Turning eggshell waste into an organic calcium source for broiler chickens

Zulfikar Ilham Tentrawinata, Hanny Indrat Wahyuni, Turrini Yudiarti, Endang Widiastuti, Ikania Agustyaningsih, Tri Agus Sartono and Sugiharto Sugiharto

Department of Animal Science, Faculty of Animal and Agricultural Sciences, Universitas Diponegoro, Semarang, Central Java, Indonesia
sgh_undip@yahoo.co.id

Abstract

The study aimed to evaluate the use of eggshell waste or eggshell extracted using Averrhoa bilimbi L. fruit filtrate as the alternative to limestone (inorganic calcium source) in feed for broiler chickens, in terms of production performance and carcass traits. The study was conducted according to a completely randomized design with 4 treatment groups and 7 replications (each pen containing 14 chicks). The treatment groups included T0 (control diet with 1% limestone as a source of inorganic calcium), T1 (feed with 1% eggshell flour as an organic calcium source), T2 (feed with 1% eggshell extracted using A. bilimbi L. fruit filtrate as an organic calcium source) and T3 (feed with 0.5% eggshell extracted using A. bilimbi L. fruit filtrate). The chickens were raised for 35 days. Final body weight and accumulative feed consumption were recorded at the end of the study. Results showed that using eggshell flour or A. bilimbi L. fruit filtrate-extracted eggshell at the level of 1% in feed led to a final body weight, total feed intake and feed conversion ratio (FCR) that were not different (p>0.05) from that of broilers given limestone 1% of feed. Administration of A. bilimbi L. fruit filtrate-extracted eggshell at a level of 0.5% resulted in lower (p<0.05) body weight and feed consumption than the control chickens. The birds receiving A. bilimbi L. fruit filtrate-extracted eggshell had lower (p<0.05) thigh proportion than the birds receiving eggshell flour. In conclusion, eggshell flour can be used as organic calcium source to replace limestone in feeds without impairing broiler performance and carcass traits. Extraction of eggshell using A. bilimbi L. fruit filtrate had no beneficial impact on the growth performance and carcass traits of broilers.

Keywords: Averrhoa bilimbi L. fruit filtrate, broiler, calcium, eggshell flour, organic acids

Introduction

The livestock industry produces various wastes, one of which is eggshells, which if not managed properly can cause environmental problems. Regulations in the European Union classify eggshell as a hazardous waste (Ummartyotin and Manuspiya 2018). Finding alternate methods to transform eggshell into useful components for other applications is therefore essential. At present, egg shell waste has not been utilized, so it has no economic value. Eggshell contains 0.81% water, 2.21% protein, 0.04% fat and 94.69% minerals (Shahnila et al 2022). Minerals in the eggshell include 36,200 mg/100g Ca, 240 Mg, 106 P, 80 Na, 60.20 K, 0.67 Zn and 11.47 Fe (Shahnila et al 2022). Calcium is a macromineral that is very important for bone formation, blood clotting, muscle contraction, and plays an important role in metabolic processes (Kristianto et al 2014). Currently the main source of calcium for broiler chickens is inorganic calcium from limestone. The use of inorganic calcium in feed is generally constrained by low calcium digestibility so that the balance of calcium in the body can be disrupted (Suthama et al 2021). From the environment point of view, there is widespread environmental problems caused by limestone mining. A number of effects of limestone mining, such as altered land use patterns, habitat loss, increased noise levels, dust emissions, and altered aquifer regimes, were noted (Ganapathi and Phukan 2020). Based on these facts, it is expected that switching from limestone to alternate calcium sources will improve the health of the environment.

