The effect of different feeding schedules on egg quality, blood, and bone parameters in broiler breeders

The aim of this study was to evaluate different feeding schedules and their relationship to calcium (Ca) and phosphorus (P) plasma levels and egg quality of broiler breeders. The feeding schedules were: single feeding at 8:00 AM; twice daily feeding (50% at 8:00 AM and 50% at 3:00 PM) and single feeding at 3:00 PM. 330 female and 45 male Cobb 500 broiler breeders were used from 40 to 60 weeks of age. The experimental design was completely randomized, consisting of 3 treatments with 5 replicates each, with 22 females and 3 males. The nutritional requirements were according to guideline recommendations. The following parameters were assessed weekly: total egg production, egg specific gravity, egg and eggshell weight, and eggshell thickness. Ca and P plasma levels, tibia weight and its length and Seedor index were evaluated at the end of the study. To determine the effect of feeding schedules, the total calcium and phosphorus plasma at oviposition time and 21 h after oviposition was evaluated. At 60 weeks of age, tibias were taken from the right leg, dried, measured and weighted. There were no differences among treatments regarding egg production, tibia length and Seedor index. Hens fed at 8:00 AM showed higher tibia weight than hens fed twice daily. Broiler breeders fed at 3:00 PM had higher egg (P = 0.0105) and shell (P = 0.0066) weight than others, and hens fed at 3:00 PM had more specific gravity (P = 0.0219) and eggshell thickness (P = 0.0419) than hens fed at 8:00 AM. Ca (P = 0.758) and P (P = 0.811) plasma levels were higher in hens fed at 8:00 AM than hens fed at 3:00 PM after 21 h of oviposition. Broiler breeders fed at 3:00 PM had better egg quality without any change in production, as well as these hens showing higher available Ca and P plasma levels.

The effect of different feeding schedules on egg quality, blood, and bone parameters in broiler breeders

The aim of this study was to evaluate different feeding schedules and their relationship to calcium (Ca) and phosphorus (P) plasma levels and egg quality of broiler breeders. The feeding schedules were: single feeding at 8:00 AM; twice daily feeding (50% at 8:00 AM and 50% at 3:00 PM) and single feeding at 3:00 PM. 330 female and 45 male Cobb 500 broiler breeders were used from 40 to 60 weeks of age. The experimental design was completely randomized, consisting of 3 treatments with 5 replicates each, with 22 females and 3 males. The nutritional requirements were according to guideline recommendations. The following parameters were assessed weekly: total egg production, egg specific gravity, egg and eggshell weight, and eggshell thickness. Ca and P plasma levels, tibia weight and its length and Seedor index were evaluated at the end of the study. To determine the effect of feeding schedules, the total calcium and phosphorus plasma at oviposition time and 21 h after oviposition was evaluated. At 60 weeks of age, tibias were taken from the right leg, dried, measured and weighted. There were no differences among treatments regarding egg production, tibia length and Seedor index. Hens fed at 8:00 AM showed higher tibia weight than hens fed twice daily. Broiler breeders fed at 3:00 PM had higher egg (P = 0.0105) and shell (P = 0.0066) weight than others, and hens fed at 3:00 PM had more specific gravity (P = 0.0219) and eggshell thickness (P = 0.0419) than hens fed at 8:00 AM. Ca (P = 0.758) and P (P = 0.811) plasma levels were higher in hens fed at 8:00 AM than hens fed at 3:00 PM after 21 h of oviposition. Broiler breeders fed at 3:00 PM had better egg quality without any change in production, as well as these hens showing higher available Ca and P plasma levels.(AU)

Effects of Ascorbic Acid Injection in Incubated Eggs Submitted to Heat Stress on Incubation Parameters and Chick Quality

Dose-dependent positive effects on hatchability and hatchling weight have been attributed to ascorbic acid (AA) when eggs were submitted or not to intermittent heat stress during incubation. Fertile breeder (Cobb(r)) eggs were used to determine if the pre-incubation injection of AA in ovo affects the incubation and hatchling quality of egg incubated under thermoneutral or intermittent heat stress conditions. Eggs were not injected or injected with 0, 2,4, or 6% AA/100µL water and incubated at continuous thermoneutral (37.5ºC) or hot (39.0ºC) temperature. Eggshell temperature (EST) increased in the second half of the incubation period in all experimental groups. The EST of non-injected eggs and of those injected with water was higher when incubated at 39°C than at 37.5°C, but EST was not different among eggs injected with AA. Egg mass loss and eggshell conductance were higher in the eggs incubated at 39°C than at 37.5°C.Hatchability was lower in the eggs injected with AA. Liver and yolk sac weights were higher, whereas heart and liver weights were lower in hatchlings from eggs incubated at 39°C; however, hatchling weight was not affected by incubation temperature. The results showed that AA doses affected egg conductive heat loss and hatchability, and that they did not minimize the effects of high incubation temperature on liver and heart development.(AU)

