Made available in DSpace on 2015-03-26T13:55:29Z (GMT). No. of bitstreams: 1 texto completo.pdf: 255338 bytes, checksum: a24cdb0238dc9c3000c663f42cc3030f (MD5) Previous issue date: 2007-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this study was to determine the digestible methionine plus cystine to digestible lysine ratio (Met+Cys/Lys) for barrows with high genetic potential for lean gain fed ractopamine (RAC) in finishing phase. Eighty barrows with an average initial body weight of 84.64±1.28 kg were allotted to dietary treatment on the basis of weight in randomized complete block design. Dietary treatments included a basal diet containing RAC (5 ppm) plus DL-Met, resulting in treatment diets containing Met+Cys/Lys of 0.54, 0.58, 0.62, 0.66 and a diet without RAC containing Met+Cys/Lys of 0.62, control (CONT). There were eight replications of barrows with two pigs per replicate during 28 days. Increasing the Met+Cys/Lys had no effects on average daily feed intake (ADFI), feed: gain ratio (F/G) and average daily gain (ADG) of pigs fed RAC. Barrows fed RAC and Met+Cys/Lys of 0.54 had the highest profitability index. The end weight of RAC-treated pigs was 2% higher compared to CONT pigs (by 2.3 kg). The RAC increased ADG by 10% and improved F/G by 13% compared to control pigs, but there were no differences in ADFI. Increasing the Met+Cys/Lys had no effects on fat depth (FD), fat-free lean mass (FFLM), carcass weight (CW), fat-free lean percentage (FFLP) and dressing (DR) for pigs fed RAC. The digestible methionine + cystine of the diet influenced in a quadratic way the cholesterol concentration, Y = -227,1900+ 9,6809X - 0,0837X², (R² = 0,99), being the Met+Cys/Lys of 0.66 for minimum cholesterol concentration, but the RAC had no effects on cholesterol concentration in muscle (Longissimus dorsi) and fat. The RAC increased FFLM by 6%, CW by 4% and DR by 2% compared to control pigs. However, the RAC had no effects on FD and FFLP of barrows. Thus, the optimum Met+Cys/Lys which will achieve maximal growth performance, carcass characteristics and economic return of finishing pigs (from 85 to 109 kg) fed RAC is 0.54. However, to minimize cholesterol concentration in muscle and fat the optimum Met+Cys/Lys is 0.66. / O experimento foi realizado com o objetivo de determinar a relação metionina mais cistina digestível/lisina digestível (Met+Cis/Lis) em suínos machos castrados suplementados com ractopamina (RAC), selecionados geneticamente para deposição de carne magra na carcaça, na fase de terminação. Foram utilizados 80 suínos machos castrados de alto potencial genético para deposição de carne magra na carcaça, com peso inicial de 84,64±1,28 kg, distribuídos em delineamento experimental de blocos ao acaso composto de cinco tratamentos, oito repetições e dois animais por unidade experimental, durante um período de 28 dias. O peso dos suínos foi adotado como critério na formação dos blocos. Os tratamentos foram constituídos de rações contendo 0,936% de lisina digestível (Lis), suplementadas (5 ppm) com ractopamina (RAC), com os níveis de 54; 58; 62; 66% de metionina + cistina digestível (Met+Cis) em relação à lisina digestível, correspondendo aos seguintes níveis de Met+Cis nas rações, 0,505; 0,543; 0,580; 0,617% e a dieta controle com 0,736% de Lis sem suplementação de ractopamina, com o nível de 62% de Met+Cis em relação à Lis, correspondendo ao nível de Met+Cis na ração de 0,456%. As relações Met+Cis/Lis não influenciaram o consumo de ração (CR), a conversão alimentar (CA) e o ganho de peso diário (GPD) dos suínos que consumiram dietas suplementadas com RAC. O maior índice de rentabilidade foi verificado em suínos suplementados com RAC e relação 0,54 Met+Cis/Lis. Os suínos suplementados com RAC obtiveram peso final de 2,30 kg a mais que os animais não suplementados com RAC, correspondendo a uma melhora de aproximadamente 2%. O GPD dos animais aumentou em 10%, enquanto a CA melhorou em 13% nos suínos suplementados com RAC. A suplementação de RAC não influenciou o CR dos animais. Em animais suplementados com RAC as relações Met+Cis/Lis não influenciaram a espessura de toucinho (ET), a quantidade de carne magra (QCM), o peso da carcaça (PC), a porcentagem de carne magra (PCM) e o rendimento de carcaça (RC). As relações Met+Cis/Lis influenciaram (P<0,01) a concentração de colesterol total no lombo de forma quadrática segundo a equação Y = -227,02+ 967,45X - 835,94X², (R² = 0,99) em que o menor teor de colesterol total foi verificado nos suínos alimentados com dietas na relação 0,66 Met+Cis/Lis, mas as concentrações de colesterol total no músculo Longissimus dorsi (lombo) e no toucinho não foram influenciadas pela suplementação de RAC nas dietas. A suplementação de RAC na dieta melhorou a QCM dos animais em aproximadamente 6% comparado aos suínos não suplementados com RAC. Os terminados suplementados com RAC apresentaram aumento de aproximadamente 4% no PC e 2% no RC quando comparado aos animais que não receberam RAC na ração. A suplementação de RAC não influenciou a ET e nem a PCM dos animais. Conclui-se que a relação 0,54 Met+Cis/Lis, atende as exigências de suínos em terminação de 85 aos 109 kg suplementados com ractopamina para melhor desempenho, características de carcaça e viabilidade econômica. A relação 0,66 Met+Cis/Lis proporciona a menor concentração de colesterol total no lombo e no toucinho de suínos em terminação suplementados com ractopamina.

