Abdel Ellah A. Gasm Elseid, Saadia Abdel Moniem1 and
Mohamed-Khair A. Ahmed1
Arab Company for Livestock Investment and Development,
Khartoum, Sudan
SUMMARY
Measurements on hen-day and hen-housed egg production, hatchability, fertility, total hatching eggs, mortality and cracked eggs were made on eight flocks belonging to the Arab Company for Livestock and Development. There were 6000 females and 600 male parent broilers in each flock. Uniformity was calculated by taking a random sample of 7% of the birds in each pen and weighing them on a weekly basis. The flocks were assigned to uniformity groups ranging from 55% to 80%. The high uniformity group (75%-80%) consistently had the highest hen-day and hen-housed production overall ages, while the low uniformity group had the lowest hen-day production. The analysis of variance showed that the effects of age and uniformity group on all studied traits were highly significant. The effect of age x uniformity group was significant only for total hatched eggs. Percentage hatchability of settable eggs varied from 69.19±1.93 in the 55%-59% group to 83.93±1.65 in the 75%-80%. The highest levels of uniformity had the highest percentage of cracked eggs (0.30±0.01), while the medium range of uniformity had the lowest percentage of cracked eggs (0.182±0.011 in the 65%-69% group). The highest fertility (86.53±1.56) was found in the 65%-69% uniformity group. The study demonstrates the importance of controlling body weight and the use of restricted feeding to achieve optimum production and fertility in broiler breeder hens.
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1 Faculty of Animal Production, University of Khartoum, Shambat, Sudan.
INTRODUCTION
Poultry producers, such as the Arab Company for Livestock Investment and Development (ACOLID), have the advantage of raising their own pullets for the breeder hen flock and consequently have greater control over costs and methods of production. Attainment of the breeder’s target body weight at any specific age and flock uniformity are the two most important criteria for pullet quality. The flock uniformity is the percentage of birds that are within ±10% of the average flock body weight recommended for the particular age, and the goal of the producer is to have 80% of the pullets within that range (Ensminger, 1980). Uniformity is a measure of the amount of body weight variation in a flock. Despite the fact that flock uniformity is an important aspect of layer production, it has received little attention by most poultry producers in the Sudan. The objective of this study was to monitor production performance of flocks of breeder hens at different body weight uniformities and to assess the impact to uniformity on egg production and reproduction traits.
MATERIALS AND METHODS
The data used in this study were collected on parent broiler in four farms of the ACOLID at Teiba Alhasanab village, south of Khartoum. Each farm contained two houses 12×90 m, and each house was divided into four pens. The number of birds in each house was 6000 females and 600 males. Houses were equipped with cooling pads on the sides and exhaust fans for evaporative cooling. Data were collected on productivity (Measured as hen-day and hen-housed), fertility, total hatching eggs, cracked eggs, hatchability and mortality. Uniformity was calculated by taking a random sample of 7% of the birds in each pen and weighing them on a weekly basis.
Fertile eggs of Lohmann’s grandparent stock were imported from Jordan and hatched at the ACOLID hatchery in Sudan. Day-old chicks were vaccinated against Mareck’s disease, detoed and dubbed on the first
day, and beak trimming was done on the 10th day. Pullets were allowed 3-4 hours access to water on feed days and 2 hours access on off feed days in the layer stage; water was restricted to 5-7 hours/day. Nests with soft wood shavings or straw were provided at a rate of 1:4, and eggs were collected four times a day.
At the chick stage, the light duration was 24 hours throughout the first three days and was decreased after the third day to 8 hours a day up to the 19th week in order to control body weight, delay sexual maturity and decrease number of double yolked eggs. After the 9th week, the light hours were increased gradually up to 15 hours at 24 weeks of age.
