Forage Quality and Livestock Nutrition on Pasture. Patrick Davis, Ph. D. Johnson County MU Extension Livestock Specialist

Transcription

1 Forage Quality and Livestock Nutrition on Pasture Patrick Davis, Ph. D. Johnson County MU Extension Livestock Specialist

2 Topics Ruminant Nutrition Factors Effecting Forage Quality Nutrient requirements Feeding Strategies Fescue Toxicity

3 Ruminant Nutrition Ruminant physiology 4 Stomachs Energy and protein metabolism

4 Ruminant Nutrition Ruminant Fore stomach fermentative digestion microbes produce energy and protein Reticulum - rumination Rumen - fermentation Omasum - Feed particle size reduction Abomasum (true stomach) Gastric stomach enzymatic digestion

5 Ruminant Nutrition Features of the Rumen Gas pocket Fiber mat Fluid fraction Resident microbial population Bacteria Protozoa Fungus Viruses

6 Ruminant Nutrition Protein RDP RUP Microbial Cell Peptides Carbohydrates Cellulose and Starch AA Microbial Enzymes Sugars NH 3 + Carbons Skeleton VFA Urea Via Urea Cycle AA Synthesis Microbial protein for use by animal to meet its needs For animal Growth Reproduction Lactation For Microbes Cell growth Cell division

7 Ruminant Nutrition Energy Intake 100% Fecal Energy 30% Digestible Energy Metabolizable Energy Urinary Energy 5% Gaseous Energy (CH 4 ) 5% Heat Increment 20 % Net or Retained Energy (NE or RE) Production 20% Maintenance 20%

8 Factor that influence forage Quality Maturity

9 Factor that influence forage Quality Species

10 Factor that influence forage Quality Plant Parts 1 st bite: leaves with low fiber 2 nd bite 3rd bite: stems with high fiber

11 Nutrient Requirements Nutrient Classes Water Energy Protein Vitamins Minerals All are required

12 Nutrient Requirements Maintenance Nutrients required to stay alive No productive functions Growth Lactation Pregnancy NEm = Mcal * (EBW kg) 0.75

13 Nutrient Requirements Type / Breed Genetic role in maintenance Maintenance Multiplier English / Angus, Hereford 1 Dairy / Holstein, Jersey 1.2 Continental Limousin, Charolais, Chianina Gelbvieh Simmental, Braunvieh Bos indicus Brangus Brahman NRC, 2000

14 Nutrient Requirements Cattle efficiency status Residual feed intake (RFI) Actual intake Predicted intake = RFI The most efficient calves consumed 4% less feed than medium cattle 15% less feed than high cattle Group DMI FCR RFI Low Medium High Nkrumah et al., 2004

15 Nutrient Requirements pound cow energy requirements Mcal NEm / day Pregnancy Lactation Maintenance Months since calving

16 Nutrient requirements Metabolizable Energy, Mcal/d Effect of replacement heifer body size 1400 lb Mature Weight 1200 lb Mature Weight 1000 lb Mature Weight Months from Conception

17 Nutrient Requirements 1 st calf heifer Energy requirements 20 Mcal NEm / day Months since calving Growth Pregnancy Lactation Maint

18 Nutrient requirements Metabolizable Energy, Mcal/d Effect of milk production level and pregnancy Months Since Calving 1200 lb Cow - 30 lb Milk/d 1200 lb Cow - 20 lb Milk/d 1200 lb Cow - 10 lb Milk/d

19 Nutrient Requirements 10 Energy Required for a 650 lb calf Mcal / day NEg NEm ADG, lb / day

20 Nutrient Requirements 10 Energy Required for 1.5 lbs ADG in 150 d grazing season Mcal / day NEg NEm Calf weight, lb / day

21 Heat stress and maintenance Mcal NEm / day % +6.2% Stocker +9.8% +13.4% 60 degrees 70 degrees 80 degrees 90 degrees 100 degrees

22 Nutrient Requirements Other things that effect energy requirements of cattle Growth Potential/efficiency Gender Intact males have 15% greater maintenance energy requirements Fat deposition versus protein deposition Growth promotants Implants Ionophore

23 Nutrient Requirements Protein Rumen Degradable protein = RDP Rumen microbes use to form microbial protein Sources Forage, feed, recycled, non protein nitrogen Deficiency leads to decreased fiber digestion Rumen Undegradable protein = RUP By-passes rumen, absorbed in lower tract Crude Protein = N%*6.25

24 Nutrient Requirements Protein Metabolizable Protein Microbial Protein + RUP Requirement 3.8 g MP / kg EBW 0.75 Lush spring pastures that are high RDP low in fermentable carbohydrates Could produce excess Urea Add energy to detoxify Urea

