Two experiments were conducted to determine the effects of various phytase concentrations on broiler growth performance, carcass composition, phosphorus digestibility, tibia ash and phosphorus utilization. The first experiment contained a positive control (PC) diet that was sufficient in all nutrients, a diet reduced in available phosphorus, calcium, amino acids and energy utilized as a negative control (NC) diet and the NC diet supplemented with two different phytase products at three inclusions (500, 1000, and 2000 FTU/kg) all fed to broilers over a 42-day period. The NC fed birds resulted in reduced growth performance by 42 days of age and phytase at 500 and 1000 FTU/kg had increased growth performance compared to NC (P<0.01), resulting in a similar response to the PC fed birds (P>0.05) indicating phosphorus and other nutrient release from the NC diet with phytase supplementation. Birds fed a diet supplemented with phytase A at 2000 FTU/kg outperformed the PC fed birds in body weight gain, feed efficiency, cold carcass weight, breast weight, breast yield, breast + tender weight and yield (P<0.01), but 2000 FTU/kg of phytase B resulted in poor responses often not improved in comparison to the NC fed birds (P>0.05). The second experiment utilized a standard curve to evaluate the use of phytase at various concentrations over a 14 day feeding assay. There were no differences between the two phytase treatments (500 and 2000 FTU/kg) in body weight gain, feed efficiency, feed intake or tibia ash weight (P>0.05). Standard curve analysis of tibia ash weight resulted in an estimate of 0.15 phytate phosphorus release from both phytase treatments. At 14 days, birds fed a treatment supplemented with phytase at 2000 FTU/kg showed an increase in apparent ileal phosphorus digestibility in comparison to 500 FTU/kg fed birds. The data may suggest that birds are digesting more phosphorus at an inclusion of 2000 FTU/kg phytase than 500 FTU/kg phytase but are not able to effectively utilize or store the nutrient as tibia ash showed similar mineral deposition between the two treatments. The concentration of non-phytate (nPP) in the Experiment 2 was 0.20% nPP (0.30% nPP in Experiment 1), which might have precluded the growth performance effects noted in Experiment 1. These two experiments indicate that phytase can act as a viable method in supplementing phosphorus and has the potential to increase broiler growth performance but results may vary depending on the phosphorus deficiency status of the diets before phytase supplementation. / Master of Science

Three experiments were conducted to determine the nutritive value of black Brassica napus (BBN), yellow Brassica juncea (YBJ) and yellow Brassica napus (YBN) in pig diets. In experiment 1, effect of multi-carbohydrase supplementation on SID of AA in BBN, YBJ and YBN was evaluated in growing pigs. The YBJ had similar SID of AA to BBN and enzyme did not affect SID of most of AA. The second and third experiments investigated the effect of high dietary inclusion of BBN and YBJ on weaned pig performance and nutrient digestibility with enzyme supplementation. The studies showed that weaned pigs can be fed diets containing up to 250 g/kg of either BBN or YBJ. Enzyme supplementation improved the nutrient digestibility. In conclusion, BBN and YBJ had similar digestible nutrient contents and there were no detrimental effects detected when pigs were fed up to 250 g/kg of BBN and YBJ in weaned pigs.

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Three experiments were conducted to determine the nutritive value of black Brassica napus (BBN), yellow Brassica juncea (YBJ) and yellow Brassica napus (YBN) in pig diets. In experiment 1, effect of multi-carbohydrase supplementation on SID of AA in BBN, YBJ and YBN was evaluated in growing pigs. The YBJ had similar SID of AA to BBN and enzyme did not affect SID of most of AA. The second and third experiments investigated the effect of high dietary inclusion of BBN and YBJ on weaned pig performance and nutrient digestibility with enzyme supplementation. The studies showed that weaned pigs can be fed diets containing up to 250 g/kg of either BBN or YBJ. Enzyme supplementation improved the nutrient digestibility. In conclusion, BBN and YBJ had similar digestible nutrient contents and there were no detrimental effects detected when pigs were fed up to 250 g/kg of BBN and YBJ in weaned pigs.

Nutrient profiles of distillers grains are primarily affected by the type of grain used for ethanol production, but the feeding value of triticale-based dry distillers grains plus solubles (TDDGS) has not been extensively studied. The first study showed that, compared to 20% corn- or wheat-based distillers grains diets, 20% TDDGS diet increased cis-9 trans-11 linoleic acid concentration in carcass fat without affecting growth performance of lambs. In the second study, lamb growth performance was not affected by the addition of up to 60% TDDGS in the diet, but the risk of urinary calculi increased at higher inclusion levels. Lambs fed 20% TDDGS had higher cold carcass weights and grade rules than lambs fed 40 or 60% TDDGS. Increasing TDDGS decreased diet digestibility, and increased nitrogen and phosphorus excretion. In conclusion, TDDGS can be used in diets for growing ruminants, and its utilization efficiency may be optimized at 20% dietary inclusion. / Animal Science

