Baby beef - exam 2

Heterosis by trait

Bull Selection

• Bull selection is one of the most important genetic decisions made for purebred and commercial producers

  • Even more important when replacement females are in the picture

• One bull can make or break a herd

• Bulls culled bc they’re sterile, disease, bad temperament

• Good commercial bull can cost up to what calves are worth

  • 4-5 steer calves

  • $6,000-8,000

Where do I buy a bull???

• Avoid buying bulls with an unknown background

  • The neighbors “good crossbred bull calf”

  • Got data???

  • Cull bulls

    • Wonder why they were culled??

Where you should buy a bull

A breeder that specializes in producing quality genetics for commercial producers

• Reputation

• Data, data, data!!!!

• Fertile

• Healthy (Trich)

Ex. Value of bulls

What do we base our selection criteria on????

• Visual Appraisal

• Individual records

• EPDs

• Ultrasound data

• Genomics Data: allows for more accuracy of traits for progeny

Objective Measurements

• Individual and Progeny Records

  • Birth Weight

  • Weaning Weight

  • Average Daily Gain

  • Feed Efficiency

  • Yearling Weights

  • Quality and Yield Grades

• Expected Progeny Difference (EPD

Expected Progeny Differences (EPDs)

• The difference in predicted performance of future progeny of a sire, when compared with that predicted from future progeny of bulls in the same sire summary

  • or the breed average

• An estimated measure of the genetic impact of a particular parent on his/her offspring

Expected Progeny Difference (EPD)

• EPD is the most effective genetic selection tool

• Adjusts data for environmental effects and accounts for genetic relationships between traits and among animals

• Most breeds have EPD for BW, WW, YW, Maternal WW plus many other

Expected Progeny Differences (EPD) example

• An estimated measure of the genetic impact of a particular parent on his/her offspring

• If both bulls were mated to similar cows, Bull B’ calves would be predicted to be 5 lbs lighter at birth than Bull A.

Example

• both bulls mated to similar cows

• calves from bull B would be expected to average 20 lbs heavier at weaning

Accuracy (ACC)

• indicates reliability of EPD – possible change as future data is added

ACC EX

Genomic Enhanced EPDs

• Genomic EPDs use SNPs to accurately describe genetic relationships which improve the accuracy of the EPD by essentially one calf crop on young (unproven) sires.

  • Most major breed associations participate.

Calving ease related to percent assisted

In what units are EPDs reported?

• Pounds

  • BW, WW, YW, CW

  • milk, TM (lbs of calf weight not milk)

• percentage

  • CED, CEM

  • stayability

  • docility

  • heifer pregnancy

• inches

  • YH

  • fat thickness

  • REA (square inches)

• centimeters

  • SC

• USDA marbling degrees

  • Marb

Example

Growth EPD Traits

Reported by all breeds using EPD are:

• Birth weight - excluding maternal influence

• Weaning weight - excluding maternal influence

• Yearling weight - excluding maternal influence

Reproduction EPD Traits

• Direct calving ease - calf’s ease of birth

• Maternal calving ease - dam’s birthing ease

• Gestation length

• Heifer pregnancy percent

• Scrotal circumference - related to testicle mass, age at puberty (male and female)

• Stayability - longevity in the herd

Carcass EPD Traits

• Weight

• Marbling - main factor in Quality Grade

• Ribeye area –factor in Yield Grade

• Fat thickness – factor in Yield Grade

• Retail product % - predicted by Yield Grade

• Ultrasound - for ribeye, fat thickness, retail product, ribeye IM fat (estimates marbling

Cowherd EPD Traits

• Milk in pounds weaning weight

• Total Maternal (Maternal Weaning Weight) - combines weaning weight and milk

• Daughter Mature Weight and Height

• Docility

• Cow Maintenance Requirements

• Yearling Height - predicts mature size

$ Value Index EPDs

• Combine relevant biological EPDs, weighted for importance and assigned $ value of trait, to estimate $ value of production

• Adjusts for $ cost of necessary inputs (nutrition, etc.)