The Effects of Different Eggshell Temperatures Between Embryonic Day 10 and 18 on Broiler Performance and Susceptibility to Ascites

The aim of the current study was to determine the effects of low (33.3-36.7 C), control (37.8-38.2 C) and high (38.9-40.0 C) eggshell temperatures (ESTs) between days 10-18 of incubation on broiler performance and susceptibility to ascites. The effects of different ESTs on hatchling weight were significant. The highest residual yolk sac weight (7.7 g) and relative yolk sac weight (18.7%) were observed in high EST group, whereas the highest yolk-free body weight (36.22 g) was obtained in the control group. Relative post-hatch heart weight was lower in the high EST group (0.64%) compared with the control (0.84%) and low (0.88%) EST groups. At 6 weeks of age, body weights of broilers of the low, control, and high EST groups were 2172.6, 2543.9, 2282.6 g respectively. During the 6-week life span, the feed conversion ratio of broilers in the low (1.86) and high (1.83) EST groups was significantly worse than of those in the control EST group (1.68). Higher packed cell volume (PCV) and red blood cell (RBC) values were obtained in the high EST group relative to the other groups, whereas hemoglobin (Hb) level was lower in the control group than in the others. The relative heart weights and right ventricular to total ventricular (RV:TV) ratio for low, control, and high EST group were 0.46, 0.40, 0.37 g and 0.27, 0.28, 0.33% respectively. In conclusion, incubation length, yolk sac absorption, residual yolk sac weight, yolk-free BW, post-hatch performance, and heart, blood parameters, abdominal fluid accumulation at slaughter age are affected by changes in EST between incubation days 10 to 18.(AU)

Effects of Ascorbic Acid Injection in Incubated Eggs Submitted to Heat Stress on Incubation Parameters and Chick Quality

Dose-dependent positive effects on hatchability and hatchling weight have been attributed to ascorbic acid (AA) when eggs were submitted or not to intermittent heat stress during incubation. Fertile breeder (Cobb(r)) eggs were used to determine if the pre-incubation injection of AA in ovo affects the incubation and hatchling quality of egg incubated under thermoneutral or intermittent heat stress conditions. Eggs were not injected or injected with 0, 2,4, or 6% AA/100µL water and incubated at continuous thermoneutral (37.5ºC) or hot (39.0ºC) temperature. Eggshell temperature (EST) increased in the second half of the incubation period in all experimental groups. The EST of non-injected eggs and of those injected with water was higher when incubated at 39°C than at 37.5°C, but EST was not different among eggs injected with AA. Egg mass loss and eggshell conductance were higher in the eggs incubated at 39°C than at 37.5°C.Hatchability was lower in the eggs injected with AA. Liver and yolk sac weights were higher, whereas heart and liver weights were lower in hatchlings from eggs incubated at 39°C; however, hatchling weight was not affected by incubation temperature. The results showed that AA doses affected egg conductive heat loss and hatchability, and that they did not minimize the effects of high incubation temperature on liver and heart development.

The Effects of Different Eggshell Temperatures Between Embryonic Day 10 and 18 on Broiler Performance and Susceptibility to Ascites

The aim of the current study was to determine the effects of low (33.3-36.7 C), control (37.8-38.2 C) and high (38.9-40.0 C) eggshell temperatures (ESTs) between days 10-18 of incubation on broiler performance and susceptibility to ascites. The effects of different ESTs on hatchling weight were significant. The highest residual yolk sac weight (7.7 g) and relative yolk sac weight (18.7%) were observed in high EST group, whereas the highest yolk-free body weight (36.22 g) was obtained in the control group. Relative post-hatch heart weight was lower in the high EST group (0.64%) compared with the control (0.84%) and low (0.88%) EST groups. At 6 weeks of age, body weights of broilers of the low, control, and high EST groups were 2172.6, 2543.9, 2282.6 g respectively. During the 6-week life span, the feed conversion ratio of broilers in the low (1.86) and high (1.83) EST groups was significantly worse than of those in the control EST group (1.68). Higher packed cell volume (PCV) and red blood cell (RBC) values were obtained in the high EST group relative to the other groups, whereas hemoglobin (Hb) level was lower in the control group than in the others. The relative heart weights and right ventricular to total ventricular (RV:TV) ratio for low, control, and high EST group were 0.46, 0.40, 0.37 g and 0.27, 0.28, 0.33% respectively. In conclusion, incubation length, yolk sac absorption, residual yolk sac weight, yolk-free BW, post-hatch performance, and heart, blood parameters, abdominal fluid accumulation at slaughter age are affected by changes in EST between incubation days 10 to 18.

