Marianas Grazing and Livestock Management Academy Range and Pasture Management 101: Range and Pasture Animal Nutrition

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1 Slide 1 Marianas Grazing and Livestock Management Academy Range and Pasture Management 101: Range and Pasture Animal Nutrition Mark S. Thorne, Ph.D. University of Hawaii at Manoa - Cooperative Extension Service College of Tropical Agriculture and Human Resources Funding Provided by: USDA-National Institute of Food and Agriculture; Outreach and Assistance for Socially Disadvantaged Farmers and Ranchers Grant # Range and Pasture Animal Nutrition I) Cattle Annual Production Cycle/Nutritional demands Biological and chronological cycle of the beef cow B) Cattle production cycle depicted by George et al. 2001, figure 1. Nutrient demands are dynamic, physiological state is the most important cause for changes in demand Lactation has highest nutrient demands, 2nd trimester the least E) George et al. 2001, table 2. i) An example of changing nutritional demands of a 1000 lb beef cow depending on physiological state. ii) Relationship of body size to maintenance energy needs. Body size also affects how much energy and nutrients are required by the animal. II) Micro/Macronutrients, other necessities Introduction - Proper nutrition for healthy animals B) Energy (TDN), Protein Important minerals/nutrients for production D) Effects of deficiencies, common deficiencies III) Annual Forage Production Cycle Stages forage of growth Nutrient composition of different HI forages from the Hawaii Forages C) Interpreting a forage analysis report (Dairy One factsheet; Redfearn et al.; CL305). IV) Synchronizing forage and animal production A) Observing their performance. Body Condition Scoring (BCS) C) What is BCS? D) BCS scale (adapted from Momont and Pruitt, CL720 and Elanco Animal Health publication AI 8301). E) Why does BCS matter? F) Managing for BCS (adapted from Bruce et al. 1999, chapter 2). G) Factors affecting calving season (George et al. 2001, pg 1). V) Effective Nutrient/Energy Supplementation (CL303; CL327) A) Daily needs for energy, protein, Ca, and P for lactating and dry cows (Sprinkle 1996, table 1 pgs 1-2). B) Determine costs of supplementation program (Sprinkle 1996, pg 4; CL316).

2 Slide 2 Annual Production Cycle: Cattle Biological and Chronological Production Cycle Biological Cycle Day Chronological Cycle 1 st Trimester Begins 1 June 1: Conception 2 nd Trimester Begins 94 Sept. 3: End 1 st Trimester 3 rd Trimester Begins 188 Dec. 6: End 2 nd Trimester Postpartum: Lactation 282 March 9: Birth of calf Rebreeding: Lactation 365 June 1: Conception Lactation Ends 488 Oct. 1: Calf weaned Source: Bruce et al. 1999, table 1.1 I) Cattle Annual Production Cycle/Nutritional demands A) Biological and chronological cycle of the beef cow (Bruce et al. 1999, table 1.1).

3 Slide 3 Annual Production Cycle: Cattle Biological and Chronological Production Cycle Source: George et al. 2001, figure 1 B) Cattle production cycle depicted by George et al. 2001, figure 1.

4 Slide 4 Annual Production Cycle: Nutrient Demands Source: Bruce et al. 1999, figure 1.2 C) Nutrient demands are dynamic, physiological state is the most important cause for changes in demand (Bruce et al. 1999, figure 1.2 graph of generalized protein and energy demands of a cow during lactation and pregnancy; for more info see CL330). D) Lactation has highest nutrient demands, 2nd trimester the least (see Bruce et al. 1999, table 4.1; CL300 has NRC 1984 values for nutrient requirements of cows of different classes).

5 Slide 5 Annual Production Cycle: Nutrient Demands Nutrient Requirements for a 1,000 lb beef cow. Stage of Production Nutrient Period 1: Calving (45 days) Period 2: breeding (45 days) Period 3: early gestation (90 days) Period 4: mid gestation (90 days) Period 5: late gestation (90 days) Dry matter (lb) Protein (lb/day) TDN (lb) Calcium (g/day) Phosphorus (g/day) Vitamin A (x1000 IU) Source: George et al. 2001/National Resource Council 1984 E) George et al. 2001, table 2. i) An example of changing nutritional demands of a 1000 lb beef cow depending on physiological state.