The formulation and the nutrient content of the rations offered at the various stages are presented in Table 1. Feeding at the chick stage was ad libitum with both males and females given the same diet, but males were provided with extra pen feeders. Between 5 and 21 weeks, the pullets were fed the pullets diet (Table 1). The feed amounts were adjusted according to the body weight of the birds. Feed restriction was started at 4 weeks and continued up to 24 weeks. This feed restriction regimen was used as a means of controlling body weight of broiler breeders. At the beginning, feed restriction was on a skip-a-day basis and towards the end of the period it was changed to skip-two-days. Males and females of 18 weeks of age and at a sex ratio of 1:10 were brought together. Culling was performed at 18 weeks to prepare for the laying period. Laying continued from 24 weeks up to the liquidation of the flock at 65 weeks. The layer diet offered is shown in Table 1. Hens were fed about 124-125 g at the onset of lay up to the peak of production, and then the allotment was increased slowly to 150 g.
Statistical analysis was performed using a model in which the main effects were uniformity group, age and uniformity group x age interactions. The flocks were grouped according to uniformity into groups in which uniformity ranged from 55% to 80%. Percentage traits including fertility, hatchability, cracked eggs and mortality were transformed prior to the analysis using the arcsine of the square root of the percentage.
Table 1. Feed formulation and nutrient composition of rations fed to
birds in different stages.
| Feed item | Percent of ration | Nutrient | Nutrient composition | ||||
| Chick | Pullet | Layer | Chick | Pullet | Layer | ||
| stage | stage | stage | stage | stage | stage | ||
| Maize | 59.7 | 59.9 | 60.0 | Energy (Kcal/kg) | 2834.00 | 2885.60 | 2760.00 |
| Groundnut meal | 14.0 | 12.0 | 19.0 | Crude protein (%) | 18.30 | 16.00 | 17.50 |
| Wheat bran | 19.0 | 20.7 | 6.6 | Phosphorus (%) | 0.46 | 0.00 | 0.79 |
| Concentrate | 6.0 | 5.0 | 5.0 | Calcium (%) | 1.05 | 0.70 | 3.50 |
| Calcium carbonate | 1.0 | 2.0 | 7.4 | Lysine (%) | 1.10 | 0.90 | 0.99 |
| Lysine | 0.3 | 0.0 | 0.0 | Methionine (%) | 0.42 | 0.40 | 0.43 |
| Sodium chloride | 0.0 | 0.1 | 0.4 | Sodium (%) | 0.14 | 0.12 | 0.11 |
| Di-calcium phosphate | 0.0 | 0.0 | 1.4 |
RESULTS AND DISCUSSION
Table 2 shows the analysis of variance of hen-day, hen-housed production and total eggs hatched. The effects of both age and uniformity group on all three traits were highly significant. Age x uniformity interactions was significant only for total hatched eggs. Some of the flocks had uniformities well below the recommended level which requires that 80% or more of the birds should be within 10% of the standard weight for the particular age. This poor level of uniformity will be compounded during the subsequent productive cycle (North 1980). Numerous factors may have played a role in the decrease of uniformity.
Table 2. Analysis of variance of egg production traits.
| Source | Trait | df | Mean squares | F |
| Age (weeks) | Hen-day | 41 | 1276.06 | 15.36** |
| Hen-housed | 41 | 1394.24 | 11.32** | |
| Total hatched eggs | 40 | 658.22 | 6.97** | |
| Uniformity group | Hen-day | 4 | 3561.63 | 42.87** |
| Hen-housed | 4 | 6503.67 | 52.80** | |
| Total hatched eggs | 4 | 3231.84 | 34.21** | |
| Age x uniformity group | Hen-day | 149 | 16.36 | 0.20 |
| Hen-housed | 149 | 16.66 | 0.14 | |
| Total hatched eggs | 132 | 175.02 | 1.85** | |
| Error | Hen-day | 115 | 83.09 | |
| Hen-housed | 115 | 123.16 | ||
| Total hatched eggs | 78 | 94.47 |
** = Significant at P=0.01
However, the major factor was probably the fact that these flocks suffered from outbreaks of Mereck disease, Gamboro and Chronic Respiratory Disease (CRD). Disease has a major impact on flock uniformity and early exposure to disease elements usually has the worst and most lasting effect on the uniformity of a flock (Matthijs et al., 2003). Uniformity had a highly significant effect on all traits under study.
