Thesis (PhD(Agric))--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Exogenous fibrolytic enzymes (EFE) as additives in ruminant feeds are being researched worldwide. Promising effects on dry matter intake (DMI), digestibility and production in especially dairy cows, but also feedlot steers and even sheep have been observed. However, lack of or negative effects are also reported and the need arises for clarity on the mode-of-action of EFE. Forages are characterised as being highly heterogenic and contain varying concentrations of fibre. The fibre, in turn, varies greatly in digestibility, due to the chemical as well as anatomical build-up of this complex carbohydrate. Fibre, however, presents a major source of potential energy for ruminant animals and EFE is a viable option to increase the digestibility of forages. Therefore, a study with the aim of establishing whether EFE can affect the digestibility of forages, how it affects the digestibility and the clarification of the mode-of-action was drafted. From the literature, the first objective was readily attained and clear indications exist that EFE can indeed improve animal performance when their diets are treated with such enzymes. From the current study, it was shown that EFE can alter the rate and extent of gas production of certain forages (lucerne, kikuyu and weeping love grass) and also improve the in vitro digestibility thereof (P < 0.05). This is in agreement with other research findings and it was concluded that these effects were likely exerted during the early stages of digestion. A complete feed for sheep, when treated with the EFE, showed positive effects on the in sacco digestibility, as well as on the digestion kinetics of the feed (P < 0.05). The in vitro digestibility of the complete feed was also improved due to EFE treatment (P < 0.05). The observations on in vitro digestibility were less marked when a purified xylanase, obtained from the partial purification of the EFE cocktail, was used as the sole fibrolytic enzyme treatment. It is apparent, therefore, that enzyme specificity plays a major role in obtaining positive effects on digestibility of forages and feeds. In agreement with the literature, it is proposed that the approach to improve the digestibility of forages should be to use EFE cocktails containing various enzymes, matching the complexity of the substrate. The major aim of the study was, however, an in depth investigation of the mode-of-action of EFE. This aim was approached by observing changes in plant tissue material at the histological level upon treatment with EFE and incubation in buffered rumen fluid. Results showed that EFE had subtle, yet significant effects on cell wall material for the various tissues studied (P < 0.05). The major effect observed here was that EFE had a thinning effect on the cell wall thickness (P < 0.05). It was deduced that as EFE affected the cell wall of the plant material, earlier access by microorganisms could be achieved. Also, nutrients caught in the cell wall matrix could then be released for digestion. Therefore, observations that EFE increases the rate of digestion, as well as the extent of digestion of not only fibre, but also protein, were explained by the enzyme’s action on cell wall material. It was concluded that there is definite merit in the use of EFE to improve the digestibility of ruminant feeds and that this is partly related to effects on the cell walls of the forages. The effects can be expected to occur during the early stages of digestion, thereby potentially increasing the passage rate of digesta from the rumen. Additionally, the effect of the EFE is not limited to fibre and increased digestibility of all nutrients can be expected, thereby increasing the overall digestibility of the feed. Future research should further elucidate the mode-of-action of EFE using advanced technologies routinely employed in the plant sciences. Additionally, the main potential advantage of EFE treatment lies in improving the digestibility of poor quality roughages. Unfortunately, this is an area where limited positive effects are observed and in depth investigations should be undertaken to classify the specificity and optimum conditions of EFE to better match the complexity of the substrate being treated. / AFRIKAANSE OPSOMMING: Eksogene fibrolitiese ensieme (EFE) word tans wêreldwyd ondersoek vir die gebruik daarvan as voerbymiddels vir herkouers. Belowende effekte op DMI, verteerbaarheid en produksie van vernaam melkbeeste, maar ook voerkraalbeeste en selfs skape is al gerapporteer. Swak en selfs negatiewe effekte word egter ook waargeneem en daarom is ʼn deeglike ondersoek na die metode van werking van EFE van belang. Ruvoere word gekenmerk deurdat dit heterogeen van aard is en bevat variërende vlakke van vesel. Vesel maak op sy beurt ʼn wesenlike deel uit van die ruvoer, maar varieer baie in verteerbaarheid weens die chemiese sowel as anatomiese samestelling van hierdie komplekse koolhidraat. Ruvoer verteenwoordig egter ʼn goeie bron van potensiële energie vir herkouers en EFE word voorgestel as ʼn haalbare behandeling om die verteerbaarheid daarvan te verhoog. Dus is ʼn studie beplan met die doelwit om die effekte van EFE te definieer, hoe dit verteerbaarheid beïnvloed en die metode van werking daarvan te ondersoek. Vanuit die literatuur is dit duidelik dat daar wel baie positiewe effekte is waar ruvoere met EFE behandel is en dat diereproduksie wel bevoordeel word daardeur. Vanuit die studie is dit getoon dat die tempo en hoeveelheid gasproduksie van sekere ruvoere (lusern, kikuyu en oulandsgras) verbeter word deur EFE behandeling (P < 0.05). Hierdie bevinding was ondersteun deur verbeterde in vitro verteerbaarheid van die ruvoere (P < 0.05). Dit is in ooreenstemming met literatuur en die gevolgtrekking is gemaak dat hierdie effekte tydens die vroeëre stadia van vertering verwag kan word. ʼn Volledige skaapvoer wat met EFE behandel is, het positiewe effekte op in sacco verteerbaarheid en verterings kinetika data gehad (P < 0.05). Weereens is die in