A comparative study of reproductive……..M. A comparative study of reproductive performance of Ross 308 and Marshall R Plus Broiler Breeder females strain stocks during production period

This study was designed to compare the production performance of both Ross 308 and Marshall R Plus broiler breeder strain, whereas the ambient temperature ranged between 7.9ºC to 30.10ºC. A total of 36,000 25 wks- old hens of broiler breeders Marshall R Plus and Ross 308 . The hen of each strain (18000 hens) was randomly distributed to five open houses as replicates (3,600 hens per house). Fed ad libitum on balanced ration and available water according to Management Guide recommendations for each strain. Production performance percentage, such as egg production of hen housed (HH) and hen day (HD), feed intake (FI), feed conversion ratios (FCR), mortality, selected and unselected eggs for hatching, broken and a double yolk, was recorded from 26 to 57 weeks of age. The whole production period divided into eight production periods for each strain by randomized complete block design as 2 × 8 factorial arrangement of treatments. The results showed significant differences in strain, production period and their interaction on HD, HH, FI and FCR. Ross 308 strain had higher HD and HH, lower FI and better FCR than Marshall Strain. Also, the strain and production period had a significant effect on the selected, unselected, broken and double yolk and mortality. Ross 308 strain had higher selected eggs for hatching, broken and mortality and lower unselected and double yolk eggs than Marshal strain during the completely experimental period. It can be concluded from this study that Ross had better performance in all studied traits except mortality and broken eggs percentages. This study was conducted on Al-Sayani Poultry Co Broiler Breeder farms located in Ibb, Yemen, during 22-4 to 1- 9- 2015 period. A total of 36,000 25 wks- old hens of broiler breeders Ross 308 and Marshall R Plus , 18000 hen of each were used in this study. The hens of each breed were distributed to five open houses. Minimum and maximum temperature during the experimental period in Ibb was 7.9-16.9 and 21-30.10C, respectively. A total of 3,600 hens was placed in each house and sex ratio was 1 male: 10 females. The birds received water and standard layer ration (Table 1) ad libitum. Egg production from 26 to 57 weeks of age was recorded for each strain. The whole production period was divided into eight (4 weeks) production periods for each strain. Hen housed (HH %) and hen day (HD %) production was calculated as follows: Daily weekly feed were different production periods each strain. In addition, feed conversion ratios (FCR) were calculated (daily feed consumed / mass of eggs produced). Selected and unselected eggs for hatching, broken and a double yolk egg number were recorded and their percentages of the total eggs produced were calculated. Feed experimental diets were prepared in the company hummer mill and all birds of the two strains were fed on productivity diets containing 15.69 and 15.99 % protein and 2708.7 and 2650.0 kcal/ kg, respectively, the the companies each strain Also, The results of this study suggest that strain Ross 308 surpassed on strain Marshall R Plus in the proportion of total egg production (HD and HH) may be due to the strain Ross 308 began early in the production of hatching eggs before strain Marshall R Plus , where egg production lasts in the increase until the end of the production period during comparison. Our results were in agreement with Dunn; et al . (7); Applegate (2) & Robinson et al . (17) that body weight plays a greater role in the chicken arrival at the age of sexual maturity in providing it's basic components necessary for the completion of sexual organ growth. Younis and Abd El-Ghany (22) reported strain differences in body weight in 4 broiler chicken strains, and 14 local strains (11). Therefore, the body weight is a key factor for the success of the arrival of the body at sexual maturity. Also noted in the current study, the production rate was up to the summit during the period 30 to 41 a week, while production decreased in other production periods of the study. This consistent with Bustany and Elwinger (4); Carnarius et al . (5), who reported that chicken progress in age was the reduction in the production rate for broiler breeder. In addition, a study by North et al . (14) showed that total egg production and hatchability was a decline with chicken progress in age. Breeder produced eggs for a short period compared with hens, where up to the production summit during 6-10 weeks from the start of production (85%) and after the production gradually with age is reduced to up to 60% at 40 weeks (19).


