Level Of Egg Production Research Articles

PENGARUH LUMPUR SAWIT FERMENTASI DENGAN SUPLEMENTASI ASAM AMINO LISIN, METIONIN, TRIPTOPAN SELAMA PRODUKSI TERHADAP PERFORMANS DAN KUALITAS INTERNAL SERTA KADAR KOLESTEROL TELUR AYAM RAS

The aim of this study was to evaluate the effect of feeding fermented palm oil sluge and critical amino acid (CAA) ; methyonine, lysine, and tryptophan supplementation on diet to performance, egg internal quality and egg cholesterol level. The research design used was complety randomized design with 4 teatments with 80 layer; each treatment consists of P0 ; the control diet, without addition of critical amino acid. P1 ; the diet contains of 50% critical amino acid (P1:50% (Lys 404.5 mg/kg ; Met 250 g/kg ; Trp 90,5 gr), P2: suplementasi 75% (Lys 606,75 mg/kg; Met 375,75 mg/kg; Trp 137,75 mg/kg), P3: suplementasi 100% (Lys 809 mg/kg; Met 501 mg/kg; Trp 90.5mg/kg) on diet.. Variable 0bserved were feed comsumption, feed conversi, egg weight, egg production, yolk colour, yolk index, albumen index, shell thickness, air cell and egg cholesterol level that feeding 100% supplementation consisting of (Lys 809 mg/kg; Met 501 mg/kg; Trp 90.5 mg/kg) significantly (P<0.05). In conclutions, P3 (Lys 809 mg/kg; Met 501 mg/kg; Trp 90.5 mg/kg) teatment group was significant on yolk colour, yolk index, albumen index, air cell and cholesterol level.

Effects of hen production cycle and egg weight on egg quality and composition, hatchability, duckling quality, and first-week body weight in Pekin ducks

This study was conducted to determine the effect of hen production cycle (HPC) and the effect of egg weight (EW) at the same egg production level on egg quality, egg composition, hatchability, duckling quality, and first-week BW in Pekin ducks. For HPC, hatching eggs were obtained from different Pekin-duck breeder flocks, aged 31 wk for the first production cycle (HPC1) and 78 wk for the second production cycle (HPC2). For EW, there were 3 categories: heavy (H), medium (M), and light (L). Ten eggs from each HPC and EW group were analyzed for the determination of egg quality, and albumen and yolk compositions. Ninety eggs from each HPC and EW group were incubated for the determination of hatchability, and duckling weight and quality. After quality scoring, 20 ducklings (10 male and 10 female) from each group were weighed, and reared to 1 wk of age in a brooder machine to determine relative growth (RG). The results showed that the albumen index; Haugh unit; shell percentage; yolk moisture, ash, protein, lipids, and triglycerides; albumen moisture, ash, and protein; yolk fatty acid contents; hatching weight; duckling weights at 1 wk of age; and RG were significantly affected by HPC. Egg weight affected shell thickness, yolk and albumen indices, Haugh unit, yolk and albumen percentages, yolk to albumen ratio, shell percentage, yolk fatty acid content, hatching weight, duckling weight at 1 wk of age, and RG.

Microbiologie de l’œuf et des ovoproduits


 
 
 
 Le risque de contamination par les microorganismes, et notamment par Salmonella, est une préoccupation majeure de la filière œufs et ovoproduits.
 Le contenu des œufs provenant d’élevages sains est en général stérile mais il peut toutefois être contaminé par une flore diversifiée contenant des microorganismes d’altération et parfois pathogènes. L’œuf dispose cependant d’un arsenal remarquable de défenses destinées à préserver l’embryon de toute invasion microbienne au cours de son développement. Cet article fait le point sur l’origine des contaminations de l’œuf et les mécanismes de défense anti-microbienne. Les mesures permettant de limiter la présence et le développement des microorganismes dans l’œuf sont discutées, au niveau de l’élevage, du stockage et du conditionnement.
 Le cassage entraîne systématiquement la contamination du blanc et du jaune par contact avec les coquilles souillées, conduisant ainsi à des ovoproduits très périssables. De nombreux microorganismes peuvent ainsi contaminer les ovoproduits. La maîtrise de leur qualité microbiologique est un impératif, en particulier lorsqu’ils sont intégrés dans des aliments crus ou peu cuits. Les moyens de maîtrise sont discutés et plus particulièrement le respect des bonnes pratiques d’hygiène et la maîtrise des procédés de stabilisation. L’importance de la maîtrise des températures pour le contrôle des microorganismes pathogènes et d’altération, dans les ovoproduits et dans les œufs, est particulièrement soulignée.
 