• Weightings of biological effects and assignment of costs can vary results of indexes

$ Index Caution

• Individuals with the same $ index value can differ tremendously for individual EPDs

• Next slide shows the range in individual EPDs for Angus sires with $ Beef at 50th percentile level in the breed ($112.52)

  • Spring, 2018, Non-parent

  • There were 6 sires

$ Beef Individual EPD Range

$ Beef Individual EPD Range

• Angus sires with $ Beef at 5 percentile level in the breed ($59.26) ± $0.25</span></p></li><li><p><span>There were 13 sires within this range$ Beef Individual EPD Range

Utility of $ Value EPDs

• In other breeds with $ Value Indexes, similar variation exists for individual EPDs

• Preceding does not mean $ Value Indexes are useless

• Probably best used as a screening tool with attention to individual EPDs

• $ Value Indexes should not be used for single-trait selection

Relevant EPDs

• Some EPDs should be of no importance in your operation

• The importance of an EPD depends on:

  • breeding system (terminal or continuous)

  • when and how you marke

Summary on EPDS

• Each producer should assess their production conditions and markets to decide what traits to select for and how much emphasis to give to each trait

• Traits that are important to one producer may be of no importance, or even counterproductive, to another producer

• So, concentrate on things that affect your profit, not somebody else’s

Subjective Evaluations

• Visual Appraisal

  • Structural Soundness

  • Composition of Gain

  • Muscling

  • Temperament

  • Balance

  • General Eye Appeal

  • Reproductive Soundness

Visual evaluation

Structural correctness

• Hoof size important

  • Issues, such as weak pasterns, can lead to pressure problems

  • Can be related to founder and acidosis

• Feet should not point straight forward, can affect angle of shoulder

Feet

Rear leg conformation

• Angle 90

• Too much angulation better than no angulation (less downward pressure)

• Defects can lead to problems down the road

Muscling

• Ribeye Area

• Visual Evaluation of Muscle Shape

• Ultrasound measurements

Areas to evaluate for muscling and shape

Muscling cons

• Larger Birth Weights

• Increased Incidence of Dystocia

• Decreased Marbling

  • Muscle inverse to marbling

• Smaller Pelvic Area

What breed is bred intentionally for double muscling

Belgian blue

Capacity

• Shape of rib

• Width and depth of the chest floor

Other things to look for

Maternal Performance

• Cow’s Milk Performance and Calving Characteristics

• Basic formula for EPD:   Measuring additional pounds of weaning weight from daughters due to genes for milk.

Temperament

• Ease of handling

• Tenderness???

  • Research is indicating a high relationship between disposition and tenderness

Ex. Unassisted births

• Longhorns discounted for color pattern & muscling

What to avoid

• AVOID single trait selection!!!!!

• Avoid buying bulls that you don’t know the background of!!!!!!!

Monogastric GIT

ruminants GIT and function

Mouth

• Has no upper incisors. Lower incisors and dental pad function in harvesting forages.

• Source of saliva secretion.

  • about 12 gallons per day in adult cattle

ESOPHAGUS

• Functions in movement of ingested food by a series of muscular contractions

• can move food either from the mouth to the stomach or from the stomach back to the mouth in the cud-chewing process

  • Regurgitation: cud nation → fermentation

The stomach is divided into 4 compartments:

• Reticulum

• Rumen

• Omasum

• Abomasum

RETICULUM

First part of the stomach. Not completely separated from the rumen, so the two are often referred to as the reticulo-rumen

• Hardware disease in reticulum

Rumen

• Carbohydrates in feed/forage are broken down by bacteria producing volatile fatty acids (VFA)

  • absorbed through the rumen wall and used as a source of energy.

• Bacteria combine nitrogen (from dietary protein or non-protein sources) and carbon (from a carbohydrate) to form protein. Bacteria are then digested and the bacterial protein is used by the animal.

Issues with rumen

• Can be seen in left side

  • Bloat, in grain based diets

• Issues can be seen going straight from forages to grain based diets

  • Melt, losing weight rapidly

Urea

• Non protein nitrogen

  • Not seen as much as it’s expensive

  • Used in combination with feedyard diets (molasses)

RUMINATION

• Allows for rapid harvest with minimal chewing, and then completion of chewing later through the cud process.

• Cattle average ruminating around 8 hours per day, depending on the diet.

• Microbial fermentation in the rumen produces large amounts of gas.

  • If gas is not released by belching, bloat can occur possibly resulting in deat

A key to ruminant nutrition

• Microbes supply nutrients to host Microbes have requirements

  • Nitrogen

  • Energy

• Cow has protein and energy requirements

  • Major proportion fulfilled by microbial protein and fermentation end products

Omasum

• Function appears to be reduction of particle size.

• Some water absorption also occurs

Abomasum

• First glandular portion of the ruminant gastro-intestinal tract.

  • Extremely acidic environment (pH 1.5-2.0) compared to the neutral (pH 6.8-7.2) rumen, reticulum, omasum.

• Functions essentially the same as the stomach in non-ruminants.

  • Muscular movements cause physical breakdown of food

  • “True stomach”

  • Some digestive juices are secreted

Small and large intestine

• Small intestine - food digestion continues, primary site of nutrient absorption.

