Comparative Performance of Bovans Nera (Rhode Black) and other Commercial Pullet Strains

The present study examined the comparative performance between Bovans Nera and other commercial pullet strains in Nigeria. This study was carried out in the pullet house at the Teaching and Research Farm of the University of Ibadan, Ibadan, Nigeria, from January to April, 2002. The experiment was carried out to compare the growth performance and profitability of Bovans Nera with three other commercial pullet strains, Bovans Godline, Lohmann White and Lohmann Tradition. All data collected were subjected to the analysis of variance using the SAS General Linear Model procedure. Differences between treatment means were separated using Duncans New Multiple Range Test. Profitability was assessed using net returns by subtracting costs (rearing pullet, feed and packaging excluding overheads and labour) from income (from egg sales and spent birds). The results showed that Bovans Nera was better in feed conversion ratio, feed efficiency (a greater weight gain per unit feed intake) and attained a greater weight and a better market value than the other pullet strains. There was a higher production cost for Bovans Nera when compared with other strains. However, Bovans Nera will give more returns on investment even when their eggs are translated to monetary terms. These differences can be attributed to variation in the genetic constitution of individual strains.


Introduction
The importance of poultry production to the biological needs, economic and social development of the people in any nation cannot be overemphasized. Oluyemi and Roberts (1979) claimed that poultry production in Nigeria as well as other warm climate countries has a high priority rating compared with other types of livestock because poultry has better energy and protein conversion ratio and that net return on investment are relatively high.
Commercial layer strains produce eggs for food and egg processing industries. Egg consumption on regular basis can effectively correct nutritional imbalance among vulnerable group particularly nursing mothers and children (Olawumi et al., 2006).
Apart from these, poultry product most especially eggs and meats (broilers) are good sources of animal protein.
Poultry production has been identified as a means of ensuring sustainable family income. Poultry can be established with minimum capital, and as a side-project (Sani et al., 2000).
Moreover, they can fend for themselves on free-range without much care (Umeh and Odo, 2002).
In egg-producing farms, day-old chicks are purchased from specialized hatcheries that produce egg-producing pullets. These pullets are either raised by the egg producer or a pullet grower until they are ready to start laying eggs, which is usually at 19 weeks of age (Beutler, 2007). Laying hens in egg producing farms are usually of small body frame and body weight compared to broilers. Egg producing chicken breeds have been bred and raised for maximum egg production (up to 300 eggs per year) rather than high meat yield (Beutler, 2007).
The black and brown plumage (feather colour) layer strains varied in their productive capability and live ability in this hot climate. Olawumi (2007) reported that parents of black layer strain had lower mortality rate and more adaptable to hot weather than parents of brown layer strain. The production potential of a good layer strain is better assessed based on the number and size of eggs produced during its lifetime and its final as spent-hen. The cost of day-old chicks, equipment, feeds, drugs and other inputs are unbearable and for a farmer to succeed in this enterprise, the most productive layer strain must be reared on the farm in order to achieve the desired maximum profit, repay the loans secured for the business and plan for expansion.
In the poultry business, farmers are quick to implicate feed when problems arise in their farms since feed constitutes over 70% of the costs of production according to Toluen and Igba (2007), Akinmutimi (2003). In many occasions, the problems may not emanate from the feed. strain. The pens thus had 10 birds each. The chicks were subjected to the same treatment and fed ad-libitum with four diet, chick mash in two diet of four weeks each, growers mash (9-17 th week) and layers mash (18-20 th week) while light was provided at night throughout the period of the experiment lasted for 20 weeks. The diets were respectively with the following composition: Starter mash Diet 1: Crude protein=20.23% and metabolizable energy of 2680 Kcal/Kg Diet 2: Crude protein=20.48% and metabolizable energy of 2780 Kcal/Kg Growers mash: Crude protein=16.00% and metabolizable energy of 2685 Kcal/Kg

Layers mash
At day-old, the chicks were given anti-stress and glucose in their drinking water up to the day three, and intraoccular Newcastle disease vaccine (NDU) at day 2. From day five, anti-bacteria drug (Neoceryl plus), gumboro vaccine at day 12 and coccidiostats (Amproteum) for 6-days from 19 th day. The birds were also vaccinated against fowl pox at the 9 th week, against Newcastle disease at 14 th week and lasota at 23 rd week. The initial weights of the chicks were taken before the commencement of the study and subsequently every week. Other records collected for the chick study include feed intake, live weight and live weight gain which were measured weekly. Costs and returns were recorded to enable net returns per bird to be determined. Data were collected also on feed consumption, total feed consumed per strain for each period, cost of day-old chicks, cost of feeding and transportation of strains, feed efficiency and feed conversion ratio. All data collected were subjected to the analysis of variance using the SAS (1999) General Linear Model procedure (GLM). Differences between treatment means were separated using Duncans New Multiple Range Test (Duncan, 1955). Profitability was assessed using net returns by subtracting costs (rearing pullet, feed and packaging excluding overheads and labour) from income (from egg sales and spent birds).