vitro verteerbaarheid van die voer verbeter (P < 0.05). Waarnemings op in vitro verteerbaarheid was veel minder opvallend wanneer ʼn gesuiwerde xylanase as enigste fibrolitiese ensiem behandeling gebruik is. Dit is dus duidelik dat ensiem spesifisiteit ʼn belangrike rol speel in die verkryging van positiewe resultate in die verteerbaarheid van ruvoere en veevoere. In ooreenstemming met literatuur word dit voorgestel dat ensiemmengsels wat verskeie ensieme bevat as EFE gebruik behoort te word ten einde aan die kompleksiteit van die substraat te voldoen. Die hoof doelwit van die studie was egter ʼn indiepte ondersoek na die metode van werking van EFE. Hierdie doelwit is benader deur die effekte van EFE op selwand strukture van plantmateriaal op ʼn histologiese vlak te ondersoek. Die ruvoere was vooraf met EFE behandel en in vitro geïnkubeer in rumen vloeistof. Die resultate het getoon dat EFE ʼn matige, dog betekenisvolle effek op die selwand materiaal van die onderskeie weefsels gehad het (P < 0.05). Die belangrikste waargeneemde effek was dat EFE ʼn verdunningseffek op die selwande gehad het. Dit is afgelei dat as EFE die selwand kan beïnvloed, mikro-organismes vroeër toegang tot die inhoud kan kry. Verder, nutriënte vasgevang in die selwand matriks raak ook beskikbaar vir vertering. Hierdie afleiding en die effek van EFE op selwande verklaar waarnemings dat EFE die tempo van vertering sowel as die vlak van vertering van nie net vesel, maar ook proteïen kan bevoordeel. Die gevolgtrekking is gemaak dat daar definitiewe meriete is in die gebruik van EFE om die verteerbaarheid van herkouervoere te verbeter en dat dit verband hou met die ensiem se werking op selwande van die ruvoere. Die effekte kan verwag word tydens die vroeë stadia van vertering om dus deurvloeitempo van digesta te verbeter. Die effek van die EFE is verder nie beperk tot vesel nie, maar positiewe effekte op ander nutriënte kan verwag word en vervolgens ʼn algehele verhoging in die verteerbaarheid van die voer. Navorsing behoort in die toekoms verder die metode van werking van EFE te ondersoek deur gebruik te maak van gevorderde tegnologie wat alledaags gebruik word in die Plantwetenskappe. Die belowendste aanwending van EFE lê in die verbetering in vertering van swak kwaliteit ruvoere. Dit is ongelukkig juis hier waar min positiewe resultate gerapporteer word en indiepte navorsing moet onderneem word om ensiem spesifisiteit en optimum kondisies te definieer sodat EFE beter opgewasse is teen die kompleksiteit van die substraat.

Winter hair coat shedding ability in southern U.S. cattle production has previously been associated with differences in adjusted birth and weaning weights of calves from dams that shed by June or later (Gray et al., 2011; Cauble et al., 2019). This study was developed to research possible avenues of why these relationships exist with winter hair coat shedding ability. The primary objectives of the following experiments were to: 1) evaluate how mineral status relates to winter hair coat shedding ability, 2) evaluate how winter hair coat shedding ability relates to apparent digestibility of forage, 3) evaluate winter hair coat shedding ability’s association with uterine artery hemodynamics during gestation, 4) evaluate how winter hair coat shedding ability is associated with growth performance and development of calves from birth until weaning, and 5) evaluate how winter hair coat shedding ability relates to loin muscle (LM) relative gene expression of dams’ calves from birth until weaning. Results indicated that plasma Cu and Zn levels were greatest for dams during the grazing month of March that reach MFS by April compared to all other groups; dams that reached MFS by July had greatest forage digestibility for DM, Ash, NDF, ADF, and CP for the grazing month of May compared to all other shedding groups; winter hair coat shedding ability had a relation with ipsilateral uterine artery pulsatility at d 150 of gestation while also influencing the growth and development of the uterine artery diameter from d 150 through 210 of gestation; dams that shed by July produced calves that had shorter hip height when measured at 120 d of age and at weaning when compared to calves of dams that reached MFS in April, May, and June; and calves of dams’ that shed by July had increased expression of IGF2 compared to calves of dams’ that shed by April, May, and June, with differing results for IGF1 having the greatest expression for calves produced from dams that shed by April compared to May and June. These results may begin to explain the existing differences in adjusted birth and weaning weight of those calves.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In vitro and in situ methods using the in sacco technique have a wide application in ruminant nutrition as they allow the degradability and quality of forages and ruminant diets to be determined quicker and at a lower cost than in vivo methods. These trials make use of artificial fibre bags, made of polyester (dacron) or nylon which are available in variable pore sizes. Results from such degradability trials are of great value to feed formulation programs such as AMTS.cattle and CPM Dairy and the more accurate the results are obtained from such trials the more accurate feed formulation models are enabling the ruminant nutritionist to formulate the best diet possible to reach the genetic potential of ruminants. The accepted method for in sacco trials (NRC, 2001) requires that the feed samples are ground through a 2 mm screen. This usually results in a variety of particle sizes, including a significant amount of extremely fine particles. Research has, however, shown that these fine particles can potentially be washed out of the dacron bags that are used in in sacco degradability trials. This would result in an overestimation of the soluble and rapidly fermentable nutrient fractions. The objective of this study was to determine the effect of fine particle removal from ground forage samples on the chemical composition and in vitro dry matter (DM) and neutral