Foram conduzidos três experimentos no confinamento experimental do Departamento de Zootecnia da ESALQ/USP com o objetivo de estudar os efeitos de diferentes aditivos em rações para bovinos terminados em confinamento. No experimento 1 foram utilizados 100 bovinos machos Nelore castrados (392 kg), distribuídos em 20 baias, por 60 dias. As rações continham 41% de sorgo moído, 40% de polpa cítrica peletizada e 15% de silagem de cana-de-açúcar. Os tratamentos foram: (1) controle, (2) monesina sódica Rumensin (MON1), (3) monensina sódica Rumenfort (MON2), levedura Saccharomyces cerevisiae Yea-Sacc 1026 (LEV1) e levedura Saccharomyces cerevisiae Biosaf SC47 (LEV2). A IMS foi reduzida pelo tratamento MON1 (P<0,05), quando comparada ao tratamento controle. O GPD dos animais não foi afetado pelos tratamentos (P>0,05). A EA dos animais não foi afetada pelos tratamentos (P>0,05). O tratamento MON2 apresentou um menor rendimento de carcaça (P<0,05) e o tratamento MON 1 apresentou uma maior AOL (P<0,05). No experimento 2 foram utilizados 96 tourinhos Nelore não castrados (396 kg), distribuídos em 16 baias por 95 dias. Os tratamentos foram: (1) Controle, (2) levedura Saccharomyces cerevisiae Biosaf SC47 (LEV), (3) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 1g /bovino/dia (PROB1) e (4) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 3g/bovino/dia (PROB2). As rações continham 59% de polpa cítrica peletizada, 35% de farelo de glúten de milho úmido e 5% de feno de tifton 65. A adição dos aditivos levedura (Saccharomyces cerevisae) e a combinação de leveduras e bactérias probióticas não afetou a IMS o GPD e a EA dos animais (P>0,05). A energia líquida de manutenção e de ganho das rações também não foi afetada pelos tratamentos (P>0,05), assim como os dados de carcaça. No experimento 3, que avaliou a digestibilidade das rações, foram utilizados 20 tourinhos Nelore, alocados em 20 baias individuais durante 15 dias, sendo 10 dias de adaptação ao marcador e 5 dias de coleta de fezes. A ração foi a mesma utilizada no experimento 2, e o marcador utilizado foi o óxido de cromo. Os tramentos utilizados foram: (1) Controle, (2) monensina sódica Rumenfort (MON), (3) levedura Saccharomyces cerevisiae Biosaf SC47 (LEV), (4) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 1g /bovino/dia (PROB1) e (5) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 3g/bovino/dia (PROB2). Os aditivos testados não afetaram as digestibilidades da MS, da MO, da FDN e da PB das rações (P>0,05). Com os resultados obtidos é possível afirmar que bovinos Nelore, castrados ou não, confinados com rações com altos teores de concentrado ricos em co-produtos como polpa cítrica e farelo de glúten de milho úmido não apresentam melhor desempenho nem melhor digestibilidade dos nutrientes quando suplementados com monensina sódica ou com micorganismos probióticos. / Three trials were conducted at the ESALQ/USP Animal Sciences Department experimental feedlot to evaluate the effects of different feed additives in feedlot finished cattle. On trial 1 100 Nellore steers (392kg) were allocated to 20 pens for 60 days. Experimental rations had 41% ground milo, 40% dried citrus pulp and 15% sugarcane silage. Treatments were: (1) control, (2) sodium monensin Rumensin (MON1), (3) sodium monensin Rumenfort (MON2), (4) yeast culture Saccharomyces cerevisiae Yea-Sacc 1026 (LEV1) and (5) yeast culture Saccharomyces cerevisiae Biosaf SC47 (LEV2). DMI was reduced by MON1 trestment (P<0,05) in relation to control. WDG was not affected by treatments (P>0,05). Treatments did not affect FE (P>0,05). Animals on treatment MON2 showed the lowest dressing percentage (DP) and those on MON1 showed the highest rib eye area (REA) (P<0,05). Trial 2 used 96 young Nellore bulls (396kg), allocated to 16 pens for 95 days. Treatments were: (1) control, (2) Saccharomyces cerevisiae Biosaf SC47 (LEV), (3) Saccharomyces cerevisiae and probiotic bacteria mix at 1g /animal/day dose (PROB1) and (4) Saccharomyces cerevisiae probiotic bacteria mix at 3g/animal/day dose (PROB2). Rations contained 59% dried citrus pulp, 35% wet corn gluten feed and 5% Tifton 65 hay. Treatments didnt affect DMI, WDG and FE (P>0,05). Rations net energy for maintenance and gain were also not affect by treatments (P>0,05), well as carcass data. Trial 3 utilized 20 young Nellore bulls allocated to individual pens for 15 days (10 days for adaptation to marker and 