Different Levels Of Silicate Minerals

Published Date: 02 Nov 2017

Key words: Kaolin, bentonite, zeolite, comparative economic analysis, diet, broiler chickens

INTRODUCTION

Poultry industry has a significant role in supplying protein requirements of human being and chicken meat with desirable level of protein and essential amino acids has high biological value. Chicken meat digests quickly because of low collagen content and is more acceptable than the other kinds of meat, and its consumption is increasing dramatically. So, during the last century many effort have been done to increase efficiency in broiler industry with the using of breeding techniques and production of rapid growing strain and improvement in rearing conditions that great success has achieved as improved notably after using of modern raising programme for broilers, feed conversion ratio decreased from over 4 to lower than 2 from last century to recent decades but nowadays increasing in broiler efficiency with this method encountered some limitations.

According to that the feed cost of broilers contains 70% of their breeding costs using of nutritional solutions can be useful to decrease the costs of diets or increase of feed efficiency (Louw et al., 2011). One of this solutions is using of feed additives to improve the growth, prevent disease, improvement of feed efficiency and as the result to increase economic indicators. Silicate minerals include about 90% of the ground minerals that due to their physical and chemical properties some kinds of them such as zeolite, bentonite, kaolin, sepiolite, perlite, illite and granite can be useful as feed additives in poultry’s diet. The most important structural properties of silicate minerals are their ability to lose and gain water reversibly and high cation exchange capacity without much major changes of structure that can be effective in improvement of poultry performance (Shariatmadari, 2008; Safaeikatouli et al., 2010a).

Previous studies have shown that supplementation of broiler chickens diet with silicate minerals would improve their performance (Shariatmadari et al., 2004 ; Shi et al., 2009; Eser et al., 2011) ileal digestibility of energy and protein (Acosta et al., 2005; Pasha et al., 2008; Safaeikatouli et al., 2012b) bone characteristics (Yalcin et al., 1995; Herzig et al., 2008; Safaeikatouli et al., 2012a) litter quality (Karamanlis et al., 2008; Turan et al., 2009; Safaeikatouli et al., 2011a), to reduce adverse effects of aflatoxin (Tomsevic-Canovic et al., 2001; Arab-Abousadi et al., 2007 ; Oguz et al., 2011). Furthermore, various research (Oguz et al., 2000; Safaeikatouli et al., 2010b; Eleroglu et al., 2011; Safaeikatouli et al., 2011b) have indicated that using silicate minerals in the diet of birds did not have any adverse effects on their health, yield and consumers. According to results of above researches that represent beneficial effects for using silicate minerals in broiler diets, expected using silicate minerals in broiler diets effective on improving economic indicators.

Therefore, the objective of this research was to assay the effect of different kinds and levels of silicate minerals (kaolin, bentonite and zeolite) in diet of broiler chickens on Feed Intake (FI), Feed Conversion Ratio (FCR), Feed Cost (FC), Feed Intake Cost (FIC), Weight Gain value (WGV), Meat Production Cost (MPC), Economic Efficiency (EE), European Production Efficiency Factor (EPEF), Profitability and Benefit Cost Ratio (BCR).

MATERIALS AND METHODS

Birds and housing:

Four hundred and forty eight day-old Ross 308 male broilers were randomly assigned to1 of 7 treatments, replicated 4 times with 16 broilers in each were reared using a completely randomized design for 42 days. The commercial recommendations were followed for climatic conditions and lighting program. Room temperature in the first week of life was 32°C, and decreased to 18°C till the end of experiment. Relative humidity of the room was about 60-70% and artificial lighting was supplied continuously for 24 h every day.

Experimental diets:

All experimental diets were formulated to meet the NRC (1994) nutrient requirement for broiler chicken. The diets were based on corn and soybean meal and were isonitrogenous and isocaloric. The starter period diets included 23% crude protein and 2900 kcal of metabolizable energy per kg of diet and the grower diets included 20% crude protein and 3000 kcal of metabolizable energy per kg of diet. Treatments were 1) control (as standard diet did not contain silicate minerals) 2) diet inclusion 15 g/kg kaolin 3) diet inclusion 30 g/kg kaolin 4) diet inclusion 15 g/kg bentonite 5) diet inclusion 30 g/kg bentonite 6) diet inclusion 15 g/kg zeolite 7) diet inclusion 30 g/kg zeolite. The birds were supplied with feed and water ad-libitum. The broilers were vaccinated via eye-drop against Gumboro, Bronchitis and Newcastle diseases.