Fig. 1 demonstrates that the high uniformity group (75%-80%) consistently had the highest hen-day production over all ages, while the low uniformity group consistently had lowest hen-day production. The same was true for hen-housed production (Fig. 2). There was a clear trend for increased hen-day and hen-housed production with improved uniformity. The high uniformity group (75%-80%) reached peak product ion earlier than the low uniformity flocks (65% or less). This is similar to the findings of North (1980), who stated that a highly uniform flock reaches peak egg production earlier and will peak higher than a non-
uniform flock. Hudson et al., (2000) divided 20 week old 400 female
broiler breeders into high and low uniformity groups, and found that hen-day production was higher in the high uniformity treatment between 26 and 35 weeks of age, but differences were significant (P<0.01) only between 29 and 35 weeks of age.
Age had highly significant effects on both hen-day and hen-housed production. However, peak production was reached by all groups at about the 30th week of production. Both hen-day and hen-housed at peak production were much lower in the uniformity flocks than the high uniformity flock. Petite et al., (1982), in a study of two groups of broiler breeders of high and low uniformity, found that the more uniform flock exhibited higher egg production than the less uniform flock. They also found that uniformity did not influence cumulative egg weight, fertility or mortality. Hudson et al., (2001) reported that high initial uniformity was associated with increased egg production.
Uniformity group and age had a highly significant effect on cracked eggs, mortality, fertility, and percent hatched of total eggs set (Table 3). There was no clear trend in the percentage of eggs hatched and fertility despite the fact that there were significant differences between uniformity groups (Table 4). Total hatched eggs and percentage hatchability of settable eggs varied from 69.19±1.93 in the 55%-59% group to 83.93±1.65 for the 75%-80% group, respectively. However, the highest levels of uniformity also had the highest percentage of cracked eggs (0.30±0.01), and the medium range of uniformity also appears to have had the highest fertility (86.53±1.56 in the 75%-80% uniformity group).
There is a direct relationship between the pullet’s development during rearing and subsequent performance and the bird’s ability to reach optimum peak production during the laying cycle. In addition, body weight at 16 weeks of age has been shown to be positively correlated with performance (Hudson et al., 2001). Usually, when flock uniformity is high at 16 weeks of age, egg production is higher and mortality is lower after 55-60 weeks of age. Thus, every attempt should be made to attain good uniformity and proper body weight at 16 weeks of age. Pullets on or above target body weight at this age are usually the best performers during the laying period. If a pullet is not target body weight by 12 weeks
of age, she will more than likely be a small pullet entering the laying house and possibly a financial burden for the rest of the laying period. The restricted feeding regime used during the rearing period in this study was designed to control pullet body weight and to reduce reproductive problems resulting from the intensive selection of meat type chicken for growth. However, it is difficult to determine the optimum degree of restriction, because of strain differences and changes in the genetic constitution of stocks by primary breeders (Robinson et al., 1993). Such programmes require intensive management to avoid under estimation of feed allotments (Lien et al., 1998). Renema et al., (1999) found that improving body weight and uniformity would be beneficial for a more uniform onset of lay and reduced early production losses from small hens. Hocking et al., (2002) reported that conventional food restriction results in a decrease in average daily food consumption during rearing and early lay and in an increase after the peak rate of egg production. Mortality was decreased by more than half. Restricted birds had higher total and settable egg production, fewer defective or damaged eggshells and higher fertility and hatchability than those fed ad libitum. Peak and Brake (2000) reported that alternate day feeding produces birds with lower body weight and similar flock performance when compared to every day feeding.
