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Measuring Cow Efficiency in the HerdRyon S. WalkerLivestock ConsultantNoble Research Institute

Does Cow Size Matter? If you don’t tag at birth, you don’t know whobelongs to who, and you don’t weigh yourcows or calves, THEN NO!– How can you make change if you don’t know whatto change! If you do all the above, THEN YES!

Guess the WeightCow 097 body weight – 1510 lbs Closest guess – 1497 lbs Range – 800 to 2050 lbs 62% missed it by 200 lbs or more 89% guessed too low 11% guessed too high

Guess the WeightCow 4016 body weight – 1225 lbs Closest guess – 1225 lbs Range – 812 to 1700 lbs 34% missed it by 200 lbs or more 75% guessed too low 25% guessed too high

Can’t Manage What You Don’tMeasure!!!

NASS, Federally Inspected Slaughter Report

U. S. Meat Animal Research Center(MARC) evaluation of current breedgeneticsBreedMature Cow SizeSimmental1,353 poundsHereford1,348 poundsAngus1,342 poundsCharolais1,339 poundsLimousin1,330 poundsGelbvieh1,282 poundsAll cows are four-year olds at a body condition score of 5.Adapted from American Gelbvieh Association

What Happened the Last 30 Years! Feedlots were putting pressure on faster gainingheavier calves going in and out of the feedlots more lbs of “Closely Trimmed Retail Cuts”! Introduction of more continental bloodlines High correlation betweengrowth and mature size,and carcass weights andmature size (.80 and .76;Bullock et al., 1993)

Dickinson Research ExtensionCenter (NDSU) Mature cows (ages 5-9)Avg. Cow Wt - lbs Avg. Weaning Wt - lbs% of Mature Body WeightWeaned1,272 lbs602 lbs47 %1,571 lbs603 lbs42 %Kris Ringwall, Beef Talk, Dickenson Extension Research Center, Dickenson, ND, NDSU

NW MN Beef Improvement Program(12 Beef Herds [914 hd] Avg Mature Wt. 1386 lbs)160014001200Ages 4 ½ and upLight Cows 1050-1385Heavy Cows 1388-191814901297100080060059657940020017 lbs. difference0(Walker et al., 2011)

NW MN Beef Improvement Program13191488169 lbs62364017 lbs14141694280 lbs59862325 lbs12571410153 lbs57459925 lbs12681482214 lbs12601398138 lbs6206233 lbs54458541 lbs12611431516516170 lbs0 lb12941447153 lbs12381380142 lbs56359532 lbs639633-6 lb12691476207 lbs58661226 lbs12501431181 lbs13691533164 lbs49851618 lbs6236274 lbs13531519166 lbs52654721 lbs

Hill Farm Research Station, LSU Mature cows (ages 5-9)Avg. Cow Wt - lbs Avg. Weaning Wt - lbs% of Mature Body WeightWeaned1,185 lbs488 lbs41 %1,343 lbs515 lbs38 %Cow weight difference - 158 lbsCalf weight difference - 27 lbs

Dean Lee Research Station, LSU Mature cows (ages 5-9)Avg. Cow Wt - lbs Avg. Weaning Wt - lbs% of Mature Body WeightWeaned1,177 lbs581 lbs49 %1,342 lbs585 lbs44 %Cow weight difference - 165 lbsCalf weight difference - 4 lbs

Distribution of Cow Weight within HerdsHerd 12Herd 11Herd 10Herd 9Herd 8Herd 7Herd 6Herd 5Herd 4Herd 3Herd 2Herd 175095011501350155017501950

Dry Matter Intake Requirements for Maintenance3525CalvingDry Matter Intake, lbs302015101000 lbs51200 lbs1400 lbs0JanFebMarAprMayJunJulAug SeptOctNovDecProducing 20 Peak Milk Production - NRC, 1996

Daily Intake Based on Cow SizePOST-WEANINGLight Group - cow 1221 lbsHeavy Group - cow 1385 lbsDMI4035302520151024.92.4 lbs27.3For every 100 lb increase in BW,1.5 lb increase in DM intake.50LightHeavy

Daily Intake Based on Cow SizeLACTATIONLight Group - cow 1200 lbsHeavy Group - cow 1369 lbsDMI403530351.8 lbs36.8252015For every 100 lb increase in BW,1.1 lb increase in DM intake.1050LightHeavy

Average Daily Temp & Average Daily DryMatter Intake for low and high RFILow RFI (1286 lbs) –9031.97 avg. daily DMIHigh RFI (1288 lbs) – 39.42 avg. daily DMI8070Mean TempLow RFIAvg. RFIHigh y10-Jun

Heifer DMI Based on Dam BW 2001000BW, lbsDamHeifer13781212403530DMI, lbs(P 16.9LightHeavyPositive correlation between dam BW and subsequent heifer: Heifer BW (r 0.54) BW gain (r 0.31) DMI (r 0.42) Frame Score (r 0.58)

Does Cow Efficiency Matter?

