Phytase Superdosing in the Diet of Lightweight Replacement Pullets: Performance, Organ Biometry and Bone Characteristics

The aim of this study was to evaluate the effect of two types of phytases (the 1st produced from Escherichia coli and the 2nd from Aspergillus oryzae) with different dosages (300 and 900 Unit Phytase or FTU) on performance, organ biometry and bone quality of replacement pullets in the period of 8 to 17 weeks of age. A total of 288 Hy-Line White laying hens were used at 8 weeks of age. A completely randomized design was adopted in a 2 x 2 factorial scheme, totaling 4 treatments with 8 replicates of 9 birds each. Performance, biometric variables and bone characteristics were evaluated. There was no significant interaction between the factors for any of the evaluated variables. The conversion and the accumulated consumption were influenced (p 0.05) by the phytase dosages, with the highest results being observed for the consumption obtained with 300 FTU, and the best results for the feed conversion obtained with the dosage of 900 FTU. The relative weight of the liver was influenced by the treatments (p 0.05), presenting higher values with bacterial phytase and a dosage of 900 FTU. The sternum length and tibial deformity were influenced by fungal phytase (p 0.05). It is concluded that the use of 900 FTU superdosing and fungal phytase improves the performance and bone characteristics of light replacement pullets.

Design and testing of a sweat meter for the cutaneous evaporation determination in cattle

The physiological processes of adaptation respond to autonomic mechanisms. Ruminants are known to regulate heat by sweating, among other mechanisms. Bos taurus cattleusually do not compensate well for exposure to high temperatures. In the tropics, sweating is the most important way for ruminants to lose heat. The objective of this research was to design and validate a non-invasive external mean to determine sweat production in Colombian Creole cattle. In a research center located in the Colombian eastern plains at4°05'N and 73°34'E, at 330 m ASL, a simple, lightweight, operational, safe, and easy-to-use device was designed to collect sweat from bovine Planum nasolabiale in 15 lactatingcows of Colombian Creole breeds. Besides, blood samples were collected and physiological constants were determinedand analyzed the relationship of this parameter with physiological measurements and heat indices. The measurement device designed and tested has proven to beefficient for sweating collection in cattle; however, the quantity of sweat collected could not reflect in a trustworthy way the overall animal response to the environmentalconditions. In contrast, the heat load index was more related to evapotranspiration and sweat production than the humiditytemperature index, indicating that a high heat load may lead to a major need for triggering high-level regulatory physiologic mechanisms like sweat production to compensate the rise of core temperature.(AU)

Phytase Superdosing in the Diet of Lightweight Replacement Pullets: Performance, Organ Biometry and Bone Characteristics

The aim of this study was to evaluate the effect of two types of phytases (the 1st produced from Escherichia coli and the 2nd from Aspergillus oryzae) with different dosages (300 and 900 Unit Phytase or FTU) on performance, organ biometry and bone quality of replacement pullets in the period of 8 to 17 weeks of age. A total of 288 Hy-Line White laying hens were used at 8 weeks of age. A completely randomized design was adopted in a 2 x 2 factorial scheme, totaling 4 treatments with 8 replicates of 9 birds each. Performance, biometric variables and bone characteristics were evaluated. There was no significant interaction between the factors for any of the evaluated variables. The conversion and the accumulated consumption were influenced (p 0.05) by the phytase dosages, with the highest results being observed for the consumption obtained with 300 FTU, and the best results for the feed conversion obtained with the dosage of 900 FTU. The relative weight of the liver was influenced by the treatments (p 0.05), presenting higher values with bacterial phytase and a dosage of 900 FTU. The sternum length and tibial deformity were influenced by fungal phytase (p 0.05). It is concluded that the use of 900 FTU superdosing and fungal phytase improves the performance and bone characteristics of light replacement pullets.(AU)

Design and testing of a sweat meter for the cutaneous evaporation determination in cattle

The physiological processes of adaptation respond to autonomic mechanisms. Ruminants are known to regulate heat by sweating, among other mechanisms. Bos taurus cattleusually do not compensate well for exposure to high temperatures. In the tropics, sweating is the most important way for ruminants to lose heat. The objective of this research was to design and validate a non-invasive external mean to determine sweat production in Colombian Creole cattle. In a research center located in the Colombian eastern plains at4°05'N and 73°34'E, at 330 m ASL, a simple, lightweight, operational, safe, and easy-to-use device was designed to collect sweat from bovine Planum nasolabiale in 15 lactatingcows of Colombian Creole breeds. Besides, blood samples were collected and physiological constants were determinedand analyzed the relationship of this parameter with physiological measurements and heat indices. The measurement device designed and tested has proven to beefficient for sweating collection in cattle; however, the quantity of sweat collected could not reflect in a trustworthy way the overall animal response to the environmentalconditions. In contrast, the heat load index was more related to evapotranspiration and sweat production than the humiditytemperature index, indicating that a high heat load may lead to a major need for triggering high-level regulatory physiologic mechanisms like sweat production to compensate the rise of core temperature.

Lightweight males of Podisus nigrispinus (Heteroptera: Pentatomidae) neglect lightweight females due low reproductive fitness / Machos leves de Podisus nigrispinus (Heteroptera: Pentatomidae) negligenciam fêmeas leves devido ao baixo desempenho reprodutivo

Sexual choice by male stink bugs is important because females that experience food shortages lay fewer eggs with lower viability compared with well-fed females. In this study, we investigated whether Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) males fed with a low-quality diet during its nymphal stage show selectivity for sexual partners resulting in high-quality progeny. Lightweight males and females were obtained from nymphs fed weekly with Tenebrio molitor L. (Coleoptera: Tenebrionidae) pupae. By contrast, heavyweight males and females were fed three times a week and received an extra nutritional source: cotton leaves, Gossypium hirsutum L. (Malvaceae). Lightweight males preferred to mate with heavy females (77.78 ± 14.69%), whereas heavyweight males did not discriminated between light or heavyweight females. Females mated with lightweight males showed similar levels of reproduction to those mated with heavyweight males. The results provide an indication of the importance of male and female body weight for sexual selection in Asopinae stink bugs.(AU)