 
 

Effects of dietary calcium levels and limestone particicle size on the performance, tibia and blood of laying hens

A total of 405 23-week-old ISA® Brown layers were distributed in a completely randomized experimental design in a factorial arrangement with nine treatments consisting of three dietary calcium levels (3.5, 3.75, and 4.5%) and three limestone particle sizes (100% fine limestone (FL), 70% FL + 30% coarse limestone (CL) and 50% (FL) + 50% (CL)), with nine replicates of five birds per cage. The following parameters were evaluated: percentage of lay, defective eggs, egg weight, egg mass, feed intake, feed conversion ratio (per kg eggs and per dozen eggs), and mortality. Dietary Ca levels significantly affected lay, with birds fed diets containing 4.5% calcium producing less eggs as compared to those fed 3.0 and 3.75% Ca. Egg production linearly decreased as dietary Ca levels increased, but blood Ca levels (mg/L) increased in 28-week-old birds. The interaction of dietary Ca levels and limestone particle sizes resulted in a reduction in tibial ash Ca content as dietary Ca levels increased and as fine limestone was replaced by coarse limestone. It is concluded that a dietary Ca level of 3.75% and 100% fine particle limestone are required to maintain adequate egg production and available Ca blood level.

Closed areas as a conservation strategy in the Newfoundland lobster fishery

The Fisheries Resource Conservation Council (FRCC) reviewed lobster resource conservation in Atlantic Canada and concluded in its 1995 report that under current management regimes the risk of recruitment failure was unacceptably high because of the low level of egg production. It recommended implementation of measures to reduce the overall level of exploitation on the resource. Closed areas were included among several management measures identified to increase egg production. In 1997, at stakeholder initiative, two closed areas were established near Eastport, Bonavista Bay, as part of a co-management agreement between a committee representing local lobster fishers and Fisheries and Oceans Canada (DFO), Newfoundland Region. These received formal marine protected area (MPA) status and protection under Canada's Oceans Act in fall 2005. Following the closures at Eastport, a series of initiatives by local stakeholders resulted in seven additional closed areas being established elsewhere around Newfoundland by 2004. Details of this extraordinary development in lobster fishery management as a way of addressing resource conservation concerns are provided. The extent to which recruitment benefit from a closed area will accrue to the surrounding local fishing grounds has consistently been an issue prior to their establishment in the foregoing areas as well as in several others where consensus to do so could not be achieved. Therefore, this study includes a consideration of lobster larval dispersal and recruitment processes as a basis for evaluating the distribution of recruitment benefits from local closed areas.

Garlic (Allium sativum) Supplementation: Influence on Egg Production, Quality, and Yolk Cholesterol Level in Layer Hens

Forty-eight 40-wk-old Hi-sex laying hens were individually caged in an environmentally controlled house to evaluate the effect of garlic (Allium Sativum) juice administration on egg production, egg quality, and yolk cholesterol. Garlic juice was prepared by blending pealed garlic cloves with distilled water (1:1, w/w). Hens were randomly divided into four equal groups; one served as a control and the other three groups were individually gavaged, 3.75 ml, 7.5 ml, or 15 ml garlic juice, three times a week, which respectively represented 0.25, 0.50 and 1% of body weight. Egg production was recorded on a daily basis; egg weight, albumen height, albumen and yolk pH, Haugh unit, and bacterial count of E. coli-challenged eggs were recorded at day of oviposition (day-1) and after 5 and 10 days of storage at room temperature. Yolk cholesterol content was analyzed for five successive weeks. Garlic juice increased (p<0.05) egg weight and mass with no change in egg production intensity. Garlic juice administration recorded higher (p<0.05) albumen height and improvement in Haugh unit. Also, eggs from garlic-treated hens recorded lower (p<0.05) albumen and yolk pH when compared to eggs collected from control hens. Garlic reduced (p<0.05) the log 10 of bacterial count in egg contents linearly when challenged with E. coli. Egg-yolk cholesterol content was not influenced by garlic juice administration. It is concluded that garlic juice improved performance characteristics and may increase egg shelf life as indicated by egg quality improvement and lower bacterial count of E. coli-challenged eggs. The levels of garlic juice used in this study were insufficient to influence egg yolk cholesterol.

