Effects of Green Oaks Acorns (Quercus ilex) based Diets Added of Calcium Bentonite on Health of Broilers Reared in the Cages and Ground Modes

In modern diets, meat is the subject of debate and criticism in a society increasingly attentive to the dietary composition and health value of its diet. Product quality has therefore become one of the major concerns of the various links in the meat industry and the consumer. Among the factors likely to alter or improve this quality is often mentioned diet, even if other parameters have a much greater influence such as genotype and age (Berri and Jehl 2001).

In this context, several research carried out by Algerian researchers have shown the possibility of using the green oak acorn (GOA) (naturally rich in  unsaturated fatty acids and bioactive compound) in the diet of broilers, without any alterations in the growth performance and body composition. Interesting results have been obtained by Bouderoua et al., (2003; 2009) on the productive performances and nutritional and dietetic qualities of white meats which are characterized by an acceptable slaughter yield. The breeding of broilers is practiced all over the world, in very variable conditions which can be done in three ways; 1) in battery, 2) on the ground and 3) Hybrid (ground and battery). The ground-based method of rearing is often observed in extensive village ranching and also in free-range ranching. In both of these cases, the ground is made up of greenery or dirt. In the industrial confined type, floor rearing is more used for fattening chicks intended for meat production, but also sometimes for laying eggs.

The battery breeding is oldest method and has the following advantages; Removal of the litter that can reduces the transfer of infectious agents, more favorable health status; because the droppings rejected through the wire mesh can reduce the risk of parasitism and infectious diseasesand, better growth because restricted locomotion helps in save energy and divert for accretion of meat.

For better control of breeding conditions, enhancing the feed quality using the few raw materials available locally is important. For example, bentonite is one of these raw materials, known for its richness in minerals and capable of being used in animal feed for binding the toxins.

The consumption of clay has been used for hundreds of years by animals and native cultures to promote internal healing and improved economic indicators and the use of marketing silicate minerals are recommended as an ingredient in the forage (Safaei et al., 2014). It is used as a feed additive in poultry feed and has no harmful effects on animal health (Prvulovic et al., 2008; Safaeikatouli et al., 2010).

Bentonite or montmorillonite is a clay belonging to the smectic family. Clays are differentiated by their absorbent and adsorbent properties. Absorption refers to the ability to mop up or even pump liquids. Adsorption refers to the ability to exchange particles, for example minerals against toxins (Bouderoua et al., 2016).

This is study, aims to monitor the effects of adding acorn and bentonite in the diet on the histopathological state of organs in broiler chickens reared under soil and battery modes.

Three hundred day-old male Hubbard ISA 15 broilers were reared conventionally and fed until 12 days of age on a standard starter diet (3,100 kcal/kg, 22% protein) were allowed free access to water and food. The 12th day, birds with initial body weight (BW) 360 kg±23 g were divided into six groups, first group reared on the ground and fed without supplementation of acorn or bentonite. Apart from the similar rearing and diet in CG, the second groups was supplemented with acron (OAGS) and the third group was supplemented acorns (19. 8 g/kg) plus calcium bentonite (2 g/kg) (OAGBS). The fourth group was similar like CG but battery-matured (TB) whereas the fifth and sixth group were also battery-matured chicks but supplemented acron alone (GB) or, acron plus bentonite (GBB). The room temperature in experimental house was maintained at 38°C during the first days of experiment and decreased gradually by 3°C in the 2^nd and 3^rd week to be fixed at 22°C there’after. Chiks on 3^rd and 30^th day of age were vaccinated against New Castle disease via drinking water. Animals used in this experiment were reared and slaughtered in compliance with ethics regulations for the humane care and use of animals in research.

In order to assess the state of health of the chickens, histological sections were made on the Fabricius bursa, liver and small intestines after fixation. The sections made are observed under a light microscope (Luna, 1968).

Histological sections of Fabricius bursa, liver and small intestines of chickens are shown in Fig 1 and Table 1.




 
Fabricius scholarships
 
Depending on the stage of the disease; lesions of hyperplasia, follicular atrophy and fibrosis were observed in control and experimental broilers. Follicular necrosis was especially dominant during the second sacrifice of broilers. During the experiment, the latter was also more intense in ground farming. Based on the diet and compared to the control lots, lymphoid follicle necrosis was moderate in the OAGS and GB group. Adding bentonite to the acorn diet nearly halved the intensity of follicular necrosis compared to the lesion appearance of CG or TB. The follicular scarring expressed by the extent of fibrosis was extensive on the bursae from the second sacrifice. Throughout the experiment and depending on the type of breeding, fibrosis was slightly more widespread on the purses from cage breeding. On the other hand, the diet based on acorn and bentonite (OAGBS and GBB) showed extensive follicular healing compared to the controls and the groups fed with the acorn (Fig 2 and 3).




