Objetivou-se com este estudo avaliar a utilização do farelo de pinhão manso (Jatropha curcas L.) detoxicado (FPMD) na dieta de suínos em terminação. Inicialmente foi realizado um ensaio biológico com ratos Wistar. Não foram observados (P>0,05) efeitos da adição do FPMD sobre o desempenho, pesos relativos do fígado, rins, coração, intestino grosso, comprimento do intestino delgado, bem como nas análises sanguíneas dos animais. No entanto, foi observada redução significativa (P<0,05) na digestibilidade das dietas em resposta à adição do FPMD, além do aumento linear (P<0,05: P<0,001) no peso relativo do Intestino (Intestino Grosso + Intestino Delgado) e do Intestino Delgado. Em um segundo ensaio, foram avaliados os conteúdos de ésteres de forbol (EF), fenóis totais (FT), taninos totais (TT), taninos condensados (TC), saponinas (SPN), perfil de aminoácidos, a digestibilidade aparente do FPMD para suínos na fase de terminação, além do biogás e do metano gerado pelos dejetos dos suínos alimentados com a dieta basal e com a dieta basal acrescida de 8% de FPMD. Os conteúdos de EF, FT, TT, TC e SPN observados, foram, respectivamente, 0,06 mg/g, 26,08 e 10,43 equivalente grama de ácido tânico, 0,05 equivalente grama de leucocianidina e 0,005%. Foram obtidos valores de 83,8% de matéria seca digestível aparente, 3,5 kcal/kg de energia digestível aparente, 13,5% de proteína digestível aparente, 1,5% de fibra digestível aparente e 2,3 % de extrato etéreo digestível aparente. A utilização do FPMD não afetou significativamente (P>0,05) a geração de biogás e metano pelos dejetos dos suínos. Posteriormente, foram avaliados os efeitos da inclusão de níveis (2, 4, 6, 8%) de FPMD na dieta de suínos na fase de terminação sobre os parâmetros de desempenho, características de carcaça, qualidade da carne e toxicidade. A inclusão do FPMD apresentou resposta quadrática negativa (P<0,001) no peso final, ganho diário de peso e consumo diário de ração. No entanto, não foi observada diferença significativa (P>0,05) quando comparados os resultados do tratamento controle e a inclusão de 2% de FPMD, havendo apenas redução (P<0,05) no consumo diário de ração. Nas características de carcaça, a inclusão de FPMD apresentou respostas lineares negativas (P<0,05) para o rendimento de carcaça quente e espessura média de toicinho, além de resposta quadrática negativa (P<0,05) no comprimento de carcaça, não havendo diferença significativa (P>0,05) quando comparados o tratamento controle e a inclusão de 2% de FPMD. Em relação à qualidade da carne, não houve efeito significativo (P>0,05) sobre as variáveis. Nas enzimas transaminases hepáticas, a alanina aminotransferase não foi alterada (P>0,05), no entanto, a inclusão deste co-produto ocasionou resposta quadrática negativa (P<0,05) nos valores de aspartato aminotransferase. Finalizando, foi avaliada a emissão de metano entérico de suínos na fase de terminação, alimentados com dietas com a inclusão de 2% de FPMD. A inclusão do FPMD reduziu significativamente (P>0,05) a emissão de metano entérico pelos suínos. Com os resultados, conclui-se que, embora a inclusão do FPMD tenha acarretado alguns aspectos deletérios, de modo geral, o farelo de pinhão manso detoxicado pode ser incluído em até 2% nas dietas de suínos em terminação / The pourpose of this study was assess the inclusion of detoxicated Jatropha meal (Jatropha curcas L.) in the diet of finishing pigs. Initially it was used in a biological assay with Wistar rats. The analysis of variance did not detect (P>0.05) effect of the addition of DJCM over the performance variables, being, however, observed a significant reduction (P<0.05) on digestibility of diets in response to the addition of the DJCM. The relative weights of liver, kidneys, heart, intestine and length of the small intestine of the animals fed with the different treatments did not differ significantly (P>0.05) with the inclusion of DJCM. For the relative weight of the total gut (intestines