New Research in Small Ruminant Nutrition

Transcription

1 New Research in Small Ruminant Nutrition Colostrum Evaluation Pregnancy Toxemia Diagnostics and Management Particle Separation and Feeding Management Robert Van Saun, DVM, MS, PhD, DACT, DACVN Professor and Extension Veterinarian Department of Veterinary & Biomedical Sciences Pennsylvania State University

2 Improper Feeding during Late Pregnancy... Metabolic disease Poor supply of colostrum Small or Large weak neonates Poor milk yield or growth High postnatal losses Poor reproduction Failing to Prepare Is Preparing to Fail!

3 Pregnancy Nutrition: Key to Performance Early pregnancy nutrition: o Dictates organ growth of embryo/fetus o Determines # of ovarian follicles and primary hair follicles Mid-pregnancy nutrition: o Alters placental development o Directly influences fetal weight Late pregnancy nutrition: o Influences maternal metabolic status o Alters maternal nutrient reserve to support lactation

4 Maternal Nutritive Effects Fetal Programming 20% reduction Shorter gestation 63% less colostrum 17% reduction Normal gestation 50% less colostrum Data from Wallace et al., 2002, 2004 and Luther et al., 2005 (Adapted from Luther et al., 2005, 2006).

5 Prepartum Diet Effects on Colostrum Production Mean ME intake (Mcal) Low Energy High Energy Mean CP intake (g) g CP / Mcal ME Colostrum Production ----kg ---- First 3h after lambing 0.15 c 0.32 b 0.38 b 0.64 a First 24h after lambing 1.02 d 1.58 c 1.89 b 2.1 a Robinson, 1987

6 Colostrum Quality Importance of Ig transfer from colostrum o Health status o Growth performance Factors influencing colostrum Ig o Genetics/Breed o Volume o Nutrition(?) % Survival Heinrichs Fleenor et al., and USDA:APHIS:VC:NAHMS, Stott, JDS > 10 g/l < 10 g/l Days of Age Does the same relationship for serum IgG concentration apply to lambs and kids?

7 Colostrum Quality Assessment Colostrometer Measures specific gravity Measurement will change with temperature Reasonably tight relationship (R 2 = 0.7) Requires larger volume of colostrum not practical for sheep and goats Fleenor and Stott, JDS 1980

8 Colostrum Quality Assessment Brix Refractometer (Optical and Digital) Measures total solids by refraction index Exact measurement is difficult in optical versions Correlation similar to colostrometer (R 2 = 0.71) Bielmann et al., 2010

9 Both digital and optical Brix measures accurately assessed IgG concentration Bielmann et al., JDS 2010

10 Can the Brix be used in Sheep and Goats? If so, what is the appropriate recommendation for minimal quality standard?

11 Preliminary Findings with Sheep and Goat Colostrum Brix measurement (n=15): Mean: 30.3 ± 8.5% Range: % Values of 15-18% were associated with goat kid deaths Frozen Sample, % Brix y = x R² = Fresh Sample, % Brix

12 Time Effects on Brix Measures - Goats Brix % Brix % h 3.5 h 14.5 h 24 h Time from parturition 0 0 h 4 h 22 h Time from parturition Data from M. Smith

13 Time Relative to Lambing Brix % y = x R² = Time from lambing, hr

14 Nutritional Challenges of Pregnancy Energy Protein Minerals Vitamins Fiber fill capacity Photo from Andrea Mongini

15 Pregnancy Toxemia aka Pregnancy disease, Twin kid/lamb disease, Pregnancy Ketosis Metabolic disease of late pregnancy due to negative energy balance o Deficiency of glucose to support fetus o Excess lipid mobilization Occurs in late pregnant ewes, does, especially with multiple fetuses Additional stresses from severe weather, sudden feed changes, transportation or other disease problems

16 Pregnancy Toxemia Clinical Signs Disease course 3 10 days, or sudden onset Characterized by poor appetite, weakness, depression, dullness Teeth grinding, limb swelling ataxia Neurologic signs, blindness, incoordination progressing to coma and death Rook VCNA 2000; Brozos et al., VCNA 2011

17 Pregnancy Toxemia Clinical Pathology Hypoglycemia, Ketonemia, Ketonuria Secondary low K, Mg, Ca Elevated NEFA Liver dysfunction? Measures of protein mobilization (CK, AST elevated) Late stage problems: o Dehydration o Metabolic acidosis (ketoacidosis) o Hyperglycemia (maybe related to fetal death?)

