Macroscopic embryonic development of Guinea fowl compared to other domestic bird species

Since few studies have addressed the embryonic development of Guinea fowl (Numida meleagris), the objective of the present study was to evaluate its embryonic development in the Cerrado region of Brazil and compare the results to published descriptions of the embryonic development of other domestic bird species. The commercialized weight for Guinea fowl eggs used in the experiment was found to be 37.57 g, while egg fertility was 92%. Embryo growth rate (%) was higher on the sixth day of incubation relative to other days. The heart began beating on the third day of development, while eye pigmentation and upper and lower limb buds appeared on the sixth day. The yolk sac was incorporated on the 24th day followed by chick external pipping and hatching on the 28th day. Comparisons revealed that the embryonic development of Guinea fowl exhibits both similarities to, and differences from, the embryonic development of other domestic birds. From three days of embryonic development, differences were observed among the compared species. Despite the same incubation period, Guinea fowl embryos develop faster than turkeys. All species begin internal pecking two days before hatching and internal pecking 24 h before hatching.(AU)

Intensified use of TAI and sexed semen on commercial farms

The livestock sector has achieved many technological advances, which have resulted in continued improvements in animal production systems and in the reproductive efficiency of herds. The associated use of reproductive biotechnology and genetic improvements combined with adequate sanitary and nutritional management are essential conditions for sustainable intensified animal production and financial autonomy within farms. Timed artificial insemination (TAI) represents one of the strategies with the greatest impact of expansion in providing genetic improvements and increased reproductive efficiency at a decreased cost. Despite the high proportion of cows receiving TAI, this market still exhibits considerable potential for expansion. After a TAI procedure, approximately 40 to 60% of females become pregnant. This result can vary depending on such factors as the hormonal protocol employed, female category, body condition score, ovarian status, farm management and aspects related to bulls and semen. The fertility and genetic quality of the bull plays an important role in the herd because a single bull can influence the entire production system. Another important strategy is the use of sex-sorted semen associated with TAI, primarily when associated with management practices to improve the pregnancy rate. This paper presents a review of the intensification of TAI, supplying practical information regarding the implementation of TAI commercial programs.(AU)

Intensified use of TAI and sexed semen on commercial farms

The livestock sector has achieved many technological advances, which have resulted in continued improvements in animal production systems and in the reproductive efficiency of herds. The associated use of reproductive biotechnology and genetic improvements combined with adequate sanitary and nutritional management are essential conditions for sustainable intensified animal production and financial autonomy within farms. Timed artificial insemination (TAI) represents one of the strategies with the greatest impact of expansion in providing genetic improvements and increased reproductive efficiency at a decreased cost. Despite the high proportion of cows receiving TAI, this market still exhibits considerable potential for expansion. After a TAI procedure, approximately 40 to 60% of females become pregnant. This result can vary depending on such factors as the hormonal protocol employed, female category, body condition score, ovarian status, farm management and aspects related to bulls and semen. The fertility and genetic quality of the bull plays an important role in the herd because a single bull can influence the entire production system. Another important strategy is the use of sex-sorted semen associated with TAI, primarily when associated with management practices to improve the pregnancy rate. This paper presents a review of the intensification of TAI, supplying practical information regarding the implementation of TAI commercial programs.

Avaliação de ocorrências de mortalidade de aves notificadas ao serviço veterinário oficial estadual na microrregião de Concórdia - Santa Catarina - Brasil

Neste artigo objetivou-se descrever o caso do surto de onfalite que ocorreu na microrregião de Concórdia,em janeiro de 2013. Este motivou um levantamento de 286 causas de mortalidade de aves na região,notificadas ao serviço veterinário oficial estadual no período de julho a dezembro de 2012 e janeiro a junhode 2013. Além da onfalite, destacaram-se adversidades como o baixo desempenho, stress térmico easpergilose, o que demonstra a necessidade de melhoria nos processos de controle dos aviários.

This article aimed to describe the case of the omphalitis outbreak that occurred in the Concórdiamicroregion in January 2013. This led to a survey of 286 bird mortality causes in the region, notified to theofficial state veterinary service from July to December From 2012 and from January to June 2013. Inaddition to omphalitis, adversities such as low performance, thermal stress and aspergillosis werehighlighted, which demonstrates the need for improvement in avian control processes.