plus small intestine) and the small intestine it self, a linear increase was observed (P<0.05) due to the increased level of inclusion of DJCM in the diet. The analysis of variance also did not detect (P>0.05) effect of the addition of DJCM on blood variables, as well as in the hepatic enzymes. In a second trial, there were investigated the contents of forbol esters (FE), total phenolics (TP), total tannins (TT), condensed tannins (CT) saponins (SPN), amino acid profile, and apparent digestibility of DJCM for finishing pigs, as well as the biogas and methane generated by the waste of pigs fed the basal diet (BD) and BD plus 8% of DJCM (DB8). The contents of FE, TP, TT, CT and SPN observed were, respectively, 0.06 mg/g, 26.08 and 10.43 gram equivalent of tannic acid, 0.05 gram equivalent of leucocianidin and 0.005%. As for the apparent digestibility results obtained, it was found values of 83.8%, 3.5 kcal/kg, 13.5%, 1.5% and 2.3% respectively for apparent digestible of dry matter, energy, protein, fiber and ethereal extract. In relation to the production of biogas and methane generated by the waste products from pigs, it can be concluded that the use of DJCM did not affect significantly (P > 0.05) the production of these gases in experimental. Subsequently, it was then evaluated the effects of levels (2, 4, 6, 8%) of DJCM at the diet of finishing pigs upon the performance parameters, carcass characteristics, meat quality and toxicity of DJCM. The inclusion of DJCM presented negative quadratic responses (P < 0.001) for the final weight; daily weight gain and daily consumption of ration. Although there has been a reduction in performance depending on the inclusion of DJCM, it is important to note that when comparing treatment outcomes of control (0%) and the addition of 2% of DJCM, it was not observed significant difference (P > 0.05) for the variables final weight, daily weight gain, feed conversion and only significant reduction (P < 0.05) in the daily ration consumption. The inclusion of DJCM showed negative linear responses (P < 0.05) for warm carcass yield, average thickness of fat and loin eye area. It was found negative quadratic responses (P < 0.05) for the length of the carcass. After the specific contrast analysis comparing the control treatment (0%) and the addition of 2% of DJCM in diet, not significant difference was observed (P > 0.05) between treatments. In relation to the quality of the meat, there was no significant effect (P > 0.05). For the liver enzymes evaluation, ALT has not changed (P > 0.05) with the inclusion of DJCM, however, for AST, the inclusion of co- product caused negative quadratic responses (P < 0.05). For concluding the work, it was evaluated the enteric methane emission by finishing pigs fed with diets with the addition of 2% of DJCM. The inclusion of this co-product reduced significantly (P > 0.05) the enteric methane emissions by pigs. With the results obtained in this work, it can be concluded that, although the inclusion of DJCM may promote some deleterious aspects, in general, the DJCM may be included up to 2% in finishing pig diets.

Thesis (M.Sc. (Animal Production)) --University of Limpopo, 2018. / Refer to the document

Climate changes and global warming are topics of scientific debate. The increase of greenhouse gases has been pointed out as one of the main causes of the changes. The study aimed to evaluate the associative effect of monensin (M) with different levels of tannins (T) on feeding, digestive and rumen fermentation (ex-situ technique) parameters as well as on anaerobic biodigestion of waste. In a 2 x 4 factorial arrangement, 8 cannulated Nellore cows were distributed in 2 contemporary 4 x 4 Latin squares and received 8 experimental diets which differed in the level of inclusion of T of A. mearnsii extract (0.0, 0.75, 1.5, and 2.25% DM) and M which was daily administered to each cow (about 32 mg/kg DM) of one square. To evaluate the production of biogas, experimental