Preventing Animal Disorders Preventing Animal Disorders on Pasture Patty Scharko, DVM, MPH Livestock Disease Diagnostic Center University of Kentucky

Animal Disorders on Pasture  Bloat  Acute Bovine Pulmonary Emphysema (fog fever)  Nitrate Toxicity  Cyanide/Prussic Acid Toxicity  Poisonous Plants  Mineral deficiency Grass Tetany Trace mineral- copper, selenium

Animal Disorders on Pasture not covered Blackleg Johne’s disease Pinkeye Footrot Salmonellosis Leptospirosis and more

Grass Tetany Dec AprJun Aug Oct Dec Feb NitrateNitrate Bloat AIP ABPE Fog fever AIP ABPE Fog fever NitrateNitrate CyanideCyanide Dec

Bloat

Bloat What is it? î gas accumulates in the rumen î animal unable to eructate (belch up gases) î can result in sudden death

Pasture bloat (legume) o Legumes favor frothy bloat; winter wheat o Frothy bloat í Stable protein foam in rumen traps gas from fermentation í Pressure on lungs

Causes of Bloat o Animal inheritance for susceptibility  High susceptible cattle have larger rumen volumes and slower passage rate í Bloating cattle consume 18 to 25% less alfalfa than non-bloaters

Causes of Bloat o Adaptation to pasture/ration í Rumen microflora need to adapt o Time of day í Dew does affect bloat í Cattle were 2-17 times at higher risk when fed between AM compared to 11 AM - noon

Causes of Bloat o Plant maturity í Soluble protein content in plant í Lush, young plants produce bloat í Alfalfa 19 inches

Treatment o Do NOT remove from pasture at first signs of bloat o Continuous grazing gives less bloat than removal and return

Effect of feeding on incidence of bloat on alfalfa Grazing System ContinuousGraze 6hrs/da -----Number of cases---- Week Week Total 541 J. Anim. Sci :

Treatment o Foam reducers- drench or tube í Bloat-Pac í Bloat treatment o Dish detergent: 1 oz in 1 L water o Vegetable oil- tube only o Beware of turpentine

Treatment o Last resort/ emergency m hole in rumen í left side í trochar, cannula, or knife í needs to be sutured by veterinarian í antibiotics

Effect of feeding treatment products on alfalfa pasture bloat Treatment Dose, mg/lbReduction Monensin0.3 a 71 Rumensin  Lasolacid* Bovatec  0.45 b a 16 Polaxalene 20 a,b 100 Bloat Guard  * Not approved in lactating dairy cattle a JAS :1400; b JAS :1246

Prevention o Bloat Guard í Pre-mix í Molasses-mineral block o Ionophores 4 Rumensin- approved in stocker, feeder, beef & dairy cows, dairy & beef replacement heifers & calves; goats 8 Bovatec o Must be consumed on the same day that bloating may occur

Prevention 1. Do NOT remove at first signs of bloat 2. Provide grass-legume mixture for pasture 3. Do NOT turn hungry cattle on lush immature alfalfa or clover

Acute Bovine Pulmonary Emphysema o Aka: Fog Fever or Atypical Interstitial Pneumonia o Nutritional disorder, resulting in sudden onset of acute respiratory distress o Caused by formation and metabolism of 3-methylindole (3MI)

“Fog Fever”/ABPE o “Fog fever” occurs often when moving from grazed down area to lush succulent growth p The better quality the pasture moved to, the greater occurrence of ABPE o Death may be sudden, average 30%

Signs: Open-mouth breathing Frothing at mouth Labored breathing with expiratory grunt “Fog Fever”/ ABPE

Atypical Interstitial Pneumonia LDDC Necropsy Case Diagnosis

ABPE Prevention with Rumensin (monensin) or Bovatec (lasalocid) * a ClinicalLung GroupTrt./DoseSignsLesionsDeads 1 M 100 mg 0/40/40/4 2x 2 M 200 mg 0/40/40/4 1x 3 L 100 mg 2/44/41/4 2x 4Control4/44/41/4 * Boavatec is not approved in lactating dairy cattle a Vet Record 107:322

Effect of Bovatec (lasalocid*) on ABPE Prevention DoseClinical Groupmg/hd/daSignsDeads 105/53/ /50/ /50/ /50/5 * Not approved in lactating dairy cattle a J. Anim. Sci. 60:232

Nitrate Toxicity o SIGNS: Depression, staggering, incoordination Excess salivation Brownish discoloration of mucous membranes o Drought o N fertilization o Grazing &/or hay o Sorghum, Sudan, Johnson grass o Stable in hay

Nitrate Toxicity LDDC Necropsy Cases

Nitrate Toxicity o Nitrite is the toxic entity; 10x more toxic than nitrates o Nitrite combines with hemoglobin to form methemoglobin; prevents oxygen transport o Chocolate brown blood o Death from asphyxiation

Nitrate Toxicity (2) ã Young cattle are more susceptible ã Hungry cattle more susceptible ã Cattle can adjust to higher levels given enough time

Nitrate Toxicity (3) ã Nitrite crosses into fetus; can lead to abortion Prevention 4 Ensiling reduces 40 to 60% 4 Dilution 4 Increase tolerance

Cyanide (Prussic Acid) Toxicity ã SIGNS: Severe respiratory difficulty, sudden death ã Sudan, sorghum-sudan, sorghum (Johnson grass), wild cherry tree ã Frost/stress ã Do NOT graze frosted plants! Wait days after non-killing frost Wait 48 hours after killing frost

Cyanide (Prussic Acid) Toxicity ã Ingest cyanogenic glycosides that yield hydrocyanic (prussic) acid in rumen ã Hydrocyanic acid stops cellular respiration; death from respiratory paralysis ã Bright red blood

Toxic Plants 4 Japanese Yew (Taxus) 4 Oak/Acorns 4 Buckeye 4 Osage orange (hedgeapple)

Mineral Deficiency 4 Magnesium 4 Selenium 4 Copper

Grass Tetany ã Hypomagnesemia, magnesium deficiency, grass staggers, winter tetany ã Affects only ruminants  Primarily in lactating beef cows in spring  Within 60 days of calving  Pastured on cool season grasses  Spring grasses are high in potassium  Heavily fertilized (nitrogen &/or potash)

Magnesium Deficiency

Grass Tetany ã Cows need 20 grams of Mg daily or 4 oz/day of 15% Mg mineral mix ã Consumption important, individual cows may not consume adequate free choice minerals ã For spring calving, start Dec/Jan and continue until daytime temperatures above 60 o F ã PREVENT!!

Copper Deficiency

Selenium Deficiency “white muscle disease”