Chelated Minerals and Limestone Particle Sizes on Performance and Bone Quality of Brown-Egg Layers

This study aimed to evaluate productive performance, egg quality, and bone quality of commercial brown-egg layers fed diets containing organic and inorganic minerals and three limestone particle sizes. A total of 288 birds at 64 weeks of age were distributed in a completely randomized design in a 2 × 3 factorial arrangement (two mineral sources and three limestone particle sizes) and eight replicates. The experiment lasted 112 days, divided into four periods. The following treatments were tested: T1 = inorganic minerals + 100% fine limestone; T2 = inorganic minerals + 50% fine limestone + 50% coarse limestone; T3 = inorganic minerals + 100% coarse limestone; T4 = inorganic + organic minerals + 100% fine limestone; T5 = inorganic + organic minerals + 50% fine limestone + 50% coarse limestone; and T6 = inorganic + organic minerals +100% coarse limestone. There was no significant interaction effect between the studied factors on any of the variables. No significant effect of the types of mineral mixes or limestone particle sizes were observed on the performance, egg quality, or bone quality variables evaluated. In conclusion, organic or inorganic minerals associated with limestone in fine, medium, or coarse particle sizes can be used in diets for brown-egg layers without affecting their productive performance, egg quality, or bone quality.

Nutritional Quality of Eggs of Amberlink and Hyline Layers Fed on Different Levels of Provitamin A-Biofortified Maize

The study was conducted to determine the interaction of types of maize (Provitamin A-biofortified maize (PABM) versus white maize) and strain of laying birds (Amberlink and Hyline) on nutritional quality of eggs. Twenty-one of each of Amberlink and Hyline laying hens were fed on three diets for 30 days. Birds were distributed in a 3 × 2 factorial arrangement constituting three diets (0, 50 or 100 % of PABM) and two strains (Amberlink & Hyline). There was a diet × strain interaction on egg shell weight, average daily feed intake, egg production, egg weight and egg shell thickness. Eggs produced by layers under 100 % PABM had lighter eggshell weight and lower eggshell percentage. In contrast, eggs produced by layers under 50 % PABM diet had signi-ficantly higher eggshell percentage, heavier egg shell weight and thicker eggshell. As the level of PABM increased, the yellow and red hue (Hunter a* and b* values) significantly increased while the lightness values (Hunter L* values) decreased. As the level of PABM in the ration increased, the vitamin A content of the egg yolk also significantly increased. Assimilation of vitamin A from feed to egg yolk in Amberlink and Hyline hens was similar. Hence, egg enrichment with vitamin A can be achieved by using PABM in layers ration. The use of high level of PABM had a negative effect on the eggshell quality traits.

Chelated Minerals and Limestone Particle Sizes on Performance and Bone Quality of Brown-Egg Layers

This study aimed to evaluate productive performance, egg quality, and bone quality of commercial brown-egg layers fed diets containing organic and inorganic minerals and three limestone particle sizes. A total of 288 birds at 64 weeks of age were distributed in a completely randomized design in a 2 × 3 factorial arrangement (two mineral sources and three limestone particle sizes) and eight replicates. The experiment lasted 112 days, divided into four periods. The following treatments were tested: T1 = inorganic minerals + 100% fine limestone; T2 = inorganic minerals + 50% fine limestone + 50% coarse limestone; T3 = inorganic minerals + 100% coarse limestone; T4 = inorganic + organic minerals + 100% fine limestone; T5 = inorganic + organic minerals + 50% fine limestone + 50% coarse limestone; and T6 = inorganic + organic minerals +100% coarse limestone. There was no significant interaction effect between the studied factors on any of the variables. No significant effect of the types of mineral mixes or limestone particle sizes were observed on the performance, egg quality, or bone quality variables evaluated. In conclusion, organic or inorganic minerals associated with limestone in fine, medium, or coarse particle sizes can be used in diets for brown-egg layers without affecting their productive performance, egg quality, or bone quality.(AU)