Orientador: Ana Sílvia Alves Meira Tavares Moura / Banca: Edson Ramos de Siqueira / Banca: Luiz Carlos Machado / Resumo: O objetivo foi avaliar o efeito do enriquecimento da gaiola sobre o comportamento e desempenho de coelhos em crescimento, com diferentes formações de grupos sociais. O experimento, conduzido em duas etapas, teve inicio na desmama, com cinco semanas, e finalizou com 11 semanas de idade. Em cada etapa foram utilizados 72 coelhos do grupo genético Botucatu, 36 machos e 36 fêmeas, alojados em 12 gaiolas de arame galvanizado, seis animais por gaiola. Os animais foram distribuídos em um delineamento inteiramente casualizado, com arranjo fatorial de 2 x 3 (com e sem enriquecimento e em três tipos de grupos sociais - fêmeas, machos e misto), totalizando 6 tratamentos com 2 repetições em cada etapa. Dois pedaços de eucalipto (15 x 3 x 3 cm), usados como enriquecimento, foram dependurados com arame no teto da gaiola e posicionados entre 20 e 30 cm do piso. Seis câmeras foram usadas para registrar imagens do comportamento dos animais por 24h contínuas, uma vez por semana, na 7ª, 10ª e 11ª semanas. Quatro pontos de luz negra foram acionados no período noturno. Foram efetuados registros pontuais dos comportamentos: lúdico, exploratório, agressivo, estereotipado, interação com o enriquecimento, interação social e cecotrofia. Para avaliação do bem-estar foram utilizadas as frequências dos comportamentos lúdico e estereotipado, além da interação com o enriquecimento. Aos 77 dias foi registrado o número de lesões cutâneas nas orelhas e em outras partes do corpo, que pudessem ter sido ocasionadas por brigas. Em seguida, os animais foram abatidos e o peso dos órgãos, incluindo o cérebro, da carcaça e de seus cortes foram coletados. Não houve diferença no desempenho entre os tratamentos. O efeito da interação enriquecimento x grupo social revelou que os machos com enriquecimento... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective was to evaluate the effect of cage enrichment on the behavior and welfare of growing rabbits in different social groups. The experiment, carried out in two phases, was initiated at weaning with five weeks of age and ended at 11 weeks of age. Seventy-two rabbits from the Botucatu genetic group, 36 males and 36 females, were housed in 12 wire cages, six per cage, in each phase. The animals were assigned to a completely randomized design with a 2 x 3 factorial arrangement (with or without enrichment and in three types of social groups - females, males, and mixed) comprising six treatments with two replicates in each phase. Two eucalyptus sticks (15 x 3 x 3 cm) were hung from the cage ceiling with wires to be positioned at 20 to 30 cm from the cage floor. Six cameras were used to record the animals' behavior continuously for 24 hours, once a week on weeks 7, 10 and 11. Four black light bulbs were turned on during the night. The following behavior activities were scored as they occurred: ludic, exploratory, agressive, stereotypes, interaction with the enrichment, social interaction, and cecotrophy. The frequencies of ludic and stereotyped activities were used to evaluate welfare in addition to interaction with the enrichment. At 77 days of age the number of skin lesions in the ears and other parts of the body, that could have been caused by fights among animals, were recorded and the animals were slaughtered. The weight of organs, including the brain, carcass and carcass parts were registered. No difference in growth performance was detected among treatments. An enrichment x social group interaction effect... (Complete abstract click electronic access below) / Mestre

