Performance Of Broiler Breeders Research Articles

Effects of Cumulative Protein Intake on Growth Performance and Body Conformation Traits in Female Broiler Breeders under Intensive System of Rearing

The present study evaluated the effects of protein intake on growth, nutrient utilization efficiency and body conformation traits in broilers. Three-hundred sixty (360) day-old chicks were distributed into 3 groups and offered starter diets containing 18, 19 or 20% protein up to 5th week. From each group, 96 pullets with higher body weight (BW) were selected and divided into high body weight (HB) and low body weight (LB) groups. The pullets of each BW group were distributed in 6 replicates. Three of the replicates were allotted to grower diets with 10 or 14% CP from 6-20 weeks. Pre-breeder and breeder diets were offered during 21-23 weeks and 24-50 weeks, respectively. For all groups, target 20th week BW was 2200g. Feed intake, BW and feed conversion efficiency were recorded. Body conformation traits were measured at 5th and 20th weeks. In conclusion, birds fed starter diet with 19% CP and grower diet with 14% CP had better body conformation, growth and feed efficiency.

Effects of different methionine sources on production and reproduction performance, egg quality and serum biochemical indices of broiler breeders.

ObjectiveThe study was conducted to evaluate the effects of different methionine (Met) sources on production performance, reproduction performance, egg quality and serum biochemical indices in broiler breeders.MethodsAfter receiving a basal diet (containing 0.25% Met) for a 2-wk pretreatment period, a total of 360 39-wk-old Lingnan yellow broiler breeders were randomly allocated to four treatments with six replicates each (15 birds per replicate). Breeders were fed with basal diets (control) or diets supplemented with DL-methionine (DLM), DL-2-hydroxy-4-methylthio butytric calcium (MHA-Ca) and coated DL-Met (CME) respectively.ResultsThe results showed that CME supplementation promoted laying rate and decreased feed-to-egg ratio (F/E) (p<0.05), DLM and MHA-Ca supplementation decreased F/E (p<0.05) when compared with control group. The rate of fertility, hatchability and birthrate were higher (p<0.05) in DLM, MHA-Ca, and CME groups than control group. Compared with control group, CME increased the eggshell thickness (p<0.05); MHA-Ca improved the eggshell thickness, shell ratio and eggshell strength (p<0.05). Results also showed that CME elevated the concentration of total protein in serum (p<0.05); MHA-Ca improved the concentration of calcium in serum (p<0.05). The concentration of serum uric acid in DLM, MHA-Ca, and CME groups was lower than that in control group (p<0.05). Besides, CME had higher concentrations of serum taurine, cysteine and cystanthionine (p<0.05) while MHA-Ca and DLM promoted the serum taurine concentration (p<0.05) compared with control group.ConclusionBased on the results, it was concluded that Met supplementation could enhance the production and reproduction performance as well as the antioxidant status and egg quality of broiler breeders. In terms of improving the production performance, reproduction performance and antioxidant performance, CME was superior to DLM and MHA-Ca; but in regard to the enhancement of eggshell quality and serum Ca concentration, MHA-Ca was superior to DLM and CME.

Improved Performance of Broilers and Broiler Breeders Associated with an Amended Vaccination Program Against Reovirosis.

A vertically integrated monitoring program was set up for breeders hatched in 2013 and their offspring to detect differences in performance related to the reovirus vaccination schedule. Within the same organization in Belgium, 17 breeder flocks were vaccinated with one dose of live and one dose of inactivated reovirus vaccine, while 14 flocks received two doses of inactivated vaccine without live priming. The hatchability of the eggs produced by these birds was examined. Further, the daily growth, feed conversion, mortality, slaughterhouse condemnation, production index, and antibiotic use were monitored in 110 broiler flocks derived from the breeders. All gathered data were examined statistically. In eggs obtained from breeders vaccinated twice with inactivated reovirus vaccine, a significant 2.88% higher hatchability rate was observed. The progeny broiler flocks of these breeders showed a significant 18.2% lower mortality during the fattening period. Although not statistically significant, the slaughterhouse condemnation rate was 10.1% lower as well. The results may indicate that-under the epidemiologic conditions of this study-double administration of inactivated reovirus vaccine in broiler breeders can at least contribute to higher hatchability of breeder eggs and lower broiler mortality.

