Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Monensin was approved in the 1970’s as a feed additive to ruminant diets. Since then, many studies on the effects of Monensin were done. Its mode of action includes the improvement of feed conversion by altering rumen fermentation. This alteration results in a change in the rumen microbial population. Some processes that benefit from the manipulation of rumen microbial population are volatile fatty acid production, peptide degradation and amino acid deamination. The use of ionophores as an antibacterial product in animal feeds were banned by the European union ( EU) in 2006 because of chemical residues found in the edible product making it potentially unhealthy for human consumption and it is also socially unacceptable. Thus, alternative sources need to be identified to help improve the rumen microbial population. Such an alternative could be plant based EO. Oregano (Origanum vulgare) is a natural anti-bacterial compound affecting a variety of gram positive and gram negative bacteria. It has been reported to improve the overall health and production of lactating dairy cows by enhancing rumen fermentation. The aim of this study was to determine the effect of an essential oil extracted from oregano on production and rumen fermentation of Jersey cows grazing ryegrass pasture during spring. Effects were determined on milk yield, milk composition, live weight body condition, rumen pH, Ammonia-nitrogen (NH3-N) and volatile fatty acid (VFA) composition, organic material (OM) and neutral detergent fibre (NDF) digestibility of pasture in the rumen. Fifty four early lactation Jersey cows were blocked, according to days in milk (DIM), 4% fat corrected milk (FCM) and lactation number. Cows within blocks were randomly allocated to one of the three treatments. The three treatments were as follows: Control (CON; maize based concentrate with no feed additives), an ionophore treatment, (MON; a maize based concentrate with monensin provided a daily dose at 300 mg per cow), and an essential oil treatment (EO; a maize based concentrate with oregano extract provided at a daily dose of 1.15 g per cow. Cows received 6 kg of concentrate in the milking parlour and were allocated 10 kg dry matter (DM) of ryegrass pasture, divided into two grazing periods after each milking. Before milking, cows were separated into their respective treatment groups for milking and the consumption of their specific concentrate treatments. Milk yield was recorded on a daily basis. Composite milk samples were collected per cow on a bi-weekly basis. Live weight and body condition score (BCS) were determined before and after the study. Six rumen cannulated cows were used in the rumen study. Two cows were randomly allocated to each of the three treatments in a 3 x 3 Latin square design (three treatments and three periods) thus all the cows were subjected to all three treatments over the experimental period. Ruminal pH, volatile fatty acids (VFA) concentration, ruminal ammonia-nitrogen (NH3-N), and in sacco degradability were determined. The daily average milk yield and milk fat content did not differ among treatments (P > 0.05) and were 20.5, 20.3 and 20.4 kg per cow and 4.5, 4.5 and 4.6 % for cows receiving the CON, MON and EO concentrates respectively. Milk protein and milk lactose content increased (P < 0.05) for the two additive treatments in comparison to control and were 3.39b, 3.55a and 3.60a % for milk protein and 4.50b, 4.80a and 4.80a % for milk lactose where cows received the CON, MON and EO treatments, respectively. Ruminal pH values did not differ among treatments, however, the average overall pH over the 24 hour profile was higher for the two additive treatments. There were no differences in total volatile fatty acid concentrations among the three treatments. With regards to individual VFA, propionate was decreased in the MON treatment when compared to the CON treatment. The ruminal ammonia nitrogen concentration did not differ among treatments. There were no differences in DM and NDF degradability (DMd and NDFd) on the 6 h incubation period but monensin increased the DMd at 30 h incubation and both monensin and oregano increased NDFd after 30 h incubation. To conclude the use of monensin and oregano oil extract have