Nutritional Quality of Eggs of Amberlink and Hyline Layers Fed on Different Levels of Provitamin A-Biofortified Maize

The study was conducted to determine the interaction of types of maize (Provitamin A-biofortified maize (PABM) versus white maize) and strain of laying birds (Amberlink and Hyline) on nutritional quality of eggs. Twenty-one of each of Amberlink and Hyline laying hens were fed on three diets for 30 days. Birds were distributed in a 3 × 2 factorial arrangement constituting three diets (0, 50 or 100 % of PABM) and two strains (Amberlink & Hyline). There was a diet × strain interaction on egg shell weight, average daily feed intake, egg production, egg weight and egg shell thickness. Eggs produced by layers under 100 % PABM had lighter eggshell weight and lower eggshell percentage. In contrast, eggs produced by layers under 50 % PABM diet had signi-ficantly higher eggshell percentage, heavier egg shell weight and thicker eggshell. As the level of PABM increased, the yellow and red hue (Hunter a* and b* values) significantly increased while the lightness values (Hunter L* values) decreased. As the level of PABM in the ration increased, the vitamin A content of the egg yolk also significantly increased. Assimilation of vitamin A from feed to egg yolk in Amberlink and Hyline hens was similar. Hence, egg enrichment with vitamin A can be achieved by using PABM in layers ration. The use of high level of PABM had a negative effect on the eggshell quality traits.(AU)

Evaluation of incubation yield, vaccine response, and performance of broilers submitted to in-ovo vaccination at different embryonic ages

The aim of this study was to evaluate the effects of in-ovo vaccination on different incubation days of broiler embryos derived from young and old breeders on incubation indexes, vaccine response, and broiler performance. A number of 20,160 fertile eggs was distributed according to a completely randomized design in a 4 x 2 factorial arrangement (in-ovo vaccination on 16, 17, 18, or 19 days of incubation, and breeders of 31 or 52 weeks of age), totaling eight treatments with 15 replicates of 168 eggs each. Vaccination procedures and vaccines (strains and doses) were those routinely applied in commercial hatcheries. After hatch, 960 male chicks were housed and distributed according to the same experimental design previously applied in the hatchery. There were hatching losses (p < 0.05) when eggs were vaccinated before 18 days of incubation. Greater Marek's disease antibody titers were obtained when the in-ovo vaccination was performed on day 19 of incubation, regardless breeder age. Embryonic age at vaccination did not compromise broiler performance in the field, and the flexibility of embryonic age for in-ovo vaccination can reduces incubation costs.

Effect of embryo thermal stimulation on the serum levels of immunoglobulins and corticosterone, and organ histopathology of 1 day-old broilers

Embryo thermal stimulation has been studied as a means to promote epigenetic changes and to improve broiler health and performance. This study aimed at evaluating immunoglobulin (IgM, IgG, and IgA) titers, serum corticosterone levels, and organ integrity of day-old male Cobb(r) and Ross(r) broilers. Embryos were submitted to hot and cold stimuli (thermal stimulation) on days 14-18 of incubation. The thermal manipulation treatments did not affect immunoglobulin titers of 1 day-old Cobb(r) or Ross(r) chicks, and caused severe bursal lesions (scores 3 and 4) in both strains. However, serum corticosterone levels of Cobb(r) chicks were higher when embryos were submitted to hot stimulus (+1.39ºC) compared with cold stimulus (+36 ºC). Serum corticosterone levels of Ross(r) chicks were not affected by embryo temperature manipulation. The only effect of broiler breeder age was observed on IgM titers of Cobb(r) chicks, which were higher in chicks from 33-wk-old breeders. Further studies are needed to detect the optimal period of embryo thermal stimulation.

