Coccidiosis is endemic in the commercial broiler industry and inflicts devastating economic losses to poultry operations. Probiotics may provide a potential alternative to the prophylactic use of anticoccidials in commercial production. This study evaluated the effects of probiotic applications (feed and water) on bird performance and resistance to a mixed Eimeria infection in commercial broilers. On day of hatch, 1008 commercial male broilers (Cobb 500) were assigned to one of 6 treatments (8 replicate floor pens; 21 birds/pen), including non-infected negative control (NEG), Eimeria-infected positive control (POS), anticoccidial control (0.01% salinomycin, SAL), intermittent high dose water-applied probiotic (WPI), continuous low dose water-applied probiotic (WPC), and feed-supplemented probiotic (FSP). On d15, all birds except those in NEG were challenged with a mixed inoculum of Eimeria acervulina, E. maxima, and E. tenella. Measurements were taken on d7, 15, 21, 28, 35 and 42. Fecal samples were collected from d20-d24 for oocyst counts, and lesion scores were evaluated on d21. Data were analyzed using the Fit Model platform in JMP Pro 10.0 (SAS). Differences in experimental treatments were tested using Tukey HSD following ANOVA with significance reported at P ° 0.05. Overall, NEG birds outperformed all other groups. For performance, the probiotic groups were comparable to the SAL treated birds, except during the 6 days immediately following the Eimeria species challenge, where the SAL birds exhibited better performance. WPC birds had lower duodenal and jejunal lesion scores, indicating a healthier intestine and enhanced resistance to Eimeria species compared to POS. Birds in the WPI treatment shed fewer oocysts in the feces, though this was not a trend for all of the probiotic treatment groups. The results of this study suggest probiotic supplementation without anticoccidials can enhance performance and help alleviate the negative effects of a mixed Eimeria infection. / Master of Science

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

Breast muscles that are deboned prior to 4 to 6 h postmortem are highly variable and lacking in tenderness. The poultry industry currently provides costly storage space for intact broiler breasts during this 4 to 6 h period. This thesis evaluates tenderization techniques that if effective could eliminate the need for this additional 4 to 6 h storage time. The first objective of this study was to determine a relationship between Warner-Bratzler shear values (WBS) (1 cm by 1cm, variable length strips) and consumer tenderness acceptability of broiler breasts. The breasts were divided into five groups based on their WBS values. Consumers were presented with one sample (1 cm by 1 cm by 2 cm strips) at a time and asked to report the acceptability of the sample's tenderness on a 9-point hedonic scale. Of the 62 panelists, 93.5 % found chicken breasts with WBS values from 2.1 to 3.1 kg to be acceptable. Only 83.9 % of the panelists found the extremely tender chicken breast to be acceptable (1.1 to 1.9 kg). The percentage of consumers that found the samples acceptable decreased as the WBS values increased beyond 3.1 kg (P<0.05). The second objective determined the effects of high pressure hydrodynamic shockwave (HSW) on tenderness (48 h postmortem) of early-deboned (52 min postmortem) breasts treated 25 minutes after deboning (70 min postmortem) or treated after storage (24 hr postmortem) and compared to the corresponding non-treated companion breasts. The effect of HSW treatment on early-deboned treated 25 min after deboned broiler breasts was determined by the following methods. Live broiler chickens were obtained from a commercial poultry company and slaughtered according to commercial processing standards. The effect of HSW on early deboned stored broiler breast was examined by deboning broiler breasts 45 min postmortem and storing (4 C) for 24 h. One breast from each bird was treated with hydrodynamic shockwave, while the companion breast was used as a control. Packaged breasts were placed in the center of a 20.23 cm diameter cylinder which was vertically positioned in the bottom of a water-filled HSW hemishell tank (30.4 cm diameter) and a shockwave was produced by and a shockwave was produced by detonating 40 grams of molecular explosive in the water. Early deboned (ED) breasts stored 24 h before treatment (2.5 kg, WBS) were 42% more tender than the companion ED control breasts (4.3 kg, WBS). The HSW treated breasts would be acceptable to approximately 94 % of consumers. The ED control breasts would be acceptable to only 67.7% of consumers. Early deboned and treated 25 min after deboning breasts (5.0 kg) were not different in WBS from their companion ED control breasts (4.6 kg). Early-deboned breasts treated immediately may require higher pressure shockwaves or delayed treatment. The HSW process can overcome the problem with tenderness associated with early deboning if the breasts are processed after storage thereby providing processors with the option to debone earlier. A third objective was to examine the effects of electrically produced shockwaves on early deboned broiler breasts and normally processed turkey breast. Broiler breasts were treated with one Pulse Firing Network (PFN) or two PFN and 45 % Energy. Breasts treated with one PFN were not different than controls. Broiler breasts exposed to two PFN were 22 % more tender and different from the controls. Turkey breast portions exposed to two PFN and 72% Energy were different (12 % lower WBS values) from the control breast portion. Electrically produced shockwaves can tenderize stored, early deboned chicken breasts and aged turkey breasts. / Master of Science

