Overview of Beef Cattle Research at the University of Missouri

1. Overview of Beef Cattle Research at the University of Missouri Michael F. Smith Division of Animal Science University of Missouri

2. Beef Cow Inventory - USA

3. The U.S. Beef Herd 31.2 million beef cows on > 600,000 farms & ranches. 69% of cow-calf herds are secondary income sources. 50% of producers report an established breeding season. 34% of beef herds are routinely pregnancy checked. Only 10% of beef cattle herds utilize AI.

4. Importance of Early Calving Females

5. Importance of Beef Females Conceiving Early in the Breeding Season Steer Progeny Heifer Progeny Weaning weight Weaning weight Hot carcass weight Prebreeding weight Marbling score Precalving weight % Average choice or greater % Cycling before breeding Pregnancy rate Carcass Value Larson and Funston, 2009 Funston et. al., 2011

6. UF-NFREC Case Study Economic Impact of Decreasing Length of the Calving Season in a Beef Herd University of Florida Lamb et al., 2015 Change in calf value

7. Ovarian Structures Graffian follicle Corpus luteum

8. GnRH- PGF- GnRH in FTAI GnRH-2 FTAI GnRH-1 PGF Day -9 Day -2 Day 0 Synchronize initiation of a new follicular wave and luteal tissue formation Synchronize ovulation of dominant follicle Luteolysis

9. Ovulatory Follicle Size and Pregnancy (FTAI)

10. Ovulatory Follicle Size and Pregnancy (Estrus) 100 80 60 40 20 0 Pregnancy rate (%) 1st Pregnancy Check 2nd Pregnancy Check Follicle size (mm) 1012 14 16

11. GnRH- PGF- GnRH in FTAI GnRH-2 FTAI GnRH-1 PGF Day -9 Day -2 Day 0 Synchronize initiation of a new follicular wave and luteal tissue formation Synchronize ovulation of dominant follicle Luteolysis

12. Split time AI in Heifers

13. 14-d CIDR-PG (Heifers) AI CIDR PG GnRH … 66 hr … 0 14 30 33 Treatmentday 14-d CIDR-PG (Heifers) – Split-time AI

14. Estrotech Patches – Detection of Estrus Estrotech Patch Score 0 = Patch is missing 1 = < 25% activated 2 = ≤ 50% activated 3 = < 75% activated 4 = ≥ 75% activated

15. Split-Time AI Using Conventional Semen Among Heifers P = .2440 P = .0021 P = .1361 P = .0240 P = .0116 a-b Pregnancy rates within rows or columns with different superscripts are different, P < 0.05 x-y Pregnancy rates are different, P = 0.0116 Thomas et al 2014 J. Anim Sci 92:4189

16. Sex Sorted Semen in Cattle USA Statistics - APHIS 2009 14% of dairy heifers 3.5% of dairy cows

17. Split-Time AI to Optimize the Use of Sex-Sorted Semen Treatment x estrous expression interaction (P < 0.0001) • Pregnancy rates within a row with different superscripts are different (P < 0.0001) Thomas et al 2014 J. Anim Sci 92:1745

18. Split-Time AI to Optimize the Use of Sex-Sorted Semen • Among estrous cows, FTAI pregnancy rates to sex-sorted semen were lower than pregnancy rates to conventional semen

19. Split-Time AI to Optimize the Use of Sex-Sorted Semen • Among non-estrous cows inseminated at the standard time, FTAI pregnancy rates to sex-sorted semen were particularly low • Potentially due to insufficient sperm longevity given the 28 h interval from GnRH to ovulation • Delayed insemination of non-estrous females until 20 h after GnRH yielded a higher pregnancy rate (P < 0.0001) • May better match optimum sperm fertility with ovulation

20. Split-Time AI to Optimize the Use of Sex-Sorted Semen • Pregnancy rates for non-estrous cows receiving delayed insemination using sex-sorted are similar to rates achieved using conventional semen at 66 h (P = 0.9)

21. Early Embryonic Loss Maternal Recognition of Pregnancy Failure Late Embryonic Loss Fertilization Pregnancy d 27 Pregnancy d 42 Calving Pregnancy Rate to a Single Insemination: Beef Cattle ~ 25% Loss ~ 8% Loss

22. Pregnancy Establishment Increase in ISG on d 16-18 Spencer et al., 2007

23. Prenatal Programming • Dutch Hunger Winter

24. Prenatal Programming in Cattle • Maternal environment (e.g. nutrition) can program heifer and steer progeny growth. • Gestational nutrition can affect placental efficiency, fetal organ development, and progeny weaning weight (heifers and steers), age at puberty (heifers), and carcass quality (steers).