detergent fibre (NDF) degradability of forages. Lucerne hay, oat hay and wheat straw samples were sourced from seven different locations in the Western Cape. Samples were milled through a 2 mm screen and then sieved through either 150 μm, 125 μm or 106 μm. All fractions were analysed for DM, crude protein (CP), NDF, fat and ash. Based on the NDF content of the original samples, four samples from each forage type were selected for in vitro trials to determine DM and NDF disappearance over time. Samples were incubated for 0, 6, 24 and 48 hours in an ANKOM Daisy II incubator. Significant variation occurred within forage types in terms of chemical composition. Fine particle removal had no effect on the NDF content of lucerne hay and wheat straw, but sieved oat hay fractions had a higher NDF content than the un-sieved samples. The NDF content was on average 635.9 for the sieved OH fractions, whereas the NDF content of the un-sieved samples was 606.8. The CP content of sieved oat hay (61.4 on average) and wheat straw fractions (47.7 on average) were lower than the un-sieved fractions (65.7 for OH and 55.4 for WS), whereas for lucerne hay, sieving had no effect on CP content. Dry matter and NDF disappearances were significantly higher for the un-sieved samples than for the sieved fractions for all three forage types at all incubation times, which indicates an overestimation of the soluble and readily digestible forage fractions. Compared to sieved samples, DMD values at 0 hours (washing only) of the un-sieved samples were, on average, 13.8% higher for lucerne hay, 27.3% for oat hay and 44.7% for wheat straw. At 48 h, the overestimation of lucerne DMD for the un-sieved samples was between 4.0% (compared to 106 μm sieve) and 7.3% (compared to 150 μm sieve). This over-estimation in the un-sieved samples was carried over to all four time points. No significant differences between the fractions (150, 125 and 106) were found within a forage type at all incubation times. The estimated degradation rates and the predicted digested proportions were also significantly higher for the un-sieved fractions compared to the sieved fractions. It was concluded that fine particle removal from forage samples would result in more accurate estimations of in sacco nutrient degradability. / AFRIKAANSE OPSOMMING: In sacco in vitro- en in situ-metodes word dikwels toegepas in die studie van herkouervoeding aangesien hierdie metodes vinniger, meer effektief en meer ekonomies is as in vivo-metodes. Hierdie studies maak gebruik van kunsveselsakkies, gemaak van poliëster (dacron) of nylon wat beskikbaar is in verskeie poriegroottes. Resultate van sulke verteringsproewe is belangrik vir toepassing in voerformuleringsprogramme soos AMTS.cattle en CPM Dairy. Die resultate wat deur hierdie studies verkry word, is belangrik vir akkurate voerformulering deur formuleringsmodelle en stel die herkouervoedingkundige in staat om die ideale voer te formuleer vir die manifestering van die dier se genetiese potensieaal. Die aanvaarde in sacco-metode (NRC, 2001) vereis dat voermonsters deur ‘n 2 mm sif gemaal word wat ‘n groot verskeidenheid partikelgroottes tot gevolg het met ‘n beduidende hoeveelheid baie fyn materiaal. Navorsing het getoon dat hierdie baie fyn partikels uit die dacronsakkies gewas kan word tydens in sacco verteringstudies, met die gevolg dat die oplosbare en vinnig-verteerbare fraksie oorskat kan word. Die doel van die huidige studie was om die invloed van die verwydering van fyn partikels op die chemiese samestelling van ruvoermonsters te bepaal, asook die in vitro droë materiaal (DM) en neutraal-onoplosbaare vesel (NDF) verteerbaarheid daarvan. Monsters van lusernhooi, hawerhooi en koringstrooi, afkomstig van sewe verskillende lokaliteite in die Wes-Kaap, is deur 'n 2 mm sif gemaal en sub-monsters is deur ‘n reeks siwwe met poriegroottes van 150 μm, 125 μm of 106 μm gesif. Al die fraksies is geanaliseer vir DM, ruproteïen (RP), NDF, vet en as. Vier monsters van elke voertipe is op grond van die NDF-inhoud geselekteer vir in vitro-studies om die DM- en NDF- verteerbaarheid oor tyd te bepaal. Monsters is vir 0, 6, 24 of 48 uur geïnkubeer. Die resultate het getoon dat daar betekenisvolle variasie in chemiese samestelling binne ruvoertipes voorgekom het. Die verwydering van die fyn partikels het geen invloed die NDF-inhoud van lusernhooi en koringstrooi gehad nie. Wat hawerhooi betref, was die NDFinhoud van die gesifte monsters egter betekenisvol hoër in vergelyking met die ongesifte monsters. Die NDF inhoud was gemiddeld 635.9 vir die gesifte monsters en vir die ongesifte monsters 606.8. Sifting het geen invloed op die RP-inhoud van lusernhooi gehad nie, maar vir hawerhooi (61.4 gemiddeld) en koringstrooi (47.7 gemiddeld) was die RP-inhoud van die gesifte monsters betekenisvol laer as dié van die ongesifte monsters (65.7 vir hawerhooi en 55.4 vir koringstrooi). In vergelyking met die gesifte monsters, was die in vitro DM- en NDF-verteerbaarhede betekenisvol hoër vir die ongesifte monsters vir al drie ruvoertipes by alle inkubasietye. Hierdie resultate bevestig ‘n oorskatting van oplosbare en maklik verteerbare fraksies in gemaalde voermonsters. In vergelyking met die gesifte monsters, was die DMV-waardes van die ongesifte monsters by 0 ure (slegs gewas) gemiddeld 13.8% hoër vir lusernhooi, 27.3% vir hawerhooi en 44.7% vir koringstrooi. Na 48 h inkubasie was die oorskatting van lusern DMV vir die ongesifte monsters tussen 4.0% (vergeleke met die 106 μm sif) en 7.3% (vergeleke met 150 μm sif). Die oorskatting is oorgedra na al vier inkubasietye. Die resultate het geen noemenswaardige verskille tussen die fraksies (150 μm, 125 μm en 106 μm poriegroottes) van ‘n ruvoertipe by enige inkubasietyd aangedui nie. Die beraamde verteringstempo’s en verteerde fraksies was ook aansienlik hoër vir die ongesifte monsters in vergelyking met die gesifte monsters. Die gevolgtrekking is gemaak dat die verwydering van fyn partikels uit gemaalde ruvoermonsters die akkurate bepaling van in sacco verteerbaarheidswaardes verhoog.