5 days for data collection) to evaluate rations digestibility. Experimental ration was the same utilized on trial 2, with chromium oxide as an external marker. Treatments were (1) control, (2) sodium monensin Rumenfort (MON1), (3) yeast culture Saccharomyces cerevisiae Biosaf SC47 (LEV), (4) Saccharomyces cerevisiae and probiotic bacteria mix at 1g /animal/day dose (PROB1) and (5) Saccharomyces cerevisiae probiotic bacteria mix at 3g/animal/day dose (PROB2). Treatments did not affect rations DM, OM, NDF and CP digestibilities (P>0,05). Results show that Nellore cattle, castrated or not, feedlot finished receiving rations with high levels of byproducts such as dried citrus pulp and wet corn gluten feed dont have higher performance nor better nutrients digestibility when supplemented with sodium monensin or probiotic microorganisms.

Thesis (M. Sc. Agriculture (Animal Production)) -- University of Limpopo, 2019 / Two experiments were conducted to determine the effect of dietary methionine level on productivity and carcass characteristics of Ross 308 broiler chickens. In each experiment, the diets were isocaloric and isonitrogenous but with different dietary methionine levels. Five diets were formulated to contain dietary methionine levels of 4, 5, 6, 8 or 9g/kg DM. The first experiment commenced with 300 unsexed Ross 308 broiler chickens with initial average live weights of 42 ± 2g per chicken. The chickens were randomly assigned to five treatments with five replications, resulting in 25-floor pens with 12 chickens per replicate. The second experiment commenced with 150 male Ross 308 broiler chickens with initial average live weight of 637 ± 12g per chicken. The chickens were randomly assigned to five treatments with three replications, resulting in 15-floor pens with 10 chickens per replicate. A complete randomized design was used in each experiment. Data was analysed using the General Linear Model (GLM) procedures of the statistical analysis of variance, Version 9.3.1 software program. Where there were significant differences, mean separation was done using the Tukey test at the 5% level of significance. A quadratic regression model was used to determine the optimal productivity of the chickens while a linear model was used to determine the relationships between dietary methionine level and responses by the chickens in the variables measured. The treatments for the first experiment were UM4 (4g methionine/kg DM), UM5 (5g methionine/kg DM), UM6 (6g methionine/kg DM), UM8 (8g methionine/kg DM) and UM9 (9g methionine/kg DM). Feed intake, growth rate, feed conversion ratio (FCR), metabolisable energy intake and nitrogen retention of unsexed Ross 308 broiler chickens aged one to 21 days were not affected (P>0.05) by dietary methionine level. Similarly, dietary methionine level did not have any effect (P>0.05) on diet crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF) and fat digestibilities in unsexed Ross 308 broiler chickens aged 14 to 21 days. Dietary methionine level did not have any effect on live weights of broiler chickens at 21 days. Live weights of unsexed Ross 308 broiler chickens aged 7 or 14 days were not improved (P>0.05) by increasing dietary methionine level from 4 to 9g/kg DM. Crop, gizzard and small intestine weights and crop, proventriculus and gizzard digesta pH values of unsexed Ross 308 broiler chickens aged 21 days were not affected v (P>0.05) by dietary methionine level. Similarly, dietary methionine level did not improve (P>0.05) caecum and large intestine lengths of unsexed Ross 308 broiler chickens aged 21 days. However, dietary methionine level affected (P<0.05) dry matter (DM) and ash digestibilities of unsexed Ross 308 broiler chickens aged 14 to 21 days. Proventriculus and large intestine weights, gastrointestinal tract and small intestine lengths of unsexed Ross 308 broiler chickens aged 21 days were improved (P<0.05) by increasing dietary methionine level. In addition, increasing dietary methionine level increased (P<0.05) small and large intestine digesta pH values of broiler chickens aged 21 days. Thus, dry matter digestibility, live weights at day 7 ad 14, caecum length, large intestine length and digesta pH were optimized at different dietary methionine levels of 7.26, 5.29, 4.99, 6.80, 4.84 and 6.37g/kg DM feed, respectively. The treatments for the second experiment were MM4 (4g methionine/kg DM), MM5 (5g