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Replacement Heifer Management: A coordinated management concept Richard F. Randle, DVM, MS Beef Extension Veterinarian University of Nebraska-Lincoln.

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Presentation on theme: "Replacement Heifer Management: A coordinated management concept Richard F. Randle, DVM, MS Beef Extension Veterinarian University of Nebraska-Lincoln."— Presentation transcript:

1 Replacement Heifer Management: A coordinated management concept Richard F. Randle, DVM, MS Beef Extension Veterinarian University of Nebraska-Lincoln

2 Adapted from (A)Willham, 1973; (B)Melton, 1995 Economic and Genetic Importance of Various Traits

3 From Dearborn et al., 1973; Laster et al., 1979 Heritability of Reproductive Traits

4 Adapted from Bellows and Short, 1990; Wiltbank, 1990 Reproductive Losses (%)

5 Adapted from Bellows and Short, 1990; Wiltbank, 1990 Bred Replacements

6 Replacement Heifers Calve by 24 months of age with minimum problems Give birth to and raise a vigorous, healthy calf Successfully re-breed

7 Importance of Replacement Heifers Dictates future performance of herd – Where will the herd be in 5 years? Substantial investment before any return – 30 months minimum before sale of 1 st calf Highest potential for reproductive problems – Dystocia, calf survival, rebreeding

8 Courtesy of Dr. Jeff Ondrak GPVEC Dr. Jeff Ondrak - GPVEC

9 Breeding: Conception Rebreeding Postpartum period; lactation Weaning PubertyGestation Parturition

10 Process…. Selection Development Procedures Monitor

11 Heifer Selection Replacement rate - 10% to 20% Select 10% to 20% more Age, Size Conformation Dam performance

12 Heifer Selection Scenarios Retain all heifers and breed Retain all heifers born in 1 st half of calving – Remove top and bottom 10% by size or weight Retain all heifers born in 1 st 30 days – Remove top and bottom 10% by size or weight Calf performance data Dam performance data

13 Heifer Development Grow Attain puberty Determine breeding strategy Bull selection

14 Puberty Function of… – Age 10 to 12 months Breed influence – Weight 55% to 65% of mature weight

15 from Byerley et al., 1987 Pregnancy Rates of Heifers Bred at Pubertal or Third Estrus Pregnancy Rates of Heifers Bred at Pubertal or Third Estrus % Pregnant Pubertal57 Third78 % Pregnant Pubertal57 Third78

16 Adapted from Fox et al., 1988 Heifers Optimum Growth Rate for Breeding Herd Replacement Heifers

17 Target Weight Determine breeding date based on when you want them to calve Determine the target weight for breeding Determine the number of days from weaning to breeding Determine ADG

18 Target Weight Breeding Weight - Weaning Weight Breeding Date - Weaning Date = ADG

19 Breeding Strategy In order for heifer to calve by 24 months of age she must conceive by 15 months of age

20 Breeding Strategy In order for a cow to calve every 365 days she must conceive by 80 days post calving – Uterine involution – Return to cycling Cows average 40 to 60 days Heifers average 60 to 80 days

21 Breeding Strategy Breed heifers to calve 2 to 3 weeks before the cow herd Calve the second time in line with the cow herd

22 Breeding Strategy Natural Service Synchronization Artificial Insemination

23 Procedures Health Pre-breeding Pregnancy Examination Pre-calving

24 Health and Vaccination Program Advice and guidance of veterinarian – Proper product use – Timing Starts at or before weaning – Prebreeding, Pregnancy Exam, Pre-calving Focus on diseases that cause reproductive losses and reduced reproductive performance – IBR, BVD, Lepto, Brucella, Campylobacter, Trichomoniasis, Neonatal diarrhea, Parasites….

25 Pre-breeding Evaluation Evaluate weaning to pre-breeding development Average age of the group should be 12.5 to 13.5 months ( days) Performed 30 to 60 days prior to scheduled breeding program

26 Pre-breeding Examination Weight and body condition – 80 % at 55% of mature body weight Pelvic measurement – 150 cm 2 or greater Reproductive tract score – 50% or greater cycling (RTS 4, 5) Conformation and structural soundness Health

27 65%55%

28 From Anderson et al., 1991 Reproductive Tract Scores

29 Identify abnormally small or shaped pelvis

30 Adapted from Fox et al., 1988 Neonatal Exposure to Progesterone & Estradiol on Reproductive Tract in Beef Heifers a Data were collected from cyclic adult beef heifers on Day 12 of induced estrous cycle. Group means (n = 5) and SEM are presented. b Treated heifers received a single Synovex-C implant sc on designated day of life. Controls were untreated. c Wet weight. d,e,f (P<0.01), g,,h (P<0.02), i,j (P<0.09): Means within a row with different superscripts differ.

31 Pre-breeding Individual and Summary Data Used to evaluate success, identify potential problems and institute management changes Pre-breeding analysis – % cycling, nutritional status, structural soundness Review breeding management

32 Pregnancy Examination Perform prior to 120 days gestation – determine fetal age Weight and body condition Distinguish AI pregnancies from natural service pregnancies – withhold clean-up bulls 2 weeks Health

33 Pregnancy Individual and Summary Data Used to evaluate success and identify management changes for improvement Pregnancy rates, pregnancy histograms, synchronization response, AI conception rates, synchronized pregnancy rates

34 Pre-calving Examination Perform 30 to 45 days before calving Weight and body condition – 85% of mature weight – BCS of 6 Health

35 Adapted from Patterson and Bullock, 1995 Reproductive Summary

36 Reproductive Performance by Reproductive Tract Score RTSExposedPregnantOpenPreg Rate TOTALS Randle RF, Patterson DJ, 2005

37 Reproductive Performance by Reproductive Tract Score 1 st 21 Days2 nd 21 Days3 rd + 21 Days RTSExposedHd% % % TOTAL Randle RF, Patterson DJ, 2005

38 Comparison of pre-breeding weights by RTS in yearling replacement heifers RTS 1RTS 2RTS 3RTS 4RTS 5 n Mean, (kg) Median, (kg) Mode, (kg) Range, (kg) Min, (kg) Max, (kg) RTS – reproductive tract score. Heifers evaluated were 350 to 410 d of age and of Angus or predominantly Angus breeding.

39 NAHMS Survey, 1994 Use of Reproductive Management Technology in Beef Heifers CHAPA – 799 operations – 18 top beef states – 70% of U.S. beef cow/calf operations Alabama, Arkansas, California, Colorado, Florida, Georgia, Iowa, Kansas, Kentucky, Mississippi, Missouri, Nebraska, New Mexico, Oklahoma, Tennessee, Texas, Virginia, Wyoming

40 NAHMS Survey, May 1994 Selected Management Practices Used on Replacement Beef Heifers


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