Pengaruh Kecerdasan Emosional dan Organizational Citizenship Behavior (OCB) terhadap Kinerja Peternak Ayam Ras Pedaging

One line of business in the livestock sector is very dynamic development of agribusiness broiler breeding with a partnership plasma core. Development of agribusiness broiler farm will be successful if farmers are able to manage the cattle business well through improved individual performance to the fullest which is characterized by an individual’s ability to control and manage emotions and behave voluntarily without any coercion by contract organizations. This study aims to determine how much influence the emotional intelligence and Organizational Citizenship Behavior (OCB) on the performance of broiler breeders. This study uses a quantitative approach with a correlation method. The selected study site is CV Amerta Farm Corp Probolinggo, because it is one of agribusiness broiler farms that implement core-plasma partnership pattern. The number of respondents in this study amounted to 69 people. Independent variables in this study are emotional intelligence and Organizational Citizenship Behavior (OCB), while the dependent variable is the performance of broiler breeders. Data analysis techniques used in this study is a Structural Equation Modeling (SEM) with the Partial Least Square (PLS) technique assisted with SmartPLS 2.0 application program.

Effects of intramuscular injections of vitamin E-selenium and a gonadotropin releasing hormone analogue (GnRHa) on reproductive performance and blood metabolites of post-molt male broiler breeders

Abstract Objective To investigate the effects of intramuscular injection of vitamin E-selenium and a GnRH analogue (GnRHa) on reproductive performance and serum biochemical parameters in post-molt male broiler breeders. Methods A total of 32 ROSS 308 male broiler breeders (60 weeks of age) were induced to molt and then were randomly distributed into four groups: group 1 (control) without any injection, group 2 subjected to intramuscular of 0.1 mL/kg body weight of vitamin E-selenium, group 3 subjected to intramuscular of 0.3 mL. Receptal solution as a GnRHa and group IV subjected to intramuscular both of vitamin E-selenium and GnRHa. Results The results showed that the egg hatchability and fertility percentages were increased and the eggs infertility percentage declined significantly in groups 3 and 4 ( P P > 0.05). The results of blood biochemical parameters indicated that serum glucose was higher in group 3 which was injected with GnRHa ( P P > 0.05). The results showed that serum testosterone concentration was increased in groups 3 and 4 ( P P P > 0.05). Conclusions It is concluded that reproductive performance and serum testosterone in post-molt male broiler breeders were improved by treated with vitamin E-selenium and GnRHa.

Effect of dietary canthaxanthin and 25-hydroxycholecalciferol supplementation on the performance of duck breeders under two different vitamin regimens.

BackgroundDietary canthaxanthin (CX), 25-hydroxycholecalciferol (25-OH-D3) and vitamins have been widely reported to be involved in productive and reproductive performance of broiler breeders. However, limited information is available for duck breeders. In this study, a total of 1,560 Cherry Valley SM3 duck breeder females and 312 males were used to assess if the addition of CX and 25-OH-D3 could increase the performance of duck breeders under two different dietary vitamin regimens. Four diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes (REGULAR and HIGH; HIGH premix had higher levels of all vitamins except K3 than REGULAR premix), and with or without the supplementation of the mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg). The ducks were fed ad libitum with pelleted diets based on corn-soybean meal from 38 to 77 wk of age.ResultsHIGH vitamin premix decreased malondialdehyde (MDA) level (P < 0.001) of egg yolk, increased hatchability of fertile eggs (P = 0.029), increased hatchability of total eggs (P = 0.029), and decreased serum protein carbonyl level (P = 0.037) of breeder males. The mixture of CX and 25-OH-D3 increased serum calcium of breeder females (P = 0.010), decreased the cracked egg rate (P = 0.001), increased the pigmentation of egg yolk (P < 0.001) and male bill (P < 0.001), and decreased MDA level of egg yolk (P < 0.001) and male serum (P = 0.034). Interactive effects were observed in cracked egg rate (P = 0.038), shell thickness (P = 0.011) and serum phosphorus (P = 0.026) of breeder females. HIGH vitamin premix together with the mixture of CX and 25-OH-D3 decreased cracked egg rate and increased shell thickness of duck breeders. Serum phosphorus was decreased in duck breeder females fed REGULAR vitamin premix without the addition of the CX and 25-OH-D3 mixture.ConclusionsDietary HIGH vitamin premix increased antioxidant status of eggs and breeder males, and increased hatchability. The mixture of CX and 25-OH-D3 enhanced egg shell quality, and promoted pigmentation and antioxidant status of eggs and breeder males.

