Starter feed particle size (FPS) is typically small (~1200 µm) due to bird beak capacity (BC). Recent research has found that chicks can consume a larger FPS than previously thought; however, preferred FPS and its relationship with BC has not been established. Experiment 1 was conducted to determine the effect of breeder flock age (BFA) and feeding strategy (FS) on 0-14 d performance, BC and FPS preference. These data found that BC was dependent upon BFA and FPS consumed was dependent upon FS. Also, chicks could consume increased FPS without impacting starter performance; thus Experiment 2 was conducted to determine the effects of BFA and Starter FS on carryover performance (0-61 d), BC and processing metrics. Significant BFA differences occurred, though no FS carryover impact occurred for the measured variables. Overall, these data suggest that chicks can consume a FPS of ~2600 µm without negatively affecting starter or carryover performance.

A proposta geral do presente projeto consistiu na avaliação do desempenho, características de carcaça, bem como possíveis efeitos adversos, em frangos de corte alimentados com dietas contendo níveis crescentes de glicerina, resultante do processo de obtenção do biodiesel. Foram criados 1575 frangos de corte machos da linhagem comercial Cobb 500. Os pintos de um dia foram pesados e alocados de acordo com o peso médio em grupos de 45 aves distribuídas em 35 boxes. O delineamento experimental utilizado foi inteiramente casualizado, com cinco tratamentos (0; 2,5; 5; 7,5 e 10% de inclusão de glicerina bruta) e sete repetições. As dietas foram isonutritivas baseadas em milho, farelo de soja e óleo de soja. Em laboratório foi avaliado a concentração de glicerol, sódio, fósforo, potássio e metanol da glicerina bruta para correção na formulação das rações. Foi considerado o valor energético de 4100 kcal EMAn/kg para o glicerol puro. As variáveis de desempenho (peso vivo, ganho de peso, consumo de ração, conversão alimentar e viabilidade) foram monitoradas semanalmente e, aos 43 dias de idade, 70 aves (14 aves/tratamento) foram sacrificadas para avaliação das características de carcaça e foi retirada também uma amostra da cama dos frangos de cada boxe para determinação de umidade. No período de 1 a 7 dias houve efeito linear positivo (P<0,05) para as variéveis: ganho de peso, consumo de ração e peso vivo, verificando-se que a inclusão de até 10% de glicerina na ração foi eficaz. No período de 1 a 21 dias ocorreu redução linear (P<0,05) da viabilidade, efeito cúbico (P<0,05) para o consumo de ração e efeito de quarto grau (P<0,05) para o ganho de peso e peso vivo, evidenciando melhores resultados de desempenho utilizando 5% de glicerina nas rações. No período total não houve efeito significativo para as variáveis de desempenho (P>0,05), embora verificado uma redução de 130 gramas no ganho de peso dos frangos alimentados com 10% de glicerina. Não houve efeito significativo para as características de carcaça (P>0,05), porém houve aumento linear (P<0,05) na umidade de cama dos frangos conforme a inclusão de glicerina na dieta. A inclusão de até 10% de glicerina na dieta até 7 dias e 5% nos períodos subsequentes, mostrou-se interessante na alimentação de frangos de corte. / The purpose of this work was to evaluate the effects of increasing levels of glycerin from biodiesel production in rations on the performance, carcass characteristics and moisture litter of broilers. The trial used 1575 Cobb male chicks. The chickens 1 day of age were weighed and allocated according to weight average to groups of 45 distributed in 35 pens in a completely randomized experimental design. Treatments were (0; 2,5; 5; 7,5 and 10%) glycerin inclusion with seven replicates per treatment. Was analyzed a contraction of glycerol, sodium, phosphorus, potassium and methanol from the crude glycerin in laboratory for formulate diets. Was considered the energy value of 4,100 kcal ME/ kg for the pure glycerol. The performance (liveweight, weight gain, feed intake, feed conversion and viability) were monitored weekly and at 43 days of age 70 broilers (14 broilers/ treatment) were sacrificed for evaluation of carcass characteristics. The moisture of the litter was analyzed in each pen. At seven days, it was found a positive linear effect (P<0.05) on weight gain, body weight and feed intake, verifying that the inclusion up to 10% glycerin in the diet was efficient. At 21 days, it was found a linear reduction (P<0.05) on viability, cubic effect (P <0.05) on feed intake and quartic effect (P <0.05) on weight gain and body weight. Results using 5% glycerin in diet showed better performance. At 42 days, there was no significant effect on the performance variables (P> 0.05), although a substantial reduction of 130 grams in weight gain was observed in broilers fed 10% glycerin. There was no significant effect on carcass characteristics (P> 0.05), but increased linear effect (P <0.05) was observed on litter moisture with the inclusion of glycerin in the diet. The inclusion of 10% of glycerin up to seven days and 5% after that was flexible in diets for broilers.

