EFFECT OF DIETARY HALLOYSITE ON THE QUALITY OF FEED AND UTILIZATION OF NUTRIENTS BY FATTENERS

Daniel Korniewicz¹, Roman Kołacz², Zbigniew Dobrzański³, Adolf Korniewicz⁴, Michał Kulok^5
1 Cargill (Polska) Sp. z o.o.
² Department of Environmental Hygiene and Animal Welfare, Wrocław University of Environmental and Life Sciences, Poland
³ Department of Environment Hygiene and Animal Welfare, The Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Poland
⁴ Department of Animal Nutrition and Feed Science, Wrocław University of Environmental and Life Sciences, Poland
⁵ Department of Animal Hygiene and Ichthyology, Wrocław University of Environmental and Life Sciences, Poland

ABSTRACT

The chemical composition of halloysite - aluminosilicate from Polish deposits and its applicability as feed supplement was investigated. Halloysite was introduced to diet in the amount of 1 and 2%. Its effect on microbiological quality of feeds in the period of storage and utilization of nutrients by growing-finishing pigs was studied. The obtained results showed that halloysite supplemented in the amount of 2% resulted in reduction of bacteria and aflatoxin B₁. It did not influenced fungi counts. Fatteners fed with diet containing this aluminosilicate, caused significantly better utilization of protein, fat, fiber and mineral components, such as calcium, magnesium, zinc and copper in comparing of control group.

Key words: blood, faeces, feed, growing-finishing pigs, halloysite, nutrients.

INTRODUCTION

The effects of pigs fattening depend highly on the quality of diet and the possibilities of utilization of nutrients present in this feed. The basic materials for preparing diets for swine are grains, which are naturally polluted by fungi and bacteria [4, 14, 15]. These microorganisms under advantageous conditions (high temperature and humidity) grow intensively and cause physical and chemical changes in feed and animals fed with such feed possess significantly lower production and health indicators [8, 18, 24, 27]. Growth of bacteria and fungi, including toxin producing, can be inhibited by supplementation of the proper chemical agents, described as preservatives [11, 13, 17, 29].

Other preparations that might be advantageous for the improvement of microbiological quality of feeds and production yield in fattening can be aluminosilicates. Among the aluminosilicates are zeolites, kaolins, bentonites, vermiculite, montmorillonite, perlite, saponite and also halloysite. They have specific catalytic properties of selective absorption and high ion-exchange capacity [2, 6, 19]. These properties cause that they can be used for feeds conditioning and can also absorb NH₄ in the digestive tract and prevent diarrhea.

The applicability of some aluminosilicates as supplements for feed mixture was shown by many authors [3, 7, 12, 26, 30]. In Poland, halloysite is available aluminosilicate. Kołacz et al. [10] used halloysite in fatteners feeding in the dosage 2% and found the increase in the live weight gain ca. 5% and 4% better feed efficiency with the simultaneous increase of meatiness indicators.

The aim of the present work was to assess the effect of halloysite supplementation to feed for growing-finishing pigs on microbiological quality of diet during storage and feed nutrients assimilation by fatteners.

MATERIAL AND METHODS

Halloysite (Hlt) that was used in the present study originated from Polish deposits in Lower Silesia that were not exploited economically. Chemical analyses the samples of halloysite with the use of plasma spectrometer ICP-OES Philips S.C. model PU 7000 equipped with monochromator Echelle at analytical laboratory of Institute of Inorganic Technology and Mineral Fertilizers, Wrocław University of Technology was made.

Thirty growing pigs with the initial body weight 28 kg and 10 weeks old. Were grouped randomly in 3 feeding groups, 10 fatteners in each group (5 sows and 5 hogs). Fatteners were kept in individual pens with concrete grid equipped with feeders and nipple drinkers.

Group I – control, fed with the conventional feed mixture.
Group II – experimental, fed with the diet containing 1% of Hlt.
Group III – experimental, fed with the diet containing 2% of Hlt.

Feeds for fatteners in all the groups were produced with the use of the same technology in a feed mixing unit of Experimental Plant of the Institute of Animal Production in Pawłowice. Feeding materials used in the production of mixture underwent chemical analyses according to the obligatory procedures [1] of the laboratory of Department of Animal Nutrition and Feed Science, Agricultural University of Wrocław. On the basis of these analyses, the content of nutrients in the feeding materials was assessed as well as in the mixture used. The energetic value of diets (metabolic energy) was calculated on the basis of own analyses of feeding materials and digestibility coefficient, and formula recommended by Feeding Standards for Swine [20].

