Feno de pornunça (Manihot spp.) na alimentação de ovinos em confinamento no semiárido

Abstract

Was evaluated the performance, economic analysis of feed, carcass characteristics and meat quality of crossbred sheep of Santa Inês fed increasing levels of pornunça hay replacing tifton hay. Was used 36 lambs uncastrated, with an average initial body weight (BWi) of 18.60 kg ± 0.3 kg, distributed in a completely randomized design with four treatments and nine replicates. The treatments consisted of four levels (0, 33, 67 and 100%) of tifton-85 hay by pornunça hay, using relationship roughage / concentrate of 40:60. The dry matter intake (DMI), all express forms, organic matter (IOM), ether extract (EE), total carbohydrates (TC) and non-fiber carbohydrates (CNFC) had a positive linear increase with the inclusion of pornunça hay. The intake of crude protein (CCP) was not affected, with average of 220.21 g/day. The neutral detergent fiber intake (CNDF) decreased linearly, ranging from 319.02 to 243.98 g/day. The water drink intake, total water intake in relation to BW%, relative to DM intake (g/kg DM) and metabolic weight (g/kg UTM), were not affected by the replacement of tifton hay by pornunça hay diets, averaging 3192.29 g; 3329.03 g; 12.84%; 2923.92 g / kg and CMS; 289.56 g / kg UTM respectively. The water of the diet intake showed positive linear effect. The digestibility coefficients of DM, OM and CHOT were not affected by treatments. However, the digestibility of CP, EE and NDF decreased with the inclusion of hay pornunça and digestibility of NFC increased. There was no effect of increased pornunça hay on feed conversion (FC), final body weight (BWFi), total weight gain (TWG) and average daily weight gain (ADG), which showed average values of 4.38, 33.22 kg, 14.66 kg and 261.71 g respectively. The replacement levels of tifton hay by pornunça hay promoted similar values for the cost of diet and leveling point, however, total revenue, gross margin, cost per kg / carcass and money increased. The replacement of tifton hay by pornunça hay not influence the final weight (FW), slaughter weight (SW), fasting losses (FL) and cooling losses (LC), with averages of 33.22 kg; 30.96 kg; 7.76% and 2.08%, respectively. No influence on the hot carcass weight (HCW), cold carcass weight (CCW), hot carcass yield (WHR) and commercial income (RC). There was no influence of diet on leg length, internal carcass length and leg compactness index, with the exception of carcass compactness index, which ranged from 0.27 to 0.30 kg / cm. The weight of the neck showed linear increase. The leg showed higher yield (33.72%), followed by the palettes (18.98%), ribs (17.35%), loin (9.94%), saw (9.84%) and neck (9, 72%). Maximum length (measure A), maximum depth (measure B), minimum and maximum thickness of fat and muscle L. dorsi and area-to-eye muscle (AOL) were not affected by the different diets. The chemical composition of lamb loin was not influenced by the inclusion of hay pornunça, with values of water, ash, protein and fat of 74.79; 1.39; 21.17 and 2.61%, respectively. The physico-chemical parameters of meat pH, color, cooking loss and shear force were not affected by increased levels of pornunça the diets. However, pornunça hay can replace tifton hay up to 40% on the power crossbred lambs of Santa Inês, making possible to obtain satisfactory performance by improving the weight of hot and cold carcass and water activity.