Can feeding the broiler breeder improve chick quality and offspring performance?

The impact of nutrition on the performance of broiler breeders in terms of bodyweight profile, egg production, egg size and shell quality, mortality, fertility and hatchability has been well documented. However, studies on the direct effects of breeder nutrition on subsequent chick quality and offspring performance are limited. The present paper reviews the nutritional factors in broiler breeders that may improve chick quality and progeny performance. Recent research has suggested that the feeding of low crude protein and medium to high energy breeder diets in both rearing and laying period will not only have a positive impact on egg production, egg size, breeder fertility, hatchability and embryonic livability, but also on offspring performance. Improvements include better chick quality, higher chick weight, lower mortality, increased immune responses, enhanced litter quality and broiler growth. Breast-meat yield in the progeny can be improved as the energy to protein ratio increases from the rearing phase to the laying phase, indicating that nutrition of pullets can also affect growth and yields. The effects of maternal diet on offspring performance may depend on the sex of the progeny, with male broilers responding more than female broilers to breeders’ dietary protein and energy concentrations. However, little work has been conducted on the effects of individual amino acids in breeder diets on the subsequent generation. There seems to be some benefits with the use of long-chain poly-unsaturated fats in breeder diets on carcass quality of offspring, but these effects appear inconsistent at this stage. There is substantial evidence that confirms the direct effects of vitamin D and E, and trace minerals, especially in organic form, such as selenium, zinc and manganese, on chick quality and progeny performance. In fact, the impact of breeder nutrition on progeny performance in the field is more likely to be greater under conditions of poor breeder-flock uniformity, low vitamin and trace mineral contents or certain types of stress in the broiler house.

Effects of environmental temperature and dietary manganese on egg production performance, egg quality, and some plasma biochemical traits of broiler breeders.

An experiment was conducted to investigate the effects of environmental temperature and dietary Mn on egg production performance, egg quality, and some plasma biochemical traits of broiler breeders. A completely randomized factorial design involved 2 environmental temperatures (a normal temperature, 21 ± 1°C, and a high temperature, 32 ± 1°C) × 3 dietary Mn treatments (a Mn-unsupplemented corn–soybean meal basal diet or the basal diet supplemented with 120 mg of Mn/kg of diet as either MnSO4·H2O or manganese proteinate). There were 6 treatments with 6 replicates (4 birds per replicate). High temperature decreased egg weight (P < 0.0001), laying rate (P < 0.0001), egg yield (P < 0.0001), feed intake (P < 0.0001), egg:feed ratio (P < 0.0001), eggshell strength (P < 0.05) and thickness (P < 0.0001), plasma triiodothyronine level (P < 0.05), and alkaline phosphatase activity (P < 0.04) whereas it increased rectal temperature (P < 0.0001); plasma malondialdehyde level (P < 0.02); and activities (P < 0.002) of lactic dehydrogenase, aspartate aminotransferase, and creatine kinase. Broiler breeders fed the diets supplemented with Mn regardless of source had greater (P < 0.05) eggshell strength and lower (P ≤ 0.05) plasma triiodothyronine level and protein carbonyl content than those fed the control diet. The broiler breeders fed the diet supplemented with the organic Mn had greater (P < 0.01) eggshell thickness than those fed the control diet. There were interactions (P < 0.05) between environmental temperature and dietary Mn in laying rate, egg yield, feed intake, and egg:feed ratio. Under normal temperature, dietary Mn did not affect the above 4 parameters; however, under high temperature, broiler breeders fed the diet supplemented with the organic Mn showed greater (P < 0.03) improvements in these 4 parameters than those fed the control diet. The results from this study indicated that high temperature significantly impaired egg production performance and eggshell quality and induced lipid peroxidation and tissue damage whereas dietary supplementation of either organic or inorganic Mn improved eggshell strength and thermotolerance and reduced protein oxidation and that the organic Mn could alleviate the negative effect of high temperature on egg production performance of broiler breeders at the period of 32 to 45 wk of age.