25. Effect of Maternal Protein Supplementation on Heifer Progeny Performance • Late gestation protein supplementation can increase heifer progeny weaning weight and decrease age at puberty of heifer progeny. Funston et al 2010

26. Effect of Maternal Protein Supplementation on Steer Progeny Performance • Late gestation protein supplementation can increase steer progeny weaning weight and carcass quality. Funston et al 2010

27. Improving Post-Weaning Beef Cattle Efficiency • Research to better understand impact of metabolic efficiency on beef calf growth performance. • Studying factors that impact beef production in Missouri • Tolerance to toxic tall fescue • Use of residual feed intake to study feed efficiency • Rapid diagnostic identification of respiratory disease

28. Fescue Toxicosis and its impact on Post-Weaning Performance in Beef Cattle • Evaluation of the effects of a Tall Fescue based stocker program on feedlot performance and carcass characteristics. • Steers were split evenly into treatment and control groups. For 54 days, treatment groups were fed a diet containing endophyte infected fescue seed to mimic the ergot alkaloid concentration of toxic tall fescue pasture, the control groups were fed an identical diet that contained no fescue seed. • After day 54, all steers were fed a common finishing diet.

29. Results • The study was conducted in the winter/early spring - heat stress was not an issue. There was little difference in animal performance between treatments for the first 54 days. • However, as the animals were transitioned to a common diet, the treatment group displayed lower performance, indicating that the ergot alkaloids have a residual effect on cattle in the feedlot. • Improvement in feedlot performance can be improved if animals are not exposed to toxic tall fescue, or if animals more tolerant to tall fescue are selected.

30. T-SNIP Test for Post-Weaning Performance • The T-SNIP Test is a genetic test that identifies animals that are more tolerant or susceptible to Fescue Toxicosis. • We are researching to verify its accuracy predicting intake/gain in stocker cattle that utilize toxic tall fescue as their primary forage.

31. Feed Efficiency Calculating Residual Feed Intake Benefits of Negative RFI Decrease feed intake by 10 to 20%. 25 to 30% reduction in methane production.. 15 to 17% reduction in manure. Progeny of low RFI animals are more efficient. • Residual Feed Intake – RFI • Can calculate the expected feed intake for an animal. • RFI is the difference between the actual feed intake and expected feed intake. • A negative RFI steer is more efficient than a positive RFI steer.

32. Measuring Residual Feed Intake

33. Bovine Respiratory Disease Complex (BRDC) diagnosis • Further research for improving sick calf identification speed and accuracy • Rapid diagnosis and treatment can improve calf health and the producer’s pocketbook • Observed daily feed intake with common visual signs of illness for combined approach

35. Background & Rationale • Accumulation of inbreeding leads to homozygosity of alleles that reduce fitness (reproduction and survival) • Homozygosity of alleles with deleterious effects on development or survival increases the overall probability of embryonic and early developmental lethals • Presumably calves that are homozygous for a loss of function (LOF) allele will abort, be born dead, die soon after birth, or will never be observed in live animals thus inferring that the allele is lethal

36. Specific Aims • Identify, validate and characterize the impact of recessive developmentally lethal alleles associated with reproductive failure in Angus cattle • Sequence ~100 Angus bulls to identify loss of function (LOF) alleles • Identify candidate embryonic lethal loci predicted to segregate within Angus • True embryonic lethals should never be observed in the homozygous state among healthy animals • Validate candidate LOF mutations by genotyping 10,000 registered and pedigreed commercial Angus females for which DNA and reproductive data will be provided • Identify candidate embryonic lethal loci predicted to segregate within Angus • Develop a male fertility EPD and enhanced heifer pregnancy rate EPD based on LOF genotype information