A seleção sexual por machos de percevejos é importante porque fêmeas que passaram por escassez alimentar poem poucos ovos com baixa viabilidade em comparação com fêmeas bem alimentadas. Nesse estudo, investigamos se machos de Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) alimentados com dieta de baixa qualidade durante seu estágio ninfal apresenta seletividade por parceiras sexuais resultando em progênie de alta qualidade. Machos e fêmeas leves foram obtidos de ninfas alimentadas semanalmente com pupas de Tenebrio molitor L. (Coleoptera: Tenebrionidae). Em contraste, machos e fêmeas pesados foram alimentados três vezes por semana e receberam uma fonte nutricional extra: folhas de algodão, Gossypium hirsutum L. (Malvaceae). Machos leves preferiram acasalar com fêmeas pesadas (77,78 ± 14,69%), enquanto machos pesados não distinguiram fêmeas leves ou pesadas para acasalamento. Fêmeas que acasalaram com machos leves apresentaram níveis de reprodução semelhantes em comparação com aquelas acasaladas com machos pesados. Os resultados fornecem uma indicação da importância do peso corpóreo de machos e fêmeas para a seleção sexual em percevejos Asopinae.(AU)

The Analysis of Computer Data regarding Obesity and Associated Diseases in Cats Examined at Private Veterinary Practices

Background: Cats can be defined as being overweight if their bodyweight is 15% above optimum weight and classified as obese if they are more than 30% above their optimum weight. There is a general agreement among investigators that the incidence of excess body weight in cats is increasing. Obesity has considerable impacts on the health of cats and is linked to a variety of health issues including orthopedic disease, diabetes mellitus and non-allergic skin conditions. The purpose of the present study was to evaluate the relationship between obesity and associated diseases in cats examined at some veterinary practices in Istanbul-Turkey.Materials, Methods & Results: Data of 2,272 patients examined at four private veterinary practices in Istanbul was studied to reveal the association between body weight and diseases. Information regarding sex, age and neutering status was also considered for each patient. Patients were classified according to their body weight to three groups as lightweight (female: 3.0 kg and under, male: 4.5 kg and under), optimum -weight (female: 3.0-4.5 kg, male: 4.5-5.5 kg) and overweight/obese (female: 4.5 kg and over, male: 5.5 kg and over). Accounting all adult cats treated by the clinics, diagnoses of osteoarthritis, heart diseases, dermatological diseases, hepatic lipidosis, metabolic syndrome - diabetes mellitus, lameness, gastrointestinal diseases,

The analysis of computer data regarding obesity and associated diseases in cats examined at private veterinary practices

Background: Cats can be defined as being overweight if their bodyweight is 15% above optimum weight and classified as obese if they are more than 30% above their optimum weight. There is a general agreement among investigators that the incidence of excess body weight in cats is increasing. Obesity has considerable impacts on the health of cats and is linked to a variety of health issues including orthopedic disease, diabetes mellitus and non-allergic skin conditions. The purpose of the present study was to evaluate the relationship between obesity and associated diseases in cats examined at some veterinary practices in Istanbul-Turkey. Materials, Methods & Results: Data of 2,272 patients examined at four private veterinary practicesin Istanbul was studied to reveal the association between body weight and diseases. Information regarding sex, age and neutering status was also considered for each patient. Patients were classified according to their body weight to three groups as lightweight (female: 3.0 kg and under, male: 4.5 kg and under), optimum -weight (female: 3.0-4.5 kg, male: 4.5-5.5 kg) and overweight/obese (female: 4.5 kg and over, male: 5.5 kg and over). Accounting all adult cats treated by the clinics, diagnoses of osteoarthritis, heart diseases, dermatological diseases, hepatic lipidosis, metabolic syndrome - diabetes mellitus, lameness, gastrointestinal diseases, musculoskeletal diseases, neoplasia and urinary diseases were statistically evaluated. Considering data coming from 2,272 cats, which were referred to veterinary practices, 33.12%, were classified as overweight-obese, 40.04% were optimum-weight and 26.84% were lightweight. It was determined that overweight-obese cats were more likely to be diagnosed with osteoarthritis and hepatic lipidosis compared to other groups (P < 0.05). Overweight-obese cats were more likely to be diagnosed with gastrointestinal disease and neoplasia compared to lightweight cats (P < 0.05).[...]

The analysis of computer data regarding obesity and associated diseases in cats examined at private veterinary practices

Background: Cats can be defined as being overweight if their bodyweight is 15% above optimum weight and classified as obese if they are more than 30% above their optimum weight. There is a general agreement among investigators that the incidence of excess body weight in cats is increasing. Obesity has considerable impacts on the health of cats and is linked to a variety of health issues including orthopedic disease, diabetes mellitus and non-allergic skin conditions. The purpose of the present study was to evaluate the relationship between obesity and associated diseases in cats examined at some veterinary practices in Istanbul-Turkey. Materials, Methods & Results: Data of 2,272 patients examined at four private veterinary practicesin Istanbul was studied to reveal the association between body weight and diseases. Information regarding sex, age and neutering status was also considered for each patient. Patients were classified according to their body weight to three groups as lightweight (female: 3.0 kg and under, male: 4.5 kg and under), optimum -weight (female: 3.0-4.5 kg, male: 4.5-5.5 kg) and overweight/obese (female: 4.5 kg and over, male: 5.5 kg and over). Accounting all adult cats treated by the clinics, diagnoses of osteoarthritis, heart diseases, dermatological diseases, hepatic lipidosis, metabolic syndrome - diabetes mellitus, lameness, gastrointestinal diseases, musculoskeletal diseases, neoplasia and urinary diseases were statistically evaluated. Considering data coming from 2,272 cats, which were referred to veterinary practices, 33.12%, were classified as overweight-obese, 40.04% were optimum-weight and 26.84% were lightweight. It was determined that overweight-obese cats were more likely to be diagnosed with osteoarthritis and hepatic lipidosis compared to other groups (P < 0.05). Overweight-obese cats were more likely to be diagnosed with gastrointestinal disease and neoplasia compared to lightweight cats (P < 0.05).[...](AU)

Comparative study of intraperitoneal adhesions related to light-weight polypropylene mesh and type I polymerized and purified bovine collagen coated light-weight polypropylene mesh in rabbits

Purpose: To compare the effectiveness of light-weight polypropylene mesh coated with polymerized and purified bovine type I collagen (Surgidry HNB) in the treatment of abdominal wall defect and the degree of adhesion formation. Methods: Two types of polypropylene mesh were implanted after creation of defect measuring 6.0cm X 5.5cm in the anterior abdominal wall of 32 male New Zealand breed rabbits, divided in two groups (n = 32): (1) light-weigh macroporous polypropylene, (2) type I polymerized and purified bovine collagen coated light-weigh macroporous polypropylene. These animals were further accessed for adhesions, histological evaluation of inflammation and walls thickness. Results: The percentage of the area adhered in group 1 (62.31 ± 16.6) was higher compared to group 2 (22.19 ± 14.57) (p 0.05). There was an association between the percentage of the covered area by adhesions and the type of adhesion, toughness and the scores obtained by the adhesion score by correlation analysis (p <0.05). There was no difference between the groups in any variables in relation to the degree of inflammation. Conclusion: The purified type I bovine collagen coated light-weigh polypropylene mesh showed to be effective in the repair of abdominal wall defects and reducing adhesion formation.(AU)