Parameters measured:

Body weight and feed consumption of each pen were recorded in starter, grower and overall periods to calculate Feed Intake (FI), Feed Conversion Ratio (FCR), Feed Intake Cost (FIC), Weight Gain Value (WGV), Meat Production Cost (MPC), Economic Efficiency (EE), European Production Efficiency Factor (EPEF), Profitability and Benefit Cost Ratio (BCR) by using the following formulas:

Feed Intake Cost ($/kg) = FI (kg) × FC ($)

Weight Gain Value ($/kg) = weight gain (kg) × price of live broiler ($/kg)

Meat Production Cost ($/kg) = FIC ($/kg) / weight gain (kg) or = FCR (g/g) × FC ($)

Economic Efficiency ($/$) = [(WGV, $/kg – FIC, $) / FIC, $] × 100

European Production Efficiency Factor = [(BW, kg × livability, %) / (FCR × age, days)] × 100

Profitability ($) = WGV ($/kg) – FIC ($/kg)

Benefit Cost Ratio = Profitability ($) / FIC ($/kg)

FI= Feed Intake, FC= Feed Cost, FIC= Feed Intake Cost, WGV= Weight Gain Value, BW = body weight, FCR = Feed Conversion Ratio

Statistical Analysis

Statistical analyses were conducted using the general linear model procedure of SAS (2003) to determine if variables differed between groups. Significant effects were further explored using Duncan’s multiple range tests (Duncan, 1955) to ascertain differences among treatment means at 5% probability level.

RESULTS AND DISCUSSION

The effect of dietary treatments on feed intake and feed conversion ratio are given in Table 1. The feed conversion ratio in starter period significantly (p<0.05) improved in treatments with 30 g/kg kaolin and zeolite, compared to the treatments with 15 g/kg zeolite and control. As well as, feed conversion ratio in treatment with 30 g/kg kaolin was significantly (p<0.05) better compared to the treatments with 30 g/kg bentonite. Feed conversion ratio did not differ significantly (p>0.05) between treatments in grower period. In the overall period, there were significant differences between 30 g/kg kaolin with 30 g/kg bentonite and control. These results are supported by previous research (Pasha et al., 2007; Abas et al., 2011; Al-Nasser et al., 2011) that found silicate minerals improved feed conversion ratio in broiler chicks. In contrast to our results, Cabuk et al. (2004) and Incharoen et al. (2009) declared that adding silicate minerals in diet of broilers did not have any influences on feed conversion ratio. The diversity among results of experiments maybe result of the structural difference among silicate minerals and also metal oxide content of them. Therefore, notice to structure of silicate minerals and excellent processing to decrease metal oxide content, will lead to better output. There were no significant differences (p>0.05) among dietary treatments in feed intake except treatment containing 30 g/kg bentonite in the grower and the overall period that feed intake was significantly (p<0.05) higher compared to the treatments with 15 g/kg bentonite, 30 g/kg kaolin and control. In agreement to our results, Salari et al. (2006) indicated that adding 1 and 2 percent bentonite to broiler diet increase feed intake. Teleb et al. (2004) and Abas et al. (2011) reported that inclusion kaolin and zeolite in diet did not have significant effect on feed intake.

Table 2 shows the effects of experimental treatments on the feed cost and feed intake cost. The feed cost in treatments containing silicate minerals was higher compared to control diet in the starter, grower and overall periods, but these differences were not significant. Feed intake cost were not affected (p>0.05) by dietary treatments in starter period, but feed intake cost in grower period in treatments containing 30 g/kg bentonite and 15 g/kg zeolite was higher compared to the control diet. Additionally feed intake cost in diet consisted of 30 g/kg bentonite significantly (P<0.05) increased compared to the treatment with 15 g/kg bentonite and 30 g/kg kaolin. In overall period, feed intake cost in treatment with 30 g/kg bentonite was significantly (p<0.05) higher compared to the treatments with 15 g/kg bentonite and control. In contrast to our results, Damiri et al. (2010) reported that inclusion of sodium bentonite in broiler diets had no significant influence on feed cost and feed intake cost.