Vitamin E and selenium in broiler breeder diets: Effect on live performance, hatching process, and chick quality

This study evaluated the effect of different dietary vitamin E levels and different selenium sources on the productive and reproductive performance of broiler breeders. In total 640 females and 64 males between 22 and 52 weeks old were studied. A completely randomized experimental design in factorial arrangement, with 4 treatments of 8 replicates with 20 females and 2 males each, was applied. Treatments consisted of 2 vitamin E levels (30 and 120 mg/kg) and two selenium sources (sodium selenite and zinc-L-selenomethionine). Egg production (rate of lay and eggs per breeder), egg characteristics (egg, yolk, eggshell, and albumen weights), fertility, incubation responses (egg weight loss during incubation, hatchability, and hatching window), and hatchling characteristics (weight and yield) were evaluated. There was no influence of dietary vitamin E levels or selenium sources on egg production (P > 0.05). Mature breeders (47 weeks old) fed zinc-L-selenomethionine and 120 mg vitamin E/kg feed produced heavier eggs and albumen. Hatchability of the eggs of breeders fed 120 mg vitamin E/kg feed was higher than breeders fed 30 mg vitamin at 29 wks. The dietary inclusion of organic selenium also promoted heavier hatchling weight until egg production peak (33 wk), but did not influence hatchling quality or hatching window. It was concluded that the dietary supplementation of zinc-L-selenomethione and vitamin E (120 mg/kg feed) could be used to improve egg characteristics and incubation response.

Effect of Dietary Vitamin A on Reproductive Performance and Immune Response of Broiler Breeders

The effects of dietary vitamin A supplementation on reproductive performance, liver function, fat-soluble vitamin retention, and immune response were studied in laying broiler breeders. In the first phase of the experiment, 1,120 Ross-308 broiler breeder hens were fed a diet of corn and soybean meal supplemented with 5,000 to 35,000 IU/kg vitamin A (retinyl acetate) for 20 weeks. In the second phase, 384 Ross-308 broiler breeder hens were fed the same diet supplemented with 5,000 to 135,000 IU/kg vitamin A (retinyl acetate) for 24 weeks. The hens' reproductive performance, the concentrations of vitamins A and E in liver and egg yolk, liver function, mRNA expression of vitamin D receptor in duodenal mucosa, antibody titers against Newcastle disease virus vaccine, and T-cell proliferation responses were evaluated. Supplementation of vitamin A at levels up to and including 35,000 IU/kg did not affect reproductive performance and quadratically affected antibody titer to Newcastle disease virus vaccine (p<0.05). Dietary addition of vitamin A linearly increased vitamin A concentration in liver and yolk and linearly decreased α-, γ-, and total tocopherol concentration in yolk (p<0.01) and α-tocopherol in liver (p<0.05). Supplementation of vitamin A at doses of 45,000 IU/kg and above significantly decreased egg weight, yolk color, eggshell thickness and strength, and reproductive performance. Dietary vitamin A significantly increased mRNA expression of vitamin D receptor in duodenal mucosa (p<0.05), increased aspartate amino transferase activity, and decreased total bilirubin concentration in serum. Supplementation of vitamin A at 135,000 IU/kg decreased the proliferation of peripheral blood lymphocytes (p<0.05). Therefore, the maximum tolerable dose of vitamin A for broiler breeders appears to be 35,000 IU/kg, as excessive supplementation has been shown to impair liver function, reproductive performance, and immune response.