Results and discussion
The average feed intake at week 4, between strains was statistically different at 5% level of significance (Tab. 1). The average feed intake of the birds was influenced by the strain difference with Lohman Tradition having the highest (548.69±2.57 g per bird) feed intake, followed by Bovans Nera (514.88±3.93 g per bird) while Bovans Goldline had the lowest (436.11±0.09 g per bird). However, at week 10, 12, 16 and 20, the average feed intake of the birds was still influenced by strain differences with Bovans Nera still having the highest (2712.00±17.25 g/bird, 3762.22±20.85 g/ bird, 6539.33±15.96 g/bird and 9243.00±22.03 g/bird) Several factors may be responsible for poor performance in a flock. These may include poor handling practices, poor water quality, poor litter management, irregular feeding intervals, poor health of the birds, poor sanitation in the poultry house and environment and poor supervision of staff among other factors (Abeke et al., 2003;Oladunjoye et al., 2005). Most important, but scarcely considered, is the strain of bird for production. Agbamu (2005) reported that poultry business is a profitable venture provided improved strains are stocked.
A high level performance, no doubt, is the aim of any enterprise involved in the production of eggs. Genetic variation in egg production between breeds, strains and lines has been reported (Hocking et al., 2003;Nawar and Abdou, 1999;Suk and Park, 2001). Pullet quality is the foundation for optimum layer performance. The genetic potential for the production and profit stream arrives on day one with the chick. Advances in genetic selection are delivering lighter body weight targets, earlier ages to 50% production, and higher hen day rates with better persistency, all on lower feed intakes. This is certainly a good formula for higher profits, but this also comes with increased pressure for the best pullet possible. Besides, monitoring the growth, production characteristics and the cost/return of the commercial pullet strains is vital to ensure that optimal performance can be achieved. Also, for good management and economic decisions, it is wise to know the short-term comparative performance of different breeds so that stockholders do not have to wait till the end of laying before taking major decisions as to the profitability or otherwise of the layer strain on their farm.
This study was, therefore, carried out to examine the place of genetic composition in the growth, nutrient utilization and cost/benefit values of pullets fed with the same feed under the same condition.