batch-type anaerobic biodigesters were used in a completely randomized design. The data were analyzed by the Statistical Analysis System (SAS 9.3, Institute Inc., 2013). The results have shown little interaction between M and T. Regarding the feeding, digestive and N balance parameters, the T linearly reduced DM and water intake, the total apparent digestibility of DM, CP, TDN and OM; for the NDF and ADF the reduction was quadratic. The T linearly reduced rumen disappearance rate by linearly reduce both passage and digestion rates. T also linearly reduced urinary urea excretion, but both additives had no effect on the synthesis and efficiency of microbial protein synthesis. M reduced the proportion of N excreted in feces, but had no effect on N balance, whereas T linearly increased fecal N and linearly reduced urinary and retained N. Regarding the parameters of rumen fermentation, no significant effect of M was observed on CH4 production, but on the reduction of acetate:propionate ratio. T linearly reduced the production of CH4 and total SCFA. Regarding anaerobic biodigestion, M and T reduced the nutrient removal efficiency. M and T had independent effects on rumen metabolism, however, the use of T of A. mearnsii extract up to 2.25% DM is a safe option for cattle, with potential to mitigate rumen CH4. The combined use of M and T reduced the potential of biogas production by reducing the nutrient use efficiency. M inhibited the effect of T on the reduction of nutrient use efficiency of the waste through antagonistic interaction. / As mudanças climáticas e o aquecimento global são temas de debate científico da atualidade. O aumento de gases de efeito estufa é apontado como uma das principais causas das mudanças. O estudo teve como objetivo avaliar o efeito associativo da monensina (M) com diferentes níveis de inclusão de taninos (T) sobre os parâmetros ingestivo, digestivo e fermentação ruminal (técnica ex-situ), bem como sobre a biodigestão anaeróbia de dejetos. Em arranjo fatorial 2 x 4, 8 vacas Nelore, canuladas foram distribuídas em 2 quadrados latinos contemporâneos 4 x 4 e receberam 8 dietas experimentais que diferiram no nível de inclusão de T do extrato da A. mearnsii (0,0, 0,75, 1,5 e 2,25% da MS) e M que foi administrada diariamente a cada vaca (cerca de 32 mg/kg de MS) de um quadrado. Para avaliar a produção de biogás foram utilizados biodigestores anaeróbios do tipo batelada, em delineamento inteiramente casualizado. Os dados foram analisados pelo Statistical Analysis System (SAS 9.3, Institute Inc., 2013). Os resultados mostraram pouca interação entre M e T. Quanto aos parâmetros ingestivo, digestivo e balanço de N, os T reduziram linearmente o consumo da MS e água, a digestibilidade aparente total da MS, PB, NDT e MO e quadraticamente a da FDN e FDA. Os T reduziram linearmente a taxa de desaparecimento ruminal pela redução linear das taxas de passagem e digestão. Os T reduziram linearmente a excreção de uréia urinária, mas ambos aditivos não tiveram efeito sobre a síntese e eficiência da síntese de proteína microbiana. A M reduziu a proporção de N fecal, mas não teve efeito sobre o balanço do mesmo, enquanto que os T aumentaram linearmente o N fecal e reduziram linearmente o N urinário e retido. Em relação a fermentação ruminal, não foi observado efeito da M sobre a produção de CH4, mas sim, redução da relação acetato:propionato. Os T reduziram linearmente a produção de CH4 e AGCC. Em relação a biodigestão anaeróbia, a M e T reduziram a eficiência de remoção de nutrientes. A M e T tiveram efeitos independentes sobre o metabolismo ruminal, porém, o uso de T do extrato da A. mearnsii até 2,25% de MS é seguro para bovinos, com potencial para mitigar o CH4 entérico. O uso combinado de M e T reduziu o potencial de produção de biogás pela redução da eficiência do uso de nutrientes. A M inibiu o efeito dos T sobre a redução da eficiência biodigestiva dos dejetos através da interação antagonista.