Comparative study of the effects of organic selenium on hen performance and productivity of broiler breeders

1. A 10-week experiment was conducted with Ross 308 broiler breeder chickens in cages to evaluate the influence of organic and inorganic sources of selenium (Se) supplementation. A total of 600 birds at 29 weeks of age were divided at random into 4 groups and fed on a maize–soya basal diet supplemented with different forms of Se.2. The first (control) group was given the basal diet without Se supplementation, whereas the second, third and fourth groups were given, respectively, the basal diet with 0.3 mg/kg of inorganic Se in the form of sodium selenite or 0.3 and 0.5 mg/kg of organic Se in the form of Se enriched yeast (Se-yeast).3. The experiment was carried out for 10 weeks to compare and evaluate the influence of Se supplementation on breeder performance, egg production, hatchability and the quality of eggs. Samples were collected for analysis at weeks 0, 5 and 10 of the experimental period.4. At the end of the experiment (39 weeks), there was a reduction in mortality in breeders given diets supplemented with 0.5 mg/kg of Se-yeast. Supplementation of feed with 0.5 mg/kg organic Se increased egg production, percentage of settable eggs and hatchability.5. Selenium supplementation increased egg weight and specific gravity compared to the control diet. However, no significant variation was found in albumen or yolk protein content at the end of week 10.6. Selenium accumulation and glutathione peroxidase (GSHPx) activity were lower in the egg albumen and yolk of control compared with Se-supplemented treatments. Se accumulation and GSHPx activity were higher in the group given 0.3 mg/kg organic compared to 0.3 mg/kg of inorganic Se.7. The results favour the use of Se-yeast at the dose of 0.5 mg/kg in broiler breeder diets for better productivity of eggs, settable eggs, hatchability and higher Se accumulation and antioxidant status in eggs.

Effects of feeder space allocations during rearing, female strain, and feed increase rate from photostimulation to peak egg production on broiler breeder female performance

A study was conducted to determine if there were differences in female broiler breeder performance of 2 strains that had been subjected to 2 feeder space allocations during the growing period followed by 2 feeding to peak programs. Ross 308 and 708 pullets were reared with a single feeding program to 23 wk of age and with 2 circumferential feeder space allocations (5.3 cm/female or 7.0 cm/female) and then assigned to 2 feed increase programs (slow or fast) from photostimulation to peak egg production. The flock was moved to the laying house with 8.8 cm/female of female feeder space and photostimulated at 23 wk of age when Ross 344 males were added to create 16 pens with 60 females and 7 males each in a 2 × 2 × 2 design. The fast feed increase program significantly increased female BW at 31 wk of age, which could have contributed to an increased female mortality during the summer weather of early lay. The 708 females with 5.3 cm/female feeder space produced smaller eggs at 28 and 30 wk of age. The 708 females exhibited better fertile hatchability than 308 females due to fewer late dead embryos. There were no differences in egg production, fertility, or fertile hatchability due to the main effects of feeding to peak program or growing feeder space, but the slow feed increase from photostimulation to peak production reduced cumulative mortality.

Effects of feeding programme and feeder space change at photo-stimulation using maize- or wheat-based diet on growth and reproductive performance of female broiler breeders

1. This study was carried out to determine the effects of breeder feeding programme to 29 weeks of age, and feeder space change at photo-stimulation using two sources of grain on breeder hen reproductive efficiency and egg characteristics.2. Fast-feathering Cobb 500 pullet broiler breeders were housed in 16 pens of 81 females each during rearing, and fed on either maize- or wheat-based diet, formulated to have similar nutrient composition. Two feeding programmes, Fast and Slow, were used from 14 to 29 weeks of age. At 22 weeks of age, 69 females that represented the body weight (BW) distribution from each pen were placed in a layer house where feeder space either remained very similar (from 6.3 to 6.5 cm/female) or was increased (from 6.3 to 8.4 cm/female). Breeder growth performance, reproductive efficiency and egg characteristics were evaluated.3. Data were analysed as a 2 × 2 × 2 factorial design with diet type, feeding programme and feeder space change as the main factors. The main effects of the treatments were found but there were no treatment interactions.4. Breeders fed on wheat were consistently heavier than breeders fed on maize from 10 to 52 weeks of age and exhibited greater hen mortality during the layer phase. Breeders fed on wheat diets exhibited improved egg production while laying eggs with a greater yolk:albumen ratio compared to the maize group.5. The Fast feeding programme increased female mortality and increased BW during the layer phase. Breeders fed according to the Slow feeding programme had better fertility, and laid eggs with lower percentage eggshell that might be associated with the lower early embryonic mortality observed in these hens as compared with the Fast feeding programme.6. Breeders having increased feeder space at photo-stimulation matured earlier and produced more eggs compared to breeders with no change in feeder space.7. It was concluded that the feeding of wheat, the use of the Slow feeding programme and an increase in feeder space improved some aspects of hen productivity and egg characteristics.