Materials and methods
This study was carried out in the Pullet house at the Teaching and Research Farm of the University of Ibadan, Ibadan, Nigeria, from January to April, 2002. Ibadan is geographically located between latitude 7 o 20'N and longitude 3 o 50'E at an altitude of 200 m. The experiment was carried out to compare the growth performance of Bovans Nera with three other commercial pullet strains, Bovans Godline, Lohmann White and Lohmann Tradition. They are exotic strains from Germany and United States of America but hatched in Nigeria. The house was partitioned into four experimental pens, each of which was demarcated and labelled A 1 , A 2 , and A 3 for Bovans Nera; B 1 , B 2 and B 3 for Bovans Godline; C 1 , C 2 , and C 3 for Lohmann White; and D 1 , D 2 , and D 3 for Lohmann Tradition each housing twelve birds per strain. The percentage mortality of the four strains of pullet birds raised in the same environment was 1.961% for Lohmann White, Bovans Nera and Lohmann Tradition but 2.445% for Bovans Goldline feed intake but Lohmann white having the lowest (2386.86 ±14.00 g/bird, 3328.69±19.42 g/bird, 5948.80±26.12 g/ bird and 8539.33±36.11 g/bird) respectively during the period (Tab. 1).
This suggests that Bovans Nera consume more feed on average than the other strains of pullets. This agrees with Yakubu et. al (2007). This difference in feed consumption can be attributed to variation in the genetic constitution of individual strains.
This suggests that, Bovans Nera strain of pullets are the most efficient in feed conversion to body weight, and thus will cost less to produce equal weight of Bovans Neras than the other strains of pullets although with the lowest variability. However, feed conversion ratio increased with age at different growing period for the different strain but with Bovans nera having the largest increase on average. This is an indication of more unit of feed consumption per unit weight gain for Bovan Nera. Bovans nera appears to be the best among the strain in terms of the feed conversion ratio.
Tab. 3 shows the pooled data result of the average feed efficiency of growing pullet strains of commercial birds fed with the same diet. Except at week 10, there was no significant difference in the feed efficiency among Bovans Goldline, Lohmann White and Lohmann Tradition at 5% level of significance, feed efficiency of the commercial birds was statistically significant at 5% level between the four strains of pullet birds. At week 4, Lohmann White had the highest feed efficiency (0.165±0.003) followed by Bovans Nera (0.143±0.003 kg/g feed) while Lohmann Tradition had the smallest (0.131±0.002). Subsequently, at week 8, 10, 12, 16 and 20, Bovans Nera had the highest feed efficiency of 0.228±0.008, 0.212±0.006, 0.206±0.006, 0.180±0.003 and 0.165±0.002 respectively.
This indicates a greater weight gain per unit feed intake by Bovans Nera compared with the other strains of pullet birds. The smallest feed efficiency was recorded for Lohmann Tradition from week 10 to the last period.
The result suggests that there was better nutrient utilization of the feed consumed for body maintenance and growth by Bovans Nera when compared with the other strains. This agrees with Olawumi and Dudusola (2012), and Yakubu et. al (2007) who reported that Bovans Nera genotypes are more feed efficient and converted feeds given to produce more eggs than the other strain under the same condition The only explanation for this difference can be attributed to genotype variability.
The average live weights of the growing Bovans Nera strain were identical and compared favourably with each other except in period 0 and 4 as there was no significant different between the live weights for period 8, 10, 12, 16 and 20 (Tab. 4). The same trend applied to Bovans Goldline. However, the live weights between pullet strains were statistically significant at 5% of significance at  in contradiction with Yakubu et al. (2007) who reported that Lohmann Brown hens had significantly higher body weight compared with others. The differences between the two studies might be due to differences in age of birds, management and other environmental conditions which vary from one location to another. The differences observed between these strains examined at different growing periods may be adjudged to be genetic, since body weight has been reported to be the most frequently used indicators of cumulative growth (Chambers, 1990)  In addition, the variability in live weight of the Bovans Nera was lowest among the pullet strains. This suggests that, Bovans Nera will attain a greater weight and a better market value than the other pullet strains. This is the fact that the exotic birds were commercial hybrids that have been selected over many generations from interbreeding between specialized breeds, lines or strains. Similarly, the findings of Akinokun and Benyi (1985) support that genotype has significant effects on body weight traits. The total cost of production per bird in Lohmann White strain for the period of 20 weeks duration of the experiment was N2475.06 while Bovans Nera had the highest total production cost (N2549.35). This was closely followed by Lohmann Tradition (N2538.49) and Bovans Goldline (N2491.07). This may suggests a higher production cost for Bovans Nera when compared with other strains (Tab. 5). However, the production cost per kg live weight for Bovans Nera was the smallest (N1.60) among the pullet strains while Lohmann White had the highest one (N1.91). The cost of medication for the different pullet strains was the same for the periods except for Bovans Goldline at period 4 (N10.87) where had a little higher value than the others. The difference in the total cost of production was the difference in their feed intake for the different periods. This was possibly the result of the greater weight gain per unit feed intake and better nutrient utilization of the feed consumed for body maintenance and growth by Bovans Nera compared with the other strains of pullet birds. The table also shows the results of the net returns from the different strains of birds. Bovans Nera had the highest net returns (N669.74), followed by Bovans Goldline (N547.11), then Lohmann Tradition (N499.13) while Lohmann White had the lowest (N353.05). Bovans Nera genotypes are therefore, more productive and profitable when compared with other genotype based on their short-term evaluation. This implies that Bovans Nera give more returns on investment even when their eggs are translated to monetary terms since it is the general belief that the higher the egg numbers of a breed of layers, the higher the net income expected from them. This is supported by Rauen et al. (1989), Spradbrow (1993), Sonaiya (1996), Alam (1997), Mallia (1999), Fattah (2000, Paul et al. (2000), Kumtakar (2000), Buza and Mwamuhehe (2001) who posited that family poultry production systems are financially economic because even if the productivity of birds is low, some poultry meat and some eggs constitute almost a net profit for poultry keepers

Conclusions
Bovans Nera is better in feed conversion ratio, feed efficiency (a greater weight gain per unit feed intake) and attains a greater weight and a better market value than Bovans Godline, Lohmann White, and Lohmann Tradition. Though, the production cost for Bovans Nera was higher when compared with other three strains, the production cost per kg live weight for Bovans Nera was least among the four strains with the highest net returns.