6 Slide 6 Annual Production Cycle: Nutrient Demands Source: Bruce et al. 1999, figure 1.1 ii) Relationship of body size to maintenance energy needs (Bruce et al. 1999, figure 1.1). Body size also affects how much energy and nutrients are required by the animal.

7 Slide 7 Essential Nutrients Important Minerals, Nutrients, and Vitamins for Production: Energy Protein Sodium (NaCl) Phosphorus (P) Calcium (Ca) Iodine (I) Potassium (K) Magnesium (Mg) Selenium (Se) Cobalt (Co) Iron (Fe) Copper (Cu) Vitamin A Vitamin D II) Micro/Macronutrients, other necessities A) Introduction - Proper nutrition for healthy animals means nutrient levels adjusted for metabolic needs for maintenance, growth, reproduction, and lactation. No single nutrient is responsible for a healthy immune system and growth. Nutrients interact with each other and can have antagonistic as well as positive effects (Bruce et al. 1999, pg 60-65). B) Energy (TDN), Protein i) Energy is often measured as Total Digestible Nutrients and is one of the most important nutritional factors for beef cows. Energy is necessary for rapid growth of immune cells. ii) Proteins are used in the structure of cells and thus replication and synthesis of antibodies and other materials of the immune system. C) Important minerals/nutrients for production (Bruce et al. 1999, chapter 9, table 9.1). i) NaCl, P, Ca, I, K, Mg, Se, Co, Fe, Cu ii) Vitamins A (carotene) and D D) Effects of deficiencies, common deficiencies (Bruce et al. 1999, pgs 65-67; George et al. 2001, table 3). i) Energy retarded growth, delayed sexual maturity, poor conception rate, loss of body weight, lowered resistance to parasites, decline in milk yield. ii) Protein reduced appetite, reduced growth rate, loss of weight, delayed estrus, poor conception, poor milk yield. iii) NaCl loss of appetite, unthrifty appearance, weakness, lack of coordination. iv) Vitamin A susceptibility to infection, abortion, scouring, night blindness.

8 Slide 8 Annual Forage Production Cycle: Season of Growth Source: Bruce et al. 1999, figure 4.1 III) Annual Forage Production Cycle A) Stages of growth (Season) i) Forage quality over time (Bruce et al. 1999, figure 4.1). Forage quality (relative amount of digestible nutrients) declines as season progresses. In other words, flowering/fruiting plants are lower quality than fresh vegetative (leaf) growth.

9 Slide 9 Annual Forage Production Cycle: Growth Form C3 C4 Source: Bruce et al. 1999, figure 4.2 Maintenance B) Stages of growth (Season, continued) ii) Metabolizable energy in forages declines as plants mature with grasses and forbs having higher amounts of energy relative to browse (brush species).

10 Slide 10 Annual Forage Production Cycle: Growth Form Source: Bruce et al. 1999, figure 4.3 A) Stages of growth (Season, continued) iii) Digestible protein in forages similarly declines as plants mature with browse maintaining higher amounts of protein than forbs and grasses respectively.

11 Slide 11 Species Nutrient Composition of Hawaii Forages: 12 weeks growth Dry Matter (%) Yield (lb/ac) Crude Protein (%) ADF (%) P (%) K (%) Ca (%) Mg (%) Na (%) Mn (ppm) Fe (ppm) Kikuyu (Whittet) Guinea grass (Natsukaze) Blue Pangola California grass Signalgrass Puerto Rican Star Source: B) Nutrient composition of different HI forages from the Hawaii Forages website < Average nutrient and yield values for samples taken from the Mealani Forage Demonstration Garden. i) Kikuyu ii) Guinea grass iii) Pangola iv) California grass v) Signal grass vi) Puerto Rican Star Refer back to the table in slide 5. A 1000 lbs cow requires 2.5 lbs of protein per day in a 20.6 lbs dry matter diet. Referring to the table above how much protein would a twelve week old kikuyu grass pasture supply (20.6 x = 1.8 lbs of CP); one AU (1000 lb cow w/calf; 26 lbs dry matter per day) will get 2.2 lbs CP. Clearly, 12 week old grass growth is not sufficient to meet the nutritional demands of lactating cows. Slide 12