25 Feeding Strategies The animal is consuming a ration and it should meet nutrient requirements for Maintenance Production Test your soil and forage and know what your basis is Determine animal requirements Varies based various factors

26 Feeding Strategies Determine if the ration fits the animals requirement Identify deficiencies and supplement to meet those need

27 Feeding Strategies Stage of Production Calving to breeding Breeding to weaning Mid gestation Late Gestation Nutrient requirements Highest Moderate Lowest High

28 Feeding Strategies Late gestation Cattle Dry matter intake 1.9 to 2.0% body weight Fetal Growth Mange to have BCS 5-6 prior to calving

29 Feeding Strategies Early Lactation Cattle Dry matter intake 2.4 to 2.6% body weight High nutrient need Milk production Repairing the reproductive tract Lack of nutrients could limit these processes Watch cattle condition closely 1 st calf heifers

30 Feeding Strategies Late Lactation Cattle Dry matter intake 2.2 to 2.5% body weight Watch BCS of the cows Below 4 consider early weaning Creep feeding

31 Feeding Strategies Body Condition Score 4 Body Condition Score 6

32 Feeding Strategies Creep feeding Beneficial when performance limited by Forage quality Forage quantity Milk production Range in creep feed conversions 5:1 to 30:1 Rule of thumb ~ 10:1 Lusby and Gill, Beef Cattle Handbook

33 Feeding Strategies 14.8% CP 28.2% fiber 53.2 % TDN Low fiber Easily digested Dr. Tom Troxel University of Arkansas 5.1 % CP 31.5% fiber 53.7% TDN Very low protein decreased digestibility 8.8% CP 32.8% Fiber 46.3% TDN Low energy

34 Feeding strategies Growing cattle Dry matter intake 2.5 to 3.2% body weight Target 2 lbs ADG Meet requirement for Maintenance Growth Forage affects performance Availability Quality Growth promotants Ionophores and implants

35 Feeding Strategies Supplemental Macro Mineral Levels Nutrient Mature High Mag Growing Salt, % Calcium, % Phosphorus, % Magnesium, % Potassium, % oz / head / day intake

36 Feeding Strategies Supplemental Trace Mineral Levels Nutrient Mature High Mg Growing Copper, ppm Manganese, ppm Zinc, ppm Iodine, ppm Cobalt, ppm Selenium, ppm oz / head / day intake

37 Feeding Strategies Supplemental Vitamin Level Cows, IU / lb Calves, IU / lb Vitamin A 250, ,000 Vitamin D 25,000 12,500 Vitamin E

38 Feeding Strategies Salt Supplementation 25% salt provides % of daily need Requirement 0.6 oz growing 1.2 oz lactating When mineral intake is excessive mix salt with mineral 38

39 Feeding Strategies Phosphorus supplementation Calcium to Phosphorus rations 2 to 1 Forage phosphorus levels less than the following require supplementation 0.18% dry cow 0.27% lactating cow 0.27% growing calf Feeding 3 lbs of DDGS is equal to 4 oz of 10% phosphorus mineral 39

40 Feeding Strategies Phosphorus supplementation P concentration is greater when Plant is vegetative Animals can selectively graze Consider P supplements when Low soil fertility Drought stress Frosted forage 40

41 Feeding Strategies Magnesium Supplementation Grass tetany caused by Excessive K in lush forage Difficulty mobilizing bone Mg Excessive non-protein nitrogen supplements Low calcium intake Provide High Mg mineral 30 days prior to green up 41

42 Feeding Strategies Potassium supplementation Weathered forages are low in K Utilize a 0.5 to 0.8% K mineral to supplement forages Remove K supplementation during early spring through fall 42

43 Feeding strategies Vitamins A, D and E need supplementation on dormant or weathered forages D is usually met through direct sunlight and conversion through the skin or consumption of sun cured roughages

44 Fescue Toxicity Caused by endophyte that lives in the fescue plant Concentrated in the seed head Symptoms Loosing ends of tails, poor conception rates, low pasture gains, low milk production, heat stress Summer

45 Fescue Toxicity Ways to reduce symptoms Moves to warm season pastures in the summer Interseed legumes Supplement with other feed stuffs to dilute effect Graze or cut fescue before it gets to the seed head stage

46 Conclusion When feeding cattle think about The bugs They have requirements maintenance and production requirements they vary so determine them and feed accordingly Grazing your pastures when they are higher quality leads to better animal performance Less supplementation to meet requirements

47 Conclusion Use your tools Testing feedstuffs Soil test BCS to identify needs of the animal Looking at the feces Manage your cattle, pastures and feedstuffs to keep fescue toxicity from happening

48 Questions Contact Information Dr. Patrick Davis, Livestock Specialist University of Missouri Extension Johnson County 135 W. Market, Warrensburg, MO, PHONE: FAX: WEB: extension.missouri.edu/johnson