Na intenção de avaliar o efeito da suplementação protéica, uso de subprodutos agroindustriais e o processamento de milho, foram conduzidos quatro experimentos. No experimento I, avaliou-se formas de processamento de milho (milho moído, M; e resíduo de pipoca doce, P) e fontes protéicas (farelo de soja, FS; uréia, U; ou farinha de peixe, FP), combinando-os para formar quatro tratamentos: MFS (M + FS); PFS (P + FS); PFP (P + FS + FP); PU (P + U). Comparado ao milho moído (MFS), o resíduo de pipoca doce (PFS) diminuiu os teores de gordura e proteína no leite. Em relação às fontes protéicas (PFS x PFP x PU), observou-se que a maior produção leiteira foi obtida no tratamento PFS. A farinha de peixe (PFP) levou ao menor teor de gordura no leite, mas aumentou o teor protéico no leite. No experimento II, avaliou-se os efeitos da inclusão de três teores (0,15 e 30% da MS) de farelo de algodão (FA) em substituição ao farelo de soja na dieta. O consumo de MS não foi afetado pelos tratamentos, contudo a inclusão de FA levou a efeitos lineares negativos sobre a produção de leite e teor e produção de proteína e efeitos lineares positivos sobre o teor e produção de gordura no leite. No experimento III, comparou-se os efeitos de uma dieta basal com 16% de PB contra duas outras com 17,5% de PB, sendo esses incrementos obtidos através da adição de uréia (U-17,5, resultando em aumento de proteína degradável no rúmen, PDR) ou farelo de soja e de algodão (FSFA-17,5, resultando em aumento de proteína metabolizável, PM). O aumento do teor de PDR (U-17,5) tendeu a aumentar o consumo de MS em relação à dieta basal. A produção de leite elevou-se com o aumento de PM (FSFA-17,5), não ocorrendo o mesmo com o aumento de PDR (U-17,5). O teor e a produção de proteína no leite também elevou-se com o fornecimento extra de PM. Concluiu-se que a elevação do teor de PM para valores acima das recomendações propostas pelo National Research Council - NRC (2001) para vacas produzindo ao redor de 29 kg/d melhorou as produções de leite e de proteína no leite. O experimento IV consistiu de dois ensaios. No primeiro, os tratamentos continham 0 (RUC-0), 10 (RUC-10) ou 20% (RUC-20) de resíduo úmido de cervejaria (RUC). Todas as dietas continham 1% de uréia. Um quarto tratamento isoprotéico, com 2% de uréia substituindo parcialmente o farelo de soja, sem RUC, foi utilizado. O consumo de MS não foi afetado. A produção de leite e o teor e produção de proteína no leite aumentaram com a inclusão de RUC e foram prejudicados com o fornecimento de 2% de uréia. No ensaio 2, foram comparados o RUC fresco com o RUC ensilado com milho moído. Ambos os tratamentos eram isoprotéicos e continham proporções semelhantes de milho moído e RUC. O consumo de MS, produção de leite e os teores e produções de gordura e proteína no leite não foram afetados pelos tratamentos. / Four studies were conducted to compare protein sources and content, corn processing method and a fibrous by-product for lactating dairy cows. Study 1: corn processing methods (fine ground, M; and popped, P) and protein sources (soybean meal, FS; urea, U; or fishmeal, FP) were compared in 4 treatments: MFS (M + FS); PFS (P + FS); PFP (P + FS + FP); PU (P + U). Compared to fine ground corn (MFS), popped corn (PFS) decreased milk fat and protein content. The 3 protein sources comparisons (PFS x PFP x PU) showed that milk yield was higher for PFS. Feeding fishmeal (PFP) decreased milk fat content, but increased milk protein content. Study 2: the cottonseed meal content in the diet (0, 15 and 30% of DM) in replacement to soybean meal were compared. Dry matter intake was not affected by treatments, but cottonseed meal supplementation had a negative linear effect on milk yield and on milk protein content and yield. Increasing cottonseed meal had a positive linear effect on milk fat content and yield. Study3: basal diet (16% CP) was compared to two diets with 17.5% CP, where crude protein content of diets were increased by feeding extra urea (U-17.5, resulting in increased rumen degradable protein content, RDP) or extra soybean and cottonseed meal (FSFA-17.5, resulting in increased metabolizable protein content, MP). Extra RDP (U-17.5) tended to increase DMI compared to basal diet. Milk yield were increased by extra MP (FSFA-17.5) but not by extra RDP (U-17.5). Milk protein content and yield were also increased by feeding extra MP. In conclusion, increasing diet MP content above National Research Council - NRC (2001) recommendations for cows producing around 29 kg/d improved milk and milk protein yields. Study 4: two trials were conducted. In trial 1, treatments were 0 (RUC-0), 10 (RUC-10) or 20% (RUC-20) wet brewers grains inclusion in diet dry matter. All 3 diets contained 1% urea on a DM basis. A fourth isonitrogenous diet, with additional urea (2% of diet DM) in partial replacement of soybean meal, without brewers grains, was compared to. Dry matter intake were not different. Milk yields and milk protein contents and yields were increased by feeding wet brewers grains and decreased by feeding 2% urea. In trial 2, weekly received fresh wet brewers grains versus wet brewers grains ensiled with ground corn were compared. Both treatments were isonitrogenous diets and contained the same proportions of ground corn and wet brewers grains on a dry matter basis. Dry matter intake, milk yield, milk fat content and yield and protein content and yield were not different.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this study was to evaluate the effect of three carbohydrate sources (corn, soybean hulls or wheat bran) in the diet on performance, carcass characteristics and meat and the components are not part of the carcass of steers finished on confinement. We used 24 steers, crossbred Charolais x Nellore, with initial age of 22 months of initial body weight 353.2 ± 10.6 kg. The animals were fed a diet with roughage: concentrate 40,2:59,8, and the volume consisting of sorghum silage. The daily intakes of DM and CP were not influenced by sources of carbohydrates. Animals fed soybean hulls had higher intake of NDF and ADF, whereas calves receiving corn consumed higher levels of NFC, and TDN ED. Animals fed corn or soybean hulls had greater weight gain and better feed conversion than steers receiving wheat bran. The slaughter weight was similar between the sources of carbohydrates, averaging 429.81; 433.18 and 430.46 kg for maize, soybean hulls and wheat bran, respectively. The weight cut sidecut was greater for steers fed corn diet compared with soybean hulls or wheat bran. The meat from the diet with soybean hulls had better flavor compared to the wheat bran. The loss of the cooking liquid and cholesterol content were higher in animals treated with maize as compared to those receiving soybean hulls or wheat bran. There was no effect of carbohydrate