methionine/kg DM), MM6 (6g methionine/kg DM), MM8 (8g methionine/kg DM) and MM9 (9g methionine/kg DM). Dietary methionine level did not have effect (P>0.05) on feed intake of male Ross 308 broiler chickens aged 6 weeks. However, dietary methionine level improved (P<0.05) feed intake of male Ross 308 broiler chickens aged 4 or 5 weeks. Live weights of male Ross 308 broiler chickens aged 28 days were not affected (P>0.05) by dietary methionine level. However, live weights of male Ross 308 broiler chickens aged 35 and 42 days were affected (P<0.05) by dietary methionine level. Similarly, dietary methionine level affected (P<0.05) DM, CP, ADF, NDF, fat and ash digestibilities of male Ross 308 broiler chickens aged 35 to 42 days. Thus, dietary methionine levels of 6.93, 7.70, 6.85 and 11.27g/kg DM optimized dry matter, CP and fat digestibilities, and live weight of male broiler chickens aged 42 days. Dietary methionine level did not affect (P>0.05) FCR, growth rate and metabolisable energy intakes of male Ross 308 broiler chickens. Increasing dietary methionine level from 4 to 9g/kg DM improved (P<0.05) nitrogen retention of male Ross 308 broiler chickens aged 22 to 42 days. Dietary methionine level did not have any effect (P>0.05) on proventriculus, gizzard, caecum and large intestine weights, caecum, small and large intestine lengths, and crop, gizzard, caecum and large intestine digesta pH values of male Ross 308 broiler chickens aged 42 days. Crop and small vi intestine weights and gastrointestinal tract lengths of male Ross 308 broiler chickens aged 42 days were improved (P<0.05) by dietary methionine level. Similarly, dietary methionine level affected (P<0.05) proventriculus and small intestine digesta pH values of male Ross 308 broiler chickens aged 42 days. Thus, dietary methionine levels of 6.558 and 7.851g/kg DM optimized broiler chicken crop weight and GIT length. Dietary methionine level affected (P<0.05) carcass organ weights of male Ross 308 broiler chickens aged 42 days. Increasing dietary methionine level increased chicken breast meat weight. However, there was no clear trend for the other carcass organs. Meat flavour and shear force values of male Ross 308 broiler chickens aged 42 days were not affected (P>0.05) by dietary methionine level. However, dietary methionine level affected meat tenderness and juiciness. Thus, dietary methionine levels of 10.09 and 13.32g/kg DM optimized broiler chicken meat tenderness and juiciness. . / National Research Foundation (NRF) and VLIROUS

Thesis (M. Sc. Agriculture (Animal Production)) -- University of Limpopo, 2021 / Two experiments were conducted to determine the effect of replacing soya bean meal with yellow mealworm larvae meal (Tenebrio molitor) in a diet on productivity, gut morphology, carcass characteristics and bone morphometrics of Ross 308 broiler chickens aged one to 42 days. In each experiment, a total of 360 Ross 308 broiler chickens were randomly assigned to the five dietary treatments, each treatment having four replications, and 18 chickens per replicate. Five diets were formulated to contain yellow mealworm replacement levels at 0, 25, 50, 75 and 100% to meet the nutrient requirements of Ross 308 broiler chickens. Data was analysed using the General Linear Model procedures of the Statistical Analysis System, Version 9.3.1 software program. Fisher’s least significant difference (LSD) test was applied for mean separation where there were significant differences (P<0.05). A quadratic regression model was used to determine the levels for optimal responses in the variables measured. The first experiment determined the effect of replacing soya bean meal with yellow mealworm larvae meal on productivity and gut morphology of unsexed Ross 308 broiler chickens aged one to 21 days. Replacement of soya bean meal with yellow mealworm meal in a diet had no effect (p > 0.05) on feed intake, growth rate, FCR, live body weight, ME intake and nitrogen retention of unsexed Ross 308 broiler chickens aged one to 21 days. Replacing soya bean meal with yellow mealworm meal in a diet did not affect (p > 0.05) caecum weight of unsexed Ross 308 broiler chickens. However, replacing soya bean meal with yellow mealworm meal in a diet increased (p < 0.05) gastro intestinal tract, crop, ileum and large intestine weights. Crop and ileum lengths of unsexed Ross 308 broiler chickens aged 21 days were not affected (p > 