 
Livers
 
Neither control diet nor accron or benotnite supplemented diets failed to prevent the development of microscopic hepatic lesions (Fig 4 and 5) which included the presence of heterogeneous perivascular infiltrates, cytogresomes, megalocytosis, hepatic steatosis, hepatitis, lysis and degeneration of hepatocytes. Depending on the type of farm, the lesions of steatosis and megalocytosis were more evident in cage culture. In contrast, the presence of cytogresomes in the cytoplasm of hepatocytes was more intense in the soil culture. Lysis and degeneration lesions were often observed on lots reared in soil compared to those in cages.




 
Small intestines
 
The majority of transverse intestinal sections exhibited tissue changes at different grades of inflammatory activity. In fact, the severity of the enteritis lesions ranged from mild, localized in the lamina propria, then from the strong infiltration of neutrophils in the crypts until diffuse ulceration with the presence of granulation tissue at the level of the cell. epithelium of the intestinal mucosa.

According to the type of breeding, in general, the enteritis lesions showed in the submucosa and the mucosa infiltration of the crypts by neutrophils and local epithelial erosions more or less important in the lots raised on soil compared to those on cages. Depending on the diet, the CG and TB exhibited less inflammatory activity compared to the other groups. On the other hand, the group fed with acorns (OAGS and GB) showed a more marked transmural inflammationthan that of the CG or TB where it was less intense compared to the batch fed with acorn and bentonite (Fig 6 and 7).





The autopsy did not reveal any obvious macroscopic lesions on the different organs taken from the different groups of experimental animals, with the exception of those observed on the bursa of Fabricius which showed swelling associated with congestion and atrophy accompanied by grayish color. The involvement of these bursaries was accompanied by mild perihepatitis, congestion and intestinal petechiae, more marked in chickens fed the control and the acorn-based diet and less pronounced in the animals that consumed the diet supplemented with bentonite.Based on the diet consumed and compared to the control batch, histology revealed necrosis of the lymphoid follicles of the Fabricius bursa more moderate with the acornbased diet. Adding bentonite to the acorn diet almost halved the intensity of follicular necrosis compared to the lesion appearance of control animals. In addition, depending on the diet consumed, hepatic infiltrates were much less in the acorn and bentonite diet, which even reduced the occurrence of hepatocyte lysis and degeneration compared to other experimental diets. Intestinal microscopy also revealed that the control batch exhibited less transmural inflammatory activity in comparison especially with the batch fed with acorns and bentonite.

De Vries et al., (2006) reported that the laying hen reared in the open air consumed soil nearly 10% of the dry matter ingested.
 
Adding bentonite to broilers’ feed strengthens the animal’s immunity more and significantly reduces:

Throughout the experiment and depending on the type of farming, the fibrosis was slightly more widespread on the purses resulting from cage farming as opposed to farming carried out on the ground. Steatosis and megalocytosis lesions, as well as lysis and degeneration lesions were also more evident in hepatocytes from battery-reared animals. On the other hand, only appearance of cytogresomes in the cytoplasm of hepatic cells was noted in the culture carried out in the soil.

At the intestinal level, enteritis lesions in the submucosa and mucosa, infiltration of the crypts by neutrophils and more or less significant local epithelial erosions were observed in the birds of the batches raised on the ground than those raised in cages.

These responses are undoubtedly due to a difference in the breeding density of which the cage breeding was carried out more suffering by the animals because of the high density of 20 subjects per square meter compared to the ground breeding. having been established according to the required standard of 10 subjects per square meter.

In view of the improvement in the health of chicken meat by the supplementation of holm oak accron and bentonite to chick diets was recommended at the dose of 19.8% and 2%. The improvement in the quality and health value of meat could be attributed to their richness in bioactive ingredients. The addition of bentonite to poultry feed remarkably reducedthe intensity of follicular necrosis of Fabricius bursa, hepatic infiltrates, as well as lysis and hepatocyte degeneration, intestinal transmural inflammatory activity in, particularly in broilers. We also conclude that the cage rearing as opposed to floor rearing showed slightly more extensive fibrosis on Fabricius bursa; lesions of steatosis and megalocytosis, as well as lesions of lysis and more marked degeneration.

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