sources on the weights of vital organs and blood. The absolute and relative weights to the weight of empty body fat of the intestines and rumen were higher in animals fed with corn. The weight of the omasum was greater for the diet with wheat bran, while animals fed soybean hulls had higher absolute weight of kidney fat. / Objetivou-se neste estudo avaliar o efeito de três fontes de carboidratos (milho, casca de soja ou farelo de trigo) na dieta sobre o desempenho, as características da carcaça e da carne e dos componentes não integrantes da carcaça de novilhos de corte terminados em confinamento. Foram utilizados 24 novilhos castrados, mestiços Charolês x Nelore, com idade inicial de 22 meses e peso inicial de 353,2±10,6 kg. Os animais foram alimentados com dieta com relação volumoso:concentrado de 40,2:59,8, sendo o volumoso constituído de silagem de sorgo. Os consumos diários de MS e PB não foram influenciados pelas fontes de carboidratos. Animais alimentados com casca de soja apresentaram maiores ingestão de FDN e FDA, enquanto que os novilhos que receberam milho consumiram maiores teores de CNF, NDT e ED. Animais alimentados com milho ou casca de soja apresentaram maior ganho de peso e melhor conversão alimentar em relação aos novilhos que receberam farelo de trigo. O peso de abate foi similar entre as fontes de carboidratos, com médias de 429,81; 433,18 e 430,46 kg, para o milho, casca de soja e farelo de trigo, respectivamente. O peso do corte costilhar foi maior para os novilhos alimentados com milho em comparação a dieta com casca de soja ou farelo de trigo. A carne proveniente da dieta com casca de soja apresentou melhor palatabilidade em relação à do farelo de trigo. As perdas de líquidos à cocção e o conteúdo de colesterol foram maiores na carne dos animais tratados com milho em relação aos que receberam casca de soja ou farelo de trigo. Não houve efeito das fontes de carboidratos sobre os pesos dos órgãos vitais e de sangue. Os pesos absolutos e relativos ao peso de corpo vazio dos intestinos e da gordura ruminal foram maiores nos animais alimentados com milho. O peso de omaso foi maior para a dieta com farelo de trigo, enquanto que os animais alimentados com casca de soja apresentaram maior peso absoluto de gordura renal.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The aim of this work was to study the use of whole dry white oat grain (Avena sativa), soybean hulls (Glycine max L.), and the mixture of these ingredients (1:1), provided in two ways: with or without a roughage source on the diet. Sixty- eight male castrated steers, Charolais x Nelore crossbred, with initial average age of 20 months were used, distributed in a factorial scheme 3 x 2, with three energetic sources on the concentrate (white oat grain; soybean hulls and the mixture of these ingredients) and two ways of provision (with or without roughage). The roughage used was sorghum silage (Sorghum bicolor (L.) Moench), with roughage: concentrate of 50:50, based on DM. The ingestive behavior characteristics and the animal's performance response were measured and compared. The final weights of the steers did not differ statistically. The daily average gain of the mixture source (1.167 kg) was superior (P<0.05) to the soybean hulls (0.940 kg), being the oat grain intermediate (1.061 kg). It was observed higher (P<0.05) intake of dry matter and neutral and acid detergent fiber on the diets that contained roughage. Animals fed without roughage presented in the average better (P<0.05) feed conversion (6.291 kg) in relation to the animals fed with roughage (8.578 kg). Independently of the energetic source tested, steers fed with roughage remained more time (P<0.05) eating (4.23 h) and ruminating (7.88 h), compared to the ones fed without roughage (2.68 and 3.52 h, respectively). Steers fed with the energetic sources of oat grain and mixture, were more efficient in the dry matter intake (DM) when fed without roughage. On the average, steers fed without roughage were more efficient in the intake of neutral detergent fiber (NDF) and more efficient in the rumination of NDF. Steers fed with or without roughage presented difference (P<0.05) for the total chewing time (13.13 and 6.19h), for the number of ruminal bolus per day (502 and 184), and for the number of rumination chews (30,774 and 11,637, respectively). Steers from the soybean hulls energetic source chewed a few (P<0.05) number of times per ruminal bolus when fed without roughage (41.63), compared to the ones fed with roughage (62.66). / Objetivou-se neste trabalho, estudar a utilização do grão de aveia branca (Avena sativa) na forma inteiro seco, e a casca do grão de soja (Glycine max L.), e a mistura desses ingredientes (1:1), fornecidos de duas formas: com ou sem a fonte de volumoso na dieta. Foram utilizados 68 novilhos cruzas Charolês x Nelore, machos castrados, com idade média inicial de 20 meses, distribuídos em um esquema fatorial 3 x 2, com três fontes energéticas no concentrado (grão de aveia branca; casca do grão de soja e a mistura desses ingredientes) e duas formas de fornecimento (com ou sem volumoso). O volumoso utilizado foi silagem de sorgo (Sorghum bicolor (L.) Moench), com uma relação volumoso:concentrado de 50:50, com base na MS. Foram mensuradas e comparadas as características do comportamento ingestivo e respostas de desempenho dos animais. Os pesos finais dos novilhos não diferiram estatisticamente. O ganho médio diário da fonte energética Mistura (1,167 kg) foi superior (P<0,05) a Casca de Soja (0,940 kg), sendo Grão de Aveia intermediária (1,061 kg). Observou-se maiores (P<0,05) consumos de matéria seca e fibra em detergente neutro e ácido nas dietas que apresentavam volumoso. Animais alimentados sem volumoso apresentaram melhor (P<0,05) conversão alimentar (6,291 kg) em relação aos animais alimentados com volumoso (8,578 kg). Independente da fonte energética testada, novilhos alimentados com volumoso desprenderam mais tempo (P<0,05) se alimentando (4,23 h) e ruminando (7,88 h), comparados aos sem volumoso (2,68 e 3,52 h, respectivamente). Novilhos alimentados com as fontes energéticas Grão de Aveia e Mistura foram mais eficientes nos consumos de matéria seca (MS) quando alimentados sem volumoso. Na média os novilhos alimentados sem volumoso foram mais eficientes no consumo de fibra em detergente neutro (FDN), e mais eficientes na ruminação da FDN. Novilhos alimentados com e sem volumoso apresentaram diferença (P<0,05) para o tempo de mastigação total (13,13 e 6,19h), no número de bolos ruminais por dia (502 e 184), e no número de mastigadas merícicas (30.774 e 11.637, respectivamente). Novilhos da fonte energética Casca de Soja mastigam em menor (P<0,05) número de vezes por bolo ruminal quando alimentados sem volumoso (41,63), em comparação aos alimentados com volumoso (62,66).