0.05) by replacement of soya bean meal with yellow mealworm meal in the diet. However, replacing soya bean meal with yellow mealworm meal in a diet increased (p < 0.05) gizzard, caecum and large intestine lengths of unsexed Ross 308 broiler chickens aged 21 days. Yellow mealworm meal in a diet did not affect (p > 0.05) gut organ digesta pH values of unsexed Ross 308 broiler chickens aged 21 days. The second experiment determined the effect of replacing soya bean meal with yellow mealworm meal in a diet on productivity, gut morphology, carcass characteristics and bone morphometrics of Ross 308 broiler chickens aged 22 to 42 days. Replacement of soya bean meal with yellow mealworm meal in a diet did not affect (p > 0.05) growth rate, FCR, ME intake and nitrogen retention of male Ross 308 broiler chickens aged 22 to 42 days. However, replacing soya bean meal with yellow mealworm meal in a diet affected (p < 0.05) feed intake and live body weight of male Ross 308 broiler chickens aged 22 to 42 days. Broiler chickens on diets containing 75 or 100% yellow mealworm meal had higher (p < 0.05) intakes than those on diets containing no yellow mealworm meal. Similarly, male broiler chickens on diets having 50% yellow mealworm meal had higher (p < 0.05) live body weights than those on diets containing no yellow mealworm. Quadratic equations indicated that feed intake and live body weight of male Ross 308 broiler chickens were optimized at yellow mealworm meal replacement levels of 13 and 61%, respectively. The present study showed that replacing soya bean meal with yellow mealworm meal in a diet did not affect (p > 0.05) gut organ digesta pH values, gut organ weights, gut organ lengths, meat colour, meat pH values, bone morphometric values, carcass part weights and meat sensory attributes of male Ross 308 broiler chickens aged 42 days. However, meat from chickens on diets containing yellow mealworm meal was softer (p < 0.05) than meat from chickens on diets having 100% soya bean meal. It is concluded that soya bean meal can be replaced with yellow mealworm larvae meal in a diet at 25, 50, 75 and 100% levels without having adverse effects on production and carcass characteristics of Ross 308 broiler chickens aged one to 42 days

An experiment was conducted using forty-one Bonsmara steers (age ± 7 months) to determine the effect of zilpaterol hydrochloride (ZH) on the growth performance and carcass characteristics. The trial was structured using a completely randomized design with two treatments, control and ZH group. The steers were fed ZH for 28 consecutive days at the end of the finishing period and ZH was withdrawn from the diet 2 days prior to slaughter of the animals. The steers were placed in individual pens and weighed fortnightly throughout the 4 months trial. Zilpaterol hydrochloride (ZH) was included in the diet at a rate of 8.3 mg/kg of DM. Feeding of ZH increased (P< 0.05) body weight (BW) gain and ADG (1.102 vs. 1.444) and tended to increase (P = 0.067) feed efficiency (F:G) during the last month of the finishing period. There were no significant differences (P> 0.05) in daily dry matter intakes (DMI). For the control group, high treatment weight gains were significantly associated with high initial weight (r = 0.424, P = 0.049) and also high pre-treatment body weight (r = 0.678, P= 0.001). Treatment weight gain increased as the initial and pre-treatment weight gain increased in the control group. For the steers that were fed ZH, there was no significant correlation between the treatment body weight gain with initial weight (r = 0.097, P = 0.694) and also pre- treatment live weight (r = 0.393, P = 0.096). Supplementation of ZH significantly increased (P < 0.0001) the dressing percentage (56.4% vs. 58.4%) and had no significant (P>0.05) effect on the carcass weight. The outcome of the study suggest that supplementation of ZH in the diet during the last month of the finishing period enhances growth performance and shows the repartitioning capacity of the feed additive as a beta- agonist. / Agriculture and  Animal Health / M. Sc. (Agriculture (Animal Science)

