Feed Intake of Bovans Brown Layer Chicken
The feed intake of a layer chicken in this study was ranged 119.67 to 124.07g. Similar study was reported by [13] the average recommended daily feed intake of the Bovans brown chicken at laying period was 117 g. Layers supplemented EM as a liquid form and Bokashi as solid form had better feed intake compared with the control group in the current study. The improvement of the feed intake was due to the presence of effective microorganisms per cc of EM-1 (104 lactic acid bacteria, 103 photosynthetic bacteria and 103 yeast), which helps to develop the beneficial microorganisms in the gastrointestinal tract [14]. Similar result was found in feed intake for broilers fed EM in feed and water followed by those fed with control diet during the starter phase [15]. However, [16] reported that the feed intake of chickens fed EM in feed and water was lower than the rest treatments. Also the same author reported that chickens provided EM in water had the lowest feed intake than the chickens provided EM in feed and control groups. However, probiotics have beneficial influence on: intestinal microflora balance [17] and immune response [18, 19]. This result is in agreement with that of [20], who reported that feed additives usually play roles by regulating feed intake and increasing digestibility of nutrients and availability of energy. Also many authors ascertained that the concentration of effective microorganisms supplemented to chicken, there was a health improvement of gastro intestinal tract and improves feed intake.
Age plays an important role on feed intake. A layer supplemented with EM as liquid and Bokashi as solid form had a better feed intake in week 20–23 up to week 48—51 age groups. When the age of the layers advanced, the daily feed intake was increased significantly, but, feed intake does not increase at a proportional rate till the end of laying period.
The water intake of the laying hens was ranged from 268.13 to 270.20ml in this study. According to [21] reported that the daily water intake of laying and non-laying hens was 230-300ml and 200-230ml, respectively. Water intake stimulates feed intake, and both water and feed are necessary for the birds' development and the production of eggs. The importance of water determines the performance of hens. If laying hens don’t get enough water they can become stressed and stop laying eggs. Under more extreme conditions, hens can get heat stroke and die. This is because water is highly essential in egg formation. The water intake is highly correlated with environmental temperature. When the temperature is at 20Oc the water intake is twice the feed intake and at 30Oc the water intake is increased five times the feed intake.
Body Weight and Body Weight Gain of Bovans Brown Layers
The mean body weight of a layer was 1.66 kg to 1. 75 kg in the current study, and had no any significant effect on body weight when layers supplemented with EM as liquid and sold form. Nearly similar result was reported by [22] the live body weight of a layer was 1.62 kg in hens given feed containing 1% EM4, 1.61 kg in hens given feed containing 2% EM4 and 1.65 kg in hens given feed containing 3% EM4 compared with 1.63 kg in the control hens. The average body weight values of layers were ranged from 1.54 to 1.75 kg [23]. Body weight at onset of egg production and throughout the production year influences the efficiency of egg production. Birds with lighter body weights produce lighter eggs [24], consume less feed per day, and convert feed to egg mass more efficiently [24, 25] in comparison with heavier birds. With the South African White Leghorns it was found that the optimum body weight at sexual maturity for egg production seems to range between 1·59 to 1·82 kg. If egg weight is considered, the optimum body weight is increased to 2·04–2·27 kg. The most recommended body weight of a bird for egg production regardless of egg weight is ranged from 1·36–2·27 kg. Young birds which weigh more than 2·27 kg at sexual maturity should be discarded for egg production. The correlation between egg production, egg weight and body weight is positive with an antagonistic relationship when the birds weighed more than 2·27 kg. In egg producing bird the body weight change is not recommended. There is a specific body weight threshold for the onset of egg production in each particular strain of egg-type chicken to be at least 1400 g [26]. There is evidence that the onset of egg production, which is indicative of sexual maturity, is closely associated with body weight [27]
In the current study, the total body weight gain of layers from age 20–65 weeks was ranged 228.70 to 330.30 gram (0.68 to 0.98 g per day). There was any gain difference among the treatment groups. Similarly, [28] did not find any positive effect of probiotic on the live weight of growing commercial pullets. However, [22], contrarily reported that more weight gain in the birds fed diet containing EM4 than the birds fed diet with or without antibiotics. Hen weight is an important characteristic because it impacts feed intake (FI), feed efficiency, and egg characteristics (Harms et al. 1981). During the first year of an egg production cycle, hens typically gain approximately 0.4 kg, with most of the gain occurring prior to 30 wk of age [29]. The body weight gain was better in the age groups from week 20–23 to week 40–43, however, the age advances the increment of body weight gain was very diminishing.