Henry and Pesti (2002) reported that organic calcium (calcium citrate) has a higher digestibility and utilization value compared to inorganic calcium (calcium carbonate) from limestone. Considering that the most abundant mineral in eggshells is calcium, eggshells have great potential as a source of organic calcium for broiler chickens (Lee et al 2018). Yet, chicken eggshells have a physical structure that is hard, rough, smells fishy, and has an unattractive colour that can reduce the palatability of chickens. According to Aminah and Meikawati (2016), soaking using acidic fluids can improve the physical structure of the shell and reduce harmful components and remove organic compounds from the eggshell. Furthermore, Rosnah et al (2021) reported that soaking using hydrochloric acid (HCl; strong acid) resulted in higher calcium and phosphorus and lower water content in eggshell powder when compared to soaking using acetic acid (weak acid). The acid solution as an immersion/extraction medium (solvent) initially degrades complex minerals into simple forms (ions), making them more soluble. Thus, an acid solution can act as an enhancer which can affect the shape and level of mineral solubility (Aminah and Meikawati 2016). Acid liquid can be obtained from various sources, both organic and inorganic sources. Averrhoa bilimbi L. fruit is a source of organic acids that have been traditionally used by the people in tropical countries. The fruit contains various organic acids such as acetic acid, citric acid, oxalic acid, where citric acid is the largest organic acid component in A. bilimbi L. fruit (Sugiharto et al 2021). Based on its organic acid content, A. bilimbi L. fruit filtrate therefore has a great potential to enhance the calcium solubility as well as improving the structure of eggshells.

To best of our knowledge, extraction of eggshell flour using A. bilimbi L. fruit filtrate and its application as an organic calcium source for broiler chickens has never been carried out. This study aimed to turn the eggshell waste into an organic calcium source for broiler chickens.

Materials and methods

Preparation of eggshell flour and eggshell extract

The eggshell was obtained from the local hatchery nearby the university. After being washed by the running water, the eggshell was sun-dried and milled using a hammer mill into flour. The A. bilimbi L. fruit was collected from the garden around the campus. The fruit was washed with running water, drained, blended and then filtered using a filter cloth to produce the fruit filtrate. To produce eggshell extract, the eggshell flour that has been sterilized (using an autoclave), A. bilimbi L. fruit filtrate and sugarcane molasses were placed into an anaerobic jar with a ratio of 1:1:0.01 (g:mL:g). After homogenization, the jar was tightly closed (anaerobic) and incubated for two days. The mixture was sun-dried, and then stored at room temperature until used for the in vivotrial.

Chicken trial

The study was conducted according to a completely randomized design with 4 treatment groups and 7 replications/pen (each pen containing 14 chicks; a total of 392 mixed-sex Cobb broiler strain). The treatment groups included T0 (control diet with 1% limestone as a source of inorganic calcium), T1 (feed with 1% eggshell flour as an organic calcium source), T2 (feed with 1% eggshell extracted using A. bilimbi L. fruit filtrate as an organic calcium source) and T3 (feed with 0.5% eggshell extracted using A. bilimbi L. fruit filtrate). The chickens were raised for 35 days. Broiler chickens were provided with a commercial pre-starer feed from the arrival until 7 days of age. The treatment feed (Table 1 and 2) was offered from day 8 until harvest (day 35). Feed and drinking water were provided ad libitum throughout the study period. Vaccines were administered according to the rearing standards for the Cobb broiler strain. Final body weight and accumulative feed consumption were recorded at the end of the study.

Results and discussion

The results of this present investigation showed that using eggshell flour or A. bilimbi L. fruit filtrate-extracted eggshell at the level of 1% in feed led to a final body weight, total feed intake and feed conversion ratio (FCR) that were not significantly (p>0.05) different from that of broilers given limestone as the source of inorganic calcium in feed by 1% (Table 3). These findings therefore suggested that eggshell can be used in place of limestone as a calcium source for broiler chicks. Previous study by Rezvani et al (2019) included 1.52% eggshell flour in starter feed (day 11-25) and 1.45% in finisher feed (day 25-39) for broiler chickens. Eggshell flour was used to replace inorganic calcium carbonate in broiler feeds. They found that the administration of eggshell flour resulted in no significant difference in body weight, feed intake and FCR compared to broilers fed inorganic calcium carbonate in the diet. Taken these above studies together, it could be confirmed that eggshell, which is a waste that can be harmful for environment, can be turned into a source of calcium for broiler chickens.