37. Progress to Date • Whole Genome Sequencing (bulls) • 109 Angus bulls have been sequenced • Genomes contributed from collaborators at Genome Canada, USDA/BARC and 18 breed associations • In total 267 bulls representing 18 breeds have been sequenced • DNA sampling and phenotypic data collection (heifers) • 10,251 heifers are sampled with complete reproductive data from 44 farms and ranches • Development of a deleterious recessive gene module for MateSel to handle variants discovered in the project. • “Use of Mate Selection Software to Manage Lethal Recessive Conditions in Livestock” • Initial stages of development of a web-based educational training program

38. Prenatal Programming – Key Points • During fetal development there are “critical periods of vulnerability to suboptimal conditions.” • Prenatal programming can have effects into adulthood. • Altered programming can cause structural changes in organs (e.g. number of cells, blood supply, etc). • The placenta has an important role in prenatal programming. • Effects of prenatal programming can differ between males and females. • Effects of prenatal programming can be carried from one generation to the next. • P. W. Nathanielz 1999 Life in the Womb

39. Mean inbreeding coefficients by birth year for 76,083 Angus animals forming a 64 generation pedigree including 3,570 genotyped animals. Effective population size (Ne = 116.15 ± 0.04) was estimated for animals born ≥1980.

40. Deregressed EBVs for Yearling Weight of 2,755 registered Angus bulls demonstrates that breeders have achieved an average increase of 4.96 lb per year (blue line) over a 50 year period.

41. Deregressed EBVs for Heifer Pregnancy Rate for 698 registered Angus bulls indicates that either as a correlated response to selection for production or due to accumulated inbreeding, Angus female fertility has decreased by 0.22% per year for about the last 25 years.

42. Identification of a Loss of Function Allele Reference G G A G A

43. Receiving Cattle Nutrition • Objective: To evaluate receiving cattle performance on diets formulated with balanced post-ruminal amino acids and gut modifiers • Diets: • Corn-based (>50%), balage/roughage, milled supplement (vitamins/minerals, amino acids, etc.) • Treatments: • 1: Balanced for post-ruminal amino acids • 2: Balanced AA + essential oil rumen modifier & sweetener product • Results • Initial data shows treatment 1 adding efficiency benefits, but no determined significance at this point

44. Nutrition and Calf Health • Objective: To analyze antibody synthesis responses in calves consuming diets formulated with balanced post-ruminal amino acids and gut modifiers • Why? • Thought process: calves more accurately supplied with fuel for the immune system will be able to mount a stronger immune response

45. Study Objective: Determine the effects of roughage removal, rumen modifier and diets balanced to meet predicted amino acid requirement on beef steer growth performance and carcass characteristics. Removing roughage from finishing diets eliminates the costs and tasks associated with producing/obtaining, handling and storage. Monensinhas been very successful in improving feed efficiency but its use has been banned in several countries within the European Union. If the United States follow this example, plant extracts might be a viable alternative. Balancing diets to meet predicted amino acid requirement instead of crude protein or metabolizable protein improves efficiency and makes it more precise

46. Animals and Management Period 2 Period 1 Receiving 105 Day 64 -26 0 162 Re-implant* Implant* Initial processing NRE – No roughage + Essential Oil + Balanced to meet predicted AA requirement NRM - No roughage + Monesin + Balanced to meet predicted AA requirement Receiving diet RE - Roughage + Essential Oil + Balanced to meet predicted AA requirement RM - Roughage + Monensin + Balanced to meet predicted AA requirement Control – Roughage + Monensin + not balanced *Implant - Component TE-IS with Tylan; Elanco Animal Health, Indianapolis, IL *Re-implant - Component TE-S with Tylan

47. Benefits when roughage is removed from feedlot diets. 11.4% improvement in feed efficiency Can monensin be substituted by a plant extract? No differences on: BW, ADG, DMI, G:F, HCW, Ribeye area, Marbling What are the benefits when feedlot diets are balanced to meet predicted amino acid requirement on growth performance and carcass characteristics? Increased: BW, ADG,DMI, G:F HCW