[1] Univ Ft Hare, Dept Livestock & Pasture Sci, Alice, Eastern Cape, South Africa
[2] Univ Ft Hare, ADRI, Alice, Eastern Cape, South Africa
[3] Univ Stellenbosch, Dept Anim Sci, ZA-7502 Matieland, South Africa
[4] Inst Nacl Tecnol Agr, Ctr Invest Agroind, Inst Tecnol Alimentos, Buenos Aires, DF, Argentina