In the samples of feeds, after applying wet digestion (mixture of nitric, sulfuric and perchloric acids) in thermostated digester PH-3 (DHN PAN) with the use of atomic absorption spectrophotometer (AAS-3), the content of mineral constituents (Ca, Mg, Na, Zn, Cu) was determined. Phosphorus was analyzed with the use of spectrophotometric method, according to PN-ISO 6491:2000.

The produced mixtures underwent microbiological evaluation after 1, 2 and 3 months of storage in jute bags. The temperature in the storage room ranged from 18 to 20°C and relative air humidity was 53-58%. In the samples of diet, total count of aerobic mesophilic bacteria, total count of fungi and aflatoxin B₁ were determined, according to methods PN-76/R-64791 and PN-ISO 14718:2001. The analyses were carried out in the laboratory of Department of Veterinary Hygiene in Wrocław.

Feed mixture in the granulated form ø 6 mm was fed separately by feeders, ad libitum. The date and the quantity of introduced feeds were recorded. After 14 weeks of fattening and reaching by fatteners ca. 100 kg of body weight, the effect of the introduced halloysite on nutrients and mineral feed efficiency was investigated. The assessment was performed on the basis of chemical analyses of faeces. In the final stage of fattening (in the morning), from each fattener blood was sampled from yoke vein and after separation of serum, the content of mineral components: calcium, magnesium, phosphorus, zinc and copper was determined.

In the fresh faeces, the content of dry mass and nitrogen was determined. The remaining constituents, such as raw fat, raw fiber, raw ash, ash insoluble in 10% HCl and mineral components, including Ca, P, Mg, Cu, Zn were determined in dry material [1].

The results of fattening of pigs fed with the investigated diets (with Hlt) were reported by Kołacz et al. [10].

The obtained results were elaborated statistically with the use of single factor analysis of variance and the difference was estimated by Duncan's multiple range tests with the use of Statgraphics v. 5.0 software.

RESULTS AND DISCUSSION

Evaluation of halloysite
The results of chemical analyses of halloysite (Hlt), presented in Table 1, showed that Al and Si dominated (13.9 mass %, each), afterwards macroelements (Ca, Na, Mg, P, K) and trace elements, such as Cu, Fe, Mn, Zn. The chemical formula of halloysite is as follows: Al₂Si₂O₅(OH)₄ and its molecular mass was 258.1 g mol, specific surface area 52.49 m²·g, pH 7.66 (pH KCl). Sorption properties of this Hlt were presented in the work of Hoffmann et al. [6] and the composition of halloysite was different comparing with other aluminosilicates [2, 16, 26].

Table 1. The chemical composition of raw halloysite

Element	% mass	V %
Al	13.94	0.30
Si	13.92	0.86
Ca	0.4976	2.10
Mg	0.3286	0.40
Na	0.3782	0.55
P	0.4440	5.75
Mn	0.2245	0.20
Fe	0.0155	0.70
S	0.0271	6.60
K	0.0817	0.70
B	0.0014	23.72
	mg× kg-1	V %
Cu	129.23	1.50
Zn	255.63	2.55
Mo	4.42	18.96
Co	412.00	0.43
Cr	591.99	0.95
Ni	511.04	4.90
Cd	0.169	21.65
Pb	0.094	29.32

V – coefficient of variation.

Evaluation of mixture
The feed for all the groups contained 17.32-17.65% total protein and 0.94% lysine, 0.65% methionine with cysteine, 0.61% threonine, 0.20% tryptophan. The content of protein and amino acids was in accordance with the recommendations of Feeding Standards for Swine [20] for meat fatteners for the period of fattening from 30 to 70 kg of body weight. In the experimental diet containing Hlt, the increase in the content of raw ash from 4.55% (group I) to 5.50 and 6.45% (group II and III) was observed. In these mashes, also slight increase of the content of Ca, P, Mg, Na, as well as Zn and Cu was encountered. Raw ash originating from halloysite was only ballast and for this reason, energetic value of experimental mashes decreased from 12.65 to 12.53 MJ (Table 2).

