Appropriate housing conditions have a significant role in successful poultry farming. Poultry birds are mostly reared on floor and cage systems and need accurate management for better health and production. Commercial poultry farming is suited to planned and managed proper housing conditions for keeping the birds productive and healthy as poultry keepers can increase the production. The Leghorn fowls are the greatest and most productive layers and used for egg production on entire globe. A fowl of leghorns is single comb and entirely covered in dense white plumage and may produce annually 300 eggs (Soomro, H et al., 2015). Leghorn has been a preferred for commercial egg production due to low height, weight and received the maximum egg production. The layers are not painstaking as broody hen, these most of eggs would have to be hatched. The energetic potential of hens has not been entirely presented and innovative techniques had not been examined to improve the performance on pre-molting housing systems of leghorn hens (Soomro, H et al., 2015). Pre-molt stage is a growing and rearing period, in this period, birds were reared on different housing conditions and organized them for modern techniques of force molting or induce molting. Pre-molting is a rearing technique, practiced commercially by the poultry keepers to observe live body weight, Feed intake and egg production in laying hens, to prepare them for innovative and modern techniques as increases the additional production. The rearing phase (70 week) called as pre-molting, production and quality may decline significantly as compared to post-molt stage, due to increasing age of birds and induce molt may stimulate egg production (Hurwitz et al., 1998). Increasing age of fowls has been accompanied with decline egg production (Bogdanova et al., 2006; Cloete et al., 2004, 2006; Williams and Christians, 2003). Higher feed intake was observed in older hens than in young birds (Mehta et al., 1986). However, Yasmeen et al., (2008) did not find effect of oldness on feed intake, whereas, the feed proficiency was decline. Egg quality was increased with the advancing age of pullets (El-Aggoury et al., 1989). Hence, a study was pre-mediated to examine the effectiveness of Pre-molt hens before force molting on growth and production performance of hi-sex layers. However, no such physical evidence is accessible concern the study on growth and egg production of leghorn layers. Keeping in view the importance of leghorn fowls in our surroundings, the existing research was objected and planned to search the pre-molting performance of different housing conditions/systems on leghorn layers as the hens will be subject to further objective on induced molting techniques.
Materials and Methods
The day-old white leghorns were purchased from the local hatchery at Karachi. One thousand (1000) Hi-sex leghorn hens reared on two conditions i.e. Floor system and Cage system (600 hens in each) and brought to Sindh Poultry Vaccine Centre (SPVC), Animal Science Complex, Korangi.
Before arrival of chicks, brooding and grower sheds was initially cleaned, washed with pressure water, painted with limestone on walls and floor, fumigated by mixing 37.5ml of formalin with 18.5g of potassium permanganate (KMNO4) for the size of 100 cubic feet(C3f) and finally the shed was allowed to dry over 24 hours. The birds were initially brooded for 04 to 08 weeks at the standard parameters and also as provided by the chick supplier. Briefly after brooding period, house temperature was maintained around 70oF and Humidity were maintained around 65percent in each group. Floor space of 1.75 square feet per bird on deep litter system was provided for layers. Feed space of 2.6 inches per bird was given or 4 large tube feeders per 100 birds were provided. One tube feeder for shell grit/ oyster shell was provided for every 250 pullets. The birds were provided feed and water ad libitum. Rice husk/wooden dust was used as bedding material, and was spread over the floor at 4-6 inch depth. Litter material (rice husk) was purchased from a local rice mill at memon goth karachi and exposed to sunlight heating for 24 hours to entirely dry before insertion/placing in to shed and then spread at floor area up to 3-6 inch depth. Care was taken to sustain optimal humidity and temperature during research trail. To reduce production of lethal/ noxious gases in farm and turning of litter material on regular basis for at least 2-4 times, as practiced for moistening of litter material. Availability of light and ventilation during the experiment was ensured through regular monitoring during research. All the experimental units were maintained in specially remodeled, individual compartments. Each compartment was provided separate feeding and egg collection space for cage system. Locally made cages equipped with isolated drinkers were used. These cages were placed in one of the well ventilated layer houses. The poultry house and its equipment was cleaned & disinfected with disinfectant solution before placing the pullet. Pullets were shifted from grower to layer house around 16 to 18 weeks to allow 1 to 2 weeks adaptation period before laying starts. The layer house was well-ventilated, reasonable warm in winter and remain cool in summer, and free from drafts. The layer birds in all groups were fed initially commercial Layer ration until they reach the age of experiment i.e. 70 weeks. Feed were given ad Libitum affordedto NRC (1994) standards and references thru by Summers and Leeson (2005). Plenty of clean water was supplied to layer chickens in all groups. The vaccination schedule was followed according to prevailing conditions of the area and as issued by the Sindh Poultry Vaccine Centre Karachi from day-1 and up-to the age of 70thweeks.