Na intenção de avaliar o efeito da suplementação protéica, uso de subprodutos agroindustriais e o processamento de milho, foram conduzidos quatro experimentos. No experimento I, avaliou-se formas de processamento de milho (milho moído, M; e resíduo de pipoca doce, P) e fontes protéicas (farelo de soja, FS; uréia, U; ou farinha de peixe, FP), combinando-os para formar quatro tratamentos: MFS (M + FS); PFS (P + FS); PFP (P + FS + FP); PU (P + U). Comparado ao milho moído (MFS), o resíduo de pipoca doce (PFS) diminuiu os teores de gordura e proteína no leite. Em relação às fontes protéicas (PFS x PFP x PU), observou-se que a maior produção leiteira foi obtida no tratamento PFS. A farinha de peixe (PFP) levou ao menor teor de gordura no leite, mas aumentou o teor protéico no leite. No experimento II, avaliou-se os efeitos da inclusão de três teores (0,15 e 30% da MS) de farelo de algodão (FA) em substituição ao farelo de soja na dieta. O consumo de MS não foi afetado pelos tratamentos, contudo a inclusão de FA levou a efeitos lineares negativos sobre a produção de leite e teor e produção de proteína e efeitos lineares positivos sobre o teor e produção de gordura no leite. No experimento III, comparou-se os efeitos de uma dieta basal com 16% de PB contra duas outras com 17,5% de PB, sendo esses incrementos obtidos através da adição de uréia (U-17,5, resultando em aumento de proteína degradável no rúmen, PDR) ou farelo de soja e de algodão (FSFA-17,5, resultando em aumento de proteína metabolizável, PM). O aumento do teor de PDR (U-17,5) tendeu a aumentar o consumo de MS em relação à dieta basal. A produção de leite elevou-se com o aumento de PM (FSFA-17,5), não ocorrendo o mesmo com o aumento de PDR (U-17,5). O teor e a produção de proteína no leite também elevou-se com o fornecimento extra de PM. Concluiu-se que a elevação do teor de PM para valores acima das recomendações propostas pelo National Research Council - NRC (2001) para vacas produzindo ao redor de 29 kg/d melhorou as produções de leite e de proteína no leite. O experimento IV consistiu de dois ensaios. No primeiro, os tratamentos continham 0 (RUC-0), 10 (RUC-10) ou 20% (RUC-20) de resíduo úmido de cervejaria (RUC). Todas as dietas continham 1% de uréia. Um quarto tratamento isoprotéico, com 2% de uréia substituindo parcialmente o farelo de soja, sem RUC, foi utilizado. O consumo de MS não foi afetado. A produção de leite e o teor e produção de proteína no leite aumentaram com a inclusão de RUC e foram prejudicados com o fornecimento de 2% de uréia. No ensaio 2, foram comparados o RUC fresco com o RUC ensilado com milho moído. Ambos os tratamentos eram isoprotéicos e continham proporções semelhantes de milho moído e RUC. O consumo de MS, produção de leite e os teores e produções de gordura e proteína no leite não foram afetados pelos tratamentos. / Four studies were conducted to compare protein sources and content, corn processing method and a fibrous by-product for lactating dairy cows. Study 1: corn processing methods (fine ground, M; and popped, P) and protein sources (soybean meal, FS; urea, U; or fishmeal, FP) were compared in 4 treatments: MFS (M + FS); PFS (P + FS); PFP (P + FS + FP); PU (P + U). Compared to fine ground corn (MFS), popped corn (PFS) decreased milk fat and protein content. The 3 protein sources comparisons (PFS x PFP x PU) showed that milk yield was higher for PFS. Feeding fishmeal (PFP) decreased milk fat content, but increased milk protein content. Study 2: the cottonseed meal content in the diet (0, 15 and 30% of DM) in replacement to soybean meal were compared. Dry matter intake was not affected by treatments, but cottonseed meal supplementation had a negative linear effect on milk yield and on milk protein content and yield. Increasing cottonseed meal had a positive linear effect on milk fat content and yield. Study3: basal diet (16% CP) was compared to two diets with 17.5% CP, where crude protein content of diets were increased by feeding extra urea (U-17.5, resulting in increased rumen degradable protein content, RDP) or extra soybean and cottonseed meal (FSFA-17.5, resulting in increased metabolizable protein content, MP). Extra RDP (U-17.5) tended to increase DMI compared to basal diet. Milk yield were increased by extra MP (FSFA-17.5) but not by extra RDP (U-17.5). Milk protein content and yield were also increased by feeding extra MP. In conclusion, increasing diet MP content above National Research Council - NRC (2001) recommendations for cows producing around 29 kg/d improved milk and milk protein yields. Study 4: two trials were conducted. In trial 1, treatments were 0 (RUC-0), 10 (RUC-10) or 20% (RUC-20) wet brewers grains inclusion in diet dry matter. All 3 diets contained 1% urea on a DM basis. A fourth isonitrogenous diet, with additional urea (2% of diet DM) in partial replacement of soybean meal, without brewers grains, was compared to. Dry matter intake were not different. Milk yields and milk protein contents and yields were increased by feeding wet brewers grains and decreased by feeding 2% urea. In trial 2, weekly received fresh wet brewers grains versus wet brewers grains ensiled with ground corn were compared. Both treatments were isonitrogenous diets and contained the same proportions of ground corn and wet brewers grains on a dry matter basis. Dry matter intake, milk yield, milk fat content and yield and protein content and yield were not different.