18 Clinical Chemistry Results Parameter Ewe 1 Ewe 2 Reference Range BUN mg/dl Creatinine mg/dl Glucose mg/dl Total protein g/dl Bilirubin, total mg/dl Creatine kinase (CK) 357 1, IU/l GGT IU/l AST (SGOT) 84 1, IU/l Van Saun, JAVMA 2001

19 Clinical Chemistry Results Parameter Ewe 1 Ewe 2 Reference Range Sodium meq/l Potassium meq/l Calcium mg/dl Phosphorus mg/dl Magnesium mg/dl Triglycerides < 100 mg/dl Cholesterol > 70 mg/dl BOHB < 10 mg/dl Van Saun, JAVMA 2001

20 Subclinical Pregnancy Toxemia Profiles Subclinical pregnancy toxemia defined as BHB 0.86 mmol/l Parameter Subclinical Preg Tox (n=53) Healthy Controls (n=100) Median Range Median Range P<F BHB, mmol/l < Glucose, mg/dl < Cholesterol, mg/dl Urea, mg/dl Total protein, g/dl Albumin, g/dl AST, IU/L Calcium, mg/dl Phosphorus, mg/dl Magnesium, mg/dl Ismail et al., Vet Clin Path 2009

21 Hand-Held Ketone Meters - Blood Human meters: Abbott Precision Xtra Abbott Precision Xceed TM CentriVet human Portacheck BHB Are they accurate and diagnostic for sheep and goats?

22 Using the Meter Insert strip into meter before applying blood Keep the meter and the strips warm o enzymatic reactions are temperature sensitive

23 Meter Performance Comparisons Cow Samples Data provided M. Gavin PortaScience

24 Dairy Sheep BHB and Glucose Determinations r 2 = 0.99, P<0.0001, n=193 r 2 = 0.76, P<0.0001, n=150 Panousis et al., Res Vet Sci 2012

25 Dairy Sheep BHB Assessment BHB Threshold criteria was established as 0.8 mmol/l Panousis et al., Res Vet Sci 2012

26 BHB Meter Performance in Dairy Goats Precision Xtra meter used Sample of 114 goats 1 mo prior to 2 mo post kidding Laboratory range for BHB was 0.1 to 3.7 mmol/l Doré et al., J Dairy Sci 2013 Regression plot (r = 0.98; R 2 = 0.95; P < 0.01) of blood BHBA concentration

27 Defining BHB Thresholds in Goats Prospective study of 1,081 dairy goats on 10 commercial farms Pregnancy toxemia defined by owners based on standardized charts describing clinical presentation Pregnancy toxemia high risk was 10% overall (0-18% herd level) Pregnancy Toxemia Risk Mortality Risk Doré et al., J Dairy Sci 2015

28 BHB Thresholds Based on Week Prepartum Week Prepartum BHB, threshold mmol/l % Goats at or above threshold Sensitivity, % Specificity, % P-value Pregnancy Toxemia Risk < < < < < 0.01 Mortality Risk < < < < < 0.01 Doré et al., J Dairy Sci 2015

29 Pregnancy Toxemia What are the underlying metabolic derangements and nutritional methods for prevention?

30 Fetal Development 16 Total Conceptus Wt (kg) Single Twin 60 70% of fetal growth Days from Mating

31 Pregnancy Effect on Intake A: 88 days, single fetus B: 111 days, single fetus C: 143 days, single fetus D: 95 days with twins Forbes, 1968 All sections taken at the same level along the spine

32 Nutrient Requirements of the Ewe (70 kg Mature BW) ME, Mcal/lb TDN, % CP, % DM DMI, ME (lbs, Mcal per day) ME DMI CP CP (g/day) NRC, 2007

33 Impact of Plant Maturity on Intake TDN% CP% NDF% TDN% CP% NDF% TDN% CP% NDF% TDN% CP% NDF% Alfalfa > 64 >19 < < 50 <13 > 51 Grass > 54 >18 < < 41 < 8 > 65 High Fiber, NDF Low Energy, Protein Low Intake

34 NDF Intake Capacity Silage 24.8 % DM, 18.8% CP, 48.5% NDF Pregnancy NDF Intake as % of Body Weight Week Singles Twins Triplets Mean Orr et al., Anim Prod 1983;36:21

35 Effect of Forage NDF Forage NDF% Week NDF Intake as %BW Singles Twins Triplets Orr et al., Anim Prod 1983;36:21

36 Effect of Diet on Conceptus Development (Twin pregnant ewes) Tissue Weights, g Low CP (8 %) Mid CP (12 %) High CP (15 %) Gravid Uterus 13,444 14,207 15,072 Fetuses 7,498 b 8,455 a 8,718 a Placenta Membranes Uterine tissues 911 b 1,025 ab 1,091 a McNeill et al., % Lighter ab P <.05