12 Annual Forage Production Cycle: Interpreting a Forage Analysis Report Common Elements of a Forage Analysis Report: % Dry Matter (DM) Crude Protein (CP) Neutral Detergent Fiber (NDF) Acid Detergent Fiber (ADF) Total Digestible Nutrients (TDN) Relative Feed Value (RFV) Interpreting a forage analysis report (Dairy One factsheet; Redfearn et al.; CL305). % Dry matter - includes protein, fiber, fat, minerals, etc.. Animals consume feeds to meet their dry matter needs, which contains all of the nutrients. Animals will have to consume more of a wetter feed to receive the same amount of dry matter as they would from a drier feed. It is important to know the dry matter content of a feed to establish feeding rates and insure that livestock receive the amount of feed to meet their daily needs. Crude Protein (CP) - the total protein in the sample. Proteins are a major component of vital organs, tissue, muscle, hair, skin, milk and enzymes. Protein is required on a daily basis for maintenance, lactation, growth and reproduction. Neutral Detergent Fiber (NDF) - a measure of hemicellulose, cellulose and lignin representing the fibrous bulk of the forage. These three components are classified as cell wall or structural carbohydrates. They give the plant rigidity enabling it to support itself as it grows, much like the skeleton in animals. Hemicellulose and cellulose can be broken down by microbes in the rumen to provide energy to the animal. NDF is negatively correlated with intake. Acid Detergent Fiber (ADF) - a measure of cellulose and lignin. Cellulose varies in digestibility and is negatively influenced by the lignin content. As lignin content increases, digestibility of the cellulose decreases. ADF is negatively correlated with overall digestibility. Total Digestible Nutrients (TDN) - denotes the sum of the digestible protein, digestible NSC, digestible NDF and 2.25X the digestible fat. Relative Feed Value (RFV) - an index for ranking forages based on digestibility and intake potential. A RFV of 100 is considered the average score. The higher the RFV, the better the quality.

13 Slide 13 Synchronizing Forage and Animal Production Are my animals getting enough from my forage? Ask them! IV) Synchronizing forage and animal production A) One of the best ways to tell if animals nutritional needs are met is by observing their performance. B) Body Condition Scoring (BCS) is a tool for estimating animal performance.

14 Slide 14 Synchronizing Forage and Animal Production: Body Condition Score (BCS) Source: Elanco Animal Health, AI 8301 Liveweight % Fat C) What is BCS? i) Simply stated: BCS is a quick, structured visual estimate of an animal s physical state given on a scale from 1-9. D) BCS scale (adapted from Momont and Pruitt, CL720 and Elanco Animal Health publication AI 8301). 1-2: Emaciated to severely emaciated. Shoulder, ribs, backbone, hooks, and pins visible with little to no muscling and fat in the hindquarters. 3: Caution, very thin with no fat on ribs or brisket. Backbone easily visible. 4-6: Optimal range. Thin to good smooth appearance throughout. Last two to three ribs visible or covered with some fat deposits in brisket and over the tailhead. Hindquarters may appear rounded. 7: Caution, brisket full and ribs smooth. Fat cover is thick and spongy. 8-9: Obese to very obese (rare). Hindquarters have square appearance and heavy fat pockets around tailhead. Mobility may actually be impaired (rare).

15 Slide 15 Synchronizing Forage and Animal Production: Body Condition Score (BCS) An animal s body condition strongly affects reproduction, parturition, and rebreeding success. Table: Sprinkle 2000, Data: Spitzer et al E) Why does BCS matter? i) An animal s BCS is directly related to pasture/feed quality and strongly affects animal reproductive success.

16 Slide 16 Synchronizing Forage and Animal Production: Body Condition Score (BCS) Bulls and cows should be at BCS 5-6 for best fertility rates. First-calf heifers and second calf cows should be BCS 6-7. A change in condition score is equivalent to at pound change in weight. Plan accordingly! E) Why does BCS matter (cont d)? ii) Researchers have reported strong correlations between BCS and percent body fat of cows. iii) Simply put, cows of higher BCS (between 5 and 7) at calving and during early lactation are more likely to cycle and become pregnant early in the breeding season or within the window to maintain an annual production cycle. The converse is also true.

17 Slide 17 Synchronizing Forage and Animal Production: Managing for Body Condition Score (BCS) Group animals of similar body condition. Reevaluate BCS3-4 months before breeding season. Evaluate returns form a higher calving rate compared to cost of supplementing and feed accordingly if necessary. F) Managing for BCS (adapted from Bruce et al. 1999, chapter 2). i) Having cows and first-calf heifers at a BCS of 5 or above increases the probability of a higher calving rate. ii) Remember that how an animal looks now is a reflection of pasture/feed conditions of the preceding months. In other words, current pasture conditions will be reflected in an animal s BCS a few months from now. iii) Give yourself plenty of time to raise an animal s BCS. An increase of 10% dietary TDN equates to 1 pound of gain per day which would move an animal up one BCS score within 3 months (60-90 pounds). Also, the payoff from a difference between a BCS 5 and 6 may not be worth the cost of feeding. Maintaining is easier than catching up!