The use of A. bilimbi L. fruit filtrate-extracted eggshell at 1% in feed did not have a significant (p>0.05) impact on broiler productivity when compared to control. These results were different from the data reported by Suthama et al (2021) which showed an improvement in the growth rate and FCR of broiler chickens given eggshell powder as a source of calcium combined with an acidifier from lime juice. However, from the acidifier point of view, the results of this present study were in agreement with Kopecký et al (2012) who reported the absent effect of acetic acid and citric acid on the growth of broilers. It remains unknown regarding the absent effect of A. bilimbi L. fruit filtrate-extracted eggshell at 1% in feed on the broiler productivity in this study. However, it is very possible that the positive impact of giving A. bilimbi L. fruit filtrate-extracted eggshell was hindered by the high temperature conditions in the broiler house during rearing (the average temperature during the day of rearing in the broiler house was 31.7 ± 0.95°C). In agreement with this inference, Açıkgöz et al (2011) reported that the expected positive impact of giving organic acids on the productivity of broiler chickens was hindered by the high temperatures in the broiler house when rearing the chickens. Furthermore, long-term administration of A. bilimbi L. fruit filtrate-extracted eggshell at the level of 1% in feed might have a detrimental effect on the morphology and functionality of the digestive system, which thereby have an adverse effect on the growth of broiler chickens. Previous study by Ali et al (2020) reported that broiler body weight was negatively impacted by administering formic acid (1%) through drinking water. Moreover, Suthama et al (2021) revealed that broiler body weight was higher in the group that received eggshell powder combined with 1.2% acidifier of lime juice, but there was no difference between the body weights of control chickens and chickens that received eggshell powder combined with 2.4% acidifier of lime juice.

In this study, administration of A. bilimbi L. fruit filtrate-extracted eggshell at a level of 0.5% resulted in lower body weight than the control (Table 3). It can also be seen at Table 3 that the feed intake was lower (p<0.05) in the group of chickens receiving A. bilimbi L. fruit filtrate-extracted eggshell at a level of 0.5% in feed compared to the birds receiving limestone or eggshell flour at 1% of feeds. This low feed intake was very likely to cause the availability of nutrients for growth to be lower than the control. It is not known exactly why the chickens receiving A. bilimbi L. fruit filtrate-extracted eggshell at 0.5% in feed consumed less feed than the other groups of chickens. Under high temperature conditions, chicken tends to have a lower ability to absorb calcium (Mir et al 2018). Considering that calcium is greatly needed for nutrient metabolism, low calcium intake therefore has an impact on low feed consumption by broiler chickens (Xing et al 2020), especially during high rearing temperatures.

Data on the commercial cuts of broiler chickens are presented in Table 4. There was no substantial different (p>0.05) in terms of eviscerated carcass and the commercial cuts, except for the thighs proportion of broiler. Indeed, the birds receiving A. bilimbi L. fruit filtrate-extracted eggshell had lower (p<0.05) thigh proportion than the birds receiving eggshell flour. It was very possible that the decrease in the portion of thigh in the group that received A. bilimbi L. fruit filtrate-extracted eggshell was due to the effect of using A. bilimbi L. fruit filtrate which functions as an acidifier. In this case, Fascina et al (2012) reported a lower proportion of thigh+drumstick yield in broiler chickens that received organic acids as an acidifier when compared to chickens that did not receive organic acids. It was not explained in more detail why organic acids can reduce the proportion of thighs, but it can be seen from their study that organic acids shifted muscle deposition from thighs to breasts (Fascina et al 2012). This condition was also seen in this present study where the proportion of breasts was greater in chickens receiving A. bilimbi L. fruit filtrate compared to chickens receiving eggshell flour (although the values were not statistically significant).

Conclusions

• Eggshell flour can be used as organic calcium source to replace limestone (inorganic calcium) in feeds without impairing broiler performance and carcass traits.
  
  
• Extraction of eggshell using A. bilimbi L. fruit filtrate had no beneficial impact on the growth performance and carcass traits of broilers.

References

Açıkgöz Z, Bayraktar H and Altan Ö 2010 Effects of formic acid administration in the drinking water on performance, intestinal microflora and carcass contamination in male broilers under high ambient temperature. Asian-Australasian Journal of Animal Sciences, 24(1), 96-102. https://doi.org/10.5713/ajas.2011.10195

Ali A M, Elagrb H M, Hamoud M M, Gamal A M, Mousa M R, Nasr S A E, ElShater M A H, Laban S F, Zahran O K and Ali M M 2020 Effect of acidified drinking water by organic acids on broiler performance and gut health. Advances in Animal and Veterinary Sciences, 8(12), 1301-1309. https://doi.org/10.17582/journal.aavs/2020/8.12.1301.1309

