is to maintain efficient productivity • nutrient requirements actually decrease • Should not lose more than 20% during the winter
Feeding in General • Obesity can be a major problem • Body Condition Scores should be utilized • Scores of 1-9, where 1 is very thin and 9 is obese : Handout • This can be breed, feed or frame size dependent
Feeding in General • Heifers - breed more than needed • breed 30 days before the mature cows • palpate 60 days after breeding season • Cows > 10 years of age; the physical condition will diminish • Bulls - during intense breeding season; requirements may increase by 2-3 X • If forage is limiting, feed bulls separate
Feeding Systems • Creep feeding- • the supplemental feeding of young nursing animals in an enclosure which is accessible to them but not to their parent • gains for young animals are cheap gains due to less fat content in young animals and less consumption/body wt. • adv.- increases weaning wt., facilitates fall calving, uniformity, achieve genetic potential, assists first calf heifers, etc.
Creep feeding- is it feasible? • whenever it is most likely profitable • usually when forage or milk is limited • conditions we see in drought that results in overgrazing by mother, thus forage is limited • young cows or very old cows • To be feasible, value difference of the calf should be over the cost of the creep feed • Over creep feeding can cause reduced subsequent milk production because of excessive fat in udders
Feeding and Management of Brood Cows • critical time of nutrition • 30 days before calving • 70 days after calving • growth of calf • reproduction efficiency of cow • Lactation • Rebreeding
Feeding and Management of Brood Cows • feed the herd according to cow reproductive pattern • dependant upon: • dry pregnancy • lactating • replacement heifers
Feeding and Management of Brood Cows • heifers – the last 3-4 months before parturition is important • weight makes a difference • provide for maintenance and growth BCS
Feeding and Management of Brood Cows • Reproduction and Nutrition • energy is more important than protein • P supplementation increases % calf crop • increase Vit A • level of feed before and after calving • pregnant cows should not gain over 100 lbs during gestation
Feeding and Management of Brood Cows • Winter Feeding • grass decreases in protein • must either drylot or supplement • energy is important and should be increased by 10% for every 10 degrees below 20 degrees F • Range Feeding Deficiencies • energy- lack of feed • protein - mature grasses • minerals - lowered salt and P/ vit. - A & ? D, E
Feeds for supplementation • Oilseed meals • Grain • Breeder/range cubes • Protein blocks • Liquid feeds (protein or protein/energy) • Syrup blocks or tubs • Hays
Supplementation • when supplementing; need to know 4 things: • nutrient composition • availability • Intake • requirements
Supplementation questions • how much to feed and still make max use • what kind • what form • how often • additives • Alternatives
Factors affecting supplementation • Forage quality • Forage quantity and availability • Body condition score • Body size • Milking level • Age
Feeding of Bulls • age and condition / exercise • increase bulk, decrease grain ( do not want them too fat) • feed young bulls more for growth and development- overfeeding results reduced sperm counts, unsoundness, etc. • mature bulls- increase lbs of grain plus roughage as needed to fit BCS