Introduction
In the second half of the twentieth century, a tremendous development was witnessed in the poultry industry in the world due to the increasing international competition and thus become a global important economic activity (13 & 15). Developed broiler breeders are a compromise between two selectively different standards, where it was stated that they have the genetic ability to grow rapidly and a high production rate of hatching eggs to producing of broiler chickens (9). The genetic selection of the broiler breeders focuses mainly on increased meat production in the chicks produced, so the productive capacity for eggs is low in broiler breeder (1).
In addition, the sexual maturity of broiler breeders is influenced by the physiological age (body weight) and chronological age (weeks) (2). The body weight and the age play an important role in broiler breeders in reaching the sexual maturity (20; 7). The sexual maturity delays in the birds that are decreased in the body weights, while the age factor has a strong effect on the beginning of reproductive cycle when the maturation of the hypothalamus (ability to respond to the optical hormone and feedback), which is related with age instead of the body weight (17).
Poultry industry was originated in Yemen since the mid-seventies of the past century and then developed gradually and continuously, where one day-old chicks and ready-made feed was imported from some European countries such as the Netherlands that had been supporting poultry production in Yemen. Thereafter, many commercial hatcheries were established by local poultry companies, which are relying on imported hatching eggs from the international companies specialized in poultry production. At present, several broiler breeders were imported for supplying the commercial local hatcheries with hatching eggs (3). In the Republic of Yemen, poultry sector contributed 38.3% of the total value of animal production in the year 2003, which accounts for 20.4% of the total local agricultural production value for the same year (12). Many commercial breeder strains were imported to Yemen (Ross 308, Hubbard ISA, Hubbard GV, Hydro BAN, Hybro G, and Marshall R Plus. Ross 308 and Hubbard ISA) as reported by Daghir, (6), but their productive performance was not evaluated under the local environmental conditions in Yemen. Although, a study was conducted in Yemen to compare some of the productive and physiological characteristics between the broilers of two strains Ross 308 and Marshall R Plus under the rearing conditions (8). So this study was conducted to evaluate productive performance of two breeder strains (Ross 308 and Marshall R Plus) raised. This study was conducted on Al-Sayani Poultry Co Broiler Breeder farms located in Ibb, Yemen, during 22-4 to 1-9-2015 period. A total of 36,000 25 wks-old hens of broiler breeders Ross 308 and Marshall R Plus, 18000 hen of each were used in this study. The hens of each breed were distributed to five open houses. Minimum and maximum temperature during the experimental period in Ibb was 7.9-16.9 and 21-30.10C, respectively. A total of 3,600 hens was placed in each house and sex ratio was 1 male: 10 females. The birds received water and standard layer ration (Table 1) ad libitum. Egg production from 26 to 57 weeks of age was recorded for each strain. The whole production period was divided into eight (4 weeks) production periods for each strain. Hen housed (HH %) and hen day (HD %) production was calculated as follows: HH% = {total number of eggs produced / (number of hens housed x number of days of production period)} *100 HD= {total number of eggs produced during a period / number of hens-days in the same period} 100.

Experimental design and Management
Daily mortality and weekly feed intake were recorded during the different production periods for each strain. In addition, feed conversion ratios (FCR) were calculated (daily feed consumed / mass of eggs produced). Selected and unselected eggs for hatching, broken and a double yolk egg number were recorded and their percentages of the total eggs produced were calculated. Feed experimental diets were prepared in the company hummer mill and all birds of the two strains were fed on productivity diets containing 15.69 and 15.99 % protein and 2708.7 and 2650.0 kcal/ kg, respectively, according to the recommendations of the breeder companies of each strain (Table 1). Also, care, vaccination and lighting programs are performed according to the instructions recommended by the breeder company for each strain.
Eggs were daily collected manually by plastic dishes during four intervals, three times in the morning from half past seven am to twelve noon, the fourth period from three to five, pm. Eggs collected were sorted well for the hatching according to the required specifications including egg shape, size as well as egg shell condition. The suitable eggs for hatching were transferred directly to the sterilizing chamber by a steam of Formaldehyde gas (methanol) Potassium permanganate provided by mixing 0.6 gram of potassium permanganate with 1.2 cc. of formalin (37.5 percent) for each cubic foot of space in the room and stored for a week at 18-20 0 C and 80% relative humidity until it was transferred to the hatchery.

Statistical analysis
All data were analyzed using the General Linear Model procedure of the Statistical Analysis System SAS, (18) by randomized complete block design as 2 × 8 factorial arrangement of treatments that included type of strain (2 strains) and period of production (8 periods), and their respective interactions. Duncan's test was applied to compare the treatment means when the treatment effect was significant at P < 0.05 statistical level.