An experiment was conducted using forty-one Bonsmara steers (age ± 7 months) to determine the effect of zilpaterol hydrochloride (ZH) on the growth performance and carcass characteristics. The trial was structured using a completely randomized design with two treatments, control and ZH group. The steers were fed ZH for 28 consecutive days at the end of the finishing period and ZH was withdrawn from the diet 2 days prior to slaughter of the animals. The steers were placed in individual pens and weighed fortnightly throughout the 4 months trial. Zilpaterol hydrochloride (ZH) was included in the diet at a rate of 8.3 mg/kg of DM. Feeding of ZH increased (P< 0.05) body weight (BW) gain and ADG (1.102 vs. 1.444) and tended to increase (P = 0.067) feed efficiency (F:G) during the last month of the finishing period. There were no significant differences (P> 0.05) in daily dry matter intakes (DMI). For the control group, high treatment weight gains were significantly associated with high initial weight (r = 0.424, P = 0.049) and also high pre-treatment body weight (r = 0.678, P= 0.001). Treatment weight gain increased as the initial and pre-treatment weight gain increased in the control group. For the steers that were fed ZH, there was no significant correlation between the treatment body weight gain with initial weight (r = 0.097, P = 0.694) and also pre- treatment live weight (r = 0.393, P = 0.096). Supplementation of ZH significantly increased (P < 0.0001) the dressing percentage (56.4% vs. 58.4%) and had no significant (P>0.05) effect on the carcass weight. The outcome of the study suggest that supplementation of ZH in the diet during the last month of the finishing period enhances growth performance and shows the repartitioning capacity of the feed additive as a beta- agonist. / Agriculture and  Animal Health / M. Sc. (Agriculture (Animal Science)

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-12-12T19:44:10Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese-Pedro Leonardo de Paula Rezende-2013.pdf: 1990022 bytes, checksum: 4763bbae50ef3499c69013720dde8eb1 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-12-16T09:26:17Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese-Pedro Leonardo de Paula Rezende-2013.pdf: 1990022 bytes, checksum: 4763bbae50ef3499c69013720dde8eb1 (MD5) / Made available in DSpace on 2014-12-16T09:26:17Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Tese-Pedro Leonardo de Paula Rezende-2013.pdf: 1990022 bytes, checksum: 4763bbae50ef3499c69013720dde8eb1 (MD5) Previous issue date: 2013-12-16 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / We studied the effect of substitution of 0, 33, 66 and 100% of ground corn (GC) by soybean hulls (SH) in diet’s concentrate portion of 144 Nellore heifers of 24 to 30 months of age and 263.40 + 13.90 kg of body weight in beginning of feedlot and slaughtered at different weights (<340, 340-370, 370-400 and >400 kg). There was no significant interaction between levels of substitution of GC by SH and slaughter weight classes being these effects studied separately. Diets were composed of 90 % concentrate and 10 % corn silage. The experimental period was 112 days, including the period of adaptation. The dry matter intake was not altered by substitution of GC by SH with mean values of 2.51 % of body weight. The substitution level of GC by SH resulted in a linear increase in NDF intake (1.08, 2.03, 2.92 and 3.78 kg/day) and reduced consumption of NDT (5.78, 5 16, 5.03 and 5.12 kg/day) with the addition of 0, 33, 66 and 100 % of GC by SH substitution, respectively. The average daily weight gain decreased linearly (1.24, 1.11, 1.02 and 0.89 kg / day), while feed conversion increased (6.20, 7.08, 7.77 and 8.67 kg DM intake/kg ADG) for the levels of 0, 33, 66 and 100% SH in the diet, respectively. The body condition score was not influenced by levels of substitution of GC by SH presenting mean values of 3.51 points. The body measurements were not affected by treatments, both on the back as the withers, with mean values of 138.5 and 133.25 cm, respectively. Measures of thorax perimeter and body length decreased linearly with the inclusion of SH levels. The slaughter weight decreased linearly with values of 383.52, 374.71, 363.25 and 366.27 kg for levels of 0, 33, 66 and 100 % replacement of GC for SH, respectively, however the hot carcass weight or cold were not affected by the replacement of GC by SH and showed average values of 203.52 and 199.25 kg, respectively. There was no effect of dietary treatment on hot carcass yield showing mean values of 54.92 %. The conformation of the carcasses was not affected by the replacement of GC by SH, with average values of 9.16 points. The