Nas pesquisas com bovinos de corte, além do bom desempenho animal e da viabilidade econômica, busca-se agregar características qualitativas à carne produzida. O fornecimento de milho alto óleo a bovinos de corte em terminação aumenta o ganho de peso e a qualidade de carcaça, quando comparado ao milho comum. Buscou-se consolidar as informações quanto aos efeitos das dietas para novilhos Nelore em confinamento, sobre os parâmetros da produção animal, como ganho de peso, rendimento de carcaça, degradabilidade das dietas, efeitos sobre os protozoários ciliados e outras medidas ruminais, parâmetros físicos do Longissimus dorsi, composição centesimal da carcaça, composição do ganho e perfil de ácidos graxos nesse músculo. Foram utilizados 48 novilhos da raça Nelore, com peso vivo inicial médio de 435 kg, submetidos a um dos seis tratamentos, usando dois tipos de milho (comum e alto óleo) e três níveis de inclusão de milho no concentrado (25%, 40% e 55%). Os animais foram confinados por um período de 84 dias. Amostras do Longissimus dorsi foram coletadas para avaliação das características físicas da carne e análise do perfil de ácidos graxos na gordura intramuscular. Os tratamentos não influenciaram o ganho de peso, o consumo de alimentos, a conversão alimentar ou os parâmetros da carcaça. A qualidade física da carne também não foi influenciada pelos tratamentos. Para as dietas contendo milho alto óleo, houve alteração na população de protozoários no rúmen e na degradação da FDN. Dietas com milho alto óleo favoreceram o aumento no total dos ácidos graxos intermediários da biohidrogenação na gordura intramuscular. Houve diferenças significativas no ácido rumênico (CLA - C18:2_cis9_trans11), passando de 0,43% para 0,49%, representando um aumento médio de 12,7%, devido ao uso de dietas contendo milho alto óleo. / Beef cattle researchers, over than animal performance and economics are looking for nutritional characteristics of the products from ruminants. Inclusion of high oil corn (HOC) on diets increases weight gain and carcass quality compared to common corn grain. This study looks for data from animal performance on diets using high oil corn, evaluating live weight gain, carcass composition, diets digestibility, dry matter degradability, effects on ciliated protozoa number and quality, muscle quality characteristics, meat composition and fatty acids profile on intramuscular fat. Where used 48 Nellore steers, with initial average live weight of 435 kg in six treatments, using two corn grain varieties (common and high oil corn) and three levels of corn grain in concentrate diets (25%, 40% and 55%). Animals were in feedlot pens for 84 days, after an adaptation period to diets and installations. The Longissimus dorsi was used for evaluating meat characteristics and fatty acids profile on intramuscular fat. There was no effect of diets on daily gain, intake, conversion, or carcass parameters. Meat quality was not also affected by treatments. Diets with high oil corn altered protozoa population and ruminal degradation of NDF. The total biohidrogenated fatty acids in intramuscular fat were increased by treatment with high oil corn and also rumenic acid. Rumenic acid was the major conjugated linoleic acid (CLA) detected in this tissue, with concentrations increasing from 0,43% to 0,49%, representing an average increase of 12,7% caused for HOC diets.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-26T10:38:54Z No. of bitstreams: 2 Tese - José Tiago das Neves Neto - 2015.pdf: 1371547 bytes, checksum: a079c3c4597fc85eeef5c725389bcc04 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-26T10:39:33Z (GMT) No. of bitstreams: 2 Tese - José Tiago das Neves Neto - 2015.pdf: 1371547 bytes, checksum: a079c3c4597fc85eeef5c725389bcc04 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-26T10:39:33Z (GMT). No. of bitstreams: 2 Tese - José Tiago das Neves Neto - 2015.pdf: 1371547 bytes, checksum: a079c3c4597fc85eeef5c725389bcc04 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-04-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The manipulation of ruminal fermentation is a valuable tool aiming at increasing productivity and efficiency by using resources for animal feed. There are different kinds of tools, such as homogeneous mixing of feed, appropriate trough management, correct feed formulation, and the use of compounds (additives) aimed at assisting rumen fermentation process. The use of antibiotics in foods for animals as growth promoters is facing a social barrier, because of the waste and bacterial resistance that these products can be generating. For that reason the use of antibiotics for this end or at the diet of ruminants has been banned from the EU since January 2006. Therefore, some technologies have been developed to replace these products, and the use of vegetable extracts in ruminants nutrition as ruminal fermentation modulators have been largely studied. Some plants are rich in active compounds with antimicrobial power that makes them useful for animal nutrition. The crude extract of Pterodon Emarginatus Vogel presents sesquiterpenes and diterpenes in its composition, and β-caryophyllene is the most representative compound. Due to the limitations of using unknown products in animal nutrition, the techniques of in vitro digestibility and metabolic studies with animals cannulated in the rumen are largely used at the first stages of research. The objective of this study was to evaluate different dosages of Pterodon Emarginatus Vogel crude extract in vitro ruminal fermentation through a system of continuous culture of double flow. The treatments corresponded to four doses: 0%; 0.6%, 0.12%; and 0.24% of Pterodon Emarginatus Vogel crude extract in dry matter (DM) of the provided diet and a treatment with Sodium Monensin (30 ppm). The experimental design was entirely in randomized blocks with four replications and five treatments. The in vitro test showed a difference of (P<0.05) in the DM and OM digestibility between the treatments 0.24% of Pterodon Emarginatus Vogel crude extract and monensin. There was no difference (P>0.05) in the digestibility of NDF and ADF. The addition of the Pterodon Emarginatus Vogel extract increased the digestibility of DM and OM when compared with Sodium Monensin without effects on NDF and ADF. The treatments affected (P<0.05) acetic acid concentration, and the concentration 0.24% showed a decrease when compared with control treatment. The same happened with the relation between acetic and propionic acids, where 0.24% treatment produced a lower ratio compared with control and 0.06% treatments. The extract of Pterodon emarginatus Vogel has potential to modulate the ruminal fermentation because of its effect on ruminal microorganisms, and it is dose-dependent. Thus it can be used as an additive to manipulate ruminal fermentation and probably as a substitute of the sodic monensin. However, more studies must be carried out to answer the questions about the use of this substances, to clarify the effects of this products on the ruminal microorganisms, its effects on animal