This thesis describes the research undertaken for the degree of Doctor of Philosophy, testing the hypothesis that spectrometer data can be used to establish usable relationships for prediction of pasture quality attributes. The research data consisted of reflectance measurements of various temperate pasture types recorded at four different times (years 2000 to 2002), recorded by three hyperspectral sensors, the in situ ASD, the airborne HyMap and the satellite-borne Hyperion. Corresponding ground-based pasture samples were analysed for content of chlorophyll, water, crude protein, digestibility, lignin and cellulose at three study sites in rural Victoria, Australia. This context was used to evaluate effects of sensor differences, data processing and enhancement, analytical methods and sample variability on the predictive capacity of derived prediction models. Although hyperspectral data analysis is being applied in many areas very few studies on temperate pastures have been conducted and hardly any encompass the variability and heterogeneity of these southern Australian examples. The research into the relationship between the spectrometer data and pasture quality attribute assays was designed using knowledge gained from assessment of other hyperspectral remote sensing and near-infrared spectroscopy research, including bio-chemical and physical properties of pastures, as well as practical issues of the grazing industries and carbon cycling/modelling. Processing and enhancement of the spectral data followed methods used by other hyperspectral researchers with modifications deemed essential to produce better relationships with pasture assay data. As many different methods are in use for the analysis of hyperspectral data several alternative approaches were investigated and evaluated to determine reliability, robustness and suitability for retrieval of temperate pasture quality attributes. The analyses employed included stepwise multiple linear regression (SMLR) and partial least squares regression (PLSR). The research showed that the spectral research data had a higher potential to be used for prediction of crude protein and digestibility than for the plant fibres lignin and cellulose. Spectral transformation such as continuum removal and derivatives enhanced the results. By using a modified approach based on sample subsets identified by a matrix of subjective bio-physical and ancillary data parameters, the performance of the models were enhanced. Prediction models from PLSR developed on ASD in situ spectral data, HyMap airborne imagery and Hyperion and corresponding pasture assays showed potential for predicting the two important pasture quality attributes crude protein and digestibility in hyperspectral imagery at a few quantised levels corresponding to levels currently used in commercial feed testing. It was concluded that imaging spectrometry has potential to offer synoptic, simultaneous and spatially continuous information valuable to feed based enterprises in temperate Victoria. The thesis provide a significant contribution to the field of hyperspectral remote sensing and good guidance for future hyperspectral researchers embarking on similar tasks. As the research is based on temperate pastures in Victoria, Australia, which are dominated by northern hemisphere species, the findings should be applicable to analysis of temperate pastures elsewhere, for example in Western Australia, New Zealand, South Africa, North America, Europe and northern Asia (China).

Sweet-potato contains a limited amount of protein, although rich in dietary fibre content and carbohydrate, so a successful combination with wheat flour for bread and biscuit production would be nutritionally advantageous. In particular, the role of these ingredients in relating to acceptability of breads and biscuit with higher percentage of sweet potato starch, flour in wheat flour. In this study, starch, flour and residue fibre of three sweet-potato varieties (red, orange and white -types) were studied. The 5 -10% combination levels for biscuit-making were found to be acceptable, without affecting the quality of the biscuit (combination of texture and biscuit size). In bread, bread containing 15% red and white replacement starches and orange replacement flour was found to be acceptable level, without affecting the quality of the bread, in an attempt to replace wheat at higher per cent level. The physicochemical study was complemented with a nutritional study to determine beneficial effects of food rich in dietary fibre and starches, in the context of improving diet related problems. RVA results showed sweet-potato ingredients affected differently the pasting temperature, peak viscosity and final viscosity of the normal wheat flour (p<0.05). Fibre inclusion showed large reduction in viscosity and swelling of sweet potato starch. Biscuits and breads containing sweet-potato starch and flour are low in amylose, and digest slowly because of lowly oriented and ‘crystalline’ areas within the granules enable to swell or to ungelatinised starch granules, whereas wheat control biscuit was able to gelatinised starch and exerted a greater effect upon digestibility. There are many other factors that need to be considered when analysing the in vitro starch digestibility such including amylose content, amylopectin structure and presence of fibre and gelatinising. Sweet-potato starch, flour and fibre addition show least effect on bread texture and size and starch, flour and fibre replacement. However, in in vitro starch digestibility test higher values RSS was recorded for starch addition followed by flour addition.