Effect of broiler breeder age on the intestinal mucosa development of the embryos at 20 days of incubation

This study investigated the effect of broiler breeder age on the morphological development of the small intestine broiler embryos (villus height, crypt depth, microvillus height, and villus density) at 20 day of incubation. Eggs obtained from 30- and 60-wk-old broiler breeders were used. The results showed that embryos from older broiler breeders presented longer villi in the duodenum, jejunum, and ileum compared with younger broiler breeders. In addition, embryos from older broiler breeders presented deeper crypts in the jejunum and ileum, longer microvilli in jejunal enterocytes, and lower villus density (microvillus number/mm2) in the duodenum and ileum than younger breeders. These results suggest that breeder age influences the gut mucosa development of broiler embryos. Embryos from older broiler breeder showed greater development of the small intestine mucosa than those from younger broiler breeder.

Effect of embryo thermal stimulation on the serum levels of immunoglobulins and corticosterone, and organ histopathology of 1 day-old broilers

Embryo thermal stimulation has been studied as a means to promote epigenetic changes and to improve broiler health and performance. This study aimed at evaluating immunoglobulin (IgM, IgG, and IgA) titers, serum corticosterone levels, and organ integrity of day-old male Cobb(r) and Ross(r) broilers. Embryos were submitted to hot and cold stimuli (thermal stimulation) on days 14-18 of incubation. The thermal manipulation treatments did not affect immunoglobulin titers of 1 day-old Cobb(r) or Ross(r) chicks, and caused severe bursal lesions (scores 3 and 4) in both strains. However, serum corticosterone levels of Cobb(r) chicks were higher when embryos were submitted to hot stimulus (+1.39ºC) compared with cold stimulus (+36 ºC). Serum corticosterone levels of Ross(r) chicks were not affected by embryo temperature manipulation. The only effect of broiler breeder age was observed on IgM titers of Cobb(r) chicks, which were higher in chicks from 33-wk-old breeders. Further studies are needed to detect the optimal period of embryo thermal stimulation.(AU)

Evaluation of incubation yield, vaccine response, and performance of broilers submitted to in-ovo vaccination at different embryonic ages

The aim of this study was to evaluate the effects of in-ovo vaccination on different incubation days of broiler embryos derived from young and old breeders on incubation indexes, vaccine response, and broiler performance. A number of 20,160 fertile eggs was distributed according to a completely randomized design in a 4 x 2 factorial arrangement (in-ovo vaccination on 16, 17, 18, or 19 days of incubation, and breeders of 31 or 52 weeks of age), totaling eight treatments with 15 replicates of 168 eggs each. Vaccination procedures and vaccines (strains and doses) were those routinely applied in commercial hatcheries. After hatch, 960 male chicks were housed and distributed according to the same experimental design previously applied in the hatchery. There were hatching losses (p < 0.05) when eggs were vaccinated before 18 days of incubation. Greater Marek's disease antibody titers were obtained when the in-ovo vaccination was performed on day 19 of incubation, regardless breeder age. Embryonic age at vaccination did not compromise broiler performance in the field, and the flexibility of embryonic age for in-ovo vaccination can reduces incubation costs.(AU)

Effect of broiler breeder age on the intestinal mucosa development of the embryos at 20 days of incubation

This study investigated the effect of broiler breeder age on the morphological development of the small intestine broiler embryos (villus height, crypt depth, microvillus height, and villus density) at 20 day of incubation. Eggs obtained from 30- and 60-wk-old broiler breeders were used. The results showed that embryos from older broiler breeders presented longer villi in the duodenum, jejunum, and ileum compared with younger broiler breeders. In addition, embryos from older broiler breeders presented deeper crypts in the jejunum and ileum, longer microvilli in jejunal enterocytes, and lower villus density (microvillus number/mm2) in the duodenum and ileum than younger breeders. These results suggest that breeder age influences the gut mucosa development of broiler embryos. Embryos from older broiler breeder showed greater development of the small intestine mucosa than those from younger broiler breeder.(AU)

Efeito do período e temperatura de armazenamento de ovos férteis sobre o rendimento de incubação e características de qualidade de codornas neonatas / Effect of period and storage temperature of hatching eggs from breeder quails on hatching results and quality characteristics of neonate quails