metabolism, parameters of in vivo ruminal fermentation, quantify the dosages to be used and quantify animal performance gain. The Culture System in Continuous Flow revealed to be an important alternative method and it showed accuracy for ruminal digestibility studies. / A manipulação da fermentação ruminal é valiosa ferramenta na busca do aumento da produtividade e da eficiência na utilização dos recursos destinados à alimentação animal. Existem diversas ferramentas como a mistura uniforme da ração, o manejo adequado de cocho, a formulação correta da ração e a utilização de compostos que visam auxiliar o processo fermentativo do rúmen denominados aditivos. O uso de antibióticos como promotores de crescimento em alimentos para animais tem enfrentado resistência, devido aos resíduos e a resistência bacteriana que estes produtos podem gerar. Por isso, o uso de antibióticos em sistemas de produção de ruminantes foi proibido na União Europeia em janeiro de 2006. Desta forma, algumas tecnologias têm sido desenvolvidas para substituir estes produtos e dentre estes, os extratos vegetais vêm sendo amplamente estudados na nutrição de ruminantes como moduladores da fermentação microbiana ruminal. Estas plantas são ricas em compostos ativos com poder antimicrobiano tornando-as úteis na nutrição animal como aditivos. O óleo bruto de sucupira apresenta, em sua composição sesquiterpenos e diterpenos sendo, o β-cariofileno, o composto de maior concentração. Diante das limitações da aplicação de produtos desconhecidos na alimentação animal, as técnicas de digestibilidade in vitro e estudos metabólicos com animais canulados no rúmen são recomendados nas etapas iniciais da pesquisa. Com o presente trabalho objetivou-se avaliar diferentes doses do óleo bruto de Sucupira sobre a fermentação microbiana ruminal in vitro através de um sistema de cultura contínua de duplo fluxo. Os tratamentos foram constituídos de quatro doses: 0%; 0,06%; 0,12%; 0,24% na matéria seca (MS) da dieta fornecida do extrato bruto de Sucupira e um tratamento com Monensina Sódica (30 ppm). O delineamento experimental realizado foi em blocos inteiramente casualizados com quatro repetições e cinco tratamentos. No ensaio in vitro, houve diferença (P<0,05) na digestibilidade da MS e MO entre o tratamento 0,24% do extrato de sucupira e os tratamentos controle e monensina. Não se observou diferenças (P>0,05) na digestibilidade da FDN e FDA. A adição do extrato de Pterodon emarginatus Vogel (Sucupira) aumentou a digestibilidade da MS e MO comparados com a Monensina Sódica, sem efeitos na DFN e DFA. A concentração do ácido acético foi afetada (P<0,05) pelos tratamentos, observando uma diminuição da concentração para o tratamento 0,24% comparado com o tratamento controle. O mesmo ocorreu com a relação entre os ácidos acético e propriônico, onde o tratamento 0,24% ocasionou uma menor relação comparado com os tratamentos controle e 0,06%. O extrato de Pterodon emarginatus Vogel (Sucupira) tem potencial de modular a fermentação ruminal devido ao seu efeito nos microrganismos ruminais, sendo seu efeito dose dependente, podendo ser usado como aditivo para manipular a fermentação no rúmen e ser um provável substituto da monensina sódica, porém mais estudos devem ser realizados para elucidar e responder as dúvidas referentes a utilização destas substancias, como esclarecer os efeitos desses produtos sobre os microrganismos ruminais, seus efeitos no metabolismo animal, nos parâmetros de fermentação ruminal in vivo, quantificar as doses a serem utilizadas e quantificar os ganhos em desempenho animal. O Sistema de Cultura em Fluxo Contínuo mostrou ser uma importante metodologia alternativa e de precisão para o estudo de digestibilidade ruminal.

Nas pesquisas com bovinos de corte, além do bom desempenho animal e da viabilidade econômica, busca-se agregar características qualitativas à carne produzida. O fornecimento de milho alto óleo a bovinos de corte em terminação aumenta o ganho de peso e a qualidade de carcaça, quando comparado ao milho comum. Buscou-se consolidar as informações quanto aos efeitos das dietas para novilhos Nelore em confinamento, sobre os parâmetros da produção animal, como ganho de peso, rendimento de carcaça, degradabilidade das dietas, efeitos sobre os protozoários ciliados e outras medidas ruminais, parâmetros físicos do Longissimus dorsi, composição centesimal da carcaça, composição do ganho e perfil de ácidos graxos nesse músculo. Foram utilizados 48 novilhos da raça Nelore, com peso vivo inicial médio de 435 kg, submetidos a um dos seis tratamentos, usando dois tipos de milho (comum e alto óleo) e três níveis de inclusão de milho no concentrado (25%, 40% e 55%). Os animais foram confinados por um período de 84 dias. Amostras do Longissimus dorsi foram coletadas para avaliação das características físicas da carne e análise do perfil de ácidos graxos na gordura intramuscular. Os tratamentos não influenciaram o ganho de peso, o consumo de alimentos, a conversão alimentar ou os parâmetros da carcaça. A qualidade física da carne também não foi influenciada pelos tratamentos. Para as dietas contendo milho alto óleo, houve alteração na população de protozoários no rúmen e na degradação da FDN. Dietas com milho alto óleo favoreceram o aumento no total dos ácidos graxos intermediários da biohidrogenação na gordura intramuscular. Houve diferenças significativas no ácido rumênico (CLA - C18:2_cis9_trans11), passando de 0,43% para 0,49%, representando um aumento médio de 12,7%, devido ao uso de dietas contendo milho alto óleo. / Beef cattle researchers, over than animal performance and economics are looking for nutritional characteristics of the products from ruminants. Inclusion of high oil corn (HOC) on diets increases weight gain and carcass quality compared to common corn grain. This study looks for data from animal performance on diets using high oil corn, evaluating live weight gain, carcass composition, diets digestibility, dry matter degradability, effects on ciliated protozoa number and quality, muscle quality characteristics, meat composition and fatty acids profile on intramuscular fat. Where used 48 Nellore steers, with initial average live weight of 435 kg in six treatments, using two corn grain varieties (common and high oil corn) and three levels of corn grain in concentrate diets (25%, 40% and 55%). Animals were in feedlot pens for 84 days, after an adaptation period to diets and installations. The Longissimus dorsi was used for evaluating meat characteristics and fatty acids profile on intramuscular fat. There was no effect of diets on daily gain, intake, conversion, or carcass parameters. Meat quality was not also affected by treatments. Diets with high oil corn altered protozoa population and ruminal degradation of NDF. The total biohidrogenated fatty acids in intramuscular fat were increased by treatment with high oil corn and also rumenic acid. Rumenic acid was the major conjugated linoleic acid (CLA) detected in this tissue, with concentrations increasing from 0,43% to 0,49%, representing an average increase of 12,7% caused for HOC diets.