Observations of research
Body weight (g/b): Weekly ten birds of each system were randomly selected for weighing on digital balance machine.
Feed consumed weekly: Weekly feed consumption was noted according to following formula: Feed intake (g/b) = Total feed offered – total feed refusal/ No. Of birds feed
Egg production and quality/ size: Fresh eggs were separately collected from different systems and weighed on an electronic digital balance and then noted the following parameters.
Egg and shell weight (g): Each egg was weighed for shell and egg weight on electronic digital balance in grams.
Eggshell thickness (mm): The shell thickness was measured by using Venire Caliper in millimeters (mm). The eggshell thickness was measured from the equator lines.
Egg mass: Egg mass was calculated on weekly basis by following formula: Average egg mass (Per hen per day in grams) = percent of HDEP X Average egg weight in grams.
Albumin height: Albumin height was recorded through Haugh unit as reported by Haugh (1937).
Yolk index: Yolk index was recorded through following formula: Yolk Index = height of yolk/width of yolk
Carcass characteristics and organ weight (g/b): The weight of the organs i.e., carcass weight and dressing percentage, heart, liver and gizzard, spleen and intestine weight was recorded after slaughtering of leghorns separately.
Data analysis: The data was collected from all the groups and analyzed statistically by using JPM Software of SAS, USA.
Results and discussion
The average feed intake of Hi-sex leghorn hen reared on floor and cage system was found non-significant (P<0.005) on 8th, 16th, 24th, 32nd, 40th, 48th, 56th, 64th, 70th (Table-1).
These findings are the arrangement with Hurwitz et al. 1998 that the production traits linked with the increased feed consumption. Furthermore, they explained that feed consumption had not been difference in feed intake among different conditions. The parallel to results also been reported in Reddy et al., 2008, suggested great variability in feed intake of different hens. Increased body weight associated with oldness and surroundings might be the cause of improved feed consumption in fowls (Hurwitz et al., 1998). The feed intake of matured hens was higher rather than in young birds (Mehta et al. 1986).
Table. N0 – 01: Weekly average feed intake of Hi-sex white leghorn layer.
The average live body weight of Hi-sex leghorn hen reared on floor and cage system was found non-significant (P>0.05) at 8th, 16th and 24th week of growth. However, significantly increased (P<0.05) in cage system compared to floor system at 32nd, 40th, 48th, 56th, 64th and 70th week of pre-molting period (Table-2).
Maximum body weight of fowls reported in this study from 32nd week to 70th week may be due to the age as compared 8thweek to 24th week. The increase trend in body weight is a natural spectacle. While, Ocak et al., (2004) did not agreed to find any difference between body weight. Greatest body weight has been observed previously in aged birds (Aslam et al., 2012).
Table. N0 – 02: Weekly average live body weight of Hi-sex white leghorn layer.
The egg production of Hi-sex leghorn hen on 40th and 70th week found non-significant (P>0.05) in floor and cage system, whereas it was significantly (P<0.05) higher in-floor system as compared to cage system on 24th, 32nd, 48th, 56th and 64th week (Table-03).