VACCINATION PROGRAMME FOR EGG DROP SYNDROME (EDS) USING LOCAL PREPARED VACCINES

The present work deals with 9 different trials as vaccination programmes against egg drop syndrome (EDS) using three locally prepared vaccine formulae induding cell allure, live attenuated and inactivated vaccines (prepared on chicken embryo fibroblasts), and inactivated duck egg vaccine. The applied programmes indude vaccination of young chicks at 4 weeks of age and older ones at 19 weeks of age prior to the start of egg production. Also, these programmes include vaccination of such birds with one and two doses. Evaluation of the applied vaccination programmes was depending on the estimation of spedfic induced EDS antibodies using serum neutralization test (SNT) and Haemagglutination test (HI), in addition to the egg production curve. All vaccinated thickens .were still healthy allover the experimental period showing no abnormal signs ,confirming safety of the vaccine, and were able to withstand the challenge virus , while, unvaccinated birds did not withstand it. The obtained results revealed that the best vaccination programme Is that which included vaccination of thickens at 4 weeks and then revaccinated at 19 weeks of age before starting of the season of egg production (programmes 4,5&6 VP4, VPS & VP6) and resulted in the highest levels of antibodies and egg production

Effects of dietary taurine on egg production, egg quality and cholesterol levels in Japanese quail

Taurine is a semi-essential amino acid and has many biological properties. The objective of this study was to determine the effect of dietary supplementation with taurine on egg production, egg quality, and cholesterol level in serum and egg yolk of quails. A total of 108 quails aged 6 weeks were randomly allocated to three dietary treatments. Each treatment consisted of four replicates of nine quails. The diets were supplemented with 0, 100, and 500 mg kg(-1) of taurine for 8 weeks. Dietary 500 mg kg(-1) taurine significantly affected egg production rate and feed conversion ratio, but had no significant effects on body weight gain, feed consumption, or egg weight. Dietary taurine had no significant effect on egg quality parameters studied. Serum triglyceride concentration was reduced significantly with supplementation of taurine at 100 and 500 mg kg(-1). Egg yolk cholesterol content was reduced significantly, and the contents of serum taurine and egg yolk taurine were increased significantly with taurine supplementation at 500 mg kg(-1). Results of the present study indicated that adding 500 mg kg(-1) taurine reduced yolk cholesterol concentration and increased yolk taurine content without adverse effects on performance and egg quality of laying quails.

Lunar and seasonal patterns in fecundity of an indeterminate, multiple‐spawning surgeonfish, the yellow tang Zebrasoma flavescens

Reproduction was investigated in relation to lunar and annual cycles in a population of yellow tang Zebrasoma flavescens, a popular aquarium species commercially harvested in Hawaii. Lunar periodicity was determined to be an inherent characteristic of reproduction; peaks in mean daily egg production, female gonado-somatic index (I(G)) and the fraction of females with eggs were observed at the full moon of each sampled month. An increase in the fraction of late-stage vitellogenic oocytes within the ovaries was also observed at the full moon. Reproductive effort peaked in the late spring and summer as indicated by high values of mean daily egg production, female I(G) and the recorded incidence of females spawning for at least two consecutive days. Mean daily egg production and I(G) of monthly samples were lowest in November to February, although some level of egg production continued throughout the year. Large individual variation in batch fecundity was observed, with a range from 44 to > 24,000 eggs per female produced on a single sampling date. Smaller females, 80-120 mm standard length (L(S)), produced limited numbers of eggs, while females > or = 120 mm L(S) were capable of maximal egg production (> 20,000 eggs per batch). In contrast to trends observed in many fish species, no significant relationship between batch fecundity and adult L(S) > 120 mm was observed in female Z. flavescens. An estimate of annual fecundity (mean +/-S.E. 1,055,628 +/- 120,596 eggs) was also generated using a simple model of the lunar variability in egg production. This study illustrates the importance of accounting for potential variation in egg production over time, especially with respect to diel and lunar cycles, in the design of reproductive studies of multiple-spawning fishes. Greater insight into the environmental factors that regulate reproductive activity may be gained by determining the relative reproductive investment allocated at each spawning event. The ability to estimate annual fecundity for more multiple-spawning species will facilitate examination of the effects of fishing on the reproductive characteristics of these populations and permit examination of life-history evolution across a broader suite of fishes.