Broiler performance is dependent on immunocompetency and the ability to respond to environmental challenges. Incubation temperature, post-hatch transportation, and vaccination may impose stress upon the embryo and post-hatch chick and impact immune system development and lifetime performance of the bird. The objective of the first study was to evaluate incubation temperature and post-hatch transportation environment on response parameters indicative of early immunity in the neonatal chick. Cobb 500 eggs (n=5200) were incubated with combinations of eggshell temperatures common to commercial multi-stage incubators during early and late incubation: low (L): 36.7°C, standard (S): 37.5°C, and high (H): 39.0°C. After hatch, chicks were transported under one of two conditions: control (C: 34°C) or distressed (D: 40°C), yielding 8 experimental treatments: LH-C, LS-C, SH-C, SS-C, LH-D, LS-D, SH-D, and SS-D. The objective of the second study was to examine the effects of incubation temperature profiles on response to vaccination in Cobb 500 broilers (n=2000). Temperature treatments were the same as the first study, and embryos were administered vaccinations for Marek's disease virus (MDV) at embryonic day (ED) 18, Newcastle disease virus (NDV) at hatch, the combination of MDV+NDV, or no vaccine (control). There were 16 resulting experimental groups: LH-Control, LH-MDV, LH-NDV, LH-MDV+NDV, LS-Control, LS-MDV, LS-NDV, LS-MDV+NDV, SH-Control, SH-MDV, SH-NDV, SH-MDV+NDV, SS-Control, SS-MDV, SS-NDV, and SS-MDV+NDV. Two and three way interactions (P<0.05) were observed for the parameters evaluated and are presented for both studies. These studies suggest an influence of incubation temperature and post-hatch stressors on chick development and early immune response parameters. / Master of Science

The current research program was designed to evaluate the impact of various dietary and ingredient nutrient profiles and exogenous enzyme inclusion on growth performance and energy utilization in broilers. Experiment one was designed to observe increasing levels of distillers’ dried grains with Solubles (DDGS) and a non-starch polysaccharide degrading enzyme (NSPase) on energy digestibility. Experiment two evaluated the influence nutrient variation in corn and xylanase supplementation on growth performance and nutrient utilization. In experiment one, DDGS concentration was increased from 0 to 15% in 5% increments and included the addition of an NSPase enzyme. Early broiler body weight and FCR was negatively affected with increasing DDGS concentration up to 15%. The decreased growth performance was associated with a decrease in energy and nitrogen utilization as a linear decrease was observed in IDE, INDC, and AMEn. Addition of the NSPase negated many of the negative effects on nutrient utilization as improvements in all digestibility measurements were observed. Interactions were observed with DDGS concentration and NSPase inclusion as the benefit of enzyme inclusion was augmented as DDGS level increase. Experiment two evaluated different corn crops from six geographical locations in the US in an effort to determine the effects of xylanase inclusion and corn nutrient variation on growth performance and nutrient utilization. Significant differences were observed in growth performance, IDE, and AMEn in broilers when fed corn. Corn source impacted early body weights, and FCR throughout the experiment. Energy utilization was also impacted on all measured parameters, following the starter phase (day 17) and at the conclusion of the trial (day 41) by corn source. Xylanase inclusion improved FCR during the finisher phase as well as the cumulative FCR (day 1-41). Digestibility data indicates that corn source impacts the xylanase effectiveness in young broilers, as improvements were not observed in all corn types. Xylanase inclusion, however, did increase IDE and AMEn in all corn sources on day 41 of age. Data from this research program confirm that ingredient nutrient content, through the presence of ingredients with anti-nutritive properties or the incidence of varying nutrient profiles, does impact observed growth performance as related to reduced nutrient digestibility. Additionally, the inclusion of a dietary exogenous enzyme does improve energy and nitrogen digestibility in broilers, ultimately improving growth performance of broilers and improving efficiency.

