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| Author(s): |
Fabíola Martinez da Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Botucatu. 2017-02-03. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu |
| Defense date: | 2017-01-19 |
| Advisor: | André Mendes Jorge; Caroline de Lima Francisco |
| Abstract | |
The aim of the study was to evaluate associations of feed efficiency measures, performance and nutrient digestibility of three water buffalo genetic groups. Seventy-five steers (25 of each breed: Jafarabadi, Mediterranean and Murrah), non-castrated, average initial weight 314 ± 117 kg and 390 ± 58 days were used. They were housed in breed groups and feed ad libitum. Pens contained automated feeding stations and automated water fountain (Intergado®) to determine the intakes during 112 days (adaptation = 28 days; trial period = 84 days). Ultrasound measures (longissimus muscle area - LMA, 12th-rib fat thickness - BF and rump fat thickness - RMFT) were taken in the beginning and in the end of the trial, and the animals were weighted and the rump height (RH) were measured each 28 days. Feed conversion ratio (FCR), feed efficiency (FE), residual feed intake (RFI), residual gain (RG) and residual intake and gain (RIG) were evaluated. Feces samples were collected to determine the nutrient apparent digestibility of the diet by indigestible neutral detergent fiber (iNDF). For statistical analysis were used the MIXED and CORR procedures (SAS Inst. Inc., Cary, NC). Final body weight (FBW; P = 0.03), average daily gain (ADG; P < 0.01) and RH (P < 0.01) were greater for Jafarabadi group, no difference were observed for Mediterranean and Murrah. No group effect were found for feed intake (DMI; DMI kg/d; DMI %PV; DMI g/kg0,75; P > 0.28) and water (P = 0.53). Greater values of LMA and RMFT (P < 0.03) were observed for Jafarabadi and Murrah, but no difference were detected among groups for BF (P = 0.14). Jafarabadi had greater feed efficiency values (FCR, FE, RFI, RG, RIG) than the others groups, however, no effect was found between Mediterranean and Murrah. There was no interaction between genetic groups and RFI classification (P > 0.12) to nutrient digestibility. Smaller values for nutrient digestibility were observed for Murrah compared to the others, nevertheless, group effect were observed for acid detergent fiber (ADF) digestibility. There was negative correlation between RFI and ADF digestibility (P = 0.04) and trend to negative correlation between RFI and crude protein (CP; P = 0.08). Positive correlation were observed between ADF digestibility and RG (P = 0.02), and RIG (P = 0.02). The results indicate that Jafarabadi group had greater results for performance and feed efficiency measures, and correlation existed between ADF digestibility and RFI, RG and RIG. (AU) | |
| FAPESP's process: | 15/04542-8 - Residual feed intake (RFI) and diet digestibility of three genetic groups of water buffaloes in the growing phase on feedlot |
| Grantee: | Fabíola Martinez da Silva |
| Support Opportunities: | Scholarships in Brazil - Master |