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| Author(s): |
Jefferson Fabiano Werner Koscheck
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Jaboticabal. 2017-02-20. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal |
| Defense date: | 2016-12-15 |
| Advisor: | Ricardo Andrade Reis |
| Abstract | |
It was aimed in this work to evaluate the forage mass, sward structure, chemical composition, intake and digestibility, performance, gastrointestinal tract content and enteric methane of young Nelore bulls reared in Brachiaria brizantha cv. Marandu submitted to different grazing heights and supplement levels during the rainy season and rainy-dry season transition under continuous stocking with variable stocking rate, as well as the effect of rearing on finishing in feedlot or pasture. The treatments in the rainy season consisted of low grass height (15 cm) (AB) and supplementation at 0.3% of body weight (PC) (AB-0.3%), AB and supplementation at 0.6% of PC (AB-0.6%), medium pasture height (AM) and 0.1% PC supplementation (AM-0.1%), AM and PC supplementation 0.3% (AM-0.3%), high grass height (35 cm) (AA) and mineral supplementation (AA-SM), AA and 0.1% PC supplementation (AA-0.1%). At the transition, treatments consisted of AM and 0.3% PC supplementation (AM-0.3%), AM and 0.6% PC supplementation (AM-0.6%), AA and 0.1 % PC supplementation (AA-0.1%), AA and 0.3% PC supplementation (AA-0.3%). In the finishing phase the animals were divided in two experiments, in the experiment 1, 24 animals were finished in grazing system, receiving 2% of the PC, while those of experiment 2, 24 animals were finished in feedlot in individual stalls. The feedlot finishing diet consisted of sugarcane bagasse as bulky (13% based on DM) and concentrated (87% based on DM). In the rainy season, 126 young Nellore bulls were used, with a completely randomized design with six treatments and three replicates (stalls) per treatment (n = 18). In the transition, 68 animals were used, and the experimental design was completely randomized, with four treatments and three replicates (stalls) per treatment (n = 12). At the finishing phase, a completely randomized design with four treatments and three replications (batch of 2 animals each) was used per treatment (n = 12). As all variables evaluated had an effect before the beginning of the experiment, they were tested as co-variables at the end of the experiment. In the rainy season, the forage grass mass of AA, as well as the mass of green leaf, green stem and dead material were higher (P <0.01) than the values observed in grass of AB in all experimental periods (P <0.01). The dry matter intake (CMS) of pasture of the animals in the pastures of AA was higher than the intake in the AB (P <0.01), however, the total CMS was equal in the three heights studied. The AB-0.6% treatment provided higher carcass gain, when compared to AB-0.3%, AM-0.1% and AA-SM (P <0.01), and lower daily gain in carcass was observed in the treatment AM-0.1% and AA-SM (P <0.01). In the rainy-dry transition season, the AM-0.3% and AM-0.6% treatments provided lower total forage mass, green leaf and green stem, higher stocking rate and lower CMS of pasture by animals. The animals in the treatment AM-0.6% of the PC present higher crude energy intake and metabolizable energy, and higher PC and carcass gain per hectare. In the present study, although the nutritional plans provided different carcass weight at the end of the rearing phase, when measuring the carcass weight at the end of the finishing phase, no statistical differences were observed between the evaluated systems. (AU) | |
| FAPESP's process: | 13/05894-0 - Intensification of pasture management and supplementation on productive parameters, environmental and economic issues in growing and finishing beef cattle |
| Grantee: | Jefferson Fabiano Werner Koscheck |
| Support Opportunities: | Scholarships in Brazil - Doctorate |