Effect of the ratio of dietary n-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid on broiler breeder performance, egg quality, and yolk fatty acid composition at different breeder ages

When added to the feed of broiler breeder hens, dietary polyunsaturated fatty acids (FA) can be incorporated into the yolk and therefore become available to the progeny during their early development. The mechanism involved in lipid metabolism and deposition in the egg may be influenced by breeder age. Before the effect of an elevated concentration of certain polyunsaturated FA on the embryo can be investigated, the effect at breeder level and egg quality must be further assessed. The aim of the present experiment was to evaluate the effects of dietary n-6/n-3 ratios and dietary eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) ratios, provided to broiler breeder hens, in terms of their zoo technical performance, egg quality, and yolk FA composition. Starting at 6 wk of age, 640 Ross-308 broiler breeder hens were fed 1 of 4 different diets. The control diet was a basal diet, rich in n-6 FA. The 3 other diets were enriched in n-3 FA, formulated to obtain a different EPA/DHA ratio of 1/1 (EPA = DHA), 1/2 (DHA), or 2/1 (EPA). In fact, after analysis the EPA/DHA ratio was 0.8, 0.4, or 2.1, respectively. Dietary EPA and DHA addition did not affect the performance of the breeder hens, except for egg weight. Egg weight was lower (P < 0.001) for all n-3 treatments. Dietary EPA improved number of eggs laid in the first 2 wk of the production cycle (P = 0.029). The absolute and relative yolk weight of eggs laid by EPA = DHA fed hens was lowest (P = 0.004 and P = 0.025, respectively). The EPA and DHA concentrations in the yolk were highly dependent on dietary EPA and DHA concentrations with a regression coefficient equal to 0.89. It can be concluded that dietary EPA and DHA can be incorporated in the breeder egg yolk to become available for the developing embryo, without compromising the performance and egg quality of the flock.

Effect of Supplementation of Organic Zinc on the Performance of Broiler Breeders

Two hundred and sixty four broiler breeder hens of 33 weeks of age were distributed randomly in four dietary treatments with three replicate containing 22 birds. The dietary treatments included broiler breeder control ration containing 40 ppm zinc (T0) or the control ration supplemented with organic zinc (zinc methionine) at 20 (T1), 40 (T2) and 60 (T3) ppm levels. The experiment was continued from 33 to 48 weeks of age. Daily eggs production, BW and hatchability were recorded. At 48 weeks, serum biochemical and tibia bone parameters were assessed. The periodical hen day egg production in all the treated groups did not differ significantly (P<0.05) from 33 to 44 weeks of age but during 45–48 weeks of age the hen day egg production of the group T1 was significantly (P<0.05) higher than all other groups. The overall hen day egg production of the broiler breeders from 33 to 48 weeks did not differ (P>0.05) among all the treated groups. The FCR of different treatments did not differ significantly from 33 to 44 weeks of age but during 45–48 weeks, the FCR of T1 was significantly (P<0.05) better than other treated groups. The overall FCR of the entire experimental period (33–48 weeks of age), was without variations (P>0.05). The overall BW change, did not differ significantly among the treatments. The overall (3348 weeks) fertility percent and hatchability percent (on fertile egg set basis) of all the groups of broiler breeder were almost similar but the hatchability percent on total egg set basis of T2 and T3 groups was significantly higher as compared to T0 and T1. Except, serum levels of total protein, urea, alkaline phosphate (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels, all other studied biochemical parameters did not differ significantly. There were no variations in the weight, length and cortex thickness of tibia including ash, calcium and phosphorus concentrations among the treatments. This experiment revealed that zinc methionine supplementation at 40 ppm level in broiler breeder ration had no consistent effect on egg production of the birds but improved hatchability on total egg set basis.