In the present study, only one of the flocks approached the breeder’s acceptable uniformity standard of 80% or more, and this flock was clearly superior in both egg production and fertility traits. Since the body weight uniformity had a significant effect on productivity (Table 3), greater efforts have to be exerted to achieve and maintain the breeder’s uniformity standards. Experience shows that under Sudan conditions it is difficult to maintain body weight uniformity because of the prevalence of disease and sub-clinical infections. However, this may be achieved through the judicious use of food restriction and effective disease control. Feed restriction must be used carefully since prolonging such restricted feeding to non-uniform hens may result in a delay in the onset of lay and low cumulative egg production up to 35 weeks (Hudson et al., 2001). The rate at which feed is withdrawn may also have an important impact on productivity (Sun and Coon 2005).
Table 3. Analysis of variance of egg production traits.
| Source | Trait | df | Mean squares | F |
| Age (weeks) | Cracked eggs | 41 | 0.013 | 2.03** |
| Mortality | 41 | 0.004 | 1.62** | |
| Fertility | 40 | 0.103 | 12.46** | |
| Egg hatched of total set | 40 | 0.123 | 9.82** | |
| Uniformity group | Cracked eggs | 4 | 0.137 | 31.71** |
| Mortality | 4 | 0.056 | 23.18** | |
| Fertility | 4 | 0.076 | 9.25** | |
| Egg hatched of total set | 4 | 0.292 | 23.35** | |
| Age x uniformity group | Cracked eggs | 114 | 0.004 | 0.81 |
| Mortality | 147 | 0.002 | 0.77 | |
| Fertility | 132 | 0.009 | 1.08 | |
| Egg hatched of total set | 132 | 0.008 | 0.63 | |
| Error | Cracked eggs | 114 | 0.004 | |
| Mortality | 114 | 0.002 | ||
| Fertility | 78 | 0.008 | ||
| Egg hatched of total set | 78 | 0.012 |
** = Significant at P=0.01
Table 4. Least squares means and standard errors of studied production
traits at different levels of uniformity.
| Trait | Uniformity group | Mean | SE |
| Cracked egg | 55-59 | 0.267 | 0.010 |
| 60-64 | 0.252 | 0.006 | |
| 65-69 | 0.182 | 0.011 | |
| 70-74 | 0.243 | 0.007 | |
| 75-80 | 0.300 | 0.010 | |
| Mortality | 55-59 | 1.452 | 0.133 |
| 60-64 | 1.068 | 0.080 | |
| 65-69 | 0.698 | 0.147 | |
| 70-74 | 1.270 | 0.099 | |
| 75-80 | 0.300 | 0.132 | |
| Fertility | 55-59 | 80.90 | 1.56 |
| 60-64 | 80.49 | 0.99 | |
| 65-69 | 86.53 | 1.56 | |
| 70-74 | 77.76 | 1.11 | |
| 75-80 | 79.00 | 1.33 | |
| Egg hatched of total set | 55-59 | 69.19 | 1.93 |
| 60-64 | 69.35 | 1.23 | |
| 65-69 | 79.20 | 1.93 | |
| 70-74 | 65.79 | 1.38 | |
| 75-80 | 83.93 | 1.65 |
REFERENCES
Ensminger, M.E. (1980). Poultry Science, 2nd ed. pp. 325-326. The
Interstate Printers and Publishers, Inc., Danville, Illinois, U.S.A.
Hocking, P.M.; Bernard, R. and Robertson, G.W. (2002). Effect of
low dietary protein and different allocations of food during rearing and restricted feeding after peak rate of lay on egg production, fertility and hatchability in female broiler breeders. British Poultry Science 43 (1) 94-103.
Hudson, B.P.; Hess, J.B. and Lien, R.J. (2000). Effects of body weight
uniformity on early egg production by groups of nonuniform broiler breeders. Poultry Science Association, 21 Annual Meeting, August 18-20, 2000, Montreal, Quebec, Canada.
Hudson, B.P.; Lien, R.J. and Hess, J.B. (2000). Effects of body weight
uniformity and pre-peak feeding programs on broiler breeder hen performance. Journal of Applied Poultry Research 10, 24-32.
Lien, R.J.; Hess, J.B.; Bilgili, S.F. and Dozier, W.A. (1998). Influence
of early skip-a-day feed removal on male and female broiler performance. Poultry Science 77 (Suppl. 1), 2.