shown to be beneficial with regards to increasing the milk protein and milk lactose content as well as the NDFd. The average overall pH from the pH profile resulted in the two additive treatments being higher when compared to the control treatment. This could be beneficial to rumen fermentation and have a positive effect on the microbial population. As monensin and oregano oil extract showed similar results, oregano oil extract can be considered as an alternative natural feed additive to monensin. / AFRIKAANSE OPSOMMING: Monensin is in die 1970's goedgekeur as 'n voerbymiddel in herkouerdiëte. Sedertdien het navorsing met betrekking tot die invloed van monensin vinnig toegeneem. Die werking van monensin sluit die verbetering van voeromsetting in deur die verbetering van rumenfermentasie. Die verandering in rumenfermentasie het ‘n invloed op die rumenmikrobiese bevolking. Sommige prosesse wat voordeel trek uit die manipulasie van die rumenmikrobiese bevolking is onder andere vlugtige vetsuurproduksie, peptiedafbraak en aminosuurdeaminering. Die gebruik van ionofore as 'n antibakteriese produk in veevoere is gedurende 2006 deur die Europese Unie verbied as gevolg van chemiese residue wat in die eetbare produk gevind is. Die residue maak dit moontlik ongesond vir menslike verbruik en dit is ook nie sosiaal aanvaarbaar nie. Alternatiewe produkte wat help om die rumenmikrobiese bevolking te verbeter en manipuleer moet geïdentifiseer word. Een alternatiewe produk is plantgebasseerde essensiële olies. Origanum (Origanum vulgare) is 'n natuurlike anti-bakteriële produk wat 'n verskeidenheid van gram-positiewe en gram-negatiewe bakterieë in die rumen beïnvloed. Daar is gevind dat die algemene gesondheid en produksie van 'n lakterende melkkoeie verbeter deur die verbetering van rumen fermentasie. Die doel van hierdie studie was om die invloed van 'n essensiele olie-ekstrak uit oreganum op die produksie en rumenfermentasie van Jerseykoeie wat raaigras gedurende die lente bewei, te bepaal. Effekte is ondersoek op melkproduksie, melksamestelling, lewende massa, liggaamskondisie, rumen pH, ammoniak stikstof konsentrasie (NH3-N) en vlugtige vetsuursamestelling (VFA) asook ruminale droeë materiaal (DMd)- en vesel-verteerbaarheid (NDFd) van die weiding. Vier en vyftig Jersey koeie in vroeë laktasie is geblok volgens dae in melk (DIM), 4% vet gekorigeerde melk (VGM) en laktasie nommer. Koeie binne blokke is ewekansig aan een van die drie behandelings toegeken. Die drie behandelings was as volg: Kontrole (CON, mielie-gebaseerde konsentraat met geen voer-bymiddel nie), ‘n ionofoor-behandeling (MON; mielie-gebaseerde konsentraat met monensin teen 300 mg / koei per dag), essensiële olie-behandeling (EO; mielie-gebaseerde konsentraat met oreganum ekstrak teen 1.15 g / koei per dag). Koeie het 3 kg konsentraat in die melkstal ontvang met elke melking en 10 kg droeë material (DM) raaigras-weiding is per koei toegeken. Weidingsessies is verdeel in twee periodes, naamlik na elke melking. Voor melking is die koeie geskei om te verseker dat hulle die regte behandeling in die melkstal ontvang. Melkproduksie is daagliks aangeteken. Saamgestelde melk monsters is tweeweekliks per koei versamel. Lewende massa (LW) en liggaamskondisie (BCS) is aan die begin en teen die einde van die studie bepaal. Ses rumen-gekannuleerde koeie is in die rumen studie gebruik. Twee koeie is toegeken aan elk van die drie behandelings in 'n 3 x 3 Latynse vierkant ontwerp (drie behandelings en drie periodes) en al die koeie het gevolglik al drie behandelings gedurende die eksperimentele periode ontvang. Ruminale pH, VFA konsentrasie, ruminale NH3-N, en in sacco degradeerbaarhede; DMd en NDFd is bepaal. Die daaglikse gemiddelde melkproduksie en melkvetinhoud het nie beduidend tussen behandelings verskil nie (P > 0.05) en was 20.5, 20.3 en 20.4 kg/koei per dag en 4.5, 4.5 en 4.6% vir koeie op die drie behandelings (CON, MON, EO), onderskeidelik. Melk proteïen en melk laktose het aansienlik toegeneem (P < 0.05) vir die twee behandelings met die supplemente in vergelyking met die CON behandeling met waardes van 3.4, 3.6 en 3.6% vir melk proteïen en 4.5, 4.8 en 4.8% vir koeie op die CON, MON en EO behandelings, onderskeidelik. Die rumen pH oor 24 uur het nie verkil tussen die drie behandelings