Feed Conversion Ratio (FCR)
The highest feed conversion ratio (2.23) was observed when layers supplemented EM in drinking water and Bokashi in feed in the current study. This result is in line with [16] who reported that feed to egg conversion ratio of the layers was 2.05 in chickens provided EM in water and feed. Similarly[30] reported that the amount of feed consumed per kg of eggs produced was lowest for groups assigned to treatment containing 4 ml of EM/liter of drinking water. Broilers fed with EM in feed and water required lower feed per unit weight increments [31]. The FCR of broilers provided EM in water and feed to be higher compared to a control group [32]. This indicated that chickens provided EM in water and/or feed have more efficient utilization of feed than chickens in the control group. The layers supplemented with EM in feed and water produced a higher number of eggs with less feed consumption. This shows that layers under this supplement eat more feed and converted feed to egg more efficiently due to the presence of beneficial microorganism that keeps the health of the GIT.
The FCR of Bovans Brown layer chicken in this study was 2.23 which is in line with [13] 2.32. Laying hens in modern commercial flocks typically produce about 330 eggs per year with a FCR of 2 kg of feed per kilogram of eggs produced [33]. The same author also reported that a laying hen may eat 11 kg of feed in producing 5 kg of eggs, which means the layer FCR as being 2.2. The edible contents of a 60 g egg weighs 55 g, the feed conversion for this production becomes 2.4:1. The extent of cooking losses may be 2%, so the FCR for the edible content would become 2.45:1 [33].
Egg Production
In this experiment, both treatment groups laid their first eggs at the age of week 20. According to [34] chickens laying its first egg is at 21 weeks of age. Brown Commercial Layers Management Guide (2019) noted that Brown layers commence to lay its first egg between the age of 18 to 20 weeks. Birds usually start to lay at around five months (20–21 weeks) of age and continue to lay for 12 months (52 weeks) on average, laying fewer eggs as they near the moulting. Different result was reported by [30] the age of the first egg in the control and EM supplemented groups ranged between 179 and 186 days. The difference might be the management of chickens during the experimental period. Also, [16] reported that the first egg lay was recorded in chickens provided EM in water and feed at 161 days of age, EM in water at 166 days of age, the control chickens started laying at 168 days of age and chickens given EM in feed started at 175 days. The effective microorganisms enhanced early maturity, thereby improving age at first lay which might be related to the fast growth of the chickens due to the presence of the beneficial microbes in the gut which helps fast utilization of essential nutrients [35]. Supplementation of dietary probiotic improved the health and microscopic structure of the ileum and cecum [36].
The total egg production in this study during the experimental period (20- 67weeks) was ranged from 241–268. Commercial egg type layers started laying eggs at the age of 20–21 weeks and produced 277 eggs till 72nd week of their production cycle [37]. The pullets will begin laying eggs at 20–22 weeks of age and once laying will eventually peak at 85–93% production. Each bird can be expected to lay 270 quality eggs by the age of 75 weeks. In areas where the climate is hot and humid, commercial hybrid laying birds produce on average between 180 and 200 eggs per year. In more temperate climates birds can produce on average between 250 and 300 eggs per year (https://www.fao.org/3/y4628e/y4628e03.htm)
According to the report of [38], the daily rate of lay averaged 81 eggs per 100 layers in 2020. On average, each laying hen produces 296 eggs per year. The increased productivity of hens is due to improved health and disease prevention, nutrition, genetics, and flock management. Egg production is a dependent variable and is influenced by several factors like strains of chicken, feeding, mortality, culling, health and management practices, age at point-of-lay, and peak lay and persistency of lay.