subcutaneous fat thickness and loin eye area were not affected by dietary treatments and showed mean values of 5.3 mm and 53.08 cm2, respectively. The yields of primary carcass cut (front, special needle and side cut) were not affected by SH inclusion levels and showed average values of 36.52, 51.72 and 11.55%, respectively. The objective measurements of carcass were not affected by replacement levels of GC by SH. It was found linear effect of treatments on the compactness of carcasses showing average values of 1.56, 1.57, 1.51 and 1.45 cm/kg of cold carcass, to replacing levels of 0, 33, 66 and 100% of SH, respectively. The color and texture of meat were not influenced by dietary treatments and showed average values of 3.30 and 3.19 points, respectively. The marbling of the meat was not influenced by the substitution of GC by SH presenting mean values 8.56 points, with amplitude values between 2 and 17 points. The elevation of slaughter weight resulted in increased weights of hot and cold carcass. Animals slaughtered with weight >400kg had hot carcass yield of 52.76 %, lower than the group of 370-400 kg (56.55 %). The subcutaneous fat thickness was not affected by slaughter weight in any of the expression forms of this variable, with mean values of 5.26 mm and 2.67% of the cold carcass weight. The loin eye area increased with the increase of slaughter weight, and the correlation between these variables was 0.62 (P=0.001), however, when this variable was expressed to 100 kg cold carcass this difference disappeared, with average scores of 26,72 cm2 for each 100 kg of cold carcass. The animals slaughtered with weight >400kg showed better conformation (9.79 points) compared to the other weight classes did not differ among themselves. There was a significant effect of slaughter weight on the carcasses length, arm perimeter and cushion thickness which increased 5.9, 2.3 and 3.12 cm, respectively, amounted to slaughter weight of <340 to >400 kg. Animals slaughtered with weight >400kg had higher carcass compactness compared to the other treatments (1.65 cm long/ kg of cold carcass weight). The absolute weights of primary cuts of the carcass increased with the slaughter weight, however to adjust the weights of the front and rear to 100 kg of cold carcass, this difference disappeared, with values of 36.59 and 51.99%, respectively. The color and texture of the meat were not influenced by slaughter weights showing average values of 3.28 and 3.19 points, respectively. The marbling of the meat was lower in the group of animals slaughtered weighing less than 340 kg compared to the other weight classes did not differ among themselves. It was concluded which although not influence the main carcass characteristics, the replace of ground corn by soybean hulls in high concentrate diets is not efficient because has depressing effect on the productive performance, notably weight gain and feed conversion. Feedlot Nellore heifers must not be slaughtered weighing less than 340 kg because they have lower carcass weight and less marbling of the meat. / Foram estudados os efeitos da substituição de 0, 33, 66 e 100% do milho moído (MM) por casca do grão de soja (CS), na porção concentrada da dieta, de 144 novilhas de descarte da raça Nelore com 24 a 30 meses de idade e 263,40 + 13,90 kg de peso vivo médio inicial, terminadas em confinamento e abatidas com diferentes pesos (<340; 340-370; 370-400 e >400 kg). Não foi constatada interação significativa entre os níveis de substituição do MM pela CS e classes de peso ao abate sendo estes efeitos estudados separadamente. As dietas foram constituídas de 90% de concentrado e 10% de silagem de milho. O período experimental foi de 112 dias, incluindo o período de adaptação. O consumo de matéria seca não foi alterado pelos níveis de CS na dieta com valores médios de 2,51% do peso corporal. A elevação do nível de CS em substituição ao MM resultou em aumento linear do consumo de FDN (1,08; 2,03; 2,92 e 3,78 kg/dia) e redução do consumo de NDT (5,78; 5,16; 5,03 e 5,12 kg/dia) com a inclusão de 0, 33, 66 e 100% de CS em substituição ao MM, respectivamente. O ganho de peso médio diário reduziu linearmente (1,24; 1,11; 1,02 e 0,89 kg/dia), enquanto a conversão alimentar aumentou (6,20; 7,08; 7,77 e 8,67 kg de MS ingerida/kg de GMD) para os níveis de 0, 33, 66 e 100% de CS na dieta, respectivamente. O escore de condição corporal não foi alterado