nie en die totale VFA konsentrasie het ook nie verskil nie. Die propionaatkonsentrasie het wel afgeneem op die MON behandeling in vergelyking met die CON. Die rumen NH3-N het nie tussen die drie behandelings verskil nie. Die DMd en NDFd verteerbaarhede van die raaigras in die rumen het nie verskil na ‘n 6 h inkubasieperiode nie. Na 30 h inkubasie het monensin ‘n hoër DM verteerbaarheid getoon en in beide die MON en EO-behandelings het die NDF-verteerbaarheid verhoog wanneer dit vergelyk word met die CON. Om saam te vat; die gebruik van monensin en oregano olie ekstrak het getoon dat dit voordelig kan wees met betrekking tot die verhoging van die melk proteïen en melk laktose inhoud, sowel as die NDFd. Die gemiddelde pH van die pH profiel het gelei tot hoër gemiddeldes vir die twee voerbyvoegsel behandelings in vergelyking met die kontrole behandeling. Dit kan voordelig wees om rumen fermentasie te verbeter en dus ‘n positiewe uitwerking te hê op die mikrobiese bevolking. Monensin en oregano olie ekstrak het soortgelyke resultate getoon en daarom kan oregano olie ekstrak beskou word as 'n alternatiewe natuurlike voerbyvoegsel.

Submitted by (edna.saturno@ufrpe.br) on 2017-05-17T14:02:54Z No. of bitstreams: 1 Maria Josilaine Matos dos Santos.pdf: 609545 bytes, checksum: 6c7d8659c798aee4fe33d56cf53317d8 (MD5) / Made available in DSpace on 2017-05-17T14:02:54Z (GMT). No. of bitstreams: 1 Maria Josilaine Matos dos Santos.pdf: 609545 bytes, checksum: 6c7d8659c798aee4fe33d56cf53317d8 (MD5) Previous issue date: 2011-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The experiment was conducted to evaluate the effects of inclusion of cassava instead of maize as feed for dairy goats of Saanen. The results were discussed in two chapters, the first consisting of the nutrient consumption, production, composition and physical characteristics of milk and the second digestibility and ingestive behavior of animals. Five lactating goats were used with an average production of 2 kg of milk per day allotted to a 5x5 Latin square design with five levels of inclusion of cassava (0, 10, 20, 30 and 40%) replacing corn. The dry matter intake in grams (g/day) in relation to body weight (%BW) and gram metabolic weight showed a quadratic behavior as a function of inclusion levels of cassava instead of maize grits. The intake of nutrients followed the behavior of dry matter intake. NDF intake, expressed in kilograms, depending on body weight and metabolic weight decreased linearly and non-fibrous carbohydrates linear increase. The replacement of cracked corn by cassava production did not affect kg of milk and milk yield corrected for 3.5% fat. The fat and total solids of milk in kg and percentage were not affected by inclusion levels of cassava instead of maize. The protein showed a linear increased and lactose quadratic effect. The physical characteristics of pH, temperature and density were not affected by inclusion levels of cassava instead of maize. The apparent digestibility of DM, CP, OM, TC was not affected by the replacement levels of ground corn for cassava. The apparent digestibility of the NDF fraction decreased linearly while that of CNF increased linearly with the increase of cassava in diets. Feeding behavior in all studied variables was not influenced by the inclusion of zest in place of corn. In dairy goats with produce of 2,0kg of milk per day, the corn grain can be completely replaced by cassava, resulting in increased nutrient intake above 30% inclusion, without changing the physical characteristics and production of milk, positively just changes the protein and lactose. The replacement of cracked corn by cassava did not affect the digestibility and chewing behavior of lactating goats. However, chalking and non-fiber carbohydrate of cassava are characteristics that should be considered. / O experimento foi conduzido com o objetivo de avaliar os efeitos da inclusão da raspa de mandioca em substituição ao milho na alimentação de cabras leiteiras de raça Saanen. Os resultados foram discutidos em dois capítulos: o primeiro tratou do consumo de nutrientes, produção, composição e características físicas do leite, e o segundo da digestibilidade de nutrientes e do comportamento ingestivo dos animais. Foram utilizadas cinco cabras lactantes com produção