1 Performance Modifiers

2 The Problem After the realization that animals had a need for protein supplementation the livestock industry was still trying to find ways to increase efficiency and productivity.

3 The Solution Practical methods of utilizing synthetic or manufactured compounds to enhance growth and efficiency were developed. These Compounds: –Performance Modifiers

4 What is a Performance Modifier? Somatotropins –Proteins that affect the utilization of energy in the body –Produced in the pituitary gland, located at the base of the brain.

5 Performance Modifiers Examples –Injectables Bovine Somatotropin (BST) Porcine Somatotropin (PST) –Implants Growth hormones and steriods

6 Bovine Somatotropin (BST)

7 BST and the Cow Produced naturally in the pituitary gland, located at the base of the brain. Causes energy derived from feed to be used for milk production rather than for weight gain.

8 Without BST? Energy From Food GrowthMilk _____________________________________ With BST Energy from Feed GrowthMilk

9 Genetic Engineering & BST The advancement in technology has allowed for the manufacture of “recombinant bovine somatotropin” (rBST) The Food and Drug Administration approved rBST for use in November of 1993.

10 Administration of BST Recommendation: –Injections should begin 9 weeks after the cow has calved –Repeat injection every 14 days throughout lactation –Discontinue use 2 weeks before the end of lactation

11 What cows should have BST? The cow should be: –In good body condition –Gaining weight –Well managed –Fed a balanced ration with high quality forage

12 Which cows should NOT have BST? Cows with: –Poor health –Poorly balanced rations –Inadequate feed –High somatic cell count –Stress –Breeding problems

13 Benefits of BST? Increase milk production –5 to 15 pounds/day

14 Is it worth it? That is for the farmer to determine!

15 Porcine Somatotropin (PST)

16 What is PST?  A protein produced in the pituitary gland  Growth Regulator  Production of PST decreases as a pig matures

17 What are the benefits of PST?  Improves feed efficiency  Improves gain  Decreases fat deposition  Causing less back fat  Produces more muscle mass  Leading to a bigger loin eye area

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20 Making PST Successful  Diet must consist of more protein and amino acids to support the increased growth rate.

21 Genetic Engineering & PST PST is produced in the pituitary gland at the base of the brain. Synthetically producing PST –Scientists have isolated the gene from the pig and inserted it into E. coli –E. coli then produces PST synthetically –The PST is then isolated and injected into the pig

22 Beef Cattle & Growth Implants

23 Growth Implants Have been extensively used in beef production for over 30 years Can be used in cattle from 45 days old and up –Use of implants in NOT recommended for replacement heifers or breeding bull calves

24 Benefits of Growth Implants Suckling Calves –Improved weaning weights of 3-5% Feeder calves –Improved feed efficiency and gain of 5-15%

25 Implant Use Injected into the middle third of the back side of the ear Outside the cartilage ring at the base of the ear

26 Nutrition Is Key! Cattle must have adequate nutrition before the use of implants positively influences feed efficiency and gain

27 Problems with Growth Implants Carcass Composition –Heavy carcass weight with large frame, exotic cattle –Poor yield grades in heifers with certain types of implants –Poor quality grades if implanting schedules are not managed appropriately

28 The key to successful results from implants depend on… Good Management