Matthijs, M.G.; Van Eck, J.H.; Landman, W.J. and Stegeman, J.A.
(2003). Ability of Massachusetts-type infectious bronchitis virus to increase colibacillosis susceptibility in commercial broilers: A comparison between vaccine and virulent field virus. Avian Pathology 32, 473-481.
North, M.O. (1980). Don’t neglect the individual bird. Poultry Digest
39, 502-506.
Peak, S.D. and Brake, J. (2000). Effect of alternative day versus every-
day feed restriction of broiler breeders during the grower and pre-breeder period. The Southern Poultry Science Society, 21st Annual Meeting, January 17-18, 2000, Atlanta, Georgia, U.S.A.
Petite, J.N.; Howes, R.O. and Gerry, R.W. (1982). The influence of
flock uniformity on the reproductive performance of broiler breeder hens housed in cages and floor pens. Poultry Science 61, 2166-2171.
Renema, R.A.; Robinson, F.E.; Newcombe, M. and McKay, R.I.
(1999). Effects of body weight and feed allocation during sexual maturation in broiler breeder hens. 1. Growth and carcass characteristics. Poultry Science 78, 619-628.
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Authors:
تأثير تماثل الأوزان علي إنتاج أمهات الدجاج اللاحم
عبدالاله أحمد قسم السيد وسعدية عبدالمنعم عباس1 ومحمد خير عبدالله أحمد
الشركة العربية لتنمية الثروة الحيوانية – الخرطوم – السودان
ملخص البحث
أجريت قياسات إنتاج البيض اليومي وإنتاج البيض بحساب نسبة النفوق ، ونسبة الفقس ، والخصوبة ، والبيض الكلي الفاقس ، ونسبة النفوق ، والبيض المشروخ ، علي ثمانية قطعان تابعة للشركة العربية لتنمية الثروة الحيوانية . حسب تماثل الأوزان بأخذ عينة عشوائية تعادل سبعة في المائة من عدد الطيور في القفص ووزنها كل أسبوع ، ومن ثم وزعت القطعان إلي مجموعات بحيث يتراوح تماثل الأوزان في هذه المجموعات بين 55% و 80%. أعطت المجموعة ذات تماثل الأوزان العالي (80%) أعلي إنتاج من البيض اليومي والبيض بحساب نسبة النفوق في كل الأعمار بمتوسط قدره 66.40±1.42 و 63.49±1.73 علي التوالي ، في حين أن المجموعة ذات نسبة تماثل الوزن الأدني أعطت أقل إنتاج بيض يومي بمتوسط قدره 45.64±1.44 وأقل إنتاج بيض بحساب النفوق بمتوسط قدره 38.42±1.06 .
أوضح تحليل التباين (ANOVA) أن تأثير العمر علي نسبة البيض المشروخ ونسبة النفوق لم يكن معنويآ أما مجموعة تماثل الأوزان والعمر فكان لها تأثير معنوي علي الخصوبة وعدد البيض الفاقس الكلي ونسبة الفقس من مجموع البيض الداخل إلي المفرخة . تراوح عدد البيض الفاقس الكلي ونسبة الفقس من البيض الداخل إلي المفرخة بين 51.91±1.78 و 69.19±1.93 في مجموعة تماثل الأوزان 55%-60% وبين 69.80±1.52 و 83.93±1.65 في مجموعة تماثل الأوزان 80% . وسجلت المجموعات ذات تماثل الأوزان العالي أعلي نسبة من البيض المشروخ (0.30±0.01) في حين أن مجموعة تماثل الأوزان المتوسطة (75%-79%) سجلت أعلي نسبة خصوبة (53.86±1.56) . وكان تأثير تماثل الأوزان علي النفوق ونسبة البيض المشروخ معنويآ بينما لم يكن اـثير العمر معنويآ .
أوضحت الدراسة أهمية التحكم في وزن الجسم واستخدام التغذية المحددة لتحقيق أفضل إنتاجية وخصوبة في قطعان أمهات الدجاج اللاحم .
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