Cottonseed and Gossypol: Effects on Lactation, Reproduction and Health

1. Cottonseed and Gossypol: Effects on Lactation, Reproduction and Health J.E.P. Santos,1 E.J. DePeters,2 and P.H. Robinson2 1Veterinary Medicine Teaching and Research Center 2Department of Animal Science University of California - Davis

2. Cottonseed and Gossypol • Cottonseed is generally fed at 10 to 15% of the diet • Provides a unique blend of protein, fat and fiber for inclusion in diets of dairy cows • Cottonseed contains gossypol (0.5 to 1.2%), which is a toxin present throughout the cotton plant that helps to control pests • However, gossypol can be toxic to mammals and it disrupts reproduction in males

3. Gossypol • Mixture of two stereoisomers: (+) and (-) gossypol • The (-) isomer is thought to be more toxic and retained in the body longer • Gossypol can be found in the free or bound forms • Free gossypol is assumed to be available for absorption in the digestive tract

4. Gossypol • Fact: • Gossypol is extremely toxic to non-ruminant animals and to young ruminants at small quantities in the diet • Ability to tolerate gossypol coincides with development of rumen functions • Affects fertility in males • Dogma: • Any gossypol is bad for lactating dairy cows • The upper safe level of plasma gossypol is  5 g/ml

5. Gossypol • First discovered in China • Until 1980’s little attention was given to gossypol as a toxin in cattle diets: • Classic work by Holmberg and colleagues in 1988 at UC Davis characterizing the pathological effects of gossypol in calves fed cottonseed meal

6. Cottonseed & Gossypol • Substantial amount of published literature on the effects of cottonseed and gossypol on lactation performance of dairy cows: • Different types of cottonseed, different levels cottonseed in the diets, different concentrations of gossypol in the diet, different sources of gossypol in the diet, short-term and long-term studies, etc. • Very limited data available on the effects of cottonseed and gossypol on reproductive functions in female cattle: • Few studies with limited number of animals and some studies utilizing in vitro techniques to replicate reproductive processes in female bovine.

7. Cottonseed & Gossypol • One method to study the effects of gossypol on cattle is to use cottonseeds with different gossypol concentrations or compare cottonseed with cottonseed meal: • Whole Upland vs Pima cottonseed • Slightly different in nutrient composition (lack of lint), but extremely different in gossypol content • Cottonseed vs Cottonseed Meal • Differ in availability of gossypol

8. Mena et al. (1997)

9. Prieto et al. (2002)

10. Effect of Type of Cottonseed and Iron Sulfate on Plasma TG in Dairy Cows(McCaughey et al., 2002) Cottonseed: P < 0.01 Iron sulfate: P < 0.01

11. McCaugheyet al. (2002)

12. Plasma gossypol (PG) concentrations in lactating dairy cows fed varying amounts of gossypol from whole cottonseed and cottonseed meal. Solid triangle () = control (0 mg/kg); Open square () = 1040 mg/kg total gossypol (TG) from whole cottonseed (WCS); Open circle () = 900 mg/kg TG from cottonseed meal (CSM); Solid circle () = 960 mg/kg TG, half from WCS and half from CSM; Solid square () = 1922 mg/kg TG, half from WCS and half from CSM (Mena et al., 2001)

13. Mena et al. (2001)

14. Plasma gossypol = 0.219815 + 0.117034 FG r2 = 0.80 Relationship between free gossypol (FG) intake (g/d) and plasma gossypol (PG) concentration (g/ml) in lactating dairy cows after 42 days of feeding diets varying in gossypol content (Mena et al., 2001).

15. Filed Study in California • Study: • 813 lactating Holstein cows in 3 commercial dairies • 10 pens (5/treatment) • 406 cows/trt • Low vs high gossypol diet (750 vs 990 mg/kg FG) • Cows were fed for the first 183 DIM • Production, reproduction and health were monitored

16. Experimental Protocol

17. Santos et al. (2002)

18. Santos et al. (2002)

19. Santos et al. (2002)

20. Plasma Total Gossypol in Primiparous and Multiparous Cows Fed WUP or a Blend of WUP and Cracked Pima Santos et al. (2002)

21. Effect of Type of Cottonseed and Gossypol Intake on Conception and Pregnancy Rates of Lactatin Dairy Cows P < 0.01 P < 0.72 Santos et al. (2002)

22. Effect of Type of Cottonseed and Gossypol Intake on Days Open in Lactating Dairy Cows Whole Upland: Blend of cracked Pima and WUP: Cottonseed: P < 0.01

23. Plasma Gossypol Concentration in Lactating Dairy Cows P < 0.01 P < 0.04 Santos et al. (2002)

24. Effect of Plasma Total Gossypol Above or Below the Mean on Days Open in Lactating Dairy Cows Above Mean: Below Mean: TG: P < 0.04

25. Effect of Plasma Gossypol Concentrations on Days Open in Dairy Cows P < 0.05

26. Effect of Type of Cottonseed and Gossypol Intake on Conception Rate of Dairy Cows (1,863 AI)(Santos et al. 2002) Cottonseed: P < 0.03 Plasma Gossypol: P < 0.01

27. Santos et al. (2002)

28. Take Home Message • Cottonseed can be safely fed to lactating dairy cows at 10 to 15% of the diet DM with minimum effects on lactation performance • Small amounts of gossypol can disrupt fertility in bulls • Consider AI vs bull breeding • There is no clear evidence that dietary gossypol up to 1,000 mg/kg of diet affects lactation or health of lactating dairy cows • High gossypol diets for extended periods increases plasma TG and can affect conception and pregnancy maintenance in dairy cows

29. Acknowledgements • SUPIMA Association of America • Cotton Incorporated • Dairy owners and their staff