pelos níveis de substituição do MM por CS apresentando valores médios de 3,51 pontos. As medidas corporais de altura não foram influenciadas pelos tratamentos, tanto na garupa quanto na cernelha, apresentando valores médios de 138,5 e 133,25 cm, respectivamente. As medidas de perímetro torácico e comprimento corporal reduziram linearmente, conforme aumentou a inclusão de CS. O peso de abate (PAB) reduziu linearmente apresentando valores de 383,52; 374,71; 363,25 e 366,27 kg para os níveis de 0, 33, 66 e 100% de substituição do MM por CS, respectivamente, entretanto os pesos de carcaça quente (PCQ) ou fria (PCF) não foram alterados pela substituição do MM por CS e apresentaram valores médios de 203,52 e 199,25 kg, respectivamente. Não foi constatado efeito dos tratamentos alimentares sobre o rendimento de carcaça quente que apresentou valores médios de 54,92%. A conformação das carcaças não foi influenciada pela substituição do MM por CS, apresentando valores médios de 9,16 pontos. A espessura de gordura subcutânea (EGS) e a área de olho de lombo (AOL) não foram influenciadas pelos tratamentos alimentares e apresentaram valores médios de 5,3 mm e 53,08 cm2, respectivamente. O rendimento dos cortes primários da carcaça dianteiro, traseiro especial e ponta de agulha não foram alterados pela inclusão de CS e apresentaram valores médios de 36,52; 51,72 e 11,55% da carcaça fria, respectivamente. As medidas objetivas da carcaça não foram influenciadas pelos níveis de substituição do MM por CS. Constatou-se efeito linear decrescente dos tratamentos sobre a compacidade das carcaças apresentando valores médios de 1,56; 1,57; 1,51e 1,45 cm/kg de carcaça fria, para os níveis de 0, 33, 66 e 100% de substituição do MM por CS, respectivamente. A cor e a textura da carne não foram influenciadas pelos tratamentos alimentares e apresentaram valores médios de 3,30 e 3,19 pontos, respectivamente. O marmoreio da carne não foi alterado pela substituição do MM por CS apresentando valores médios 8,56 pontos, com valores de amplitude entre 2 e 17 pontos. A elevação dos pesos de abate resultou em aumento dos pesos da carcaça quente e fria. Animais abatidos com peso superior à 400 kg apresentaram rendimento de carcaça quente de 52,76%, inferior ao grupo de 370-400 kg (56,55%). A EGS não foi influenciada pelos pesos de abate em nenhuma das formas de expressão desta variável, apresentando valores médios de 5,26 mm e 2,67% em relação ao peso da carcaça fria. A AOL aumentou com a elevação dos pesos de abate, sendo a correlação entre estas variáveis de 0,62 (P=0,001) entretanto quando esta variável foi ajustada para 100 kg de carcaça fria esta diferença deixou de existir, apresentando resultados médios de 26,72 cm2 para cada 100 kg de carcaça fria. Os animais abatidos com peso superior a 400 kg apresentaram melhor conformação (9,79 pontos) que os demais grupos experimentais que não diferiram entre si. Verificou-se efeito significativo dos pesos de abate sobre o comprimento das carcaças, perímetro de braço e espessura de coxão que aumentaram 5,9; 2,3 e 3,12 cm, respectivamente, quando elevou-se o peso de abate de <340 à >400 kg. Animais abatidos com peso superior à 400 kg apresentaram maior compacidade das carcaças em relação aos demais tratamentos (1,65 cm de comprimento/kg de carcaça fria). Os pesos absolutos dos cortes primários da carcaça aumentaram conforme elevou-se o peso de abate, entretanto ao ajustar os pesos do dianteiro e do traseiro em relação à 100 kg de carcaça fria, esta diferença deixou de existir, apresentando valores de 36,59 e 51,99%, respectivamente. A cor e textura da carne não foram influenciadas pelos pesos de abate apresentando valores médios de 3,28 e 3,19 pontos, respectivamente. O marmoreio da carne, foi menor no grupo de animais abatidos com peso inferior à 340 kg em comparação ás demais classes de peso que não diferiram entre si. Concluiu-se que apesar de não influenciar as principais características da carcaça, a casca de soja não é eficiente para substituir o milho moído em dietas de alta inclusão de concentrado para novilhas confinadas, pois tem efeito depressivo sobre as principais variáveis de desempenho produtivo, notadamente o ganho em peso e a conversão alimentar. Novilhas de descarte da raça Nelore terminadas em confinamento não devem ser abatidas com peso inferior à 340 kg pois apresentam menor peso de carcaça e menor grau de marmoreio da carne.