Pelleting of diet for weaning pigs of different initial weights

ABSTRACT: Physical form effect of the pre-starter diet supplied during the post-weaning period from 21 to 41 days of age on diet digestibility and animal performance in terms of zootechnical performances of light-weight (5.82kg) and heavy-weight weaning piglets (6.32kg) was evaluated, as well as the residual effects of the treatments until slaughter. Forty-eight female pigs at 21 days of age were evaluated. The experimental design was completely randomized in a 2x2 factorial scheme (meal/pelleted diet vs. light-weight/heavy-weight piglets), with six replicates for the nursery phase and 12 replicates for the growing-finishing phases. Animals received the experimental diet from 21 to 41 days of age. Data were analyzed with ANOVA, setting the significance in 5%. Feeding with the pelleted diet resulted in a 39% greater daily weight gain and a 28% greater feed conversion rate for piglets from weaning to 40 days of age. Pelleting also resulted in a decrease in feed wastage during the first week after weaning (9.15% for meal diet vs. 1.68% for pelleted diet) and; consequently, the results showed an increase in feed consumption. Digestible energy of the pelleted diet (3,626kcal kg-1) was greater than that of the meal diet (3,424kcal kg-1). The physical form improved the performance of weaning pigs and the digestibility of the pre-starter diet, but there wasn't residual effect of the physical form and the weight of a piglet at weaning on live weight at slaughter.

RESUMO: Avaliou-se o impacto da forma física da dieta pré-inicial em leitões leves (5,82kg) e pesados (6,32kg) no período pós-desmame sobre o desempenho zootécnico e digestibilidade da dieta, bem como o efeito residual dos tratamentos até o abate. Foram utilizados 48 leitões fêmeas com 21 dias de idade, distribuídos em delineamento inteiramente ao acaso, em esquema fatorial 2x2 (farelada/peletizada vs. leitões leves/pesados), com seis repetições na fase de creche e 12 repetições na fase de crescimento e terminação. Os leitões receberam as dietas experimentais dos 21 aos 40 dias de idade. Os dados foram submetidos à análise de variância ao nível de 5% de probabilidade. Observou-se que a peletização melhorou em 39% o ganho de peso diário e 28% a conversão alimentar do desmame aos 40 dias de idade. Ao considerar a redução de desperdício da ração peletizada (9,15 vs. 1,68%) na primeira semana pós-desmame, a peletização da dieta proporcionou aumento do consumo de ração. Ao avaliar a digestibilidade da dieta, observou-se que a energia digestível aumentou de 3.424kcal kg-1 na forma farelada para 3.626kcal kg-1 na forma peletizada. A forma física da dieta proporcionou efeitos positivos sobre o peso vivo dos leitões desmamados e energia digestível da dieta. Porém, não foi observado efeito residual da forma física ou peso ao desmame sobre o peso vivo ao abate.

Age influence on quality of shell and penetration in bacterial laying lightweight eggs / Influência da idade na qualidade da casca e na penetração bacteriana em ovos de poedeiras leves

This study evaluated the influence of the bird's age on the quality of the shell and percentage of bacterial penetration in commercial eggs. White-shelled commercial eggs were used, laid by light laying hens in their first laying cycle at 21, 39, 51, and 62 weeks of age. Shell quality evaluations comprised: egg weight, specific gravity, percentage and thickness of shell, number and size of pores. For evaluations regarding bacterial penetration, strains of several enterobacterias and one salmonella were used, all of which resistant to Nalidixic acid (100µg/ml). The method employed for evaluation of bacterial penetration was filling the eggs with growth medium. The data were subjected to variance analysis with 5% of probability using SAS (Education Analytical Software, 2013). Eveb though increase in the laying hen's age caused reduction of the quality of eggshells, it failed to affect the percentage of penetration of the bacterial samples evaluated.(AU)

O presente estudo avaliou a influência da idade da ave sobre a qualidade da casca e na porcentagem de penetração bacteriana em ovos comerciais. Foram utilizados ovos brancos comerciais provenientes de poedeiras leves em primeiro ciclo de postura com 21, 39, 51 e 62 semanas de idade. As avaliações de qualidade da casca realizadas foram: peso do ovo, gravidade específica, porcentagem e espessura da casca, número e tamanho dos poros. Para as avaliações da penetração bacteriana, foram utilizadas cepas de diversas enterobactérias e uma salmonela, sendo todas resistentes ao ácido nalidíxico (100µg/mL). O método utilizado para a avaliação da penetração bacteriana foi por meio do preenchimento dos ovos com meio de cultura. Os dados foram submetidos à análise de variância com 5% de probabilidade utilizando-se o programa SAS - Statistical Analisys System (Education Analytical Software, 2013). O aumento da idade da poedeira promoveu a redução da qualidade da casca dos ovos, porém não foi capaz de influenciar a porcentagem de penetração das amostras bacterianas avaliadas.(AU)

Age influence on quality of shell and penetration in bacterial laying lightweight eggs / Influência da idade na qualidade da casca e na penetração bacteriana em ovos de poedeiras leves

This study evaluated the influence of the bird's age on the quality of the shell and percentage of bacterial penetration in commercial eggs. White-shelled commercial eggs were used, laid by light laying hens in their first laying cycle at 21, 39, 51, and 62 weeks of age. Shell quality evaluations comprised: egg weight, specific gravity, percentage and thickness of shell, number and size of pores. For evaluations regarding bacterial penetration, strains of several enterobacterias and one salmonella were used, all of which resistant to Nalidixic acid (100µg/ml). The method employed for evaluation of bacterial penetration was filling the eggs with growth medium. The data were subjected to variance analysis with 5% of probability using SAS (Education Analytical Software, 2013). Eveb though increase in the laying hen's age caused reduction of the quality of eggshells, it failed to affect the percentage of penetration of the bacterial samples evaluated.(AU)