18 Slide 18 Synchronizing Forage and Animal Production: Calving Season Factors Affecting Calving Season: Quality and availability of forage Weather conditions Supplemental feed Labor Capital inputs Calf crop production goals Disease G) Factors affecting calving season (George et al. 2001, pg 1). i) The reproductive year of a beef cow is very tight. The period from conception to birth is about 283 days (9.4 months), and most cows will not be ready to rebreed until days after calving (longer is nutrition is poor). A cow-calf producer only has a window of about 42 days to successfully rebreed a cow to stay on an annual calf producing cycle (George et al. 2001, pg 2). ii) In other words, as the nutritive needs of a cow are highest during lactation, plan for a calving season when forage is of high enough quality to maintain the cow s BCS for rebreeding. You cannot expect to increase a cow s BCS while she s lactating, but on quality pasture you can keep her from slipping too much too fast for rebreeding purposes.

19 Slide 19 Effective Supplementation The object of supplementation programs is to match forage quality deficiencies so as to increase forage intake by the animal. Supplements need to be designed not only for the nutritional health of the herd but also for the profitability of the operation. Evaluation of the herd: Key indicators = GOLD calf Growth Open cows Length of calving season calf Death loss If any of these indicators are below industry standard nutrition is not adequate nutrient or energy supplementation maybe necessary. V) Effective Nutrient/Energy Supplementation (CL303; CL327) A) Daily needs for energy, protein, Ca, and P for lactating and dry cows (Sprinkle 1996, table 1 pgs 1-2). B) Determine costs of supplementation program (Sprinkle 1996, pg 4; CL316).

20 Slide 20 Summary Range and Pasture animal nutrition is a function of the grazing animals nutritional needs and the quantity and quality of the forages over time. The nutritional requirements of the grazing animal are defined by the kind and class of animal, their physiologic status, and the age of the animal. The quality and quantity of forage available for the grazing animal changes over time, is influenced by the environment, and can be affected by previous grazing events. Maintaining herd productivity requires matching the animal nutritional demands with the available forage resources or providing supplementation to make up for deficiencies.

21 Slide 21 When is the highest nutritional demand for a cow s normal production cycle? 1. During the 1 st trimester 2. During the 2 nd trimester 3. During Lactation 4. During the 3 rd Trimester 5. Both 3 and 4 During the 1st trimester 0% 0% 0% 0% 0% During the 2nd trimester During Lactation During the 3rd Trimester Both 3 and 4

22 Slide 22 What is the daily protein intake for cattle consuming 26 lbs of guinea grass with a CP concentration of 8.1%? lbs of Protein lbs of Protein 3. 3 lbs of Protein 4. I don t know and does it really matter? 2.1 lbs of Protein 0% 0% 0% 0% 1.5 lbs of Protein 3 lbs of Protein I don t know and does it...

23 Yes Slide 23 Is the protein intake in the previous slide enough to support a lactating cow? (refer to the table in slide 5) 1. Yes 2. No 0% 0% No

24 Slide 24 The optimal Body Condition Score range for a mature cow at breeding time is? 1. BCS 7-9; as fat as can be 2. BCS 1-3; skinny makes it easy for the bull 3. BCS 4-6; not too fat, not too skinny 4. What is BCS? BCS 7-9; as fat as can be 0% 0% 0% 0% BCS 1-3; skinny makes it... BCS 4-6; not too fat, not... What is BCS?

25 Slide 25 What is the weight difference between Body Condition Scores? pounds pounds pounds pounds 5. What difference? pounds 0% 0% 0% 0% 0% pounds pounds pounds What difference?

26 Slide 26 What does the acronym GOLD stand for when evaluating herd nutritional health? 1. Good cows, Old cows, Lazy cows, Damn cows. 2. Nothing, GOLD is a semihard yellow metal used for money and teeth. 3. calf Growth, Open cows, Length of calving season, calf Death loss. Good cows, Old cows, La.. 0% 0% 0% Nothing, GOLD is a semi... calf Growth, Open cows,...