Use of dietary thyroxine as an alternate molting procedure in spent turkey breeder hens

In the turkey industry, molting is traditionally achieved by reducing photoperiod and withdrawing feed and water for several days. Although it is the most effective method, this practice is discouraged in Canada and alternative strategies need to be established. Thyroid hormone levels naturally change during molt, and dietary thyroxine (T4) supplementation was previously shown to induce molt in chickens. This study aimed at evaluating the effectiveness of supplemental dietary T4 in inducing molt in spent turkey breeder hens. One hundred twenty 75-wk-old hens were randomly divided into 4 groups (5 floor pens/replicates, 5 hens each) with the control group kept under a 14-h photoperiod and fed a breeder's diet throughout, whereas hens from the 3 other groups were supplemented with 40 ppm (45.76 mg/kg) T4 for 10 d. One treatment group was maintained under 14 h of light and fed a breeder's diet, whereas the 2 others were subjected to a drop in photoperiod to 6 h during or after supplementation and then were fed a maintenance diet. Egg production, feed intake, BW, molt, and plasma levels of T4, prolactin, and luteinizing hormone were measured. All treated hens ceased laying by d 20; however, several individuals spontaneously returned to lay when left on 14 h of light, suggesting incomplete involution of the reproductive tract. Supplementation significantly reduced feed consumption and induced rapid BW loss. All hens returned to their initial weight by the end of the experiment. Most treated hens initiated molt by d 8 of supplementation and all completed molt by d 37. Plasma T4 in treated hens increased significantly by d 3 (P < 0.05) and remained significantly higher than in controls until d 9 (P < 0.01). Levels returned to initial values by d 35. Prolactin levels did not appear to be influenced by T4 but were mainly dependent on photoperiod and reproductive stage, whereas luteinizing hormone levels remained low throughout. In summary, dietary supplementation with 40 ppm (45.76 mg/kg) T4 was successful in inducing molt in turkey breeder hens. However, dropping the photoperiod was necessary to completely reset the reproductive system.

Effects of singing on copulation success and egg production in brown-headed cowbirds, Molothrus ater

We examined the relationship between singing and reproductive success in cowbirds. We amassed data from 17 captive flocks (164 males, 167 females) that we have studied over 4 years. For each flock, we conducted extensive observations on social interactions as the birds competed, courted, and reproduced. We collected and incubated all eggs laid during the breeding season and performed parentage analyses on the 7 flocks with the highest levels of egg production. Finally, we measured males’ song quality in playback tests. Here, we assessed what aspects of singing were associated with 1) copulation success and 2) offspring production. Results differed for these 2 measures of reproductive success because of high variance in egg production within and across groups. The overall amount of songs males directed to females, a measure of courtship persistence, was the one variable strongly associated with males’ copulation success. For offspring production, there was significant between-flock variability that was more pronounced than the within-group variability. The one variable that was found to be strongly associated with eggs laid within and across groups was the amount of countersinging males produced; a measure of male‐male singing competition. Song attractiveness did not predict any unique variance in either measure of reproductive success. The relationship between female egg production and male competition suggests that females may be trading off current versus future reproduction based on the opportunities available in groups to evaluate males’ competitive abilities.Key words:birdsong, cowbird, egg production, reproductive success, social behavior.[Behav Ecol]

Estrogen-Related Fecundity Reduction of Lymnaea ollula Following Fasciola gigantica Infection

Infection by trematode parasites generally affects life history traits of their intermediate hosts. Reduction in life expectancy and reproductive capacity have previously been documented in Fasciola gigantica-infected Lymnaea ollula, but the influence of the endocrine system on this specific host–parasite interaction has not been previously examined. In the present study, we observed survival, growth pattern, and reproductive output of L. ollula following exposure to F. gigantica. Both the survival and the growth pattern of infected snails were similar to those of the non-infected control group. However, a significant difference was apparent in fecundity, as infected snails consistently showed lower levels of egg and embryo production throughout a 7-wk observation period. Semi-quantitative RT-PCR also revealed down-regulation of estrogen receptor expression in infected snails during the first 4 wk of infection. Nonetheless, the inhibition of estrogen signaling was transient, as they regained expression in the later phase of infection. It is, therefore, suggested that other hormones of the complex endocrine system may be involved in the reduced fecundity of L. ollula following F. gigantica infection.