O presente estudo avaliou a influência da idade da ave sobre a qualidade da casca e na porcentagem de penetração bacteriana em ovos comerciais. Foram utilizados ovos brancos comerciais provenientes de poedeiras leves em primeiro ciclo de postura com 21, 39, 51 e 62 semanas de idade. As avaliações de qualidade da casca realizadas foram: peso do ovo, gravidade específica, porcentagem e espessura da casca, número e tamanho dos poros. Para as avaliações da penetração bacteriana, foram utilizadas cepas de diversas enterobactérias e uma salmonela, sendo todas resistentes ao ácido nalidíxico (100µg/mL). O método utilizado para a avaliação da penetração bacteriana foi por meio do preenchimento dos ovos com meio de cultura. Os dados foram submetidos à análise de variância com 5% de probabilidade utilizando-se o programa SAS - Statistical Analisys System (Education Analytical Software, 2013). O aumento da idade da poedeira promoveu a redução da qualidade da casca dos ovos, porém não foi capaz de influenciar a porcentagem de penetração das amostras bacterianas avaliadas.(AU)

Pelleting of diet for weaning pigs of different initial weights / Peletização da dieta para leitões recém-desmamados com diferentes pesos iniciais

Physical form effect of the pre-starter diet supplied during the post-weaning period from 21 to 41 days of age on diet digestibility and animal performance in terms of zootechnical performances of light-weight (5.82kg) and heavy-weight weaning piglets (6.32kg) was evaluated, as well as the residual effects of the treatments until slaughter. Forty-eight female pigs at 21 days of age were evaluated. The experimental design was completely randomized in a 2x2 factorial scheme (meal/pelleted diet vs. light-weight/heavy-weight piglets), with six replicates for the nursery phase and 12 replicates for the growingfinishing phases. Animals received the experimental diet from 21 to 41 days of age. Data were analyzed with ANOVA, setting the significance in 5%. Feeding with the pelleted diet resulted in a 39% greater daily weight gain and a 28% greater feed conversion rate for piglets from weaning to 40 days of age. Pelleting also resulted in a decrease in feed wastage during the first week after weaning (9.15% for meal diet vs. 1.68% for pelleted diet) and; consequently, the results showed an increase in feed consumption. Digestible energy of the pelleted diet (3,626kcal kg-1) was greater than that of the meal diet (3,424kcal kg-1). The physical form improved the performance of weaning pigs and thedigestibility of the pre-starter diet, but there wasn’t residual effect of the physical form and the weight of a piglet at weaning on live weight at slaughter.

Avaliou-se o impacto da forma física da dieta pré-inicial em leitões leves (5,82kg) e pesados (6,32kg) no período pós-desmame sobre o desempenho zootécnico e digestibilidade da dieta, bem como o efeito residual dos tratamentos até o abate. Foram utilizados 48 leitões fêmeas com 21 dias de idade, distribuídos em delineamento inteiramente ao acaso, em esquema fatorial 2x2 (farelada/peletizada vs. leitões leves/pesados), com seis repetições na fase de creche e 12 repetições na fase de crescimento e terminação. Os leitões receberam as dietas experimentais dos 21 aos 40 dias de idade. Os dados foram submetidos à análise de variância ao nível de 5% de probabilidade. Observou-se que a peletização melhorou em 39% o ganho de peso diário e 28% a conversão alimentar do desmame aos 40 dias de idade. Ao considerar a redução de desperdício da ração peletizada (9,15 vs. 1,68%) na primeira semana pós-desmame, a peletização da dieta proporcionou aumento do consumo de ração. Ao avaliar a digestibilidade da dieta, observou-se que a energia digestível aumentou de 3.424kcal kg-1 na forma farelada para 3.626kcal kg-1 na forma peletizada. A forma física da dieta proporcionou efeitos positivos sobre o peso vivo dos leitões desmamados e energia digestível da dieta. Porém, não foi observado efeito residual da forma física ou peso ao desmame sobre o peso vivo ao abate.

Pelleting of diet for weaning pigs of different initial weights / Peletização da dieta para leitões recém-desmamados com diferentes pesos iniciais

Physical form effect of the pre-starter diet supplied during the post-weaning period from 21 to 41 days of age on diet digestibility and animal performance in terms of zootechnical performances of light-weight (5.82kg) and heavy-weight weaning piglets (6.32kg) was evaluated, as well as the residual effects of the treatments until slaughter. Forty-eight female pigs at 21 days of age were evaluated. The experimental design was completely randomized in a 2x2 factorial scheme (meal/pelleted diet vs. light-weight/heavy-weight piglets), with six replicates for the nursery phase and 12 replicates for the growingfinishing phases. Animals received the experimental diet from 21 to 41 days of age. Data were analyzed with ANOVA, setting the significance in 5%. Feeding with the pelleted diet resulted in a 39% greater daily weight gain and a 28% greater feed conversion rate for piglets from weaning to 40 days of age. Pelleting also resulted in a decrease in feed wastage during the first week after weaning (9.15% for meal diet vs. 1.68% for pelleted diet) and; consequently, the results showed an increase in feed consumption. Digestible energy of the pelleted diet (3,626kcal kg-1) was greater than that of the meal diet (3,424kcal kg-1). The physical form improved the performance of weaning pigs and thedigestibility of the pre-starter diet, but there wasnt residual effect of the physical form and the weight of a piglet at weaning on live weight at slaughter.(AU)

Avaliou-se o impacto da forma física da dieta pré-inicial em leitões leves (5,82kg) e pesados (6,32kg) no período pós-desmame sobre o desempenho zootécnico e digestibilidade da dieta, bem como o efeito residual dos tratamentos até o abate. Foram utilizados 48 leitões fêmeas com 21 dias de idade, distribuídos em delineamento inteiramente ao acaso, em esquema fatorial 2x2 (farelada/peletizada vs. leitões leves/pesados), com seis repetições na fase de creche e 12 repetições na fase de crescimento e terminação. Os leitões receberam as dietas experimentais dos 21 aos 40 dias de idade. Os dados foram submetidos à análise de variância ao nível de 5% de probabilidade. Observou-se que a peletização melhorou em 39% o ganho de peso diário e 28% a conversão alimentar do desmame aos 40 dias de idade. Ao considerar a redução de desperdício da ração peletizada (9,15 vs. 1,68%) na primeira semana pós-desmame, a peletização da dieta proporcionou aumento do consumo de ração. Ao avaliar a digestibilidade da dieta, observou-se que a energia digestível aumentou de 3.424kcal kg-1 na forma farelada para 3.626kcal kg-1 na forma peletizada. A forma física da dieta proporcionou efeitos positivos sobre o peso vivo dos leitões desmamados e energia digestível da dieta. Porém, não foi observado efeito residual da forma física ou peso ao desmame sobre o peso vivo ao abate.(AU)

