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| Author(s): |
Pedro Augusto Ribeiro Salvo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2016-02-02 |
| Examining board members: |
Luiz Gustavo Nussio;
João Luiz Pratti Daniel
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| Advisor: | Luiz Gustavo Nussio |
| Abstract | |
Corn silages are prone to deterioration when exposed to air. The lactate-assimilating yeast species are frequently the first microorganisms to initiate the aerobic deterioration. Some studies reported that aerobically unstable corn silage is associated with reduced feed intake, milk production and milk fat depression. Therefore, the objective of this study was evaluate the influence of yeast inoculation (Pichia norvegensis) and the air exposure by 48 hours on the nutritive value of corn silages and the performance of dairy cows. Corn crop was harvested at 34% DM, treated without (Control) or with P. norvergensis at 1×105 cfu/g fresh matter (Yeast) and packed in bag silos (40 t/silo). After 123 d of storage, silos were opened and fed to lactating dairy cows. Every day, the silages were unloaded and fed immediately (Fresh) or after 48 h of air exposure (Exposure). Twenty Holsteins cows were assigned to five replicated 4×4 Latin squares, with 21 d periods (15 d for adaptation + 6 d for sampling). Diets were formulated to contain 53% corn silage, 8% whole cottonseed, 18% soybean meal, 9.5% citrus pulp, 9% dry corn meal, and 2.5 % vitamin and mineral premix. The four treatments were: control-fresh silage (CF), control-exposed silage (CE), yeast inoculated-fresh silage (YF), and yeast inoculated- exposed silage (YE). The yeast inoculation enhanced DM losses (P<0,001) and reduced aerobic stability (P=0,03) of corn silages. On the animal performace, decreased 3,5% fat correct milk (P=0,03) and the feed efficiency (ELL leite/CMS) (P<0,01), but did not alter the milk fat content. The effects of air exposure by 48 hours reduced lactic acid concentration (P<0,001), which consequently increased the pH (P=0,004) of silages, and reduced others fermentation products. Also, the exposure decreased the 3,5% fat correct milk (P=0,02) and the feed efficiency (P=0,10). Neither treatment altered the DM intake. There was tendency of reduction for the DM and NDF digestibility and TDN, when the silages were exposed to air. The yeast inoculation and air exposure by 48 hours decreased animal performance by the reduction on the nutritive value of corn silages. (AU) | |
| FAPESP's process: | 14/05914-3 - Identification and impact of yeasts on nutritive value of corn silage for dairy cows |
| Grantee: | Pedro Augusto Ribeiro Salvo |
| Support Opportunities: | Scholarships in Brazil - Master |