Two experiments were conducted to determine the effects of high dietary calcium (Ca) on broiler chicks fed low phosphorus (P) diets from either nonphytate (nPP) or phytate P (PP) with or without phytase. The response criteria that were analyzed was bird performance, tibia ash, Ca and P digestibility and duodenal P transporter mRNA abundance. Newly hatched broiler chicks were housed in raised-wire starter batteries (65.8 in2) for 16 d. Each experiment had 12 treatments were replicated 6 times using 8 chicks per cage that resulted in a total of 576 Cobb 500 chicks. Experiment 1 had a 3x2x2 factorial arrangement included 3 P treatments (0.225%nPP, 0.225 + 0.1%P from nPP and 0.225 + 0.1%PP), 2 concentrations of Ca (0.9 vs.1.7%Ca) and either (0 or 1,000 FTU of phytase). Experiment 2 also had a 3x2x2 factorial arrangement but set closer to commercial standards (0.325% nPP, 0.325 + 0.1% P from nPP and 0.325 + 0.1% P from PP), 2 concentrations of Ca (0.9 vs.1.4% Ca) with and without phytase (0 or 1,000 FTU of phytase). Body weight gain (BWG), feed intake, feed conversion and mortality were calculated over the 16d period. On 16d, all remaining chicks were euthanized, and the right tibia was analyzed for tibia ash weight (TAW) in mg/tibia and expressed as a percentage (TAP). All data were analyzed as a 3x2x2 factorial using ANOVA in JMP 14 (P ≤ 0.05). In Experiment 1, the phytase interactions were driving FI, which increased BWG (P ≤ 0.05). However, the phytase interactions did not influence bone mineralization (P ≤ 0.05). So, the diet is potentially more appetizing with phytase supplementation. Calcium x phosphorus interaction was driving bone mineralization, but not influencing BWG or FI (P ≤ 0.05). Additionally, bone mineralization was impacted when additional P was put into high Ca diets (P ≤ 0.05). Phytase upregulated P transporter mRNA abundance in normal Ca diets, but the results were muted in high Ca diets (P ≤ 0.05). Experiment 2 used more practical P and Ca conditions to validate the responses from Experiment 1 with the understanding that the potential responses would be blunted. The addition of phytase improved tibia ash when Ca and P were unbalanced (P ≤ 0.05). High concentrations of Ca lowered BWG and FI, but again the addition of phytase to the diet had a more beneficial effect (P ≤ 0.05). Diets with reduced P had an improved P and Ca digestibility and upregulation of P transporter mRNA abundance (P ≤ 0.05). Also, the addition of phytase improved both P and Ca digestibility and downregulated P transporter mRNA abundance (P ≤ 0.05). Overall, both experiments exhibited that source of P did not influence performance but did influence tibia ash. High calcium had a negative effect on performance and digestibility. However, phytase was able to ameliorate negative impacts of high calcium diets. The multiple interactions of Ca, P and phytase indicate a complex relationship among the three factors that require balancing when looking for optimal conditions commercially, especially to maximize performance and skeletal health while balancing cost and environmental considerations. / M.S. / Phosphorus and calcium have many important functions within the body including energy metabolism, cell signaling, bone development and mineralization. When deficiencies of these minerals are seen in broiler chickens a decrease in skeletal health will be one of the first visual signs, where commercially will show up as leg issues. However, meeting the dietary requirements for P and Ca is not a simple task. A considerable amount of P in poultry diets is in the form of phytate P, which is an organic form of P that is hard to digest by the bird. In most cases inorganic P must be fed to meet the broiler requirements for P because its easily absorbed by the animal. Another way to increase the utilization of these minerals is with the supplementation of phytase into the diet. Supplementing phytase allows for a decrease in the amount of inorganic P being added to the diet. The decrease of inorganic P put in the diet saves industries money and is more beneficial for the environment. The addition of phytase also increases the utilization of Ca from the diet, which is brought into consideration during the formulation of the diet. However, there is still a potential for over supplementation of Ca commercially if there are feed mixing errors or high concentrations of Ca from new feed additives. Over supplementation of Ca can lead to many issues which include reduced nutrient digestibility, reduced performance, and an influence on the effectiveness of phytase. Therefore, the effects of feeding high dietary Ca on broiler chicks fed phosphorus from either nonphytate P or phytate P sources with or without phytase were determined with a focus on bird performance, tibia ash, Ca and P digestibility and duodenal P transporter mRNA abundance. Across both experiments source of P did not influence performance but did influence tibia ash. High calcium had a negative effect on performance and digestibility. However, phytase was able to ameliorate negative impacts of high calcium diets. The multiple interactions of Ca, P and phytase indicate a complex relationship among the three factors that require balancing when looking for optimal conditions commercially, especially to maximize performance and skeletal health while balancing cost and environmental considerations.

Master of Science / Department of Animal Sciences and Industry / R. Scott Beyer / Three experiments were conducted to evaluate the effects of gelatinized starch created during the pelleting process. Effects of gelatinization were first broadly tested to find if either increased or decreased gelatinization levels would increase broiler weight gain and feed efficiency during the starter period, 0 to 21 days of age. Results of the first experiment indicated a decrease (P<0.05) in broiler performance with increased levels of gelatinization, and a significant effect when the inclusion of gelatinized starch in the diet increased from 0 to 35%. A second experiment was conducted using a smaller range, 0 to 21% versus 0 to 35% inclusion of gelatinized starch in the diet and a smaller increment of increase, 3 versus 5%. Results of this experiment confirmed the results of the first experiment, and regression analysis was performed on the data. A linear decrease in body weight gain and quadratic increase in feed:gain (P<0.05) was observed as gelatinized starch was increased from 0 to 21% of the diet. A survey of the literature was conducted showing that most of the simulated levels of gelatinization were larger than those achieved with typical pelleted broiler diets. A third experiment was designed to investigate the levels of gelatinization observed in a pelleted diet and combined with three corn particle sizes, small (466 μm), medium (878 μm), and large (1240 μm), to find if any interactions existed. Chicks fed with the highest gelatinization level of 20%, (7.86% inclusion of pregelatinized starch) had lower body weight gains (P<0.05), and higher feed:gain (P<0.05) compared to chicks fed with 0% gelatinization. Small particle size had the lowest live body weight gain and lowest pen feed intake (P<0.05). There were no interactions found between gelatinization level and particle size (P>0.10). The results demonstrated a negative effect on chick body weight gain and feed efficiency by gelatinization of starch.