Performance and eggs quality of light-weight laying hens submitted to different methods of the beak trimming / Desempenho produtivo e qualidade de ovos de poedeiras leves submetidas a diferentes níveis de debicagem

The aim of experiment was to evaluate the effect of different methods of the beak trimming on performance and eggs quality of light-weight laying hens. 216 birds were distributed in a completely randomized design with four treatments and six replicates. The treatments evaluated were: hens no beak trimmed, hens beak trimmed to 7 mm, hens beak trimmed to 6 mm and hens beak trimmed to 5 mm in relation from nostrils to beak. The variables evaluated were feed intake (g), egg production (%), egg weight (g), mortality (%), egg mass (g), conversion per egg mass (kg/kg), conversion per dozen eggs (kg/dz), albumen (%), yolk (%), eggshell (%), broken eggs (%) and cracked eggs (%). There was effect of treatments on variables evaluated. The hens no beak trimmed shown higher feed intake and mortality then other treatments. The conversion per mass and dozen eggs (kg/dz) was few to hens no beak trimmed (P < 0.05). There was no effect of treatments on eggs quality variables. The beak trimming to 5, 6 or 7 mm in relation from nostrils to beak can used to laying hens.

Objetivou-se avaliar a influência dos diferentes níveis de debicagem, sobre o desempenho e qualidade dos ovos de poedeiras comerciais leves. Foram utilizadas 216 aves em um delineamento inteiramente casualizado, distribuídas em quatro tratamentos, com seis repetições. Os tratamentos utilizados foram: aves não debicadas, aves debicadas a 7 mm, aves debicadas a 6 mm e aves debicadas a 5 mm, sendo essa distância tomada da narina ao bico. As variáveis avaliadas foram: mortalidade, consumo de ração (g), produção de ovos (%), peso dos ovos (g), mortalidade (%), massa de ovos (g), conversão por massa de ovos (kg/kg), conversão por dúzia de ovos (kg/dúzia), percentual de albúmen (%), de gema (%), de casca (%), ovos quebrados (%) e trincados (%). O consumo e a mortalidade foram significativamente maiores nas aves não debicadas. A conversão por massa e por dúzia de ovos foram piores nas aves não debicadas (P < 0,05). As variáveis de qualidade de ovos não foram influenciadas pelos tratamentos. As debicagens a 5, 6 ou 7 mm de distância da narina ao bico podem ser utilizadas em poedeiras leves sem causar prejuízos sobre o desempenho produtivo ou a qualidade dos ovos.

Performance and eggs quality of light-weight laying hens submitted to different methods of the beak trimming / Desempenho produtivo e qualidade de ovos de poedeiras leves submetidas a diferentes níveis de debicagem

The aim of experiment was to evaluate the effect of different methods of the beak trimming on performance and eggs quality of light-weight laying hens. 216 birds were distributed in a completely randomized design with four treatments and six replicates. The treatments evaluated were: hens no beak trimmed, hens beak trimmed to 7 mm, hens beak trimmed to 6 mm and hens beak trimmed to 5 mm in relation from nostrils to beak. The variables evaluated were feed intake (g), egg production (%), egg weight (g), mortality (%), egg mass (g), conversion per egg mass (kg/kg), conversion per dozen eggs (kg/dz), albumen (%), yolk (%), eggshell (%), broken eggs (%) and cracked eggs (%). There was effect of treatments on variables evaluated. The hens no beak trimmed shown higher feed intake and mortality then other treatments. The conversion per mass and dozen eggs (kg/dz) was few to hens no beak trimmed (P < 0.05). There was no effect of treatments on eggs quality variables. The beak trimming to 5, 6 or 7 mm in relation from nostrils to beak can used to laying hens.(AU)

Objetivou-se avaliar a influência dos diferentes níveis de debicagem, sobre o desempenho e qualidade dos ovos de poedeiras comerciais leves. Foram utilizadas 216 aves em um delineamento inteiramente casualizado, distribuídas em quatro tratamentos, com seis repetições. Os tratamentos utilizados foram: aves não debicadas, aves debicadas a 7 mm, aves debicadas a 6 mm e aves debicadas a 5 mm, sendo essa distância tomada da narina ao bico. As variáveis avaliadas foram: mortalidade, consumo de ração (g), produção de ovos (%), peso dos ovos (g), mortalidade (%), massa de ovos (g), conversão por massa de ovos (kg/kg), conversão por dúzia de ovos (kg/dúzia), percentual de albúmen (%), de gema (%), de casca (%), ovos quebrados (%) e trincados (%). O consumo e a mortalidade foram significativamente maiores nas aves não debicadas. A conversão por massa e por dúzia de ovos foram piores nas aves não debicadas (P < 0,05). As variáveis de qualidade de ovos não foram influenciadas pelos tratamentos. As debicagens a 5, 6 ou 7 mm de distância da narina ao bico podem ser utilizadas em poedeiras leves sem causar prejuízos sobre o desempenho produtivo ou a qualidade dos ovos.(AU)

Chlorinated drinking water for lightweight laying hens / Cloração na água de dessedentação para poedeiras leves

The study aimed to evaluate the effect of different levels of chlorine in drinking water of laying hens on zootechnical performance, eggs shell quality, hemogasometry levels and calcium content in tibia. 144 Hy-Line laying hens, 61 weeks old, were used distributed in 24 metabolism cages. They were subjected to water diets, for a period of 28 days, using sodium hypochlorite as a chlorine source in order to obtain the following concentrations: 5ppm (control), 20ppm, 50ppm, and 100ppm. Their performance was evaluated through water consumption, feed intake, egg production and weight, egg mass, feed conversion. Shell quality was measured by specific gravity. At the end of the experiment, arterial blood was collected for blood gas level assessment and a poultry of each replicate was sacrificed to obtain tibia and calcium content measurement. There was a water consumption reduction from 20ppm of chlorine and feed intake reduction in poultry receiving water with 100ppm of chlorine. The regression analysis showed that the higher the level of chlorine in water, the higher the reduction in consumption. There were no differences in egg production and weight, egg mass, feed conversion, specific gravity, tibia calcium content, and hemogasometry levels (hydrogenionic potential, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, chloride, bicarbonate, carbon dioxide total concentration, anion gap and oxygen saturation). The use of levels above 5ppm of chlorine is not recommended in the water of lightweight laying hens.(AU)