The only available broiler strain to use in organic chicken meat production, until recently, has been conventional fast growing broiler hybrids. The Rowan Ranger is a broiler strain that has a naturally slower growth rate which makes this strain suitable for organic farming, meeting the demands of KRAV without being subjected to a feed restriction. One of the farms in Sweden using Rowan Ranger in their organic production is Bosarp farm in Skåne County where they produce KRAV certified chickens and where the animals used in this study were raised. This study compared differences between a naturally slow growing strain of chicken to a fast growing strain to see whether there were differences in behaviour between the two, if one of the strains was more susceptive to stress than the other and whether they differed in outdoor use and activity level. Regardless of strain, chickens used the outdoor perimeter the same, although the Rowan Rangers did not range as far from the chicken house as Ross 308. Even so, they seem to be more suitable in an organic setting than Ross 308 due to the fact that they seem less hungry and more content, this based on the fact that they perform less feeding behaviour and spend more time laying down. Also, they grow nicely to slaughter weight with a good diet quality whereas Ross 308 need to be qualitative feed restricted to do the same, giving the Rowan Rangers better welfare.

Orientador: Raphael Lucio Andreatti Filho / Banca: Paulo Lourenço da Silva / Banca: Renée Laufer Amorim / Resumo: O objetivo deste trabalho foi verificar por meio de imunoistoquímica se a inoculação oral de culturas de Lactobacillus acidophillus, L. reuteri, L. salivarius e a microbiota cecal de aves estimula a resposta imune celular no intestino de pintos de linhagem comercial, desafiadas ou não por Salmonella Enteritidis, na forma de infiltrado leucocitário por células T CD3+, CD4+ e CD8+. Foram utilizados 320 aves com um dia de vida, não sexados e livres de quimioterápicos. Cada grupo foi subdividido em quatro subgrupos com 20 aves cada e classificados em grupo que não recebeu tratamento (controle negativo), tratamento com L. spp ou MC, tratamento com L. spp ou MC e desafio com S. Enteritidis e tratamento com S. Enteritidis (controle positivo). Os resultados obtidos mostram que o tratamento com L. reuteri, L. salivarius, L. acidophillus ou microbiota cecal e o desafio com S. Enteritidis, determina resposta imune na forma de infiltrado leucocitário por linfócitos CD3+, CD4+ e CD8+ no epitélio e na lâmina própria do duodeno, jejuno e ceco de aves com até 12 dias de idade. / Abstract: The bacteria of the Lactobacillus sort have been very studied currently had to its important paper in the process of competitive exclusion where they contribute in the reduction of pathogenically genus, in special infections for Salmonella spp. it saw oral in the first days of life. These bacteria with probiotically characteristics provide beneficial effect to the general health of the host, through the stimulation and anti tumor modulation of the immune reply and properties, had probably the action on the cellular immune system. The objective of this work was to verify if Lactobacillus acidophillus, L. reuteri, L. salivarius and microbiota cecal of broiler chicken have been imunostimulated activities through its inoculation in birds of commercial ancestry with one day of life, defied or not for Salmonella Enteritidis, determining immune reply in the form of infiltrated leucocytes for cells T in the epithelium and intestinal proper blade.The gotten results demonstrate that the cultures of L. acidophillus, L. reuteri, L. salivarius and microbiota cecal defy or not with S. Enteritidis, they determine immune reply on the part of the host in the infiltrated form of leucocytes for lymphocytes CD3+, CD4+ and CD8+. / Mestre