média de 2kg de leite/dia, distribuídas em um quadrado latino 5x5, com cinco níveis de inclusão de raspa de mandioca (0, 10, 20, 30 e 40%) em substituição ao milho. O consumo de matéria seca em grama (g/dia), em relação ao peso vivo (%PV) e grama por peso metabólico apresentou comportamento quadrático em função dos níveis de inclusão da raspa de mandioca em substituição do milho triturado. O consumo dos nutrientes seguiu o comportamento do consumo de matéria seca. O consumo de FDN, expresso em quilograma, em função peso vivo e peso metabólico, apresentou comportamento linear decrescente e carboidratos não fibrosos linear crescente. A substituição do milho triturado pela raspa de mandioca não influenciou a produção de leite em kg e produção de leite corrigido para 3,5% de gordura. A gordura e sólidos totais do leite em percentuais e em kg não foram influenciados pelos níveis de inclusão de raspa de mandioca em substituição ao milho. A proteína apresentou efeito linear crescente e lactose efeito quadrático. As características físicas pH, densidade e temperatura não foram influenciadas pelos níveis de inclusão da raspa de mandioca em substituição ao milho. A digestibilidade aparente da MS, PB, MO, CHOT não foi influenciada pelos níveis de substituição do milho triturado por raspa de mandioca. A digestibilidade aparente da fração FDN diminuiu linearmente enquanto que a dos CNF aumentou linearmente em função do aumento de raspa de mandioca nas dietas experimentais. O comportamento ingestivo, em todas as variáveis estudadas, não teve influência da inclusão da raspa em substituição ao do milho. Em cabras leiteiras com produção de 2,0kg de leite/dia o milho triturado pode ser substituído pela raspa de mandioca em níveis superiores de 30% até a completa substituição, com aumento de consumo de nutrientes, sem alterar a produção e características físicas de leite, apenas altera positivamente os teores de proteína e lactose. Não interfere na digestibilidade, assim como no comportamento ingestivo de cabas em lactação.

Made available in DSpace on 2017-07-10T17:47:52Z (GMT). No. of bitstreams: 1 Joana_Karin_Finkler.pdf: 807546 bytes, checksum: 6fd6fd164abbf7c0ca6f67ba18c541a7 (MD5) Previous issue date: 2013-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Current analysis evaluates the inclusion effect of feather meal in diets with and without aminoacids supplementation on the performance, centesimal composition, hematological parameters and feeding costs of Nile tilapia fingerlings, Oreochromis niloticus. One thousand and four hundred Nile tilapia fingerlings, initial average weight 4.98±0.08 g, distributed in 28 small cages of 1m³, with 50 fish each, were used. Three levels (8, 16 and 24%) of hydrolyzed feather meal (FM) inclusion and two groups, one with and the other without synthetic aminoacids supplementation (AAs), were evaluated during 65 days. Control treatment with neither feather meal nor aminoacids supplementation was also employed, totalizing seven treatments and four replications. Productive performance analysis including total length (TL), weight gain (WG), apparent food conversion (AFC), survival (SU), condition factor (CF) and protein efficiency rate (PER) was performed at the end of the experiment, coupled to body parameters such as visceral fat index (VFI) and hepatosomatic index (HIS). Blood samples were collected for erythrocytes counting and determination of hemoglobin, hematocrit, average corpuscular volume (ACV) and average corpuscular hemoglobin concentration (ACHC). The entire fish was used for the analysis of centesimal composition, namely, moisture (MO), protein (P), ether extract (EE) and mineral matter (MM)). Diet costs per kilo of WG were also assessed. Treatments did not influence (p>0.05) SU, HIS, CF, MO and MM and best results for FM and WG were those of treatments with 8% FM with or without AAs supplementation. AFC was higher and PER lower in treatments with 24% FM without supplementation. P rate was lower in treatment with inclusion of 24% FM without supplementation when compared to control, whereas EE had higher levels of inclusion when compared to control. Hematologic parameters were kept within the species´s normal variation level. Treatment with 8% FM with supplementation presented lower feeding