Objetivou-se avaliar o efeito de diferentes níveis de cloro na água de dessedentação de poedeiras sobre o desempenho zootécnico, a qualidade da casca dos ovos, os índices hemogasométricos e o teor de cálcio na tíbia. Foram utilizadas 144 poedeiras leves Hy Line, de 61 semanas de idade, distribuídas em 24 gaiolas de metabolismo. As aves foram submetidas, durante um período de 28 dias, a dietas hídricas utilizando-se hipoclorito de sódio como fonte de cloro para compor as seguintes concentrações: 5ppm (controle), 20ppm, 50ppm e 100ppm. O desempenho foi avaliado mediante o consumo de água e ração, a produção e o peso dos ovos, a massa de ovos e a conversão alimentar. A qualidade da casca foi aferida por meio da gravidade específica. Ao final do experimento, coletou-se sangue arterial para avaliação dos índices hemogasométricos e sacrificou-se uma ave de cada repetição para coleta de tíbias e aferição do teor de cálcio. Verificou-se redução do consumo de água a partir de 20ppm de cloro e no consumo de ração em aves que receberam água com 100ppm de cloro. A análise de regressão demonstrou que quanto maior for o nível de cloro na água, maior será a redução no consumo. Não foram observadas diferenças na produção e no peso dos ovos, na massa de ovos, na conversão alimentar, na gravidade específica dos ovos, no teor de cálcio nas tíbias e nos índices hemogasométricos (potencial hidrogeniônico, pressão parcial de gás carbônico, pressão parcial de oxigênio, sódio, potássio, cloro, bicarbonato, concentração total de dióxido de carbono, ânion gap e saturação de oxigênio). Não se recomenda a utilização de níveis superiores a 5ppm de cloro na água de dessedentação de poedeiras leves.(AU)

Chlorinated drinking water for lightweight laying hens / Cloração na água de dessedentação para poedeiras leves

The study aimed to evaluate the effect of different levels of chlorine in drinking water of laying hens on zootechnical performance, eggs shell quality, hemogasometry levels and calcium content in tibia. 144 Hy-Line laying hens, 61 weeks old, were used distributed in 24 metabolism cages. They were subjected to water diets, for a period of 28 days, using sodium hypochlorite as a chlorine source in order to obtain the following concentrations: 5ppm (control), 20ppm, 50ppm, and 100ppm. Their performance was evaluated through water consumption, feed intake, egg production and weight, egg mass, feed conversion. Shell quality was measured by specific gravity. At the end of the experiment, arterial blood was collected for blood gas level assessment and a poultry of each replicate was sacrificed to obtain tibia and calcium content measurement. There was a water consumption reduction from 20ppm of chlorine and feed intake reduction in poultry receiving water with 100ppm of chlorine. The regression analysis showed that the higher the level of chlorine in water, the higher the reduction in consumption. There were no differences in egg production and weight, egg mass, feed conversion, specific gravity, tibia calcium content, and hemogasometry levels (hydrogenionic potential, carbon dioxide partial pressure, oxygen partial pressure, sodium, potassium, chloride, bicarbonate, carbon dioxide total concentration, anion gap and oxygen saturation). The use of levels above 5ppm of chlorine is not recommended in the water of lightweight laying hens.(AU)

Objetivou-se avaliar o efeito de diferentes níveis de cloro na água de dessedentação de poedeiras sobre o desempenho zootécnico, a qualidade da casca dos ovos, os índices hemogasométricos e o teor de cálcio na tíbia. Foram utilizadas 144 poedeiras leves Hy Line, de 61 semanas de idade, distribuídas em 24 gaiolas de metabolismo. As aves foram submetidas, durante um período de 28 dias, a dietas hídricas utilizando-se hipoclorito de sódio como fonte de cloro para compor as seguintes concentrações: 5ppm (controle), 20ppm, 50ppm e 100ppm. O desempenho foi avaliado mediante o consumo de água e ração, a produção e o peso dos ovos, a massa de ovos e a conversão alimentar. A qualidade da casca foi aferida por meio da gravidade específica. Ao final do experimento, coletou-se sangue arterial para avaliação dos índices hemogasométricos e sacrificou-se uma ave de cada repetição para coleta de tíbias e aferição do teor de cálcio. Verificou-se redução do consumo de água a partir de 20ppm de cloro e no consumo de ração em aves que receberam água com 100ppm de cloro. A análise de regressão demonstrou que quanto maior for o nível de cloro na água, maior será a redução no consumo. Não foram observadas diferenças na produção e no peso dos ovos, na massa de ovos, na conversão alimentar, na gravidade específica dos ovos, no teor de cálcio nas tíbias e nos índices hemogasométricos (potencial hidrogeniônico, pressão parcial de gás carbônico, pressão parcial de oxigênio, sódio, potássio, cloro, bicarbonato, concentração total de dióxido de carbono, ânion gap e saturação de oxigênio). Não se recomenda a utilização de níveis superiores a 5ppm de cloro na água de dessedentação de poedeiras leves.(AU)

CRESCIMENTO PONDERAL E BIOMÉTRICO DE POEDEIRAS LEVES POR MEIO DO MODELO DE GOMPERTZ: MODELAGEM DAS VARIÂNCIAS E DENSIDADES DE CRIAÇÃO

