Lipídios em dietas à base de palma forrageira para cordeiros em crescimento

• Autor(a) principal: Chagas, Ellio Celestino de Oliveira
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1888
• topic: Cordeiro - Alimentação e rações; Algodão - Semente; Ácidos graxos; Lamb - Food and feed; Cotton - seed; fatty acids; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA

The result of the inclusion of increasing levels of lipids in diets based on cactus pear in growing lambs was evaluated in terms of determination of consumption and digestibility of nourishing essences, practice, evaluation and lipoidic profile found in the carcasses. The study was able to make use of 40 crossbred and castrated lambs of the Dorper race, with a 19.5 + 1.0 kg initial corporal weight which were confined during 70 days in a entirely randomized order supported by five treatments indicating levels of lipids in the diet ( 2.0; 3.9; 5.8; 7.7; e 9.6% ), and eight repetitions using the animal as the experimental unit. The diets were elaborated using an invariable proportion of cactus-pear (Opuntia ficus-indica Mill), and ground maize in proportion of 40 and 18% in the MS, respectively. Otherwise, the tifton hay and the soybean meal were gradually replaced by whole cotton seed. The mixture of concentrates was prepared taking maize, soybean meal and minerals as a basis. After the twenty-fifth day of the experimental period, a data collection was put in practice, regarding digestibility for a period amounting five days (26° to 30° in the experimental period). Soon after the 56-day experimental period the animals were slaughtered. The absorptions of DM, CP, NDF, ADF, CHOT e NFC were not significant without all the studied variants , but the consumption of EE increased lineally (P<0.01), manifesting the highest content of this nutrient in the diet of animals fed with increased levels of lipids. The consumption of EE, in g.day-1, diversified from 27.43 to 113.7 g.day-1, and the regressing equation obtained showed the rise of 22.74 g for each 1% of the lipid increase. The water absorption expressed in kg.d-1 and kg.DMI-1, suffered influence of the lipid levels in the diet and showed a quadratic effect. Otherwise the evident digestibility of the nutrients was not affected by the elevation of the lipid levels in the diet. The initial and final corporal weight, the whole and daily weight gained and the nutrient conversion were not modified. The same occured with the variants during the slaughter and the income obtained from the carcass cuts. As a result there were no influences of the dietary treatment. The addition of lipids in the diet did not significantly change (P>0.05) the greasy acids from C10:0 to C17:0, except the C16:1 which represented the reduction of 0.13% for each 1% in the addition of the lipid (P<0.001). As for the mono- unsaturated greasy acids, the study was able to show that the lipid levels in the diet decreased the concentration of palmitic acid (C16:1) and the concentration of the oily acid (C18:1n9c), which was analysed together with its isomer trans (C18:1n9t - linoelaidic). The increase in the concentration of linoleidic acids and the elevation of the lipid levels in the diet were expected, because this resultant greasy acid is produced to be ruminated inertly. Nevertheless, the increase of the acid proportions and the totality of unsaturated fat occured when 9.30% of lipids were provided in the diet. This conduct was believed to conclude that when the lipids in the diet were maintained until the level of 7.40% the consequent biohydrogenation was more efficient. The use of high levels of lipids associated with diets with a high concentration of non-fibrous carbohydrates do not compromise the performance of growing lambs. This way it is possible to elevate the lipid levels above the recommendable one in order to improve the growing standard and utilization of nutrients to reduce the application of supplements that usually raise the costs of alimenting the livestock.