In the beef cattle industry, sustainable beef production is a primary focus, as it has direct effects on environmental stewardship, farm profitability, and public concerns. Research has been and is continually being conducted to evaluate alternative forages such as Brown Midrib Corn Silage (BMRCS) as a major component in growing beef cattle diets, to improve animal performance, ruminal fermentation, and economic returns. The objective of this study was to determine growth performance, ruminal fermentation characteristics, and economic returns of growing beef steers when fed a brown midrib corn silage-based TMR (BMRT) compared with a conventional corn silage-based TMR (CCST). This growing beef study was performed in a completely randomized design with 24 Angus crossbred steers (initial body weight (BW) = 258 ± 23.2 kg) to test 2 treatments: CCST vs. BMRT. All animals were placed in individual pens, and 12 animals allocated to each treatment (n = 12). All steers were adapted to the CCST for a 2-wk period prior to start of the trial. The CCST contained 48.1% CCS whereas the BMRT consisted of 49.0% BMRCS on a dry matter (DM) basis. All steers were fed once per day, and feed bunks assesed each afternoon and prior to morning feeding, which was used to determine the amount of feed to deliver to each pen the following day. The experiment lasted 84 d. For all steers, BW and ruminal fermentation characteristics were measured on wk 4, 8, and 12. Intake of DM averaged 9.54 kg/d across the treatments and was similar between the treatments. Steers fed the BMRT tended to increase average daily gain (ADG) compared to those fed the CCST (1.54 vs. 1.42 kg/d; P = 0.09). In addition, feeding the BMRT tended to increase G:F compared with the CCST (0.165 vs. 0.146; P = 0.07). Feeding the BMRT decreased ruminal pH (6.42 vs. 6.67; P < 0.01), whereas it increased total VFA concentration (P = 0.01) compared with the CCST. Feeding the BMRT decreased molar proportion of acetate (P < 0.01), but increased propionate proportion (P = 0.01), resulting in decreased acetate-to-propionate ratio compared with the CCST (P < 0.02). Steers fed BMRT increased feed margin (P = 0.05) and net return (P = 0.02) compared to those fed CCST throughout the trial. Overall data in this study indicate that feeding the BMRT to growing beef steers enhanced ruminal fermentation and beneficially shifted VFA profiles, which contributed to improved growth performance and economic performance of steers fed the BMRT.

Two trials were conducted to evaluate effects of grain adaptation protocol on subacute acidosis, feeding behaviour and ADG of cattle. In trial one, 12 crossbred heifers (384 ¡À 25 kg) were stepped from 40% to 90% dietary concentrate by either rapid adaptation (RA; one step-up diet fed for 3 d) or by gradual adaptation (GA; five step-up diets fed for 3 d each). Mean daily ruminal pH variables did not differ (P > 0.10) between treatments but variances of a number of ruminal pH variables were greater (P < 0.05) for RA than GA during adaptation to 65% and 90% concentrate. Mean hourly pH did not differ over the first 24 h of adaptation to 65% concentrate, but variance of hourly pH tended (P < 0.10) to be greater for RA than GA for eight of the first 24 h of adaptation to 90% concentrate. Increased variance in ruminal pH parameters was associated with detection of acidosis in certain individuals. On d 1 of 90% concentrate, ruminal pH tended (P = 0.07) to be lower at 11 and 12 h post-feeding with RA than with GA. Ruminal volatile fatty acids (VFA) and osmolality were similar between treatments. In trial two, 120 crossbred heifers (366 ¡À 23 kg) were adapted from 40% to 90% concentrate. A protocol identical to trial one was used with the addition of moderate adaptation (MA; three step-up diets fed for 3 d each). The increase to 65% concentrate caused reduced daily bunk attendance and increased maximum intermeal interval for RA compared to MA and GA cattle but the increase to 90% did not. ADG was reduced for RA compared to MA or GA during adaptation but over day 1 to 69 ADG did not differ between treatments (P ¡Ý 0.41). Current management strategies for preventing acidosis in pens of cattle are based on responses of the most susceptible individuals. Improved understanding of individual responses to acidotic challenge may allow development of more effective acidosis prevention practices.