Feeding Weather Damaged Forage to Beef Cattle Juanita Kopp, Ph.D., P.Ag. Manitoba Agriculture, Food & Rural Initiatives Farm Production Extension Specialist – Beef Livestock Knowledge Centre P.O. Box 180, 8 Fraser St., Pilot Mound, MB Cell:

What is weather damaged forage? Weathered due to:  Excessive sun exposure  Over drying  Precipitation Rain leaches the most soluble nutrients  Loss is greatest with the higher quality forages  Leaching loss can be as high as 15% of the total DM  Moulds & other microbes greater growth during wet weather, these organisms utilize the most nutritious portions

Weathered Forage Forage in a windrow harvested too late or rained on  Lower energy  Lower protein Heat damaged  Moulds Mycotoxins Forage species, growing conditions & stage of maturity affect nutritive value

Once cut--rain, rain--Go Away Each rain event can have an affect on quality The closer to fresh forage the less damage  Within a few hours very little damage is done As the length of time increases from cutting to when it rains, losses increase

Utah research found  Alfalfa receiving 1” of rain 3 hours after cutting lost ~ 2% of CP yield & 3.7% DM yield compared to alfalfa with no rain  If the rain fell 12 hours after cutting, CP yield was reduced 3.5% & DM yield was reduced 5% As the amount of rainfall increases, losses increase  Alfalfa that received 0.2” of rain yielded about 5% less dry matter & 4% less CP/acre than hay that received no rain  When the amount of rainfall increased to 0.8 inches, DM yield & CP were reduced by 10%

As a general rule, the loss in quality & yield due to a 1” rain event will exceed the losses in quality caused by allowing alfalfa to mature an additional week This is not true for grasses since the decline in quality due to maturity is much more rapid than it is for alfalfa

Rainfall effect on energy content of hay DescriptionRainfall % Decrease in Energy Content Alfalfa Hay0.50 inches (Sept 30 – Oct 20) 0.70 Timothy Mixture0.98 inches (Aug 15 – Aug 31) 3.9 Alfalfa-Timothy*1.5 inches (July 15 – Aug 12) 17.9 Timothy1.3 inches (Aug 15 – Sept 14) 5.6 Brome-Timothy-Alfalfa1.5 inches (July 16 – Aug 13) 14.0 Mean8.4 * Raked before baling, U of A 1980 –raking losses of 5 to 10% of total DM for one event

Loss of nutritive value with advancing maturity Decreased proportion of leaves & the corresponding decrease in protein  Legumes – 70% of protein in the leaves Increased proportion of stem & the corresponding increase in fibre Increased lignification of the stem & the corresponding decrease in energy value

Feeding value of forages as influenced by stage of growth at harvest TDN %CP % Grass CP % Legume Intake % Body Weight Vegetative Boot or Bud Bloom Mature Fisher, L.J. 1980

Heat damaged protein Brownish colour –useful protein content 80% of original value Dark brown or black –less than 50% of protein may be digestible  ADIN

Maturity effects on forage quality of alfalfa & quackgrass Growth StageDDM %CP%ADF %NDF %DMI % Body Wt RFV Alfalfa Mid-bud % bloom % bloom Quackgrass Pre-head Heading Anthesis NDSU 1993

RFV Beef Cow Replacement Heifers Backgrounders Lactating Cows

Crested Wheat Grass quality during the grazing season

Theoretical amounts of DMI required to meet the energy (TDN) requirements of a 1200 lb lactating beef cow (20 lb milk/d) when grazing Crested Wheat Grass with different protein and energy concentrations

Forage Intake Guidelines as a percent of body weight Straw & Poor Forage Medium Quality Forage Excellent Quality Forage Dry Mature Cows & Bulls 1.25 to 1.5 %1.8 to 2.0 %2.3 to 2.6 % Suckled Cows1.6 to 1.8 %2.0 to 2.4 %2.5 to 3.0 % Growing & Finishing Cattle 1.0 %1.8 to 2.0 %2.5 to 3.0 %

Feed Test!!!!

Beef Nutrition

Cattle Need: Water Energy Protein Minerals Vitamins

Cattle Nutrition Nutrient requirements of cattle change throughout the year based on the stage of the production cycle  Age  Sex  Breed  Level of activity  Pest load  Environment All these factors have an additive effect on the nutrient requirements

Nutritional Priority: Where the Feed Nutrients Go Alive & moving Including weight gain Milk for calf Requirements increase Heat cycles & conception Fat deposition

Protein  Third most important dietary component  “Building Blocks” of the body  Degradable intake protein (DIP) requirements need to be met for microbial growth first Then & only then consider bypass protein or undegradable intake protein (UIP) Manage for heat damaged protein if hay/feed baled too wet ADIN!!!

Energy Requirements (TDN %) for Beef Cattle

Crude Protein (%) Requirements for Beef Cattle

Needed when feeding:  Slightly over-heated hay Denatures protein, molds use sugars – Browning of forage » Carmalized sugars, tobacco smell  Rained damaged hay  Poor quality hay, straw Energy & Protein Supplementation

Energy Supplements Feed Name Dry Matter % TDN %CP %Ca %P % Barley Screening Pellets Canola Screening Pellets Grain Screening Pellets Barley Grain Oats Grain Corn Grain

Roughage TypeRecommended Grain Intake, lb/d Dry Beef CowsStraw4 to 8 Suckled Beef CowsStraw6 to 12 Good Hay0 to 8 BullsStraw6 to 10 Good Hay3 to 7 Grain supplementation Cowbytes Ration Guidelines

Protein Supplements Feed NameDry Matter%TDN %CP %Ca %P % Canola meal Soybean meal Wheat DDGS Corn distillers dry grain Beef supplement

Moulds

Mould Estimated to reduce feed value by at least 10% Vitamins destroyed  Vitamins A, D, E, K & thiamine Mould requires oxygen, heat, moisture & nutrients to grow  Moulds grow rapidly at 75 to 90 ◦ F  Above 15% moisture

Mouldy Feeds Very dusty  Mold organisms & spores Inhaled dust – fungal pneumonia – Some spores may pass through lesions in rumen wall & carried to blood stream – Settle in the uterus » uterine infections & mycotic abortions

Mouldy Feeds Estrogenic metabolites  may affect lactation & cycling Do not give mouldy feeds to pregnant or lactating cows Dilute moldy feed with good quality feed  reduce potential for problems when feed non- pregnant, dry, older animals Supply adequate levels of Vitamin A

FEED TEST!!! Supplement for deficiencies in energy & protein Balance rations  Feed vitamins & minerals  Check for mineral interactions Ca:P, K/Mg+Ca, S To utilize weathered forages

Questions???