Dois experimentos foram realizados no Departamento de Zootecnia da Universidade de São Paulo (USP), na faculdade de Zootecnia e Engenharia de Alimentos (FZEA), em Pirassununga/SP, com o objetivo de estudar o desempenho de frangos de corte alimentados com rações suplementadas com enzimas exógenas. A ração experimental foi constituída de milho, farelo de soja, vitaminas, minerais e enzimas exógenas (50 g / 100 kg). No experimento I foram utilizados 504 pintainhos Cobb distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2x3: 2 sexos - fêmeas e machos, 3 níveis nutricionais - Reduzido, reduzido + complexo enzimático e convencional, totalizando 6 tratamentos com 7 repetições de 12 animais cada. Os resultados revelaram que machos e fêmeas, recebendo dietas com níveis nutricionais reduzidos com adição de enzima, apresentaram maiores peso médio e ganho de peso aos 21 e 42 dias de idade quando comparados aos demais tratamentos (P&lt;0,05). Não foram encontradas diferenças significativas para as características de carcaças. No experimento II foram utilizados 1.080 frangos de corte, machos, de sete dias de idade, Cobb 500, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 3X3: sendo três níveis nutricionais - convencional, reduzido e reduzido + complexo enzimático e três níveis de restrição - 0%, 2% e 4% - totalizando 9 tratamentos com 10 repetições de 12 animais. Os resultados encontrados revelaram um efeito significativo sobre o desempenho das aves com a redução do ganho de peso dos animais e conversão alimentar. Não foram observados efeitos sobre a mortalidade e incidência de transtornos metabólicos. Não foram encontradas diferenças significativas para as características de carcaças e percentagem de gordura abdominal, porém, ocorreu um aumento no rendimento de peito para aves alimentadas com o complexo enzimático na dieta. / Two experiments were conducted at the Department of Animal Science, University of São Paulo (USP), College of Animal Science and Food Engineering (FZEA) in Pirassununga / SP, with the aim of studying the performance of broilers fed diets supplemented with exogenous enzymes. The experimental diets consisted of corn, soybean meal, vitamins, minerals and exogenous enzymes (50 g / 100 kg). In the first experiment were used Cobb 504 chicks distributed in a completely randomized 2x3 factorial: two sexes - males and females, three nutritional levels - Low, low + enzyme complex and conventional, totaling 6 treatments with seven replicates of 12 animals each. The results revealed that males and females, fed diets with reduced nutrient levelswith the addition of enzyme, showed higher average weight and weight gain at 21 and 42 days of age when compared to other treatments (P&lt;0.05). There were no significant differences for carcass traits. In experiment II were used 1080 broilers, males, seven-day-old Cobb 500, distributed in a completely randomized design in factorial 3X3: with three levels of nutrition - conventional, reduced and reduced + enzyme complex and threelevels of restriction - 0%, 2% and 4% - a total of nine treatments with 10 replicates of 12animals. The results showed a significant effect on broiler performance with reducedweight gain and feed the animals. No effects on mortality and incidence of metabolic disorders. There were no significant differences for carcass traits and abdominal fat percentage, however, there was an increase in breast yield for birds fed the enzyme complex in the diet.