Effect of time, amount and frequency of feeding on total egg production, fertility and hatchability in broiler breeders

Abstract. The effects of timing, the amount and the frequencies of feeding on the performance of broiler breeders (Ross 308) at the age of 31–38 weeks were studied. The broiler breeders were randomly assigned to each of 15 treatments (T). These included day feedings, in which birds were fed once at 4.00 (T1 = control), twice (T2 to T7), thrice a day (T8 to T13) and four (T14 and T15) times per day. The daily feed allotment was divided into different ratios with different time schedules. The nutritional composition of all experimental groups was similar. Eggs were collected at 8.00, 10.00, 14.00 and 16.00. The results obtained showed that feeding schedule resulted in significant differences (P &lt; 0.05) in egg production (% hen), as well as in fertility and hatchability. Results obtained in our study suggest that allocation of restricted feed two times a day, in a 75 : 25 ratio (4.00 and 12.00) improved egg production, fertility and hatchability.

English

A study was conducted to determine the effects of diet formulation type on broiler breeder performance of 50 to 64 weeks of age. 336 female and 48 male breeders in eight treatments with six replicates (7 females with a male) were used in the form of a randomized trial design 2&times;2&times;2 factorial. Eight experimental diets were formulated based on three factors: first factor included two levels of apparent and true metabolizable energy corrected for nitrogen (AMEn and TMEn) of feed, the second factor included two levels of total amino acids (TAAF) and digestible (DAAF) of feed and the third factor included two levels of broiler breeder hens requirements based on total amino acids (TAAR) and digestible (DAAR). The results show that egg weight was significantly different which was affected by diets formulation based on energy (P&lt;0.05). Diet formulation based on amino acids of feed and requirements had no effect on egg weight (P&gt;0.05). Treatment 3 (AMEn+DAAF+TAAR) was at the best level significantly different in egg weight 68.97 (g), egg production 62.45%, egg mass 43.1 (g/hen/day) and feed conversion ratio 3.59 (P&lt;0.05). Hatching eggs and hatchability was significantly different, which was affected by diet formulation based on energy, amino acids of feed and requirements (P&lt;0.05). This experiment shows that the type of formulation of diets had significant effects on broiler breeder performance. Key words:&nbsp;Broiler breeders, performance, digestible amino acids, fertility.

Dietary iron effects on broiler breeder performance and egg iron contents

Sixty Cobb 500 broiler breeder hens, 22 wks of age, were individually placed in galvanized cages and fed diets without iron (Fe) supplementation for 12 weeks. Birds were then randomly allocated to six dietary treatments with the same nutrient profile, except for Fe, in a factorial of two diets (all vegetable and meat and bone meal - MBM) and three Fe sources (control, inorganic and complexed). The all-vegetable diet was formulated with maize, soybean meal and wheat bran whereas the MBM containing diet included 25g MBM/kg. The control diets were not supplemented with Fe, whereas inorganic and complexed diets had 60mg Fe/kg as supplement from Fe2+ sulfate or Fe-amino acid (Fe-AA), respectively. Diets were provided for three periods of four weeks each and eggs were collected daily. Hen day egg production and Fe content of yolk and albumen were analyzed using a two-way anova with repeated measures. Egg production was lowest (P<0.05) for birds fed diets without Fe supplementation but no difference (P>0.05) was detected between the inorganic and complexed Fe sources. Contents of Fe in yolk increased from the first to the second period (P<0.001) without changes afterwards, whereas it decreased in albumen from the second to the third period (P<0.001). Egg yolk Fe concentration was highest for the MBM containing diet supplemented with Fe-AA and lowest for the all-vegetable diet not supplemented with Fe, with all the other treatments being intermediate (P<0.001). Albumen Fe concentration increased when Fe was supplemented to diets containing MBM, but further increases depended on the use of Fe-AA (P<0.001). It is concluded that breeder hens have reduced hen day egg production when diets are not supplemented with Fe and that Fe supplementation can affect yolk and albumen contents depending on the presence of MBM in the diet.