costs. Results show that feather meal may be used in diets for Nile tilapia up to 8% inclusion, with or without supplementation of AAs, without any liability in performance, chemical composition and higidity. In fact, supplementation at the above inclusion level with AAs is economically more viable / Esse estudo teve por objetivo avaliar o efeito da inclusão de farinha de pena em dietas com e sem suplmentação de aminoácidos sobre o desempenho, composição centesimal, parâmetros hematológicos e custos de alimentação de alevinos de tilápia do Nilo Oreochromis niloticus. Para isso, foram utilizados 1.400 alevinos de tilápia do Nilo com peso inicial médio de 4,98 ± 0,08 g distribuídos em 28 hapas de 1 m³ com 50 peixes cada. Durante 65 dias foram avaliados três níveis de inclusão de farinha de pena hidrolisada (FP) (8, 16 e 24%) e dois grupos, um com e outro sem suplementação de aminoácidos sintéticos (AAs). Além disso, foi utilizado um tratamento controle, cuja dieta não continha nem farinha de pena e nem suplementação de aminoácidos, totalizando sete tratamentos com quatro repetições. Ao final do experimento foram realizadas análises de desempenho produtivo (comprimento total (CT), ganho de peso (GP), conversão alimentar aparente (CAA), sobrevivência (SO), fator de condição (FC) e taxa de eficiência proteica (TEP) e dos parâmetros corporais, (índice de gordura visceral (IGV) e índice hepatossomático (IHS)). As mostras de sangue foram coletadas para contagem de eritrócitos e determinação de hemoglobina, hematócrito, volume corpuscular médio (VCM) e concentração de hemoglobina corpuscular média (CHCM). Foram utilizados peixes inteiros para a análise da composição centesimal (umidade (UM), proteína (PB), extrato etéreo (EE) e matéria mineral (MM)). Também foi avaliado o custo das dietas por quilo de GP. Os tratamentos não influenciaram (p>0,05) na SO, IHS, FC, UM e MM. Os melhores resultados de PF e GP foram dos tratamentos com 8% de FP com ou sem suplemetação de AAs. A CA foi maior e a TEP menor no tratamento com 24% de FP sem suplementação. A PB foi menor no tratamento com inclusão de 24% FP sem suplementação em relação ao controle, e o EE aumentou com níveis mais altos de inclusão em relação ao controle. Os parâmetros hematológicos mativeram-se dentro da faixa de variação normal para a espécie. O tratamento com 8% de FP com suplementação apresentou o menor custo de alimentação. Conclui-se que a farinha de penas pode ser utilizada em dietas para tilápia do Nilo em até 8% de inclusão, com ou sem suplementação de AAs, sem prejuízos no desempenho, composição química e higidez, sendo que a suplementação deste nível de inclusão com AAs é economicamente mais viável

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-30T14:29:22Z No. of bitstreams: 1 2008 - Ant?nio Roque Sarmento de Oliveira.pdf: 2410060 bytes, checksum: 48fb15db1a9375b37517df56da372cd5 (MD5) / Made available in DSpace on 2017-05-30T14:29:22Z (GMT). No. of bitstreams: 1 2008 - Ant?nio Roque Sarmento de Oliveira.pdf: 2410060 bytes, checksum: 48fb15db1a9375b37517df56da372cd5 (MD5) Previous issue date: 2008-07-09 / Due to the shortage in the labour market, it is necessary to provide an education that stimulates the student to conquer a profession. Not just the mere transmission of knowledge. There is a need for action liberating, in which the teaching profession give rise to the task of educator. Thus, the technical-vocational education represents an alternative, because at the same time that teaches, ensures a profession. The objective of this research was improving knowledge in the field of education and understand the reality of vocational education, taking as the object of study the Agrot?cnica Federal School of Salinas. This study was conducted with the students of the second series of technical course in Agriculture. The methodology is based on qualitative research. A questionnaire was used by students, supervised by Professor advisor for the collection of information among family farmers. The council was divided into 05 regions, totaling 50 respondents. The search diagnosed the economic importance of the creation of pigs and the parameters evaluated were the profile of the interviewees, position in the process of agricultural production, current insertion in the labour market