A proposta geral do presente projeto consistiu na avaliação do desempenho, características de carcaça, bem como possíveis efeitos adversos, em frangos de corte alimentados com dietas contendo níveis crescentes de glicerina, resultante do processo de obtenção do biodiesel. Foram criados 1575 frangos de corte machos da linhagem comercial Cobb 500. Os pintos de um dia foram pesados e alocados de acordo com o peso médio em grupos de 45 aves distribuídas em 35 boxes. O delineamento experimental utilizado foi inteiramente casualizado, com cinco tratamentos (0; 2,5; 5; 7,5 e 10% de inclusão de glicerina bruta) e sete repetições. As dietas foram isonutritivas baseadas em milho, farelo de soja e óleo de soja. Em laboratório foi avaliado a concentração de glicerol, sódio, fósforo, potássio e metanol da glicerina bruta para correção na formulação das rações. Foi considerado o valor energético de 4100 kcal EMAn/kg para o glicerol puro. As variáveis de desempenho (peso vivo, ganho de peso, consumo de ração, conversão alimentar e viabilidade) foram monitoradas semanalmente e, aos 43 dias de idade, 70 aves (14 aves/tratamento) foram sacrificadas para avaliação das características de carcaça e foi retirada também uma amostra da cama dos frangos de cada boxe para determinação de umidade. No período de 1 a 7 dias houve efeito linear positivo (P<0,05) para as variéveis: ganho de peso, consumo de ração e peso vivo, verificando-se que a inclusão de até 10% de glicerina na ração foi eficaz. No período de 1 a 21 dias ocorreu redução linear (P<0,05) da viabilidade, efeito cúbico (P<0,05) para o consumo de ração e efeito de quarto grau (P<0,05) para o ganho de peso e peso vivo, evidenciando melhores resultados de desempenho utilizando 5% de glicerina nas rações. No período total não houve efeito significativo para as variáveis de desempenho (P>0,05), embora verificado uma redução de 130 gramas no ganho de peso dos frangos alimentados com 10% de glicerina. Não houve efeito significativo para as características de carcaça (P>0,05), porém houve aumento linear (P<0,05) na umidade de cama dos frangos conforme a inclusão de glicerina na dieta. A inclusão de até 10% de glicerina na dieta até 7 dias e 5% nos períodos subsequentes, mostrou-se interessante na alimentação de frangos de corte. / The purpose of this work was to evaluate the effects of increasing levels of glycerin from biodiesel production in rations on the performance, carcass characteristics and moisture litter of broilers. The trial used 1575 Cobb male chicks. The chickens 1 day of age were weighed and allocated according to weight average to groups of 45 distributed in 35 pens in a completely randomized experimental design. Treatments were (0; 2,5; 5; 7,5 and 10%) glycerin inclusion with seven replicates per treatment. Was analyzed a contraction of glycerol, sodium, phosphorus, potassium and methanol from the crude glycerin in laboratory for formulate diets. Was considered the energy value of 4,100 kcal ME/ kg for the pure glycerol. The performance (liveweight, weight gain, feed intake, feed conversion and viability) were monitored weekly and at 43 days of age 70 broilers (14 broilers/ treatment) were sacrificed for evaluation of carcass characteristics. The moisture of the litter was analyzed in each pen. At seven days, it was found a positive linear effect (P<0.05) on weight gain, body weight and feed intake, verifying that the inclusion up to 10% glycerin in the diet was efficient. At 21 days, it was found a linear reduction (P<0.05) on viability, cubic effect (P <0.05) on feed intake and quartic effect (P <0.05) on weight gain and body weight. Results using 5% glycerin in diet showed better performance. At 42 days, there was no significant effect on the performance variables (P> 0.05), although a substantial reduction of 130 grams in weight gain was observed in broilers fed 10% glycerin. There was no significant effect on carcass characteristics (P> 0.05), but increased linear effect (P <0.05) was observed on litter moisture with the inclusion of glycerin in the diet. The inclusion of 10% of glycerin up to seven days and 5% after that was flexible in diets for broilers.