37 Maternal Tissue Nitrogen Partitioning in Pregnant Ewes Wool Mammary Organs Carcass Nitrogen Accretion (g) a a a b b a ab ab b -80 Low CP Mid CP High CP McNeil et al., JAS 1997;75:809

38 Nutrient Intake Comparison Low Protein Mid Protein High Protein DMI, lb % of BW ME, Mcal/lb Mcal/day CP, % g/day NDF, % % of BW NRC Require lb DMI 3.94 Mcal ME 183 g CP McNeil et al., JAS 1997;75:809

39 Feed Analysis Comparison Ingredient Previous Pellet Current Pellet Grass Hay Dry matter, % Crude protein, % DE, Mcal/kg ADF, % NDF, % Crude fat, % Ash, % Calcium, % Phosphorus, % NFC (calc), %

40 Custom Pellet Composition Ingredient Previous Pellet Current Pellet Ground corn 650 Wheat millrun Sun-cured Alfalfa Tallow Barley screenings 500 Limestone 14 Molasses 50 Salt 10 Vit-Min premix 1.5 Selenium 0.58 OTC crumbles 10 10

41 Dietary Evaluation Feed Hay Only DMI DE CP NDF Ca P lb/d Mcal/d g/d lb/d g/d g/d (1.6%) Hay Pellet Total NRC Req (2.6%) 4.4 (1.08 Mcal/lb) 192 (10.3%) 2.09 (1.36%) 1.23 (0.8%) (0.48%) 5.3 (0.29%)

42 Dietary Re-Evaluation Accounts for NDF Limitation on Intake Feed DMI DE CP NDF Ca P lb/d Mcal/d g/d lb/d g/d g/d Hay Pellet Total NRC Req (2.6%) 4.4 (1.08 Mcal/lb) 192 (10.3%) 1.23 (0.8%) 8.8 (0.48%) 5.3 (0.29%)

43 Adjusted NRC Requirements Mature ewe, 70 kg, late pregnancy % lambing rate DMI ME TDN NDF CP Ca P Total 4.03 lbs 4.37 Mcal 2.66 lb 560 g 192 g 8.8 g 5.3 g Density 2.6 % BW 1.08 Mcal/lb 66.0% 30.6% 10.3% 0.48 % 0.29 % Adjusted Intake Level lbs % BW Mcal/lb % DM % DM % DM % DM % DM NRC, 2007

44 Adjusted NRC Requirements Mature doe, 70 kg, late pregnancy twin kids DMI ME NDF CP Ca P Total 4.12 lbs 4.48 Mcal 560 g 233 g 6.6 g 4.0 g Density 2.7 % BW 1.08 Mcal/lb 30.0% 11.0 % 0.31 % 0.19 % Adjusted Intake Level lbs % BW Mcal/lb %DM % DM % DM % DM NRC, 2007 (corrected Table 15-4)

45 Pregnancy Toxemia Prevention Monitor and manage body condition score, minimize over conditioned animals Ensure adequate intake by addressing: o Social hierarchy, pen moves o Feed bunk space o Feed availability Ensure sufficient glucose precursors in diet (1-3 lbs cereal grains; >20% starch) hand feeding better than TMR Adjust dietary protein for observed intake rate (may need to increase to 13-15%)

46 Feed Delivery and Refusals

47 Goat Sorting Behaviors How to feed an appropriate diet to meet requirements of high production?

48 Use of the Penn State Particle Separator

49 Particle Size Challenges with the TMR Mixer

50 TMR Particle Separation Mixed aged doe group in extended lactation (>300 days) Screen As Delivered 3 hrs Post Feeding 7 hrs Post Feeding Orts Aug 10 No chopping of hay forages in the mixer wagon Top nd rd Pan Aug 11 Alfalfa/grass hay mixed for 6 minutes before alfalfa hay and water added Top nd rd Pan

51 TMR Particle Separation Mixed aged doe group in extended lactation (>300 days) Screen As Delivered 3 hrs Post Feeding Orts Top nd rd Pan Younger doe group in early lactation Screen As Delivered 3 hrs Post Feeding Orts Top nd rd Pan

52 TMR Nutrient Analysis (%DM) by Sieve Parameter Particle CP NDICP ADF andf Lignin Ca P NFC NSC As delivered Calculated hrs Post Calculated Orts Calculated % Consumed

53 Key Points Although not all sheep and goat farms feed a TMR ration it would seem that use of the PSPS can be a useful tool in evaluating The challenge is defining the appropriate distribution of particles to ensure animal health and milk components Optimal particle distribution may not be the same for dairy goats and sheep or for meat goats or sheep Much more information and research are needed to better develop appropriate feeding practices

54 Thank You! Any Questions?