The egg production during the experimental period didn’t show any significant difference among treatment groups in the current study. Similarly [39] reported that no significant differences were found among the treatment groups in egg production supplemented with EM. Contrarily [22] egg number was significantly greater in hens given feed containing 1 and 2% EM4 than the control hens. According to [40] who observed 3% increases in egg production during a 6-week field trail when EM was administered at the rate of 1m per liters of drinking water to 58-weeks old layers. Similarly, addition of EM with different levels improved egg number during the laying period [41]. A significant increase in total egg production, feed conversion efficiency per dozen eggs and specific gravity of eggs with addition of EM in feed was observed [42]. The effect of EM on the performance and egg quality of laying hens, observed that all of the values were better in the EM group with regards to the control group [35]. The group receiving 4 ml of EM/liter of drinking water was significantly higher in egg production than the others [30]. Differently, [43] reported significant increase in the egg production performance of White leghorn layers with dietary supplementation of a probiotic (L. sporogenes) at the rate of 100 mg/ kg − 1 diet (6 × 108 spores). Difference in EM experiment was due extreme number of organisms in the digestive system can increase intestinal motility then altering nutrient availability for absorption at desired dots and the population of other beneficial bacteria can be changed, thereby the coexistence of established microflora is disturbed [44]. Regardless of the possible cause, birds fed with higher probiotic levels have a parabolic dose relationship [45]
In week basis of egg production of layers supplemented with EM in drinking water and bokash in feed was statistically differing from the control group at the age of week 32–35. However, no any significant differences were observed in other age groups of production period. Similarly [30] reported that the mean weekly egg production to an age of 37 weeks of the groups placed on the treatment containing 4 ml of EM/liter of drinking water was significantly higher than all the others.
Layers except week 32–35 age groups didn’t show a marked statistical difference among the treatments. At week 20–23 of age the egg production was less. In the age of week 24–27 the production had shown an increment. The maximum egg production was recorded in week 28–31, 32–35, 36–39 and 40–43. The production had shown a decreasing order at the age of week 44–47 then to the end of the experimental period. According to [46] egg production commences at about 22 weeks of age, rises sharply, reaching a peak at about 32–35 weeks of age, and then gradually declines at the rate of half a week. It is thus a usual routine practice to replace the layers at the period of 18 months. The period from 19 weeks (age of first laying) of age to 42 weeks of age, the layer is expected to increase in egg production from zero to a peak of approximately 85% production; from 43 weeks to 62 weeks of age, the egg production declines up to 65%, and from 63 weeks up to 72 weeks the egg production is less than 65% [46]. The egg production will increase from the start of first cycle to the peak point; this percentage is increasing, and after two months of production reached peak and then slowly diminishing return [47]. In the first two months of production, not only the percentage of eggs increased, weight and large size of eggs also increased. In this phase, the need for feed also increased, as described by [48] that this phase should get a chicken meal maximum intake, diet provided ad libitum. The age of 72–74 weeks the chickens are no longer productive [49].
Economic efficiency of EM supplementation
The highest feed cost was observed for a group supplemented EM with drinking water and in feed than the control group. However, the highest net revenue was obtained from EM supplemented with drinking water and in feed than the control group and EM supplementation with drinking water only. EM supplemented groups with drinking water and in feed had better economic efficiency, relative economic efficiency and egg to feed cost ratio than other treatment groups. The higher the total cost was for the control group than the EM supplemented groups [50] Considering the cost of EM and the price of an egg, the profitability of adding EM to poultry feed and water is analyzed and found to be profitable. A significant economic implication after the use of 4 ml of EM/liter of drinking water was found by [30] similarly, cost analysis of EM treatment [16] showed a tremendous gain over the use of other chemicals. Inclusion of 5% EM in feed (bokashi) was also found profitable in lambs fed low protein diet [51]. According to [16] the inclusion of EM in feed and water enhanced egg quality; as a result, the improved quality can increase the market value and demand for the eggs.