The effects of dietary treatments on the weight gain value and meat production cost are presented in Table 3. In the starter period, weight gain value in treatment with 30 g/kg kaolin was significantly higher compared with 15 g/kg bentonite and control (p<0.05). Treatments containing two levels of zeolite (15 g/kg and 30 g/kg) showed a significant increase in weight gain value compared to 15 g/kg bentonite and control treatments in the grower period (p<0.05). In the overall period, treatment containing two levels of zeolite (15 g/kg and 30 g/kg) and 30 g/kg kaolin has shown better results in comparison with 15 g/kg bentonite and control treatments (p<0.05). Inclusion of 30 g/kg kaolin in starter, grower and overall periods and 30 g/kg zeolite in overall period in broiler diet significantly (p<0.05) decreased meat production cost. On the other hand, treatment containing 30 g/kg bentonite showed highest meat production cost among dietary treatments in grower and overall periods (p<0.05). Zarin-Kavyani et al. (2007) observed that adding zeolite in broiler diets decreased meat production cost and they reported best level of zeolite for using in broiler diet was 3 and 4 percent. Whereas, Damiri et al. (2010) declared that no significant differences (p>0.05) were seen in meat production cost among treatments containing sodium bentonite and control treatment.

Economic efficiency and European production efficiency factor of broilers supplemented with different kinds and levels of silicate minerals in diets are shown in Table 4. In the starter period (0-21 d) economic efficiency was significantly (p<0.05) increased in treatment with 30 g/kg kaolin compared with 15 g/kg zeolite and control. Although, the difference in economic efficiency between dietary treatments and control treatment was not significant (p>0.05) in grower period and overall period but showed significant (p<0.05) differences between treatments with 30 g/kg kaolin and 30 g/kg bentonite in overall period. European Production Efficiency Factor (EPEF) in starter period (0-21 d) increased significantly (p<0.05) in treatments with 30 g/kg kaolin and zeolite compared to control. In the grower period (21-42 d), EPEF in chickens fed kaolin (15, 30 g/kg) and zeolite (15, 30 g/kg) were higher than control, but the differences were not significant (p>0.05). In the overall period (0-42 d), EPEF in treatments containing 30 g/kg kaolin and zeolite were significantly higher than treatment with 15 g/kg bentonite and control. According to the results reported by Lotfollahian et al. (2004) impacts of different levels of two kinds of zeolites on EPEF showed an increase in EPEF with the increased level of zeolite in the diet, while, In contrast, Safari et al. (2009) reported that the inclusion of zeolite in the diet of broilers had no effect on the EPEF.

Table 5 presents effects of the dietary treatments on profitability and benefit cost ratio. In the starter period, treatment containing 30 g/kg kaolin showed significantly (p<0.05) greater profitability compared to 15 g/kg bentonite and control treatments. In the grower period, no significant differences were observed between dietary treatments and control (p>0.05). In the overall period diets containing 30 g/kg kaolin and zeolite had a significant (P<0.05) greater profitability than chicken fed control diet. In the starter period (0-21 d), inclusion 30 g/kg kaolin in diet significantly (p<0.05) improved benefit cost ratio compared with 15 g/kg zeolite and control diets. Benefit cost ratio did not show any significant (p>0.05) difference between dietary treatments in grower and overall periods, but in overall period treatments with 30 g/kg kaolin and 30 g/kg bentonite showed significant differences (p<0.05). These results indicate that inclusion of silicate mineral to broiler diets increased the profitability and benefit cost ratio. Kaolin, bentonite, and zeolite have not been reported to influence profitability and benefit cost ratio.

CONCLUSION

In conclusion, Diets containing kaolin and zeolite showed better result in comparison to diets containing bentonite; also it seems that adding of 30 g/kg of kaolin and zeolite in diets is more beneficial than the 15 g/kg in improving economic indicators in broiler chickens. Based on the results of this study, feeding broiler chickens with silicate minerals was effective in the improvement of economic indicators and commercial utilize of silicates minerals is recommended as an ingredient of broiler diets.