Recent breeds of layer may yield more egg production than in the earlier (Korver et al., 2004) and they also investigated that body weight significantly affected by modern methods of egg production. It is also notified that the increasing age may significantly affect the egg production. Existing results showed similar pattern with Buhr and Cunningham, 1994, who suggest that the increasing age may affect or decrease egg production. The researcher disagreed with reporting of Ahmad et al., (1995) and Akram (1998) who, identified that egg weight improved significantly.
Table. N0 – 03: Weekly average egg production of Hi-sex white leghorn layer.
Egg quality and size
The egg weight, egg length, egg width, yolk weight, yolk width of Hi-sex leghorn was observed non-significant (P<0.05) in floor and cage housing system. The egg mass and shell thickness were significantly higher in floor housing system as compared to cage housing system, while shell weight and albumin weight was significantly higher in cage system as compared to floor system (<0.05) (Table-4).
Table no. 04. Weekly average of egg quality of Hi-sex white leghorn layer
The higher shell thickness was prescribed in-floor system and lower in the cage system was achieved, similar results have been described by Al-Batshan et al., (1994) and Sharma and Bhatti (1996). Aged layers of first cycle of production may reduce shell quality connected to the condensed shell gland efficacy (Joyner et al., 1987). Thus, calcium requisite protein Ca BP D28 K played a vital role in shell formation (Nys et al., 1986).
The researcher encouraged by the points of Seeland et al., 1995; Summers and Leeson, 1983; Weatherup and Foster, 1980, who reported that the younger hens have better egg mass than the older layers, which may be ascribed to reduction in egg production with oldness. The researcher disagrees with the point of Aygun and Olgun, 2010, who compared that the improved egg mass may be attributed to maximum egg production.
Izat et al., (1986), who stated that internal and external quality of egg decreased as age increased. Significant differences in the egg production and characteristics may be due to reduction in reproductive organ linked by ovarian and oviduct regeneration which was regularly induced in mature layers as a resource of successful enhance in egg quality and the equal level of egg production (Attia et al., 1994). Ottinger (1991) also reported that an older or mature poultry layer is accompanied by a gradual deterioration in egg production. At the end of the laying cycle, the egg quality, and production may decline, and may lead to some producers to encourage a molt in the flocks, to attempt and enhance performance.
As eggs increase in size with age, shell thickness will decrease. Cracked or broken eggshells account for 80 to 90% of the eggs that are consistently downgraded. The eggshell assist to comprise the egg substances, but it is also the first defense line against microbial diffusion and must be free from defects to improve the wellbeing or safety of the egg contents for human intake.
Carcass characteristics and organ weight
The average carcass, liver, gizzard, heart, spleen, and intestine length of Hi-sex leghorn hen was non-significant (P>0.05) in floor housing system and cage housing system, whereas average live weight and dressing percentage of floor housing system and cage housing system found significant (P<0.05) (Table-05).
Brake et al., (1979), Zia-ur-Rehman and Ahmed (1995), Stevenson et al., (1983) reported that liver weight of the forced molted fowls was decreased rather than pre-molt stage. Similar results were also notified by Piray et al. (2007) they found that mean weight of spleen, heart, gizzard, was liver was not significantly affected by treatments, although supplementation of mineral added feed slightly increased organ weight of immune compromised chickens. Analogues researches had been reported with aspect of feed restriction on the dressing percentage by Azahan (1984) and Mahmood et al., (2005) on heart, liver, spleen and gizzard weights.
Table. N0 – 05: Weekly average weight of carcass and dressing percentage of Hi-sex Leghorn Layer
The productivity was enhanced in-floor system compared to cage system throughout the research with improved production performance. The egg production, body weight and dressing fractions were recorded better in cage system during pre-molting period; although, the housing systems/ circumstances could not affect body organs/parts of hen.
The authors were grateful for the Executive Director and acknowledge administration of Sindh Poultry Vaccine Center, Karachi, Department of Livestock and Fisheries, Govt: of Sindh, for facilitating and funding the present experiment.