BRUSAMARELO, EMANUELE. Crescimento ponderal e biométrico de poedeiras leves por meio do modelo de Gompertz: modelagem das variâncias e densidades de criação. 2020. 65 f. Tese (Doutorado em Ciência Animal) Faculdade de Agronomia e Zootecnia, Universidade Federal de Mato Grosso, Cuiabá, 2020. Objetivou-se predizer o crescimento ponderal e biométrico de poedeiras leves por meio do modelo de Gompertz e modelagem das variâncias. Para isso, dois experimentos foram conduzidos. No primeiro experimento, com duração de 112 dias, para a fase de cria (1 a 14 dias de idade), 2500 pintainhas com um dia de idade (Hyline W-36) foram pesadas individualmente e distribuídas, em delineamento inteiramente casualizado (DIC), em cinco densidades de 100,00; 105,66; 112,00; 119,15 e 127,27 cm2/ave, com dez repetições cada. Para a fase de recria (15 a 112 dias de idade), 750 frangas (Hyline W-36) foram pesadas individualmente e distribuídas em DIC, em cinco densidades de 294,74; 329,41; 373,33; 430,77 e 509,09 cm2/ave, com dez repetições cada. As aves receberam rações formuladas para atender às exigências nutricionais de cada fase, sendo ração e água fornecidas ad libitum. Os dados de massa corporal e idade de poedeiras leves criadas em diferentes densidades populacionais foram obtidos com 1, 7, 14, 21, 28, 42, 56, 70, 84, 98 e 112 dias de idade. As análises estatísticas foram realizadas no programa computacional estatístico SAS (Statistical Analysis System, University Edition), por meio do procedimento para modelos não lineares mistos, com o nível de significância estabelecido em p<0,01, em todas as análises. No segundo ensaio, 280 pintainhas, com um dia de idade (Hyline W-36) foram distribuídas em gaiolas metálicas e acompanhadas até 140 dias de idade. Para o ajuste da densidade de criação, o período experimental foi dividido em três etapas de 1 a 14; 15 a 112 e 113 a 140 dias de idade. As rações foram formuladas para atender às exigências das aves. A ração e a água foram disponibilizadas ad libitum. Semanalmente, todas as aves das gaiolas foram pesadas. Dentre estas, cinco aves com peso médio foram selecionadas e empregadas nas análises. As aves foram sacrificadas por meio de deslocamento cervical e em seguida, amostras de penas foram coletadas. A coleta de penas sucedeu à evisceração direcionada para a biometria de órgãos. Os dados observados de 1 a 140 dias de idade de poedeiras leves foram utilizados nas análises. No experimento 1, a partir dos resultados das avaliações dos multimodelos obtidos pela combinação de Gompertz e funções de variância, conclui-se que, para descrever o crescimento de poedeiras leves em diferentes densidades, o modelo de Gompertz e função de variância escalonada, comum para as densidades de criação, explica melhor o comportamento da variância da variável dependente massa corporal das aves em relação ao tempo. Na análise de verificação de significância dos parâmetros nas diferentes densidades, as estimativas das médias dos parâmetros de massa assintótica, de taxa de crescimento e de tempo (dias) não foram interferidas pelas diferentes densidades de criação de poedeiras leves. Curvas de crescimento de poedeiras leves em diferentes densidades, ajustadas e ilustradas graficamente por meio do modelo unânime, apresentam aspecto sigmoide e as ajustadas por meio da derivada, detalham os incrementos em ganhos de massa. No experimento 2, nas avaliações dos multimodelos obtidos pela combinação do modelo de Gompertz e associação de funções de variância, para mais da metade das variáveis dependentes, o modelo unânime foi Gompertz e função de variância escalonada. Assim, conclui-se que, para descrever o crescimento corporal, de penas e de órgãos de poedeiras leves, o modelo de Gompertz e função de variância escalonada explica melhor o comportamento da variância das variáveis massa corporal com ou sem penas, massa de penas, massa de fígado, de proventrículo, de coração e de intestino grosso total, enquanto que, a função de variância exponencial elucida melhor o comportamento da variância das variáveis moela, intestino delgado total e pâncreas das aves. Curvas de crescimento corporal, de penas e de órgãos de poedeiras leves ajustadas e ilustradas graficamente por meio do respectivo modelo unânime, apresentam aspecto sigmoide e as ajustadas por meio da derivada, detalham os ganhos em massa para cada variável.

BRUSAMARELO, EMANUELE. Ponderal and biometric growth of lightweight laying hens through the Gompertz model: modeling of the variances and creation densities. 2020. 65 p. Thesis (Ph.D. in Animal Science) Faculdade de Agronomia e Zootecnia, Universidade Federal de Mato Grosso, Cuiabá, 2020. The objective was to predict the ponderal and biometric growth of lightweight laying hens through the Gompertz model and modeling of the variances. For this, two experiments were conducted. In the first experiment, with lasting 112 days, for start phase (1 to 14 days of age), 2500 one-day-old female chicks (Hyline W-36) were weighed individually and distributed, in a completely randomized experimental design, in five densities of 100.00; 105.66; 112.00; 119.15 and 127.27 cm2/bird, with ten repetitions each. For the rearing phase (15 to 112 days old), 750 pullets (Hyline W-36) were weighed individually and distributed in a completely randomized design in five densities of 294.74; 329.41; 373.33; 430.77 and 509.09 cm2/bird, with ten repetitions each. The birds were given rations formulated to meet the nutritional requirements of each phase, with ration and water provided ad libitum. The Body mass and age data of lightweight laying hens reared at different population densities were obtained at 1, 7, 14, 21, 28, 42, 56, 70, 84, 98, and 112 days of age. The statistical analyses were performed in the SAS (Statistical Analysis System, University Edition) software, through the procedure for mixed nonlinear models, with the level of significance established at p<0.01, in all analyses. In the second trial, 280 one-day-old female chicks (Hyline W-36) were distributed in metal cages and accompanied until 140 days old. For the adjusted rearing density, the experimental period was divided into three stages from 1 to 14; 15 to 112 and 113 to 140 days of age. The rations were formulated to meet the requirements of the birds. The ration and the water were made available ad libitum. Weekly, all the birds in the cages were weighed. From these, five birds with average weight were selected and employed in the analyses. The birds were sacrificed by cervical dislocation and then samples of feathers were collected. The collection of feathers followed evisceration directed at organ biometry. The data observed from 1 to 140 days of the age of lightweight laying hens were used in the analysis. In experiment 1, from the results of the evaluations of the multi models obtained by the combination of Gompertz and functions of variance, it is concluded that to describe the growth of lightweight laying hens in different densities, the model of Gompertz and function of staggered variance, common for the densities of rearing, better explain the behavior of the variance for body mass the birds. In the significance check analysis of the parameters in the different densities, the estimates of the averages of the parameters of asymptotic mass, growth rate, and time (days) were not interfered with by the different densities rearing of lightweight laying hens. Growth curves of lightweight laying hens in different densities, adjusted and graphically illustrated through the unanimous model, have a sigmoid aspect and those adjusted through the derivative, detail the increases in mass gains. In experiment 2, in the evaluations of multi models obtained by combining the Gompertz model and the association of functions of variance, for more than half of the dependent variables, the unanimous model was Gompertz and function of stepped variance. Thus, it is concluded that to describe the growth of body, feather, and organs of lightweight laying hens, the Gompertz model and function of staggered variance better explain the behavior of variance of the variables body mass with or without feathers, feather mass, liver mass, proventriculus mass, heart mass, and total large intestine, while the function of exponential variance better elucidates the behavior of variance of the variables gizzard, total small intestine, and pancreas of birds. Body growth curves, of feather and organs of lightweight laying hens, adjusted and graphically illustrated through the respective unanimous model, present sigmoid aspect and those adjusted through the derivative, detail the mass gains for each variable.