Foram estudados parâmetros de incubação e de qualidade física de codornas japonesas neonatas oriundas de ovos submetidos a diferentes condições de armazenamento. Os tratamentos constituíram-se de combinações entre temperaturas e períodos de armazenamento dos ovos férteis. O delineamento foi em blocos casualizados em arranjo fatorial 2x5, temperaturas (ambiente (28±1,5ºC) e refrigerada (14ºC)) x períodos de armazenamento (um, três, seis, nove ou doze dias), totalizando 10 tratamentos com 105 repetições, sendo cada ovo uma unidade experimental. Os ovos foram incubados nas condições de 37,9ºC e 60% de umidade relativa (UR). Houve aumento de perda de peso do ovo com o período de armazenamento, com efeito linear positivo. Observou-se maior taxa de eclosão/ovos férteis para os ovos armazenados sob refrigeração. Houve efeito linear negativo para o período de armazenamento sobre a taxa de eclosão somente para os ovos armazenados em 28ºC. Para o peso da codorna neonata, houve efeito linear negativo, independentemente da temperatura de armazenamento. O comprimento do intestino delgado em temperatura ambiente sofreu influência do período de armazenamento, sendo que o período de 12 dias apresentou pior resultado. O pior escore de qualidade física foi encontrado em codornas neonatas oriundas de ovos armazenados em temperatura ambiente por 12 dias. Pode-se concluir que, para melhorar a eclosão e a qualidade física da progênie, ovos de codorna devem ser armazenados por até nove dias e em temperatura de 14ºC(AU)

Incubation parameters and physical quality of neonate Japanese quails hatched from eggs that were subject to different storage conditions were evaluated. The treatments consisted of a combination of temperatures and storage periods of hatching eggs from breeder quails. The experiments were conducted in a randomized block design in a factorial arrangement 2x5, with two storage temperatures (ambient temperature ± 28°C and refrigerated temperature 14°C) and five storage periods (one, three, six, nine and twelve days), totaling 10 treatments with 105 repetitions, each egg considered to be an experimental unit. The eggs were incubated at 37.9°C with 60% of relative humidity (RH). There was a positive linear effect between egg weight loss and storage period. Higher rates of hatching/fertile eggs were observed for eggs stored in refrigerated conditions. A negative linear effect was observed between storage period and hatching rate when the eggs where stored at a temperature of 28ºC. There was a negative effect for neonate quail weight, independent of storage temperatures. The intestine length was influenced by storage period and 12 days of storage showed the shortest intestine length. Lower scores of physical quality were observed in quails that hatched from eggs stored in ambient temperatures during 12 days. In this context, to improve hatching rates and physical quality of neonate quails the eggs should be stored up to nine days at a temperature of 14°C(AU)

Efeito do período e temperatura de armazenamento de ovos férteis sobre o rendimento de incubação e características de qualidade de codornas neonatas / Effect of period and storage temperature of hatching eggs from breeder quails on hatching results and quality characteristics of neonate quails

Foram estudados parâmetros de incubação e de qualidade física de codornas japonesas neonatas oriundas de ovos submetidos a diferentes condições de armazenamento. Os tratamentos constituíram-se de combinações entre temperaturas e períodos de armazenamento dos ovos férteis. O delineamento foi em blocos casualizados em arranjo fatorial 2x5, temperaturas (ambiente (28±1,5ºC) e refrigerada (14ºC)) x períodos de armazenamento (um, três, seis, nove ou doze dias), totalizando 10 tratamentos com 105 repetições, sendo cada ovo uma unidade experimental. Os ovos foram incubados nas condições de 37,9ºC e 60% de umidade relativa (UR). Houve aumento de perda de peso do ovo com o período de armazenamento, com efeito linear positivo. Observou-se maior taxa de eclosão/ovos férteis para os ovos armazenados sob refrigeração. Houve efeito linear negativo para o período de armazenamento sobre a taxa de eclosão somente para os ovos armazenados em 28ºC. Para o peso da codorna neonata, houve efeito linear negativo, independentemente da temperatura de armazenamento. O comprimento do intestino delgado em temperatura ambiente sofreu influência do período de armazenamento, sendo que o período de 12 dias apresentou pior resultado. O pior escore de qualidade física foi encontrado em codornas neonatas oriundas de ovos armazenados em temperatura ambiente por 12 dias. Pode-se concluir que, para melhorar a eclosão e a qualidade física da progênie, ovos de codorna devem ser armazenados por até nove dias e em temperatura de 14ºC.