• Large intestine - storage and transportation of undigested gastro-intestinal contents for elimination from the body

Nutrients Cattle Require

• Protein

  • Essential amino acids(not essential in diet)

• Energy

  • Carbohydrates

  • Lipids

    • Short or long chain

  • Excess protein

• Vitamins

  • A (Green plants), D(sun), E(green leafy forages and whole grains, K(not essential in diet), B(not essential in diet)

Nutrients cattle require part 2

• minerals

  • macro: Ca P Na Cl K Mg S

  • micro: Mn Zn Fe Cu Co Se Mn I

• Water

  • Enhanced by seasons and diet and quality

Division of nutrient requirements

• Energy: most important, 14-18 lbs per day

• Protein: 1.5-2.5 lbs per day

• Minerals: most expensive, best in advertising

Nutrient requirements are important for

• Maintenance

  • maintenance energy – the amount of energy it takes to maintain an animal

  • Influenced by temperature and activity

• Pregnancy

• Lactation

• Gain

Factors Affecting Nutrient Requirements

• weight

• breed

• physiological status

  • lactation

  • energy req. ↑ 50%

  • protein req. ↑ 100%

• fetal size

• milk production

• weather

• activity

• genetics

  • animal to animal variation

• age

ENERGY REQUIREMENTS 1000 LB COW, 11 LB PK MILK, 70 LB BW

Crude Protein Requirements of Mature Cows

TDN RequirementS of Mature Cows

Nutrient Requirements of Beef Cows

Forage digestibility

Feed values for various forages

The effect of forage quality' on predicted forage dry matter intake of ruminants.

Determining Nutrient Intake - fecal pad scoring

• 1 = High quality

  • CP > 12%

  • TDN > 65%

• 2= Medium quality

  • CP 10 – 12

  • TDN 50 – 65%

• 3 = Low quality

  • CP < 10

  • TDN < 50%

Supplementation

• To provide nutrients deficient in forages that limit forage intake and digestion

• Forages should be the main source of nutrition for cow-calf or stocker producers

  • Economical source of protein and energy

  • Limited during droughts and when you want to increase gain

A small amount of supplement stimulates forage intake and digestibility

• The supplement has an additive effect on the forage

• Will eventually have negative forage intake

Forage intake in relation to crude protein content in the forage

Supplemental feeding

• Animal intake is usually the limiting factor associated with nutrient deficiencies on dormant forages or poor quality hay

• When the protein content of a forage drops below 7 percent, dry matter intake will decline rapidly

  • Feeding a protein supplement will improve the protein and energy status of cattle by improving forage digestibility and intake

Adequate forage is …

• Adequate forage is necessary when supplementing protein

  • If not, the protein source becomes an expensive source of energy

• Re-group and explore other alternatives to meet the energy requirements of the animal

Supplementation strategies

• To add to the value of low-quality forage and increase diet quality

• Also could be to stretch out forage, limiting forage

  • Enhancement feeding

Enhancement Feeding

• Poor quality hay (<6% CP)

• Feeding medium quality hay to lactating cows in poor or borderline body condition

  • 20% protein breeders cube to lactating cows during the winter

• Increasing body condition of thin cows

• Forage is limited

Nutrient Requirements (Last 1/3 Gestation, .9 ADG, and Early Lactation, maintenance)

Example of feeding cows

• 1,100 lb dry cow needs

  • 1.6 lbs CP

  • 11.2 lbs TDN

• Our hay is 8% CP and 52% TDN. She will eat 22 lbs per day

• CP - 0.08 x 22 = 1.76 lbs

• TDN - 0.52 x 22 = 11.4 lbs

Value of forage quality

Feedstuffs That May Be Available - protein sources

• cottonseed meal, most common

• soybean meal, most common

• corn gluten meal, most common

• sunflower meal

• peanut meal

• 40% cubes

• alfalfa hay, most expensive

• winter pastures (cows)

Feedstuffs That May Be Available - energy sources

Gradually increase levels in diet

• corn

• 12% cubes

• soybean hulls

• wheat midds

• rice bran

• rice mill feed

Feedstuffs That May Be Available - Energy and Protein Sources

Gradually increase levels in diet

• 20% cubes

• corn gluten feed

• distillers grains

• whole cottonseed

  • (max. 25% of diet)

High Risks Feeds

• acidosis and founder concerns

  • bakery products

  • bread

  • flour

  • flour tortillas

  • many others

• any feed with rapidly fermentable CHO, wheat

• bloat concerns due to blocking of the esophagus

  • potatoes

  • sugar beets

What feed to use

• Good quality hay

• Byproducts (cheapest)

• Cottonseed meal

• Soybean meal

• Corn

• Personal supplement mix

• Cubes

• Liquid

• Protein block

  • most expensive because processing but most convenient