Results
As it is shown in Table 2, strain (S), production period (PP) and their interaction had a significant (P <.0001) effect upon a hen-day egg production (HD), hen-house egg production (HH), feed intake (FI) and feed conversion ratio (FCR). Broiler breeders of Ross 308 strain had significantly (P <.0001) higher percentage of HD and HH, lower FI and better FCR than broiler breeders of Marshall Strain. The same Table also shows that HD, HH and FI reached their peak during the third production period, thereafter started to decrease and FCR was the best during the second and third production period. Ross and Marshall reached their peak HD during the second and third production period, respectively.
Ross had significantly (P < 0.05) higher HD during the 1 st , 7 th and 8 th production periods than Marshall and tended to have lower HD during most of the other production periods (Fig.1). A similar trend was noticed for HH (Fig.2). Ross had significantly (P < 0.05) lower during the 3 rd, to 6 th and higher FI during the 1 st and 8 th , and better feed conversion during the 1 st , 7 th and 8 th production periods than Marshall (Fig. 3 and 4). Table 3 shows that strain (S) and production period (PP) had a significant (P <.0001) effect upon selected, unselected, broken and double yolk and mortality. Broiler breeders of Ross 308 strain had significantly (P <.0001) higher percentage of selected, broken and mortality and lower unselected and double yolk eggs, compared to Marshal during the whole experimental period. Selected eggs for hatching were significantly (P <0.05) the lowest during the 1 st and the highest during the last three production periods, whereas unselected eggs were the highest during the 1 st and lowest during the 3 rd production periods (Table 3).    Broken eggs percentages are statistically similar during all production periods and double yolk eggs were the highest during the 3rd and the lowest during the last two production periods. Mortality rate was significantly (P <0.05) the highest and lowest during the 5 th and 8 th production periods, respectively (Table 3). On the other hand, Ross had significantly (P < 0.05) lower selected and double yolk eggs, higher unselected and broken eggs and higher mortality rate most of the production periods, compared to Marshall (Fig. 5, 6,7, 8 and 9).

Discussion
The results of this study suggest that strain Ross 308 surpassed on strain Marshall R Plus in the proportion of total egg production (HD and HH) may be due to the strain Ross 308 began early in the production of hatching eggs before strain Marshall R Plus, where egg production lasts in the increase until the end of the production period during comparison. Our results were in agreement with Dunn; et al. (7); Applegate (2) & Robinson et al. (17) that body weight plays a greater role in the chicken arrival at the age of sexual maturity in providing it's basic components necessary for the completion of sexual organ growth. Younis and Abd El-Ghany (22) reported strain differences in body weight in 4 broiler chicken strains, and 14 local strains (11). Therefore, the body weight is a key factor for the success of the arrival of the body at sexual maturity. Also noted in the current study, the production rate was up to the summit during the period 30 to 41 a week, while production decreased in other production periods of the study. This consistent with Bustany and Elwinger (4); Carnarius et al. (5), who reported that chicken progress in age was the reduction in the production rate for broiler breeder. In addition, a study by North et al. (14) showed that total egg production and hatchability was a decline with chicken progress in age. Breeder produced eggs for a short period compared with hens, where up to the production summit during 6-10 weeks from the start of production (85%) and after the production gradually with age is reduced to up to 60% at 40 weeks (19).
Strain Marshall R Plus was higher in daily feed intake (DFI) compared with strain Ross 308, may be due to that Marshall R Plus strain was the largest weight than strain Ross 308 which could lead to higher consumption of feed to cover part of the needs for maintaining on weight. Also noted, during the arrival of egg production to production summit, both strains consumed the largest amount of feed to cover their production of eggs, whereas a greater amount of eggs is large in size during this period, this reflected in FCR to decline during the period of production summit. While we note that FCR in strain Marshall R Plus was higher may be due to that feed intake was higher and lower in egg production. Strain Ross 308 was higher in percentage of selected egg, broken and mortality compared with strain Marshall R Plus, may be a result of higher production strain Ross 308 than Marshall R Plus, and there is a general tendency of broken to increase with age. This is consistent with Tona et al. (21); Joseph and Moran (10) who reported that the hen's age effects on shell quality. Eggshell was significantly affected by strain Rayan et al., (16).

Conclusion
In conclusion, the results of this study show that Ross had better performance in all studied traits except mortality and broken eggs percentages. However, both strains showed lower peak and average hen day production and higher feed intake than reported in the company management guide for the same production period. This might be due to the fact that birds were raised in open houses where minimum and maximum reaches 7.9 and 30.10C, respectively.