Incubation parameters and physical quality of neonate Japanese quails hatched from eggs that were subject to different storage conditions were evaluated. The treatments consisted of a combination of temperatures and storage periods of hatching eggs from breeder quails. The experiments were conducted in a randomized block design in a factorial arrangement 2x5, with two storage temperatures (ambient temperature ± 28°C and refrigerated temperature 14°C) and five storage periods (one, three, six, nine and twelve days), totaling 10 treatments with 105 repetitions, each egg considered to be an experimental unit. The eggs were incubated at 37.9°C with 60% of relative humidity (RH). There was a positive linear effect between egg weight loss and storage period. Higher rates of hatching/fertile eggs were observed for eggs stored in refrigerated conditions. A negative linear effect was observed between storage period and hatching rate when the eggs where stored at a temperature of 28ºC. There was a negative effect for neonate quail weight, independent of storage temperatures. The intestine length was influenced by storage period and 12 days of storage showed the shortest intestine length. Lower scores of physical quality were observed in quails that hatched from eggs stored in ambient temperatures during 12 days. In this context, to improve hatching rates and physical quality of neonate quails the eggs should be stored up to nine days at a temperature of 14°C.

Granulometria e textura do milho: parâmetros produtivos, qualidade dos ovos de poedeiras comerciais e consumo de energia elétrica / Maize kernel size and texture: production parameters, quality of eggs of the laying hens and electricity intake

O objetivo foi avaliar como os fatores granulometria e textura do milho podem alterar os parâmetros de desempenho produtivo de poedeiras comerciais, bem como o consumo de energia elétrica para moagem dos grãos. Foram utilizadas 384 poedeiras da linhagem Isa Brown com 36 semanas de idade, alojadas em aviário de produção convencional com taxa de lotação de 562,5 cm2 ave-1. Os tratamentos foram distribuídos em delineamento inteiramente ao acaso em esquema fatorial 2 x 3 (texturas de milho: duro e dentado e graus de moagem: fino, médio e grosso), com oito repetições de oito aves por parcela. Os dados foram avaliados com o auxílio do pacote estatístico SISVAR com médias comparadas pelo teste de Tukey a 5% de probabilidade. Foi constatada diferença para o fator textura, em que a textura dura apresentou aumento nas variáveis: consumo de ração e peso dos ovos. As características de qualidade dos ovos demonstraram diferença significativa apenas quanto à cor da gema. Maiores granulometrias consumiram menos energia elétrica durante a moagem. A cultivar de milho duro teve consumo de energia elétrica 31,66% menor comparativamente à cultivar dentado.(AU)

The influence of maize corn size and texture on the performance parameters of laying hens and power consumption required for grinding maize corn were evaluated. The experiment was carried out on 384 Isa Brown hens, 36 weeks old, penned in a conventional aviary with 562.5 cm2 bird-1 stocking rate. The treatments were distributed in a completely randomized 2 x 3 factorial design (maize textures: flint and dent; and milling degree: fine, medium and coarse) with eight replicates of eight birds per plot. Data were evaluated with SISVAR and means were compared by Tukeys test at 5% probability. Difference was reported for the variable texture and flint increased the variables feed intake and egg weight. Significant difference in the characteristics of egg quality occurred only for the colorof the yolk. Larger corn sizes consumed less electricity during grinding. The maize flint cultivar had a lower 31.7% power consumption when compared to that of the dent cultivar.(AU)

Granulometria e textura do milho: parâmetros produtivos, qualidade dos ovos de poedeiras comerciais e consumo de energia elétrica / Maize kernel size and texture: production parameters, quality of eggs of the laying hens and electricity intake