Table 2. Ingredients, chemical composition and calculated metabolizable energy of experimental diets (%)

Specification	Group
	I control		II Hlt - 1%		III Hlt - 2%
Ground wheat	25.0		25.0		25.0
Ground triticale	35.0		35.0		35.0
Ground maize	10.0		10.0		10.0
Rapeseed meal	11.0		11.0		11.0
Soya bean meal	5.0		5.0		5.0
Fish meal	2.0		2.0		2.0
Wheat bran	9.6		8.6		7.6
Limestone	0.8		0.8		0.8
Dicalcium phosphate	0.15		0.15		0.15
Salt	0.40		0.40		0.40
HCl Lysine	0.25		0.25		0.25
Premix	0.50		0.50		0.50
Adhesive	0.30		0.30		0.30
Halloysite (Hlt)	-		1.0		2.0
Total	100.0		100.0		100.0
In 1 kg of mixture [%]
Dry matter	89.54		89.61		89.71
Metabolizable energy [MJ]	12.72		12.63		12.53
Total protein	17.65		17.48		17.32
Crude fat	2.29		2.25		2.22
Crude fibre	4.96		4.86		4.76
Crude ash	4.55		5.50		6.45
N-free extractives	60.09		59.52		58.96
Lys	0.96		0.95		0.94
Met + Cys	0.66		0.66		0.65
Thr	0.62		0.61		0.61
Trp	0.20		0.20		0.20
Ca	0.65		0.70		0.75
P	0.48		0.52		0.56
Mg	0.19		0.22		0.25
Na	0.21		0.25		0.29
Zn [mg·kg-1]	123		126		129
Cu [mg·kg-1]	25		26		27

Microbiological evaluation
The results of microbiological evaluation of feeds, presented in table 3, showed that the control diet after 4 weeks of storage contained 1.7 x 10³ mesophilic bacteria. This quantity was similar in the further period of storage, up to 12^th week. Halloysite applied in the dosage 2% influenced the reduction of bacterial counts to 5.9 x 10² after 4, and after 12 weeks to 5.5 x 10¹. Less efficient was activity of halloysite in the dosage 1 %. Total counts of fungi in 1 g of control mash after 4 weeks of storage was 1.0 x 10². In the further period of storage, decrease in fungi counts to 3.0 x 10¹ was observed. It was found that Hlt introduced in the dosage 1 and 2% did not influence the reduction of fungi counts during the whole storage period.

Table 3. Microbiological evaluation of experimental diets

Specification	Time of storage (weeks)	Groups
		I control	II Hlt – 1%	III Hlt – 2%
Total number of aerobic mezophilic bacteria CFU·g	4 8 12	1.7 x 103 1.0 x 105 4.3 x 103	5.5 x 103 3.7 x 103 3.2 x 102	5.9 x 102 1.2 x 102 5.5 x 101
Total number of fungi CFUˇg	4 8 12	1.0 x 102 3.6 x 101 3.0 x 101	1.0 x 102 3.6 x 101 1.0 x 101	1.0 x 102 1.0 x 101 1.5 x 101
Aflatoxin B1 µg·kg-1	4 8 12	3.0 3.1 3.0	*bld bld bld	bld bld bld

*bld – below limit of detection.

In the studies carried out by Korniewicz et al. [11] it was found that zeolite in the dosage 0.5 and 1%, introduced to feed mixture for piglets with the humidity 10% did not influence counts of mesophilic bacteria and fungi during storage of mashes for the period of 8 weeks under good storage conditions.

In the control diet, the presence of aflatoxin B₁ was detected in the amount of 3 µg·kg^-1. This level remained unchanged during the whole period of mash storage. The addition of halloysite in the quantity 1 and 2% resulted in decrease of the concentration of aflatoxin below detection limit. Oguz et al.[22] and Ortatali and Oguz [23] showed that supp-lementation with clinoptiolite on the level 1.5 and 2.5% to mixture containing 2.5 mg aflatoxin, was found to be efficient in decontamination of aflatoxins. Harley et al. [5] reported that introduction of synthetic zeolite HSCAS (Hydrated Sodium Calcium Aluminosilicate) to mixture containing 3 mg·kg^-1 aflatoxin, reduced harmful effect of this mycotoxin.