Dois experimentos foram realizados no Departamento de Zootecnia da Universidade de São Paulo (USP), na faculdade de Zootecnia e Engenharia de Alimentos (FZEA), em Pirassununga/SP, com o objetivo de estudar o desempenho de frangos de corte alimentados com rações suplementadas com enzimas exógenas. A ração experimental foi constituída de milho, farelo de soja, vitaminas, minerais e enzimas exógenas (50 g / 100 kg). No experimento I foram utilizados 504 pintainhos Cobb distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2x3: 2 sexos - fêmeas e machos, 3 níveis nutricionais - Reduzido, reduzido + complexo enzimático e convencional, totalizando 6 tratamentos com 7 repetições de 12 animais cada. Os resultados revelaram que machos e fêmeas, recebendo dietas com níveis nutricionais reduzidos com adição de enzima, apresentaram maiores peso médio e ganho de peso aos 21 e 42 dias de idade quando comparados aos demais tratamentos (P&lt;0,05). Não foram encontradas diferenças significativas para as características de carcaças. No experimento II foram utilizados 1.080 frangos de corte, machos, de sete dias de idade, Cobb 500, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 3X3: sendo três níveis nutricionais - convencional, reduzido e reduzido + complexo enzimático e três níveis de restrição - 0%, 2% e 4% - totalizando 9 tratamentos com 10 repetições de 12 animais. Os resultados encontrados revelaram um efeito significativo sobre o desempenho das aves com a redução do ganho de peso dos animais e conversão alimentar. Não foram observados efeitos sobre a mortalidade e incidência de transtornos metabólicos. Não foram encontradas diferenças significativas para as características de carcaças e percentagem de gordura abdominal, porém, ocorreu um aumento no rendimento de peito para aves alimentadas com o complexo enzimático na dieta. / Two experiments were conducted at the Department of Animal Science, University of São Paulo (USP), College of Animal Science and Food Engineering (FZEA) in Pirassununga / SP, with the aim of studying the performance of broilers fed diets supplemented with exogenous enzymes. The experimental diets consisted of corn, soybean meal, vitamins, minerals and exogenous enzymes (50 g / 100 kg). In the first experiment were used Cobb 504 chicks distributed in a completely randomized 2x3 factorial: two sexes - males and females, three nutritional levels - Low, low + enzyme complex and conventional, totaling 6 treatments with seven replicates of 12 animals each. The results revealed that males and females, fed diets with reduced nutrient levelswith the addition of enzyme, showed higher average weight and weight gain at 21 and 42 days of age when compared to other treatments (P&lt;0.05). There were no significant differences for carcass traits. In experiment II were used 1080 broilers, males, seven-day-old Cobb 500, distributed in a completely randomized design in factorial 3X3: with three levels of nutrition - conventional, reduced and reduced + enzyme complex and threelevels of restriction - 0%, 2% and 4% - a total of nine treatments with 10 replicates of 12animals. The results showed a significant effect on broiler performance with reducedweight gain and feed the animals. No effects on mortality and incidence of metabolic disorders. There were no significant differences for carcass traits and abdominal fat percentage, however, there was an increase in breast yield for birds fed the enzyme complex in the diet.

Genetic variation between individuals is of great importance for the development of breeding programmes, to select for animals with the most favourable traits. Many production companies routinely measure the feed intake of their animals, in order to calculate efficiency traits such as feed conversion ratio. The development of electronic feeders which automatically record individual intake on a visit-by-visit basis now allows the short-term feeding behaviour of animals to be monitored and analysed as another source of variation between individuals. Due to differences in the resolutions of these feeders as a measurement tool, a standard unit of feeding event needs to be estimated to allow for comparisons between studies. Different models for estimation of the defining value of a meal, the meal criterion, have been used, with the most recent incorporating the change in satiety with time since last feeding as part of the model. In this study I developed a new methodology, based on these models, for use when a within meal population of intervals cannot be easily modelled. I then used this model for application to data from four lines of broiler chickens to estimate meal criteria and compare feeding behaviour within and between the lines. Significant differences were found between fast and slow growing birds, with the faster growing birds having fewer but larger meals than the slower growing birds. However, the lines showed similar structure and bouting of their feeding behaviour, indicating that the fundamental controls of feeding behaviour, such as hunger and satiety, in these lines had been unaltered despite intensive selection for growth. The models were also applied across poultry species, kept in different experimental conditions. A similar structure to the feeding behaviour was found across all these species, with all showing clear separation of feeding events into bouts. In order to estimate the potential use of these behavioural observations in a breeding programme, the heritabilities and genetic correlations with existing performance traits were calculated for the four broiler lines. Heritabilities of all feeding behaviour traits were found to be moderate to high, and very similar across the lines. Correlations with performance traits, however, were low, meaning that there were no clear links of the traits with the current production goals investigated. This indicates that past selection for production has had limited impact on feeding behaviour and also that potential selection for feeding behaviour will have little effect on production gains. To identify the areas of the genome controlling feeding behaviour, traits were associated with a SNP panel. Many regions were found to have highly significant association with feeding behaviour traits, with the most highly correlated traits showing associations with the same regions, suggesting pleiotropic effects of genes in these regions. Future work in this area should include identification of individual genes controlling feeding behaviour to allow prediction of the effects of selection for favourable feeding behaviour on other traits, and comparison of the genotypes of different lines of broilers, to further understand the control of feeding behaviour.