agricultural, socioeconomic and participation policy. Through the results, it was concluded that most respondents residing for a long time in the farm and are owners of the property. Although the sugar cane is cultivated by most producers it is not widely used as an alternative food for pigs. It assessed the participation of students in the search through a questionnaire aimed at assessing the importance of research for them and encourage them to basic scientific research. Another segment was the search done with pigs in the process of termination. The Escola Agrot?cnica, provided a complete cycle of pigs, facilitated the conduct of the trial. The objective of the research was to evaluate the effects of the replacement of 15% of sugar cane by the diet provided. The effects were studied performance, quality of the carcass, morphology of gastrointestinal tract and economic analysis. The study based on the inclusion of sugar cane in the diet of pigs, replacing 15% of the dry matter-of the diet, because by its energy wealth to sugar cane can be considered a viable alternative in the feeding of these animals. The ration provided to them was formulated in order to meet nutritional requirements. In performance were analyzed the consumption of diet, weight gain and feed conversion. The amount of feed given not caused reduction in the thickness of bacon and not influenced the weight of the digestive and other organs of finish pigs. / Devido ? escassez de m?o-de-obra especializada no mercado de trabalho, ? necess?rio ministrar uma educa??o que estimule o estudante ? conquista de uma profiss?o. N?o basta a simples transmiss?o de conhecimentos. Torna-se necess?ria uma a??o libertadora, em que a profiss?o de professor ceda lugar ? miss?o de educador. Assim, o ensino t?cnico-profissionalizante representa uma alternativa, pois ao mesmo tempo em que ensina, garante uma profiss?o. O objetivo desta pesquisa foi aprimorar os conhecimentos na ?rea da educa??o e compreender a realidade educacional do ensino profissionalizante, tomando como objeto de estudo a Escola Agrot?cnica Federal de Salinas. O presente trabalho foi desenvolvido juntamente com os alunos das segundas s?ries do curso t?cnico em Agropecu?ria. A metodologia fundamentou-se na pesquisa qualitativa. Um question?rio foi utilizado pelos discentes, supervisionados pelo professor orientador, para a coleta de informa??es junto aos agricultores familiares. O munic?pio foi subdividido em 05 regi?es, totalizando 50 entrevistados. A pesquisa diagnosticou a import?ncia econ?mica da cria??o de su?nos e os par?metros avaliados foram: o perfil dos entrevistados, posi??o no processo de produ??o agropecu?ria, atual inser??o no mercado de trabalho agr?cola, n?vel socioecon?mico e participa??o pol?tica comunit?ria. Atrav?s dos resultados, concluiu-se que a maioria dos entrevistados reside h? muito tempo na fazenda e s?o propriet?rios dos im?veis. Embora a cana-de-a??car seja cultivada pela maioria dos produtores ela ? pouco utilizada como alternativa alimentar para su?nos. Foi avaliada a participa??o dos alunos na pesquisa atrav?s de um question?rio visando a avaliar a import?ncia da investiga??o para os mesmos e incentiv?-los a inicia??o cient?fica. Outro segmento foi ? pesquisa feita com su?nos em fase de termina??o. A Escola Agrot?cnica, provida de uma suinocultura de ciclo completo, facilitou a condu??o do experimento. O objetivo da pesquisa foi avaliar os efeitos da substitui??o de 15% de cana-de-a??car pela dieta fornecida. Os efeitos estudados foram: o desempenho, qualidade da carca?a, morfologia do trato gastrointestinal e an?lise econ?mica. O estudo fundamentou-se na inclus?o da cana-de-a??car na dieta alimentar dos su?nos, substituindo 15% da mat?ria-seca da dieta, porque pela sua riqueza energ?tica a cana-de-a??car pode ser considerada uma alternativa vi?vel na alimenta??o desses animais. A dieta fornecida a eles foi formulada de modo a atender ?s exig?ncias nutricionais. No desempenho, foram analisados o consumo de ra??o, ganho de peso e convers?o alimentar. A quantidade de dieta ministrada n?o ocasionou redu??o na espessura de toucinho e nem influenciou no peso dos ?rg?os digestivos e demais ?rg?os de su?nos em termina??o