Broilers are nearing their genetic potential and nutritional strategies are the primary means to improve their performance. Improving raw material quality, especially soybean meal, could improve broiler performance, health and welfare. Inadequate processing of soybean meal leads to high residual anti-nutritional factors (ANF) which has a negative influence on broiler performance. High trypsin inhibitor content in low- quality soybean meal causes decreased protein digestion and absorption. The main aim of this study was to evaluate the optimal quality of soybean meal for commercial use to promote performance and welfare parameters of broiler chickens. Ten dietary treatments were formulated to the same nutritional specifications, but with different soybean meals that ranged from very high-quality (Treatment 1) to the lowest quality (Treatment 10). The quality of soybean meal was determined using Table 2.1 as target values for each soybean meal quality parameter. Soybean meal quality was evaluated using urease levels (pH change), TIA (trypsin inhibitor activity), Evonik TIA, KOH (potassium hydroxide solubility), Evonik KOH, Evonik PDI (protein dispersibility index) and Evonik PCI (processing conditions indicator). The treatment diets were fed to 4800 broilers that were randomly allocated to 80 pens, each with 60 birds and eight replicates. Over a 35-day growth trial, broiler performance, welfare and physiological traits were measured on a weekly basis. Overall, improved performance was observed with higher-quality soybean meal outperforming the lower-quality soybean meal. High-quality soybean meal showed significantly better feed conversion ratio’s (FCR) and European performance efficiency factor (PEF) throughout the 35-day period, and significantly higher average daily gain (ADG) up until day 21. Bodyweight (BW), feed intake (FI) and mortality showed no significant differences irrespective of soybean meal quality. No significant differences were found in physiological traits namely: pancreas weight as a percentage of bodyweight, pancreas length to bodyweight ratio, gizzard and proventriculus weight as a percentage of bodyweight and gizzard erosion score, (PW%BW, PL:BW, GPV%BW, GE score) irrespective of soybean meal quality. High quality soybean meal showed lower incidence and lower severity of rapid feed passage (RFP) and foot pad dermatitis (FPD). Evonik PCI and urease levels (pH change) showed the strongest correlation to broiler performance, health and welfare. This study suggests using soybean meal with the following quality parameters: urease levels of around 0.05, TIA levels of below 4mg/g, KOH levels of 78-80%, PDI levels of around 15 and PCI levels of around 11. The Evonik PCI and urease (pH change) analyses for soybean meal quality was found to be the easiest and cheapest method and can be recommended as the primary quality assays for commercial feed companies in the future. / Dissertation (BSc (Agric) Animal Science)--University of Pretoria, 2020. / AFGRI / Animal and Wildlife Sciences / BSc (Agric) Animal Science / Restricted

Le déoxynivalénol (DON) est l'une des mycotoxines trichothécènes les plus abondantes et les plus importantes produites par les espèces de Fusarium. Les aliments contaminés par les mycotoxines peuvent affecter négativement la santé des poulets de chair. La présente étude a été menée pour évaluer les effets du déoxynivalénol (DON) sur les performances des poulets de chair, le poids des organes, les paramètres biochimiques sériques, la réponse immunitaire et l'histologie intestinale. L’expérience a permis d’évaluer l'efficacité d'un additif alimentaire commercial, basé sur les synbiotiques (SFA), et ayant la capacité d'oxyder le DON. Au total, six cents poussins mâles d'un jour d'une souche commerciale (Ross 308) ont été vaccinés avec un vaccin vivant combiné contre le virus de la maladie de Newcastle (NDV) et le virus de la bronchite infectieuse (IBV) et ont été répartis de façon aléatoire entre 6 traitements (100 oiseaux dans chaque groupe) pour 5 semaines. Ces groupes ont été nourris avec la même nourritures naturellement contaminés par DON mais à des concentrations différentes : < 0,5 (régime témoin), 1,5 et 3 mg/kg avec et sans SFA à 250 g/tonne. Les