O objetivo foi avaliar como os fatores granulometria e textura do milho podem alterar os parâmetros de desempenho produtivo de poedeiras comerciais, bem como o consumo de energia elétrica para moagem dos grãos. Foram utilizadas 384 poedeiras da linhagem Isa Brown com 36 semanas de idade, alojadas em aviário de produção convencional com taxa de lotação de 562,5 cm2 ave-1. Os tratamentos foram distribuídos em delineamento inteiramente ao acaso em esquema fatorial 2 x 3 (texturas de milho: duro e dentado e graus de moagem: fino, médio e grosso), com oito repetições de oito aves por parcela. Os dados foram avaliados com o auxílio do pacote estatístico SISVAR com médias comparadas pelo teste de Tukey a 5% de probabilidade. Foi constatada diferença para o fator textura, em que a textura dura apresentou aumento nas variáveis: consumo de ração e peso dos ovos. As características de qualidade dos ovos demonstraram diferença significativa apenas quanto à cor da gema. Maiores granulometrias consumiram menos energia elétrica durante a moagem. A cultivar de milho duro teve consumo de energia elétrica 31,66% menor comparativamente à cultivar dentado.

The influence of maize corn size and texture on the performance parameters of laying hens and power consumption required for grinding maize corn were evaluated. The experiment was carried out on 384 Isa Brown hens, 36 weeks old, penned in a conventional aviary with 562.5 cm2 bird-1 stocking rate. The treatments were distributed in a completely randomized 2 x 3 factorial design (maize textures: flint and dent; and milling degree: fine, medium and coarse) with eight replicates of eight birds per plot. Data were evaluated with SISVAR and means were compared by Tukeys test at 5% probability. Difference was reported for the variable texture and flint increased the variables feed intake and egg weight. Significant difference in the characteristics of egg quality occurred only for the colorof the yolk. Larger corn sizes consumed less electricity during grinding. The maize flint cultivar had a lower 31.7% power consumption when compared to that of the dent cultivar.

Effect of dietary energy concentration on performance parameters and egg quality of white leghorn laying hens

An experiment was carried out with 1200 23-week-old white Dekalb commercial laying hens to investigate production responses, egg quality, and energy utilization of laying hens fed different dietary energy levels at the beginning of lay. Birds were housed and divided in five groups of 240 birds according to dietary apparent metabolizable energy corrected for nitrogen (AMEn): 2700 kcal/kg; 2775 kcal/kg; 2850 kcal/kg; 2925 kcal/kg; and 3000 kcal/kg, with six replicates of 40 birds each. Birds were fed the experimental diets based on corn and soybean meal for 17 weeks. Diets were iso-nutritive, except for energy level. Increasing AMEn levels had a negative effect on egg production and egg mass (p0.05). AMEn levels did not influence body weight, egg weight, or livability (p>0.05). Increasing AMEn levels increased (p0.05) feed intake and AMEn conversion ratio and feed conversion ratio. AMEn intake remained constant, independently of dietary AMEn level (p>0.05). There were no differences in albumen height, yolk total solids content, or egg component percentages (p>0.05). Egg specific weight improved with increasing AMEn levels (p0.05). Therefore, the energy level of 2700 kcal/kg of feed may be fed to young laying hens.

Effect of dietary energy concentration on performance parameters and egg quality of white leghorn laying hens

An experiment was carried out with 1200 23-week-old white Dekalb commercial laying hens to investigate production responses, egg quality, and energy utilization of laying hens fed different dietary energy levels at the beginning of lay. Birds were housed and divided in five groups of 240 birds according to dietary apparent metabolizable energy corrected for nitrogen (AMEn): 2700 kcal/kg; 2775 kcal/kg; 2850 kcal/kg; 2925 kcal/kg; and 3000 kcal/kg, with six replicates of 40 birds each. Birds were fed the experimental diets based on corn and soybean meal for 17 weeks. Diets were iso-nutritive, except for energy level. Increasing AMEn levels had a negative effect on egg production and egg mass (p0.05). AMEn levels did not influence body weight, egg weight, or livability (p>0.05). Increasing AMEn levels increased (p0.05) feed intake and AMEn conversion ratio and feed conversion ratio. AMEn intake remained constant, independently of dietary AMEn level (p>0.05). There were no differences in albumen height, yolk total solids content, or egg component percentages (p>0.05). Egg specific weight improved with increasing AMEn levels (p0.05). Therefore, the energy level of 2700 kcal/kg of feed may be fed to young laying hens.(AU)