A whole-cell DHA-rich algal product (A-DHA, provided by Evonik Industries) that is rich in DHA (125 mg DHA/g dry matter) is a possible replacement for fish oil in salmonid diets. The nutrient digestibilities of the algal product were measured in rainbow trout in freshwater and in Atlantic salmon in saltwater (32-33 ppm). In experiment 1, rainbow trout (initial weight ~ 300g) were randomly assigned to 12 x 120 L tanks (n = 10 per tank). A reference diet containing 1% Celite as an indigestible marker and three test diets with increasing percentage of A-DHA substitution (6.67%, 13.33% and 20%) were fed. Feces were collected using a settling column and feed and feces analyzed for digestible dry matter (DM), gross energy (GE), ash, crude protein (CP), essential amino acids and total lipid. The digestibility of six long-chain fatty acids including 18:1n-9 (OA), 18:2n-6 (LA), 18:3n-3 (ALA), 20:4n-6 (ARA), 20:5n-3 (EPA) and 22:6n-3 (DHA) was measured. In experiment 2, Atlantic salmon (~170g) were randomly distributed to 12 fiberglass tanks (600L) with 106 fish per tank. The fish were assigned to four diets with the same levels of A-DHA inclusion as for rainbow trout and yttrium oxide (Y2O3) was used as an inert marker. Feces were collected by stripping and the digestibilities of DM, CP and lipid as well as OA, LA, ALA, ARA, EPA and DHA were determined. In experiment 1, the apparent digestibility of dietary DM, GE and lipid in rainbow trout declined significantly with increasing inclusion of A-DHA (P < 0.01). The inclusion of A-DHA had no effect on the digestibility of CP and ash as well as the availability of essential amino acids (P > 0.05). Furthermore, increased inclusion of A-DHA resulted in significantly lower digestibility of ARA, EPA and DHA (P < 0.05). A similar pattern was seen in the digestibility of OA, LA and ALA, although the effect of A-DHA inclusion was not statistically significant. Regression analysis revealed that nutrient contribution from A-DHA had significantly negative linear and quadratic effects on the apparent digestibility of DM, GE, and lipid. The inclusion levels of A-DHA had both significantly negative linear and quadratic effects on digestibility of LA and ALA, whereas only significantly negative linear effect was found on OA. Significantly negative linear and quadratic regressions were observed for the digestibility of ARA, EPA and DHA. The linear regression for CP was significantly negative and the regressions for the individual amino acids were not significant (P > 0.05). In experiment 2, dietary inclusion of A-DHA had a significantly negative effect on lipid digestibility in Atlantic salmon, at all inclusion rates whereas the significant negative effect on digestibilities of DM and CP was only observed in fish fed 20% A-DHA. The digestibilities of OA, LA, ALA and EPA were greater than 91%. In contrast, the apparent digestibilities of ARA and DHA decreased significantly with increasing substitution of A-DHA (P < 0.01). Significantly negative linear and quadratic regressions were found between nutrient contribution from A-DHA to the diets and apparent digestibility of DM, CP and lipid, so were LA, EPA and DHA. However, there were only significant quadratic regressions for OA, ALA and ARA, but not significant linear effects. Subsequently, a twelve-week feeding trial in rainbow trout was conducted to investigate the impact of replacing fish oil with A-DHA in canola-oil-based diets on the growth performance and fatty acid composition and retention. Four experimental diets containing only canola oil (CO; 13.5%), fish oil (FO; 13.5%), canola oil and fish oil (C+F; 7.4% and 6.1%, respectively) or canola oil and A-DHA (C+A; 15.5% and 6%, respectively) were formulated to contain 386.2 g/kg digestible crude protein and 17.58 MJ/kg digestible energy. In addition, the C+A diet was formulated to have the same DHA concentration as in the C+F diet. Each diet was fed to three tanks of rainbow trout (average initial weight of 70g; n = 17/tank) and the fish were fed to apparent satiation 2 times daily. At the end of the growth trial, all fish approximately tripled their weight. No significant differences were noted between the dietary treatments in growth performance as measured by final weight, average weight gain, feed intake, specific growth rate (SGR) and feed conversion ratio (FCR). Although FO and C+A fed fish tended to accumulate more lipids, final whole body lipid content did not differ significantly between dietary treatments (P = 0.11). The concentrations of EPA, DHA as well as total n-3 fatty acid were significantly higher in fish fed the FO diet than fish fed the other 3 diets. The C+A fed fish had lower EPA and higher DHA concentrations compared with the CO and C+F fed fish; however, the differences were not significant. Apparent retention of total lipid in the trout was not significantly influenced by treatments (P > 0.05). Similarly, dietary treatments had no significant effect on the apparent retention of total saturated fatty acids, total mono-unsaturated fatty acids, n-3 polyunsaturated fatty acids and n-6 polyunsaturated fatty acids. The retention of 18:4n-3 (SDA) was significantly higher (> 100%) in fish fed CO and C+A compared with fish fed FO and C+F (< 51%), indicating greater bioconversion of ALA to SDA in the CO and C+A fed fish than in FO and C+F fed fish. The retention of EPA in the CO and C+A fed fish was over 100%, suggesting a net synthesis of EPA in these treatment groups. In contrast, the EPA retention in the FO and C+F fed fish was 55 and 21%, respectively, which showed a tendency to be significantly lower than that in the other two groups (P = 0.09). The CO fed fish had significantly higher DHA retention than fish fed the other 3 diets. The DHA retention in the FO fed fish (112%) was numerically but not significantly higher than in the C+F (66%) and C+A fed fish (73%). Thus, feeding the C+A to rainbow trout resulted in DHA retention equal to feeding the C+F.