paramètres, y compris le poids corporel, la consommation d'aliments, et le taux de mortalité, ont été enregistrés sur une base hebdomadaire. De plus, des échantillons de sang ont été prélevés sur quatre oiseaux de chaque groupe pour déterminer les caractéristiques biochimiques sériques, et les titres d'anticorps contre NDV et IBV. Au cours de la semaine 5, quatre des poulets sélectionnés ont été euthanasiés, et les organes, coeur, foie, rate, bourse de Fabricius, ont été pesés. Des tissus de l'intestin, segments de 2 cm du duodénum, du jéjunum, de l'iléon et du cæcum, et de la bourse de Fabricius et thymus ont été prélevés pour des examens histologiques. Les résultats obtenus démontrent que les oiseaux dont l’alimentation était contaminée au DON présentaient une diminution (P < 0,05) du poids moyen aux jours 28 et 35 par rapport aux groupe témoin et groupes traités avec le SFA. De plus, l'inclusion de DON dans l'alimentation a réduit le titre d'anticorps contre le NDV (P < 0,05) et l'IBV (P < 0,001). Les paramètres biochimiques sériques, et le poids des organes pendant toute la période expérimentale (P > 0,05) n’ont pas montré de différences significatives. De plus, chez les oiseaux nourris avec des aliments contaminés, le DON a provoqué un processus de nécrose au niveau des villosités du duodénum et du thymus. Cependant, cela n'a pas modifié la morphométrie du tissu intestinal et de la bourse de Fabricius. Il a été conclu que les performances des poulets de chair, ainsi que la réponse vaccinale et paramètres histologiques, étaient négativement affectées par une alimentation contaminée par le DON. La supplémentation alimentaire avec un additif alimentaire à base de synbiotiques, serait une alternative pour atténuer les effets causés par cette mycotoxine chez les oiseaux. / Deoxynivalenol (DON) is one of the most abundant and important trichothecene mycotoxins produced by Fusarium species. Mycotoxin-contaminated feeds may negatively affect broiler chickens’ health, a sustainable approach to achieve mycotoxin elimination is necessary. An experiment was conducted to study the effects of deoxynivalenol (DON) on the performance of broilers, organ weights, serum biochemical parameters, immune response, and intestinal histology and to evaluate the efficacy of a commercial feed additive, based on synbiotics (SFA), with the ability to deepoxidize DON. In total, six hundred 1-d-old male broiler of a commercial strain (Ross 308) were vaccinated with combined live Newcastle disease virus (NDV) and infectious bronchitis virus (IBV) vaccine and were randomly allotted to 6 dietary treatments (100 birds in each group) for 5 wk. These groups were fed 3 diets naturally contaminated with DON at concentrations of < 0.5 (control diet), 1.5, and 3 mg/kg with and without SFA at 250 g/ton. The parameters including body weight, feed intake, and mortality rate were recorded on a weekly basis. In addition, weekly blood samples were collected from four birds in each group to determine serum biochemical characteristics and antibody titers to NDV and IBV. In week 5, four selected chickens were euthanized, and organs (heart, liver, spleen, bursa of Fabricius) were weighed. Tissues from intestine (2-cm segments of duodenum, jejunum, ileum, and caecum) and immune system (bursa of Fabricius and thymus) were collected for further histological examinations. The results indicated that DON-challenged birds had decreased (P < 0.05) average body weight (ABW) at days 28 and 35 as compared to control and treated groups with SFA. Furthermore, the inclusion of DON in the diet reduced antibody titer against NDV (P < 0.05), and IBV (P < 0.001). However, there were no significant differences in serum biochemical parameters and organs weight during the whole experimental period (P > 0.05). Moreover, in birds fed contaminated diets, DON caused necrosis in duodenum villus and in the thymus but did not alter the intestinal or the immune system morphometrics. It was concluded that broiler performance, histological, and immunological parameters were adversely affected by feeding diets contaminated with DON. However, the dietary supplementation with Synbiotics as a detoxifying agent would be an alternative to alleviate adverse effects on birds.