The effects of pullet body weight, dietary nonpyhtate phosphorus intake, and breeder feeding regimen on production performance, chick quality, and bone remodeling in broiler breeders

A 3 × 2 × 2 factorial experiment, consisting of 52 hens per treatment, was conducted to determine the effects of pullet BW, dietary nonphytate phosphorus (NPP), and feeding regimen on performance, progeny quality, and bone remodeling. Cobb 500 broiler breeder pullets were reared to 3 different growth curves: 20% under, Cobb standard, and 20% over. Body weights were recorded weekly and feed adjustments made accordingly. At 21 wk, 624 hens were fed one of 2 breeder diets differing only in the amount of dietary NPP: 0.15 or 0.40%. A normal feeding regimen was appropriate for the particular growth curve; an alternative regimen considered the 3 growth curves together as a flock. At 24, 26, and 29 wk, blood was collected from 5 hens per treatment every 4 h over a 24-h period. Plasma samples were analyzed for total alkaline phosphatase, tartrate-resistant acid phosphatase, parathyroid hormone-related peptide, Ca, and inorganic P. Eggs per hen housed were diminished in hens fed the low dietary NPP and by low pullet target weight. Hens fed low dietary NPP also had lower egg weights but better eggshell quality. Mortality was significantly higher in hens fed low dietary NPP. Breeder tibia relative strength and ash were also significantly lower in hens fed low dietary NPP, regardless of the quantitative amount. Progeny tibia ash was not affected by any treatment. Total alkaline phosphatase responded to pullet BW, however by wk 29, total alkaline phosphatase also became sensitive to dietary NPP. The NPP by pullet BW interaction for tartrate-resistant acid phosphatase levels became significant by 29 wk, and pullet BW was significant at wk 24. The NPP by pullet growth curve interaction was also critical for plasma inorganic P levels throughout the sampling period. In summary, both 0.15% dietary NPP and reared pullets 20% under standard BW negatively affect egg production but do not impair progeny productivity. Body composition appears to be a main contributor in bone remodeling mechanisms, especially during the transition into egg production.

Effects of canthaxanthin on the productive and reproductive performance of broiler breeders

The effects of supplementing canthaxanthin on productive and reproductive aspects of broiler breeders were examined in this study. In total, 360 female pullets and 36 roosters were placed in an open-sided house with 12 pens, each pen with an area of 7.0 m2 (3.5 × 2.0 m). At 42 wk of age, the breeder hens and roosters were distributed into 2 experimental groups with similar BW and uniformity. From 46 to 66 wk of age, one group received 6 mg/kg of canthaxanthin supplemented in the diet and the other group received the diet without the addition of canthaxanthin (control diet). Body weight was measured every 28 d, the laying rate was calculated weekly, and mortality was evaluated at the end of the study. Twenty-one weekly incubations were performed to evaluate fertility and incubation responses. To evaluate the antioxidant effect of canthaxanthin at different storage times and during the incubation process, eggs from each treatment were subject to thiobarbituric reactive substances analysis. Body weight, mortality, and laying rate were not affected by the inclusion of canthaxanthin in the breeder's diets. An increase in hatchability of total and fertile eggs (P ≤ 0.0001 and P ≤ 0.0003, respectively) in breeders fed canthaxanthin during the experimental period was observed. Canthaxanthin also improved breeder fertility and reduced embryo mortality. This can be attributed to reductions in embryo mortality in the first 48 h of incubation and in the last wk of incubation. No differences were observed in BW and quality of the chicks. A reduction of thiobarbituric reactive substances was observed in yolks from stored hatching eggs produced by breeders fed diets plus canthaxanthin. The same effect was observed in yolks of eggs stored for 4 d and incubated for 7 d. The supplementation of broiler breeder diets with canthaxanthin improved the hatchability rate, fertility, and reduced the presence of thiobarbituric reactive substances in eggs.