Chemical analysis of faeces and blood serum
In the final stage of fattening, when the samples of faeces were taken up for the analysis, fatteners consumed daily ca. 3 kg of feed. The content of the basic components in 1 kg of dry mass of faeces of fatteners is shown in table 4. Dry mass in feces of fatteners in the control group constituted 26.31%, and in the experimental groups was higher and was evaluated as, 27.29 and 28.26%, respectively. This increase was the result of increased content of raw ash present in halloysite. The content of raw ash in dry mass of fatteners faeces in the control group was evaluated as 15.36% and in the experimental groups 16.50 and 17.54%, respectively. The difference that was observed between the control group and III group was confirmed statistically (p≤0.05). Also, significant (p≤0.01) increase of the content of ash insoluble in 10% HCl in faeces of fatteners from the experimental groups was observed.

Table 4. Content of basic nutrients in dry matter faeces of pigs (%)

Nutrient	Statistical measure	Groups
		I control	II Hlt – 1%	III Hlt – 2%
Dry matter *	SD	26.31 3.60	27.29 0.86	28.26 1.57
Crude protein	SD	23.23a 2.46	21.72 2.15	20.46b 1.43
Crude fibre	SD	15.13a 1.66	13.84 1.14	13.26b 1.26
Crude fat	SD	5.87A 1.0	3.90B 0.45	3.71B 0.75
Crude ash	SD	15.36a 2.20	16.50 0.86	17.54b 1.80
Ash insoluble in 10% HCl	SD	0.65A 0.12	1.35B 0.26	2.52B 0.53

– mean value. SD – standard deviation. A, B – highly significantly (p< 0.01). a, b – significantly (p< 0.05). * – in fresh mass.

When considering feeding aspects, important indicator is digestibility of the mostly significant nutrients. In the present study, indicator of nutrients efficiency was their content in feces. The content of protein in dry mass of faeces of fatteners from the control group was 23.23% and in groups II and III was lower, 6.5 and 12%, respectively. These data may indirectly prove better absorption of protein from the feed. In other digestibility-balance studies carried out by Korniewicz et al. [12] it was found that piglets fed with the mixture containing zeolite, accumulated 6.2% more nitrogen in their organism than from the control group. Halloysite introduced in the quantity 2% also influenced significantly the improvement of digestibility of fiber. In particular, high differences between the groups were observed in the case of fat. In faeces of fatteners from the control group, fat constituted 5.87% and in the experimental groups 3.90 and 3.71%, respectively. The content of fat decreased 34%. The explanation of this phenomenon requires further investigation.

The objective of the experiment was also assessment of the effect of the applied Hlt on the utilization of the most important mineral constituents by fatteners. This was assessed through chemical analysis of excreted faeces. The results of analyses are presented in table 5. In faeces from fatteners from groups II and III fed with mash containing 1 and 2% Hlt, significantly lower (p≤0.01) levels of calcium and magnesium (p≤0.05) were determined when compared with faeces of fatteners from the control group. These data showed that calcium and magnesium originating from halloysite were used by fatteners.

Table 5. Content of nutrient minerals in faeces of pigs (in 1 kg dry matter)

Nutrient	Statistical measure	Groups
		I control	II Hlt – 1%	III Hlt – 2%
Ca (g)	SD	9.84A 0.81	7.78B 0.77	8.06B 1.27
P (g)	SD	5.10 0.70	4.67 0.36	4.93 0.44
Mg (g)	SD	3.03a 0.32	2.80 0.10	2.74b 0.14
Cu (mg)	SD	69.38A 15.9	39.68B 8.48	37.59B 14.55
Zn (mg)	SD	248A, a 44	206C, b 32	163B, D 19

– mean value. SD – standard deviation. A, B, C, D – highly significantly (p< 0.01). a, b – significantly (p< 0.05).

The concentration of phosphorus in faeces of fatteners from the experimental groups was lower than fatteners from the control group but as the result of high individual variability, these differences were not confirmed statistically. Halloysite, introduced to feed in the groups II and III significantly (p≤0.01) influenced efficiency of zinc and copper, the consequence of which was lower content of these microelements in excreted faeces. Fatteners from the control group excreted in 1 kg of dry mass of feed 69.38 mg Cu and in the experimental groups ca. 45% less. The content of zinc in dry faeces of control fatteners was 248 mg and in the group II and III was 17 and 34 % lower, respectively.