A major challenge for the pig industry is to formulate starter diets that primarily fit the digestive capacity, maintain GIT health and promote growth without recourse to in-feed antimicrobials. Experiments were conducted to evaluate the efficacy of carbohydrase enzymes (CE) targeting non-starch polysaccharides (NSP) in enhancing gut health and function in piglets. First, an experiment was conducted to evaluate the effects of adding CE in piglet diets on growth performance, GIT bacterial activity and nutrient digestibility. Pigs fed diets containing CE had a higher ileal lactobacilli count, total organic acids concentrations, NSP digestibility and low ammonia compared with control. The effectiveness of CE targeting NSP was further evaluated using enterotoxigenic E. coli (ETEC) in a challenge model to evaluate the impact on gut health and function. Two approaches for the ETEC challenge were adopted; an in situ small intestine segments perfusion model and an in vivo model. Initially, a pilot study was conducted to establish and validate the in situ model. In the pilot study, conventional anti-diarrhea agents; fumaric acid, ZnO, egg yolk antibodies against ETEC K88 fimbriae and carbadox, attenuated fluid losses in ETEC-infected jejunal segments. Following the establishment of the in situ model, four experiments were conducted to study the effects NSP hydrolysis products (HP) from various feedstuffs (i.e. wheat, soybean meal, canola meal and flaxseed) on ETEC-induced secretory diarrhea. The results demonstrated that HP protected against ETEC-induced fluid and electrolyte losses. A further study was conducted to investigate the response of piglets fed diets containing HP and EYA singly or in combination upon oral challenge with ETEC. Feeding HP and EYA alone or in combination attenuated ETEC-enteritis symptoms such that piglets fed additives showed less pronounced acute phase responses and superior performance. Piglets fed diets containing additives had lower gastric pH, fewer ETEC adhered to ileal mucosa and lower incidence of diarrhea. Overall, reduction of intestinal pathogens or toxic bacterial metabolites contributes to enhanced GIT health and function. These novel results expand the scope of enzyme technology in animal nutrition within the new paradigm of dietary approaches to gut health and function.

A major challenge for the pig industry is to formulate starter diets that primarily fit the digestive capacity, maintain GIT health and promote growth without recourse to in-feed antimicrobials. Experiments were conducted to evaluate the efficacy of carbohydrase enzymes (CE) targeting non-starch polysaccharides (NSP) in enhancing gut health and function in piglets. First, an experiment was conducted to evaluate the effects of adding CE in piglet diets on growth performance, GIT bacterial activity and nutrient digestibility. Pigs fed diets containing CE had a higher ileal lactobacilli count, total organic acids concentrations, NSP digestibility and low ammonia compared with control. The effectiveness of CE targeting NSP was further evaluated using enterotoxigenic E. coli (ETEC) in a challenge model to evaluate the impact on gut health and function. Two approaches for the ETEC challenge were adopted; an in situ small intestine segments perfusion model and an in vivo model. Initially, a pilot study was conducted to establish and validate the in situ model. In the pilot study, conventional anti-diarrhea agents; fumaric acid, ZnO, egg yolk antibodies against ETEC K88 fimbriae and carbadox, attenuated fluid losses in ETEC-infected jejunal segments. Following the establishment of the in situ model, four experiments were conducted to study the effects NSP hydrolysis products (HP) from various feedstuffs (i.e. wheat, soybean meal, canola meal and flaxseed) on ETEC-induced secretory diarrhea. The results demonstrated that HP protected against ETEC-induced fluid and electrolyte losses. A further study was conducted to investigate the response of piglets fed diets containing HP and EYA singly or in combination upon oral challenge with ETEC. Feeding HP and EYA alone or in combination attenuated ETEC-enteritis symptoms such that piglets fed additives showed less pronounced acute phase responses and superior performance. Piglets fed diets containing additives had lower gastric pH, fewer ETEC adhered to ileal mucosa and lower incidence of diarrhea. Overall, reduction of intestinal pathogens or toxic bacterial metabolites contributes to enhanced GIT health and function. These novel results expand the scope of enzyme technology in animal nutrition within the new paradigm of dietary approaches to gut health and function.