The Effects of Final Treated Effluent and In-Mill Waste Streams from a Canadian Thermomechanical Pulp and Paper Mill on Mummichog (Fundulus heteroclitus) Reproduction

Abstract The effect on fish reproduction of final treated effluent from a thermomechanical pulp mill in Saint John, New Brunswick, Canada, was studied using mummichog (Fundulus heteroclitus), an endemic fish species of the Atlantic coast of North America. A 1997 artificial stream study at the same mill showed a reduction in gonad sizes in mummichog after a 28-day exposure to 3% final treated effluent. In 2005, we reevaluated final treated effluent, and conducted a toxicity source evaluation to identity waste stream sources within the mill that may cause reproductive effects. Relative to reference, no significant differences in gonad size, plasma levels of gonadal sex steroids, egg production, or stage of egg development were observed in fish exposed to 1, 3, 10, 30, and 100% final treated effluent or in-mill waste streams. Unlike the previous study in 1997, these data indicate a low potential for an effect of final effluent on fish reproduction. Since the 1997 study there were no major process changes that could explain the differences in the results. However, there was high variability in gonad size, egg production, and endocrine endpoints measured in the more recent test, which resulted in low power to detect differences. This has prompted research to refine the current reproductive test by optimizing study design.

The biology and fecundity of the citrus red mite Panonychus citri (McGregor) (Acari: Tetranychidae) at different temperatures under laboratory conditions

The developmental time and fecundity of Panonychus citri (McGregor 1916) (Acari: Tetranychidae) on Washington navel sweet orange (Citrus sinensis (L.) Osb.) leaves were determined at 15, 20, 25, 30 and 35 ± 1 °C, 65 ± 10% RH, and a 16:8-h (L:D) photoperiod under laboratory conditions. Total development time of P. citri females was 37.2, 16.6, 12.2, 9.8, and 9.0 days at 15, 20, 25, 30, and 35 ± 1 °C, respectively. Total and daily egg production levels of P. citri were highest at 25 °C (25.6 and 2.1 eggs), followed by 20 °C (22.1 and 1.8 eggs) and 30 °C (16.6 and 1.7 eggs). The lowest total and daily egg production levels were at 15 °C (16.5 and 0.8 eggs). The development threshold for female eggs and egg to adult stages was 9.22 °C and 9.77 °C, respectively, while total effective temperature was 100 and 192.30 degree-days, respectively. The intrinsic rate of increase (r_m) at 30, 25, 20, and 15 °C was 0.148, 0.160, 0.111, and 0.042 females female^{-1} day^{-1}, respectively.

Chicken Management Systems and Egg Production in Delta State Nigeria

The study was necessitated by the need to stir the minds of chicken egg producers towards adopting the best chicken management system. The extensive system of rearing chicken for egg is old and still remained the most popular in the study area. Commercial eggs production was carried out on a large scale by the few farmers who practiced the intensive (battery cage) chicken management system. A significant (p < 0.05) and high degree of positive relationship (r = 0.70) was found between chicken management system and level of egg production. Majority of the farmers would require general education, fund and technical training in poultry production to enable them adopt the intensive (battery cage) management system of rearing chickens for egg production. Mostly local chickens were reared under the extensive system. No matter the popularity, the extensive system of rearing chickens lacks the potential for increased egg production. Egg protein is regarded as luxury to the extent that children who consume eggs are regarded as thieves among most of the poor in Nigeria. More poultry farmers need to embrace the intensive (battery cage) system in order to meet the egg protein needs of the people of Delta State, Nigeria.

Effect of retinyl palmitate supplementation on egg yolk retinol and cholesterol concentrations in quail

1. The purpose of this study was to assess the incorporation of retinol into quail egg yolk and cholesterol concentration in response to supplementation with different quantities of retinyl palmitate (600, 1200, 2400 and 4800 µg). 2. Supplementations were performed weekly for 4 weeks and the yolk retinol was measured using high performance liquid chromatography. 3. The results showed a progressive increase in the incorporation of retinol into the egg yolk in response to supplementation, reaching values 384% higher than control values. 4. At the end of supplementation we observed a significant decrease in egg yolk retinol concentrations with supplementations of 2400 and 4800 µg, the most enduring showing high retinol contents even after 3 weeks. 5. Supplementation increased egg weight but neither egg production nor cholesterol levels were significantly altered.