U.S. Cow Herd Forage DM RequirementsForage DM Requirement250200Tons DM(1,000,000)1501005019751980198519901995Forage DM20002005

Cow Inventory Decline in the U.S.Number of Producing Beef 0198519901995Cow Inventory20002005

Forage Dry Matter Required to Supportthe Beef Cow HerdCow Inventory and Forage DM 010030.05025.0197519801985Forage DM199019952000Cow Inventory2005Tons DM(1,000,000)

Why is the forage requirement thesame for 13 million fewer cows?Because we have made the cowsbigger and asked them to do more!

Positive Feed Efficiency Correlations Dam BW and Offspring Heifer BW (Walker et al., 2015)and Offspring Heifer DMI (Walker et al., 2015) Heifer DMI on forage then on grain Heifer RFI on forage then on grain0.540.42(Cassady et al., 2016)(Cassady et al., 2016) Repeatability of RFI as a Heifer and later a Cow0.580.400.51 62.2% remained in same classification 37.8% changed classification (Morgan et al., 2010) Pre- vs Post-pubertal RFI remaining the same(Loyd et al., 2011) Repeatability of RFI as Heifer and later as 3 yr old Cow (Black et al., 2013)0.480.13

So What Do We Want? Bigger calves – means bigger cows Smaller cows – means smaller calves but morecows IDEAL – smaller cows with bigger calves

What do we Want in a Cow? Forage Efficiency50 Pounds of Product20 High Fertility20 Moderate Size10X X X

Feed EfficiencyHill Farm Research Station Cow Production and Feed Efficiency Data!Dam Light BW GroupDam Heavy BW GroupTraitLight Calf WWHeavy Calf WWLight Calf WWHeavy Calf WWCalf Adj. WW485540507560Dam DMI34.535.636.237.8Dam BW1204119513451391

Feed EfficiencyHill Farm Research Station Cow Production and Feed Efficiency Data!Dam Light BW GroupDam Heavy BW GroupTraitLight Calf WWHeavy Calf WWLight Calf WWHeavy Calf WWCalf Adj. WW485540507560Dam DMI34.535.636.237.8Dam BW1204119513451391Small Cow – Heavy Calf versus Big Cow – Light Calf Small cows weigh 150 lbs less 8.76 Small cows eat 0.6 lbs DM/day less Small cows wean 33 lbs more 52.80

Feed EfficiencyHill Farm Research Station Cow Production and Feed Efficiency Data!Dam Light BW GroupDam Heavy BW GroupTraitLight Calf WWHeavy Calf WWLight Calf WWHeavy Calf WWCalf Adj. WW485540507560Dam DMI34.535.636.237.8Dam BW1204119513451391Small Cow – Heavy Calf versus Big Cow – Heavy Calf Small cows weigh 200 lbs less 32.10 Small cows eat 2.2 lbs DM/day less Small cows wean 20 lbs less - 32.00

What’s Our Goal?To Produce: Little Cows with Little Calves Little Cows with Big Calves Big Cows with Little Calves Big Cows with Big Calves

What do we Need to Measure? Who Belongs to Who30 Cow Size25 Calf Weaning Weight20 Body Condition Score15 Pregnancy Rates10 Economics5

Minnesota -Cow BCS and calf weaning weight27 lb diff in weaning wt.267 lb diff in true cow wt.Minnesota Beef Herds

Hill Farm -Cow BCS and calf weaning weight1400Avg AdjCow Wt120010 lb diff in weaning wt.1000Avg TrueCow Wt92 lb diff in true cow wt.Avg WWWt80060040020004.6 BCS5.2 BCSMinnesota Beef Herds6.1 BCS

Adjusting for BCSHow do I estimate the weight of a1300 pound cow at a BCS 5 if sheis a BCS 6?1300 (SBW, percent of CS 5for the CS in question)So,1300 1.08 1203 pounds

Selection based on an Economic Ranking SystemBreakevenavg. adjusted mature cow wt. & avg. adjusted 205 day calf weaning wt.Economic Value RankingIndividual cow cost difference individual calf cost differenceCow Cost Differences(avg. herd adjusted cow BW – individual adjusted cow BW) x diff DMI/lb x /lb hay x 210 days feedingCalf Cost Differences(individual adjusted 205 d calf wt. – avg. herd adjusted 205 d calf weight) * /lb

Road Blocks Factors affecting production efficiency:–––––BreedGeneticsDam ageForage QualityWeather Not all producers have a set of scales. Not all producers:– Tag calves and pair up– Collect birth dates– Collect birth weights

What We Learned! Our cows have gotten bigger. Approximately 30% of herds do not wean bigger calvesfrom bigger cows. Differences in DMI exist based on cow size. Moderate correlation with dam BW and multipleoffspring growth traits, such as DMI. We are not good guessers at cow body weight.

QUESTIONS?

Positive Feed Efficiency Correlations Dam BW and Offspring Heifer BW (Walker et al., 2015) 0.54 and Offspring Heifer DMI (Walker et al., 2015) 0.42 Heifer DMI on forage then on grain (Cassady et al., 2016) 0.58 Heifer RFI on forage then on grain (Cassady et al., 2016) 0.40 Repeatability of RFI as a Heifer and later a Cow 0.51 62.2% remained in same classification