Idade ao desmame no desempenho de suínos: Parâmetro produtivo, sanitário e econômico

IDADE AO DESMAME DOS SUÍNOS: IMPACTO PRODUTIVO, SANITÁRIO E ECONÔMICO Autor: Jamil Elias Ghiggi Faccin Orientador: Prof. Dr. Fernando Pandolfo Bortolozzo Coorientadores: Prof. Dr. Mike Tokach e Prof. Dr. Rafael da Rosa Ulguim A suinocultura moderna tem enfrentado cada vez mais desafios durante a fase de creche. Ainda, são escassos os estudos sobre o impacto da idade ao desmame realizados em granjas comerciais com as práticas atuais de produção e idades maiores de 21 dias. O objetivo deste estudo foi avaliar o impacto das variáveis peso ao desmame e ganho de peso na primeira semana de creche nos índices de desempenho nesta fase. Além disso, avaliar o impacto da idade ao desmame na performance, sobrevivência e nível de estresse pós-desmame. Também, buscar entender a relação entre idade ao desmame e a capacidade de se reduzir o uso de antibióticos na produção, bem como com a quantidade de quilogramas produzido por leitão desmamado. No primeiro estudo, 4 lotes de suínos em fase de creche foram utilizados. Os animais foram pesados individualmente ao desmame e aos 7 dias de creche. Foi observado que tanto o peso ao desmame como o ganho de peso diário (GPD) da primeira semana apresentam grande importância para o desempenho e sobrevivência do leitão na creche. O terço de leitões mais leve de um desmame, merece receber mais atenção que os demais, pois quando combinado com perda de peso na primeira semana, resultam em altas chances de remoção por desempenho insuficiente. Por fim, apesar de as duas variáveis estudadas apresentarem grande impacto na creche, concluiu-se que, através de uma equação de predição aplicada em novo lote de desmame, tanto peso ao desmame como GPD da primeira semana conseguem predizer somente 50% da performance de creche. No segundo estudo, leitões desmamados com 19, 22, 25 e 28 dias de vida foram acompanhados do nascimento ao abate. Na medida que se aumentou a idade ao desmame, melhorias lineares foram encontradas no GPD de creche e terminação, remoções na creche, percentual de leitões que perdem peso na primeira semana pós-desmame e percentual de leitões com vício de sucção de umbigo na fase de creche. Além disso, o aumento da idade ao desmame se mostrou eficiente em maximizar os quilos vendidos por leitão desmamado em três cenários distintos de mercado. Apesar de todos os resultados significativos apresentarem comportamento linear, foi possível observar que a magnitude das melhorias foi muito representativa até 25 dias de idade ao desmame, com pouca diferença até 28 dias. Já o terceiro estudo, leitões desmamados com 18,5; 21,5 e 24,5 dias de idade foram submetidos a dois protocolos alimentares: com uso de antibióticos (AB) ou livre de antibióticos (ABF) configurando um delineamento em fatorial 3 x 2. Contrariando as expectativas, nenhuma interação importante foi observada entre idade e AB. Do desmame ao abate, aumentar a idade ao desmame promoveu melhorias lineares em GPD e consumo de ração e quadrática no percentual de leitões que necessitaram antibióticos injetáveis. Leitões desmamados com 24.5 dias necessitaram menos intervenções quando comparados com os desmamados mais jovens. O uso de AB melhorou GPD e consumo de ração e reduziu as perdas por mortalidade e subdesenvolvimento. Ambos fatores resultaram em aumento dos quilos vendidos por desmamado. Este estudo demonstrou que o aumento da idade ao desmame pode ser satisfatório para sistemas que adotaram programas ABF. Os resultados destes estudos mostram como a primeira semana interfere na performance de creche, bem como o grande impacto que a idade ao desmame exerce em todas as fases de produção.

PIGS WEANING AGE: IMPACTS ON PRODUCTION, HEALTH AND ECONOMICS Autor: Jamil Elias Ghiggi Faccin Orientador: Prof. Dr. Fernando Pandolfo Bortolozzo Coorientadores: Prof. Dr. Mike Tokach e Prof. Dr. Rafael da Rosa Ulguim The modern swine production has faced increasing challenges during the nursery phase. Moreover, there is a lack of studies regarding the impact of the weaning age in commercial pig farms with current production practices and ages beyond 21 days of age. The objective of this study was to evaluate how much the weaning weight and the growth rate in the first week post-weaning influence the overall nursery performance. Besides, to understand the effects of increasing weaning age in the wean-to-finish performance, surveillance, and the stress level after weaning. Finally, find out the relationship between weaning age and the use of antibiotics, as well as the impact in the weight sold per pig weaned. In the first study, 4 weaning batches were used in the nursery. At weaning and at day 7, pigs were individually weighed. It was observed that both weaning weight and the average daily gain in the first week post-weaning (AGD7) exhibited an essential role in the nursery performance and surveillance. The lighter third of weaned pigs should receive more attention because when lightweight pigs lose weight in the first week, it results in higher odds to present poor performance. In conclusion, even though those two studied variables show a significant impact in the nursery phase, through a prediction equation applied in another weaning batch, weaning weight and ADG7 can predict only 50% of the nursery performance. In the second study, pigs weaned at 19, 22, 25 e 28 days of age were evaluated from birth to slaughter. As weaning age increased, linear improvements were found in average daily gain (ADG) in the nursery and finishing phase, removal rate, percentage of pigs losing weight in the first week post-weaning as well as belly nosing prevalence in the nursery. Moreover, increasing weaning age resulted as an efficient tool to maximize the weight sold per pig weaned in three marketing scenarios. Although all significant results presented a linear manner, the magnitude of the improvement was greater until 25 d and diminishing returns from 25 to 28 d. Finally, the third study evaluated pigs weaned at 18.5; 21.5 and 24.5 days of age combined (AB) or not (ABF) to antibiotics in the diet and water, setting as 3 x 2 factorial design. On the contrary to the expectations, no significant interaction was found between weaning age and AB use. From weaning to marketing, increasing weaning age linearly improved ADG and feed intake. In a quadratic manner, the percentage of pigs requiring antibiotic treatments was reduced, as pigs weaned at 24.5 d had fewer shots than the ones weaned younger. The AB use improved ADG and feed intake and decreased total losses rate. Both factors resulted in an improvement in the weight sold per pig weaned. This study showed that increasing weaning age may be an effective strategy for systems that belong to No antibiotics ever production protocols. The results of these studies have shown that the first week post-weaning plays an essential role in the overall nursery performance, as well as weaning age which seriously influences performance, health and economic parameters through all production phases