Subprodutos da agroindústria do algodão na dieta de ovinos confinados

Abstract

An experiment was carried out in order to evaluate the carbohydrate and protein fractionation and the kinetics of the dry matter (DM), crude protein (PB) and neutral detergent fiber (NDF) of soybean meal and soybean meal. cotton by-products (FA), cotton cake (TA), whole cottonseed (CAI), delineated cottonseed (CAD), linter (LA) and cottonseed (CA). Then, a further six experiments were carried out to evaluate the different by-products of cotton (CDLA, cotton delignate-CAD and CAA cotton husk) on confined sheep feed, apparent digestibility of nutrients, parameters nitrogen balance and ingestive behavior. Experiment 01: Fractions A+B1, B2 and C of carbohydrates were determined, whereas the protein fractions were NNP, B1+B2, B3 and C. FS differed from the other cotton by-products at the time the fraction A+B1. TA was similar to CAA when analyzing the A+B1 fraction, with averages of 39.53 and 39.47%, respectively. Carbohydrate fraction B2 did not differ for FS, FA, LA and CAA. The C fraction of the carbohydrates was observed higher value for the CAA (41.95%), while the lower for the FS (9.10%). The highest and lowest value of the A fraction of the protein was observed for LA and CAA. As for kinetic parameters of MS degradation, the water soluble fraction at time zero (a) was more representative for FS, TA and CAD. Among the foods studied, the ones that obtain higher values for the degradability are the soybean meal and the cotton pie, the same foods stood out as the fractions of the carbohydrates and proteins that presents/display rapid degradation in the rúmem. The cotton bark and linter have the lowest rates of degradability. Experiment 02: Twenty sheep, uncastrated male, with an average weight of 27 kg were distributed in a completely randomized design with four treatments and five replicates. The treatments consisted of CAD in the contents of 0, 8, 16 and 24%, in the dry matter of the diets. The dry matter (DM), crude protein (CP), organic matter (OM) and neutral detergent fiber (NDF) values expressed in g/animal/day did not change (P>0.05) kg PC0.75. The digestibility of DM, OM, NDF, EE, CNF and CT was significantly lower (P<0.05), whereas the apparent digestibility of CP did not show a significant effect (P>0.05) with mean 63.95%. The CAD did not influence (P>0.05) the blood parameters and nitrogen balance. By affecting some parameters like digestibility, and, for a high performance in sheep production, the inclusion in the diet of the CAD is not justified. However, its inclusion in the diet of animals that do not aim for high weight gain can be adopted the level of up to 8% in the diet. Experiment 03: The objective of this study was to evaluate the inclusion of delineated cottonseed (CAD) in sheep feed to evaluate ingestive behavior. Twenty male, uncastrated sheep were used. The CAD changed linearly the ingestion efficiency g MS/hours (P<0.05). The inclusion of CAD changed linearly the number of cured cakes per day and total chewing time (min/day), increasing 6.66 (n °/cakes) and 4.16 (min/day) for each 1% of inclusion of CAD. The mean chewing time seg/cake presented a quadratic behavior (P<0.05), with maximum estimated at 49.14 sec/bolus, at the level of 8.21% of CAD. There was a quadratic behavior (P<0.05) for cheer chewing hours/day estimating a maximum value of 12.99 hours/day for the level of 12.7% inclusion of CAD. Because it affects some parameters of the ingestive behavior, it is not justified the inclusion of delineated cotton seed in the diet of sheep that aims at high yield of weight gain. However, for minor purposes the level of up to 8% of the DAC can be adopted in the sheep diet. Experiment 04: Twenty sheep, uncastrated, with an average weight of 33 kg were distributed in a completely randomized design with four treatments and five replicates. The treatments were constituted by the inclusion of LA at the levels of 0, 7, 14 and 21% in DM of the diets. The inclusion of LA in the diet promoted a reduction (P<0.05) in the intakes of DM, PB, OM, EE, CNF and CT in g/animal/day. The LA did not change (P>0.05) the apparent digestibility of DM, OM, NDF and CNF with a mean of 65.61; 67.36; 63.64 and 86.26% respectively. No significant effect (P>0.05) was observed for blood urea concentration, mean of 17.66 mg/dL. The inclusion of LA in the diet promoted reduction (P<0.05) in nitrogen balance (g/day) and in glucose levels (mg/dL). The LA of cotton did not present satisfactory results that justified its inclusion in the diet of confined sheep. Experiment 05: The objective of this study was to evaluate the inclusion of cotton lint (LA) in sheep feed on ingestive behavior. Twenty male sheep were used. LA did not change (P>0.05) the intakes of DM and NDF expressed in meal per kg. However, the intakes of MS and NDF expressed in minute/kg showed an increasing linear effect (P<0.05) with the inclusion of LA in the diet. LA altered linearly (P<0.05), the ingestion efficiency of DM and NDF in g/hour. There was no change when the dietary LA (P>0.05) was included for the number of cured cakes per day, chewing time and total chewing time, with mean values of 529 cakes/day, 44 sec/bolus and 320 min/day, respectively. LA is not indicated for the confined sheep diet. Experiment 06: Twenty sheep, uncastrated males, with an average weight of 32 kg were distributed in a completely randomized design with four treatments and five replicates. The treatments were constituted by the inclusion of 0, 10, 20 and 30% CAA in the dry matter of the diets. The inclusion of CAA in sheep diet altered the intakes of DM, PB, MO, EE, CNF and CT, expressed in g/animal/day, %PC and g/kg PC0,75. The inclusion of CAA (P>0.05) reduced the apparent digestibility of DM, NDF and EE, however, the CAA in the experimental rations provided an increase (P>0.05) in CP digestibility. The inclusion of CAA in sheep rations altered linearly (P<0.05) the nitrogen balance, reducing 0.51 g/day for each 1% CAA inclusion. No significant effects (P>0.05) were observed for blood urea and glucose with a mean of 19.23 and 72.35 mg/dL, respectively. The inclusion of different levels of cotton bark in the confined sheep diet leads to reduced consumption and digestibility of nutrients, so it is not recommended to place this by-product in the diet of high performance sheep. However, it is justified to use up to 5% of this by-product in creations that do not aim at high performance, that is, subsistence. Experiment 07: The objective of this study was to evaluate the inclusion of CAA in sheep feeding on ingestive behavior. Twenty male, uncastrated sheep were used. There was no effect (P>0.05) for the intake of the FDN min/kg with a mean of 1038.78 min/kg. The ingestion and rumination efficiency of DM and NDF in g/hours showed a linear decreasing effect (P<0.05) as it was added to CAA in the diet. The number of couscous cakes per day reduced 4.74 n°/cakes for each 1% CAA inclusion. The chewing time seg/cake had no effect (P>0.05) with a mean of 44 seconds. CAA altered the time spent with rumination and leisure, respectively, in a linear decreasing and increasing (P<0,05). CAA altered the rumination g of MS and NDF/cake in a decreasing manner (P>0.05). The inclusion of different levels of cotton bark in the confined sheep diet leads to a reduction in dry matter intake, ingestion efficiency and rumination, so it is not recommended to place this by-product in the sheep diet with high performance. However, it is justified to use up to 5% of this byproduct in creations that do not aim at high performance, that is, subsistence and maintenance of the body weight of the general herd.