UAB „Naujasis Nevėžis“ 2012 metais buvo sukurta ekstruduoto baltyminio priedo LAKTOMIL-1 receptūra, šis produktas skirtas melžiamoms karvėms skirtingais produktyvumo tarpsniais. Baltyminio priedo LAKTOMIL – 1 poveikio, karvių produktyvumui ir pieno kokybei, įvertinimui Lukšių žemės ūkio bendrovėje (Lauciškių komplekse) buvo atliktas 90 dienų trukmės bandymas. Bandymui analogų principu atrinkta 30 Lietuvos juodmargių karvių, jos suskirstytos į dvi grupes (kontrolinę ir bandomąją), po 15 gyvulių kiekvienoje. Kontrolinės grupės karvės buvo šeriamos įprastiniu racionu, sudarytu iš kukurūzų siloso, žolių šienainio, kukurūzų grūdainio, rapsų išspaudų, sojų išspaudų ir mineralų. Bandomosios grupės karvės šertos analogišku racionu, tačiau sojų išspaudos pakeistos baltyminiu priedu LAKTOMIL-1. Siekiant nustatyti LAKTOMIL-1 baltymų virškinamumo laipsnį didžiajame prieskrandyje ir plonosiose žarnose, bendradarbiavome su valstybiniu Estijos „Gyvybės Mokslų Universitetu“, Mitybos ir gyvūnų produktų kokybės katedra (Tartu). Baltymų ir sausosios medžiagos virškinamumas didžiajame prieskrandyje buvo nustatytas in sacco metodu. Tyrimui atrinktos trys karvės, kurioms į didįjį prieskrandį įvestos fistulos. Pašarų mėginiai buvo inkubuojami prieskrandyje 2, 4, 8, 16, 24, 48 ir 72 valandas. Darbo tikslas – nustatyti ekstruduoto baltyminio priedo LAKTOMIL-1 virškinamumą in sacco metodu ir įvertinti skirtingo šėrimo poveikį karvių produktyvumui ir pieno sudėčiai. Darbo uždaviniai: 1. in sacco metodu... [toliau žr. visą tekstą] / Object and tasks of work: Investigate extruded protein additive LAKTOMIL-1 ruminal digestibility, determine influence on cow productivity and milk composition. 1. Explore extruded protein additive ruminal digestibility using in sacco method; 2. Set extruded protein additive impact on dairy cows milk production and composition. Research methodology: In 2012 JSC „Naujasis Nevėžis“ specialists developed new extruded protein additive LAKTOMIL-1, for dairy cows in different stages of productivity. To investigate influence of extruded protein additive to cow’s productivity and milk composition, 90 days experiment was carried out in Lukšiai agricultural company (Lauciškiai farm). Analogues of the principle selected thirty Lithuanian Black/white breed cows, they were divided into 2 groups (control and experimental), each group containing 15 animals. The control group was fed a normal cow ration consisting of corn silage, grass silage, maize, rapeseed meal, soybean cake, and minerals. Experimental cows fed a similar diet, but soybean cake was replaced to extruded protein additive LAKTOMIL-1. During the investigation milk yield was determined by the control milking. Milk quality indices have been analyzed in PE “Milk Analysis” (“Pieno tyrimai”). Been studied milk protein, fat, lactose and urea concentration in milk content. Effective degradability of protein and dry matter was determined by the in sacco method using three fistulated cows. The cows were fed the same basal ration... [to full text]

Mud crabs of the genus Scylla are widely exploited for aquaculture in the Asia- Pacific region. In the current study, a series of in vivo experiments were carried to assess the protein requirement, protein sparing effects of starch and the capacity of Scylla serrata to digest diets that contained different animal and plant-based feed meals and different levels and types of starch. Results from a protein requirement study indicated that juvenile S. serrata fed diets containing 45% or 55% protein demonstrated significantly higher growth responses than those fed the diet containing 25% protein. The subsequent study was carried out to determine if responses to dietary protein could be influenced by using purified wheat, potato, rice or corn starch to manipulate the gross energy level of fishmeal- based diets (18 or 15.5 MJ kg-1), i.e., to see if starch had a protein sparing effect in these animals. Overall, growth responses in this study appeared to be positively correlated with the level of protein in the diet with the highest growth rates achieved using diets containing 45% protein, regardless of the energy level of the diet. In addition, at a dietary protein level of 40% there was no evidence that the source of starch had any significant impact on growth performance or feed utilisation suggesting it had no protein sparing effect. By contrast, it was found that growth of juvenile S. serrata was