Effect of rooibos tea (Aspalathus linearis) on Japanese quail growth, egg production and plasma metabolites

1. Birds have been proposed as a suitable model for studies on ageing because of their long life in comparison with similar-sized mammals. However, some weak fliers, such as Galliformes, are the exception to this rule. The aim of the present study was to determine the effects of the treatment with rooibos tea (Aspalathus linearis), a natural source of flavonoid antioxidants and compounds with phyto-oestrogenic activity, on postnatal development and egg production of aged Japanese quail (Coturnix coturnix japonica). 2. Substitution of drinking water with traditional rooibos tea or diet supplementation with ground rooibos tea affected body weight of Japanese quail up to 100 d of age. The body weight of males drinking rooibos tea or eating rooibos-supplemented food decreased significantly. There was a trend toward increased body weight of tea drinking females and a significant increase in the body weight of hens fed the rooibos-supplemented diet. Although rooibos treatment did not significantly increase egg production in young hens, the decrease in egg production of rooibos-treated aged hens (360 d of age) was significantly reduced, regardless of the egg production levels (high—80%; low—20%) before the treatment. 3. The results suggest that treatment with rooibos tea positively affected body weight and egg production in quail hens and prolonged the productive period of aged animals. Further studies would be needed to address the question whether these effects are due to the antioxidant or phyto-oestrogenic activities of rooibos.

Differences in Adult Egg Output of Schistocephalus solidus From Singly- and Multiply-Infected Sticklebacks

In this study, we recovered Schistocephalus solidus plerocercoids from singly and multiply infected three-spine sticklebacks, Gasterosteus aculeatus, transferred them individually to in vitro culture conditions, and quantified their lifetime egg output. We found a significant difference in the relationships between plerocercoid mass and lifetime egg output for parasites recovered from singly and multiply infected sticklebacks. Although egg output was strongly and positively related to plerocercoid mass amongst worms from singly infected fish, for those recovered from multiply infected sticklebacks the relationship was marginally nonsignificant and negative, with small worms achieving high levels of egg production. We suggest 2 hypotheses that may explain differences in the egg production of plerocercoids from singly and multiply infected fish. One possibility is that smaller plerocercoids in asymmetric multiple infections develop precocially, in response to host manipulation strategies of larger worms that decrease survival prospects of the host. Alternatively, small worms in singly infected sticklebacks may be prevented from becoming sexually mature because they face energetic constraints associated with having to overcome the host's immune response alone. We discuss our results in terms of recent studies examining strategic egg production in helminths.

The influence of different single dietary sources on moult induction in laying hens

An investigation was carried out to assess the possibility of using single dietary sources as alternatives to feed deprivation for the induction of moult in commercial laying hens. The study involved six dietary groups of 29 laying hens: unmoulted, dried tomato pomace, alfalfa meal, rice bran, cumin seed meal and feed withdrawal. The birds received the above diets during the moulting period (11 days), and body weight loss and ovary weight regression were measured. Post-moult production parameters (number of eggs produced per hen per day, egg weight, shell weight, yolk colour and Haugh unit) were measured for 12 weeks. Results showed that all dietary sources were as effective as feed withdrawal in causing ovary weight regression in birds. Birds provided with tomato pomace or alfalfa showed lower weight losses than feed-deprived birds at the end of the moulting period. Hens moulted by tomato pomace or alfalfa exhibited post-moult levels of egg production over a 12 week period that were superior to those of hens moulted by feed withdrawal. Post-moult eggs laid by hens moulted by all dietary sources were of comparable quality to eggs from feed-deprived hens and superior to those from unmoulted hens. As fibrous feeds with low metabolisable energy and an appreciable amount of protein, dried tomato pomace and alfalfa meal may be fed to hens on an ad libitum basis for effective moult induction while reducing the stress of severe starvation and retaining comparable egg quality and production. Copyright © 2007 Society of Chemical Industry.

Reproductive Performance of Broiler Breeders as Affected by Age at Initiation of Laying Cycle Lighting Program

The control of lighting for broiler breeders is an extremely important aspect of controlling their reproductive performance. The length of light available to broiler breeder hens significantly effects the age at which they begin producing eggs and their subsequent peak egg production levels. Although most broiler breeders in the U.S. are grown in light-tight houses, in many areas of the world they are not and these producers must rely on natural daylight supplemented by artificial lighting. Therefore, it is important to understand the effects of delaying the age of initiation of artificial lighting programs when birds are grown under natural lighting conditions. In this experiment, June-hatched broiler breeders were grown under natural day length and artificial photostimulation was begun at either 18, 20 or 22 weeks of age. The results of this experiment showed that early egg production is decreased significantly in birds in which photostimulation has been delayed until 22 weeks of age. However, this significant decrease did not affect the overall egg production. This study indicated that delaying the artificial photostimulation of June-hatched broiler breeders until 22 weeks of age was not detrimental to their overall performance.