PEREIRA, G. E. S.; http://lattes.cnpq.br/9658886957087745; PEREIRA, George Estêfano dos Santos.
Résumé:
The potential for forage production in the semiarid region of Brazil is viable as long as there
is necessary planning. Choosing correct and adapted cultures is the best choice. The recovery
of cultures that was part of ruminant feeding in the past is a way to think about it. In this
context, Mocó cotton (Gossypium hirsutum L. r. Marie galante Hutch) presents itself as a crop
that returns to the forage production scenario. Armed with references, this research aimed to
evaluate the dynamics of fermentation and chemical composition of Mocó cotton silage with
urea additives. The experimental design was completely randomized in a 3x3 factorial
scheme, with three times of silage fermentation (14, 21 and 28 days) and three levels of urea
(0,3 and 6% based on ensiled dry matter), with six repetitions, totaling 54 mini silos. The mini
silos were evaluated from a fermentative point of view by the parameters of pH, electrical
conductivity, loss by gases, loss by effluent, and dry matter recovery. The bromatological
analyzes evaluated dry matter (DM), mineral matter (MM), moisture, organic matter (OM),
ammoniacal nitrogen based on dry matter (NNHMS), ammoniacal nitrogen based on total
nitrogen (NNHNT), crude protein ( PB), neutral detergent fiber corrected for ash and protein
(cPDF), hemicellulose, acid detergent fiber (ADF), cellulose, total carbohydrates (CHOT),
non-fibrous carbohydrates (NFC), ether extract (EE) and total digestible nutrients (NDT).
Urea increased the pH from 5.56 at the 0% dose to 8.62 at the 6% dose of silage additive,
which promoted higher levels of electrical conductivity. The additivation with urea positively
influenced (P<0.05) in all the parameters mentioned above. It is worth highlighting the
increase in the CP content of the silage from 9.81% at the 0% urea level to 14.81% at the 6%
level and the improvement in the FDNcp contents at the 0% dose was 63.62% and went to
69.03 and 68.20 at levels 3 and 6% of additivation. Regarding the days of fermentation, the
analysis of variance detected a significant difference (P<0.05) only for DM, moisture, CP,
FDNcp, FDA, CHOT and CNF. With a significant interaction (P<0.05) urea x days only for
the electrical conductivity, with the increase in the urea dose and as the days went by, the CE
levels in the additive silos increased by 1.63; 1.64 and 1.85 dS m-1 at dose 3, and 2.12; 2.17
and 2.30 dS m-1 at the 6% dose, as opposed to the 0% dose of urea which, over the days,
promoted a reduction in EC, with the following results: 1.22; 1.20 and 1.18 for 14, 21 and 28
days, respectively. In general, the 3% level of additivation showed results similar to the 6%
level, being seen as the best tested. Mocó cotton silage is viable to be used as food for
ruminants in the semiarid region, which can lower costs and avoid the purchase of foreign
food by producers.