strongly correlated with the intake of digestible dietary protein. The investigation of the capacity of sub-adult S. serrata to digest different animal and plant- based feed meals showed that apparent dry matter digestibility (ADMD) and apparent gross energy digestibility (AGED) values were not significant different for most selected feed meals (cotton seed, poultry, canola, fishmeal, soybean, and lupin meal). Apparent crude protein digestibility (ACPD) for all test feed meals were relatively high (86-96%). A subsequent study was carried out to determine if purified starch from different sources influenced the digestibility of fishmeal based diets. Overall, most diets containing starch were readily digested by mud crabs. In particular, there were no negative impacts on the digestibility of major nutrients (e.g. protein) observed following the inclusion of wheat, rice or corn starch in formulated feeds. Nevertheless, the apparent starch digestibility (ASD) of wheat starch decreased significantly as the inclusion level was increased from 15% to 60%, although there was no significant effect on ACPD values. At a 30% inclusion level, the ASD of diets containing different starches decreased in the order corn > wheat > potato = rice. Moreover, ACPD values were significantly higher for diets containing corn or rice starch than for those containing wheat or potato starch. The capacity of another species of mud crab commonly exploited for aquaculture in South East Asia, S. paramamosain, to digest the local plant-based ingredients (defatted soybean meal, rice bran, cassava and corn flour) was also conducted in Vietnam. Overall, the findings of this study showed that at a 30% inclusion level diets containing soybean meal or rice bran were well digested by mud crabs. In particular, the ACPD and AGED values for all diets containing soybean meal were not significantly different from the fishmeal based reference diet. Likewise, all digestibility values for the diet containing 30% rice bran were relatively high and not significantly different from the reference diet. By contrast, diets containing cassava flour appeared to be poorly utilised since their digestibility values for all parameters were lower than those from other testingredients. In summary, the apparent digestibility of dry matter, protein and energy was in the following order (from most to least digestible) soybean meal ~ rice bran > corn flour > cassava flour. In the next study the effects of attractants in diets (chicken meal, betaine, tuna oil and bait enhancer), temperature (26.5oC, 28.5oC and 30.5oC), sex (female and male) and size (small, medium and large) on feeding responses of S. serrata were investigated. Significant differences were observed in the behavioral responses of mud crabs to diets containing different attractants. Specifically, consumption of diets with chicken meal or betaine was significantly higher than for other treatments. With the exception of betaine, no significant difference in food consumption was observed when attractant inclusion levels were raised from 2% to 5%. Overall, small crabs consumed significantly more of the ration (as a percentage of body weight) than larger crabs. Temperature showed a significant impact on most behaviour of mud crabs, excepting continuation response and there was some evidence that females were significantly more active than males. Light intensity was considered as a main factor effect to crab response since there were extremely high percentage time of crab spent in half-shaded of the Y –maze which valued at 95.6%, 93.8 and 94.4% (corresponded to small, medium and large size respectively) in comparison to those of crabs spent in the unshaded side. Overall, the findings from these studies demonstrated that mud crabs have a high capacity to digest a range of plant based feed ingredients. In particular, soybean meal appeared to be well digested by both species of mud crabs examined. It was also shown that a range of purified starches were well digested by S. serrata although starch inclusion in diets did not appear to reduce the requirement for protein to promote growth. Subsequent attractant studies demonstrated that chicken meal and betaine produced significantly elevated feeding responses and food consumption when added to diets. Based on these results we propose that these ingredients can be utilised to increase the attractiveness and consumption of artificial mud crab feeds.