Associação de carboidrases e fitase em dietas valorizadas e seus efeitos sobre desempenho e qualidade dos ovos de poedeiras leves / Association of carbohydrases and phytase in enriched diets ranked and its effects on performance and quality of eggs from light laying hens

Foram utilizadas 350 aves da linhagem comercial Bovans White, com o objetivo de avaliar a associação de carboidrases e fitase em dietas valorizadas sobre o desempenho e qualidade dos ovos de poedeiras leves. O delineamento experimental foi inteiramente ao acaso, com 5 tratamentos e 7 repetições. Os tratamentos foram: T1- Controle positivo sem adição de enzimas e sem valorização dos nutrientes, T2- Controle negativo (CN) 1, valorizando em 1,5% e 6% a EMA (kcal/kg), respectivamente para o milho e o farelo de soja, e em 2% a proteína bruta (PB) e os aminoácidos digestíveis limitantes mais a matriz completa para a enzima fitase, T3- CN 2, valorizando em 1,5% e 6% a EMA (kcal/kg), respectivamente para o milho e o farelo de soja, e em 2% a proteína bruta (PB) e os aminoácidos digestíveis limitantes mais a matriz incompleta para a enzima fitase, T4- suplementado com 100g ton-1 de carboidrase e 30g ton-1 de fitase, T5- suplementado com 100g ton-1 de carboidrase e 30g ton-1 de fitase. Os tratamentos controle positivo, T2, T3, T4 e T5, com ou sem suplementação enzimática, garantiram o desempenho no que diz respeito ao consumo de ração, produção, peso e perdas de ovos e qualidade da casca.(AU)

A total of 350 commercial Bovans White laying hens were used to evaluate the association of carbohydrases and phytase in enriched diets and its effects on performance and egg quality of laying hens. The experiment used a randomized design with five treatments and seven replicates. The treatments were: 1. Positive control without added enzymes and without nutrient enrichment, 2. Negative control (NC) 1 with 1.5% and 6% AME (kcal/kg) enrichment for corn and soybean meal respectively, 2% crude protein (CP) enrichment, and digestible limiting digestible amino acids plus the full matrix for the phytase enzyme, 3. NC 2 with 1.5% and 6% AME (kcal/kg) enrichment, respectively, for corn and soybean meal and 2% crude protein (CP) enrichment, and digestible limiting amino acids plus the sparse matrix for the phytase enzyme, 4. NC 1 supplemented with 100 g ton-1 carbohydrase and 30g ton-1 phytase, 5. NC 2 supplemented with 100 g ton-1 carbohydrase and 30g ton-1 phytase. According to the results, the positive control treatments, NC1 and NC2, with or without enzyme supplementation, showed guaranteed performance for feed intake, egg yield, weight, egg loss and shell quality.(AU)

Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.

Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.(AU)

Ensaios de penetração de Salmonella Enteritidis em ovos de galinha com diferentes qualidades de casca, submetidos ou não a lavagem industrial e a duas temperaturas de armazenagem / Penetration of Salmonella Enteritidis in chicken eggs, comparing different shell quality, industrial washing and temperature of storage

Estudou-se o comportamento da Salmonella Enteritidis quando em contato com a superfície de ovos de consumo, classificados de acordo com a qualidade da casca ou com tratamentos (lavados ou não), usando fezes de aves como veículo de contaminação, e armazenados a 8ºC e 70 por cento de umidade relativa ou a 30ºC e 90 por cento de umidade relativa. A 8ºC, o microrganismo permaneceu viável na superfície dos ovos, ao longo do tempo, enquanto a 30ºC foi possível identificar a sua inibição e até sua eliminação da superfície. A contaminação do conteúdo de ovos com defeito de casca foi mais frequente quando os ovos foram submetidos a temperaturas inadequadas de armazenagem (30ºC).(AU)

Salmonella Enteriditis behavior was studied when present on the surface of consume eggs, classified according to the shell quality or treatments (washed or not). Stools of fowls were used as a vehicle for contamination. The eggs were stored at 8ºC and 70 percent relative humidity or at 30ºC and 90 percent of relative humidity. At 8ºC, the microorganism stayed viable on the surface of the eggs throughout the study, while at 30ºC it was inhibited and eliminated from the egg shell. The contamination of content of the eggs with shell defect was more frequent when they were submitted to inappropriate temperatures of storage (30ºC).(AU)