Similar concentrations of these microelements in faeces were reported by other authors. Nowotny et al. [21] determined the following levels of microelements in faeces of fatteners: 136.6 – 178.6 mg Zn and 19.3 – 22.5 mg Cu per kg of dry mass depending on the age of animals and the type of mineral premix in mixture.

Reports of Ward [28] showed that supplementation of 0.5% of sodium zeolite A to piglets diet resulted in increase of the level of zinc in liver and bones and decreased the level of calcium and inorganic phosphorus in blood serum. Kyriahis et al. [16] and Papaioannou et al. [25] analyzed the effect of another aluminosilicate, clinoptiolite, on the level of vitamin A and E and phosphorus, calcium, magnesium, copper and zinc in pregnant and lactating sows did not report disadvantageous effect of this preparation on production yield and biochemical parameters of blood.

Table 6. Content of mineral elements in pigs blood serum (mmol·l-1)

Element	Statistical measure	Group
		I control	II Hlt – 1%	III Hlt – 2%
Calcium (Ca)	SD	2.10A 0.19	2.41B 0.15	2.35B 0.18
Magnesium (Mg)	SD	1.05a 0.10	1.16b 0.22	1.18b 0.10
Phosphorus (P )	SD	2.84 A 0.24	2.95 0.43	3.17 B 0.30
Zinc (Zn)	SD	17.0a 3.16	16.15 1.49	15.99b 1.70
Copper (Cu)	SD	31.81A 4.98	27.83 5.27	25.70B 5.80

– mean value. SD – standard deviation. A, B – highly significantly (p < 0.01). a, b – significantly (p < 0.05).

The results of analyses of blood serum, showed in table 6, proved that supplementation of halloysite in the experimental groups increased the concentration of Ca, Mg, P and decreased the content of Zn and Cu. The observed differences were significant statistically. These results suggested increased accumulation of Cu and Zn in organs (liver, kidneys) and tissues (muscles). This results are very important when taking into consideration the results of Papaioannou et al. [25] and requires further studies, including digestibility-balance investigation.

CONCLUSIONS

Kołacz et al. [9] showed that in blood serum of fatteners fed with the mixture containing 2% halloysite, significant increase of the concentration of total protein and decrease of the concentration of triglycerides and HDL when compared with the control group was observed. Dietary halloysite has positive effect on the profile of fatty acids muscles, liver and backfat of finishing pigs [12].

Summarizing the results of the present work, we have found that the studied halloysite as an additive to feed mixture for fatteners in the quantity 2 % had an advantageous effect on the microbiological quality of mixture during the period of storage. Fatteners fed with diets containing this aluminosilicate, assimilated protein, fat, fiber and mineral components, such as calcium, magnesium, zinc and copper more effectively. Interaction of halloysite is of particular physiological significance to animals and environment, due to lower excretion of nitrogen and minerals in faeces.

ACKNOWLEDGEMENTS

Supported by the Polish Ministry of Science and Higher Education (project no 6 PO 6Z 06126).

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Accepted for print: 29.12.2006

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Daniel Korniewicz
Cargill (Polska) Sp. z o.o.
2/4 Rolna Str., 62-280 Kiszkowo, Poland
email: daniel.korniewicz@lnb.pl

Roman Kołacz
Department of Environmental Hygiene and Animal Welfare,
Wrocław University of Environmental and Life Sciences, Poland
Chełmońskiego 38 C, 51-630 Wrocław, Poland
Phone: (+48 71) 32 05 865

Zbigniew Dobrzański
Department of Environment Hygiene and Animal Welfare, The Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Poland
J. Chełmońskiego 38 C
51-630 Wrocław
Poland
Phone: +48 71 320 5865
email: zbigniew.dobrzanski@up.wroc.pl

Adolf Korniewicz
Department of Animal Nutrition and Feed Science,
Wrocław University of Environmental and Life Sciences, Poland
Chełmonskiego 38 C, 51-630 Wrocław, Poland
email: Phone: (+4871) 320-58-39

Michał Kulok
Department of Animal Hygiene and Ichthyology,
Wrocław University of Environmental and Life Sciences, Poland
Chełmonskiego 38 C, 51-630 Wrocław, Poland

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Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed 'Discussions' and hyperlinked to the article.

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