Aminah S and Meikawati W 2016 Calcium content and flour yield of poultry eggshell with acetic acid extraction. The 4 ^th University Research Coloquium 2016. ISSN 2407-9189

Fascina V B, Sartori J R, Gonzales E, Carvalho F B D, Souza I M G P D, Polycarpo G D V, Stradiotti A C and Pelícia V C 2012 Phytogenic additives and organic acids in broiler chicken diets. Revista Brasileira de Zootecnia, 41, 2189-2197. https://doi.org/10.1590/S1516-35982012001000008

Ganapathi H and Phukan M 2020 Environmental Hazards of limestone mining and adaptive practices for environment management plan. In: R. M. Singh et al. (eds.), Environmental Processes and Management, Water Science and Technology Library 91. https://doi.org/10.1007/978-3-030-38152-3_8

Henry M H and Pesti G M 2002 An investigation of calcium citrate-malate as calcium source for young broiler. Poultry Science, 81(8), 1149-1155. https://doi.org/10.1093/ps/81.8.1149

Kopecký J, Hrnčár C and Weis J 2012 Effect of organic acids supplement on performance of broiler chickens. Animal Sciences and Biotechnologies, 45(1), 51-54.

Kristianto V, Mahfudz L D and Suprijatna E 2014 Kalsium, protein dan rasio heterofil limfosit pada darah ayam broiler yang diberi ransum mengandung enzim fitase dan level protein berbeda. Journal of Animal Agriculture, 3(4), 498-504 (full article in Indonesian language).

Lee W D, Niu K M, Lim J M, Yi K J, Kee B J, Kim K W, K im K D, Hur S W, Han H S and Kim S K 2018 Characteristics of eggshell powder as carriers of probiotics. Journal of Life Science, 28(1), 90-98. https://doi.org/10.5352/JLS.2018.28.1.90

Mir S H, Pal R P, Mani V, Malik T A, Ojha L and Yadav S 2018 Role of dietary minerals in heat-stressed poultry: A review. Journal of Entomology and Zoology Studies, 6(5), 820-826.

Rezvani M R, Moradi A and Izadi M 2019 Ileal digestibility and bone retention of calcium in diets containing eggshell, oyster shell or inorganic calcium carbonate in broiler chickens. Poultry Science Journal, 7(1), 7-13. https://doi.org/10.22069/PSJ.2019.14720.1319

Rosnah R, Taslim N A, Aman A M, Idris I , As’ad S, Bukhari A and Wahyudin E 2021 Physicochemical characteristics of chicken eggshell flour produced by hydrochloric acid (HCl) and acetic acid (CH3¬COOH) extraction. Open Access Macedonian Journal of Medical Sciences, 9(A), 428-432. https:/doi.org/10.3889/oamjms.2021.6238

Shahnila , Arif S, Pasha I, Iftikhar H, Mehak F and Sultana R 2022 Effects of eggshell powder supplementation on nutritional and sensory attributes of biscuits. Czech Journal of Food Science, 40(1), 26-32. https://doi.org/10.17221/309/2020-CJFS

Sugiharto S, Pratama A R, Yudiarti T and Ayasan T 2021 Effect of novel natural feed additive containing Averrhoa bilimbi L. fruit filtarte, wheat bran and Saccharomyces cerevisiae on growth performance and meat characteristics of broiler. Veterinary World, 14, 3007-3014. https://doi.org/10.14202/vetworld.2021.3007-3014.

Suthama N, Sukamto B, Mangisah I and Krismiyanto L 2021 Immune status and growth of broiler fed diet with microparticle protein added with natural acidifier. Tropical Animal Science Journal, 44(2), 198-204. https://doi.org/10.5398/tasj.2021.44.2.198

Ummartyotin S and Manuspiya H 2018 A critical review of eggshell waste: An effective source of hydroxyapatite as photocatalyst. Journal of Metals, Materials and Minerals, 28, 124-135. https://doi.org/10.14456/jmmm.2018.17

Xing R, Yang H, Wang X, Yu H, Liu S and Li P 2020 Effects of calcium source and calcium level on growth performance, immune organ indexes, serum components, intestinal microbiota, and intestinal morphology of broiler chickens. Journal of Applied Poultry Research, 29(1), 106-120. https://doi.org/10.3382/japr/pfz033