Effects of monensin, virginiamycin and functional oils of castor and cashew for Nellore bovines abruptly changed to a high concentrate diet

Author(s)

Ana Paula dos Santos Silva

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2014-08-28

Examining board members

Paulo Roberto Leme; Ives Cláudio da Silva Bueno; Danilo Domingues Millen

• Advisor: Paulo Roberto Leme

Abstract

The aim of this trial was to evaluate the use of monensin, virginiamycin, and functional oils on bovines feedlot fed without adaptation a 92% concentrate diet. Forty eight Nellore bovines, with initial body weight (322 ± 23 kg) and 20 months old, raised on pastures, were allocated in individual pens and divided in four blocks according to BW, and fed a basal diet with 92% concentrate. Treatments consisted of the inclusion of: monensin 30 mg/ kg of DM (M30), monensin 40 mg/kg of DM of MS (M40), monensin 30 mg/kg of DM plus virginiamycin 25 mg/kg of DM (MV) and functional oils of castor oil and cashew nut shell on 400 mg/kg of DM (FO). The dosage of M40 decreased to 30 mg/kg of DM after 14 days. Statistical analyses were conducted according to GLM proceedings of SAS, and repeated measures were analyzed using MIXED proceeding of SAS. Animals were fed for 120 days. The first 21 days were evaluated to determine the additives effects after the abrupt change challenge. Feed intake characteristics, blood parameters, fecal pH and fecal starch were measured. DMI was lower for MV animals and the BW was heavier for M40 and FO animals. Animals receiving M30 and MV additives had higher fecal pH (P=0.0004) than those receiving M40 and FO, but without difference in the starch amount (P=0.068). Blood parameters were not influenced by the additives (P>0.05). Animals were slaughtered after 120 days on feed and performance, feeding behavior, and carcass characteristics were evaluated. Animals receiving OF had higher DMI than animals M30 and MV, without difference (P=0.22) between OF and M40. Animals from treatments M40 and FO spent less time (min/kg DM)) eating (P=0.02) and masticating (P=0.03). There was no treatment effect (P>0.05) for meat and carcass characteristics, except for pelvic, kidney and heart fat that was heavier (P=0.006) for animals receiving OF, but without difference with M40. Feed additives had similar results among themselves on the characteristics evaluated. Apparently the absence of adaptation with the use of high energy diets did not cause any injury for animal performance probably because of the protection offered by the additives, and the use of functional oils was as efficient as antibiotics on avoiding metabolic disturbances on Nellore bovines. (AU)

• FAPESP's process: 11/15818-3 - Effects of monensin, virginiamycin and functional oils Essental® on the rapid adaptation of high concentrate diets for Nellore catte
• Grantee: Ana Paula dos Santos Silva
• Support Opportunities: Scholarships in Brazil - Master