Made available in DSpace on 2014-08-20T14:38:50Z (GMT). No. of bitstreams: 1 Tese_Juliana_Klug_Nunes.pdf: 3840037 bytes, checksum: ea550450e1744b73f51a0136117e7789 (MD5) Previous issue date: 2010-07-30 / A study was run to evaluate the partial replacement of corn by sweet potato meal, with or without supplementation of enzymes, in broiler diets from 1 to 47 days of age. A total of 150 day-old male broiler chicks were distributed in 30 pens of metallic batteries. A complete experimental block design in 3 x 2 experimental factorial arrangement was used (0, 20 and 40% of sweet potato meal and 0 and 200 g/ton of enzyme complex) with a total of 5 experimentals units per treatment (pen with 5 birds). Feed intake, body weight, feed conversion, and factor of efficiency rate and uniformity were evaluated at 14, 21 and 28 days of age. At that same age, 5 birds per treatment were sacrificed by cervical dislocation to evaluate allometric development of heart, liver, proventriculus and gizzard and the biometry of duodenum jejunum, ileum, ceca and rectum-colon. From 15 to 17 days of age, feed intake, weight gain, wet excreta weight, fecal moisture content, dry matter, crude protein, crude fiber, éter extract, ash, calcium and phosphorus of the excreta were recorded. After 28 days, the remaining birds were reallocated on in 6 floor pens. At 39 and at 47 days of age, carcass traits, organ allometry and intestinal biometry were evaluated the 3 birds per treatment. The variables were subjected to analysis of variance for main effects the sweet potato meal and enzyme, followed by splitting into levels of o the factor sweet potato meal into polinomial components. Results indicated that the replacement of corn by sweet potato meal, with or without enzyme complex addition, have not improved the productive performance of the broilers, adverselly affected carcass traits, allometry of organs, intestinal biometry and digestibility; and had a negative effect on body weight at 14, 21 and 28 days of age of the birds. The enzyme complex used has not altered the variables examined. / Um estudo foi conduzido para avaliar a substituição parcial do milho pela farinha de batata doce, com ou sem suplementação enzimática, nas dietas de frangos de corte de 1 a 47 dias de idade. Cento e cinquenta pintos de corte machos, com um dia de idade foram distribuídos em 30 boxes de duas baterias metálicas. O delineamento experimental utilizado foi o de blocos ao acaso em arranjo fatorial 3 × 2 (0, 20 e 40% de farinha de batata doce e 0 e 200 g/ton de complexo enzimático) com cinco unidades experimentais (boxe com cinco aves). Aos 14, 21 e 28 dias de idade dos frangos de corte foram avaliados consumo de ração, peso corporal, conversão alimentar e índice de eficiência produtiva. Nestes mesmos dias, foram pesadas e sacrificadas por deslocamento da articulação crânio-cervical, cinco aves por tratamento, para coleta e determinação alométrica do coração, fígado, proventrículo e moela, e biométrica do duodeno, jejuno, íleo, cólon-reto e cecos. Entre 15 e 17 dias de idade das aves também foram analisados consumo de ração, ganho de peso, peso das excretas úmidas, quantidade de umidade nas excretas, matéria seca, proteína bruta, fibra bruta, extrato etéreo, cinzas, cálcio e fósforo nas excretas. Após os 28 dias de idade, as aves remanescentes, segundo o tratamento, foram realojadas em seis boxes com cama de maravalha e aos 39 e 47 dias de idade foram avaliados características de carcaça, alometria de órgãos e biometria intestinal de três aves por tratamento. As variáveis foram submetidas à análise da variação para os testes de significância dos efeitos principais e da interação de farinha de batata doce e complexo enzimático, seguido da decomposição da variação entre os níveis do fator farinha de batata doce em componentes polinomiais. Os resultados indicaram que a substituição do milho pela farinha de batata doce, com ou sem a suplementação do complexo enzimático, não foi efetiva sobre o desempenho produtivo das aves, afetou adversamente características de carcaça, alometria de órgãos, biometria intestinal e digestibilidade; e interferiu negativamente sobre o peso corporal, aos 14, 21 e 28 dias de idade das aves. A suplementação do complexo enzimático não demonstrou benefícios sobre as variáveis analisadas.

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