Feeding regimens and housing system represented the most important factors that control commercial poultry production. Poultry industry worldwide relayed for centuries mainly on deep litter housing systems, as litter usually provided broilers with more comfortable conditions and influence the financial outcomes. Good litter materials should maintain indoor temperature, absorb extra moisture, help to minimize the volatilization of ammonia gas into microclimatic air, and resist the multiplication of many pathogenic microorganisms. Litter witnessed the usage of many materials like rice husk and wheat straw as experimented by Sreehari and Sharma, (2010), soybean straw as recommended by De Avila et al. (2008), gypsum that was tested and recommended by Grimes et al. (2006), and sand as reported by Shields et al. (2005).
The current results recorded that the usage of wood shaving, rice husks, and wheat straw litters compared to slats and cage systems contributed to higher levels of carbon dioxide and ammonia gases in the microclimatic air developing some conditions that might contribute to the development of many diseases. The results were consistent to those reported by Lin et al. (2017), Pereira et al. (2017) and Naseem and King, (2018) who agreed that litter material undergoes decomposition and fermentation under the influence of many factors like litter management factors, microclimatic temperature, humidity, and ventilation rate contributed to increases in the concentration of carbon dioxide, ammonia, nitrous oxide, and methane. The finding of the present study were consistent with those reported by Jugowar et al. (2017). They recorded an increase in the levels of carbon dioxide and ammonia gases, and they attributed this increase to the decomposition of litter material in the presence of significantly lower ventilation rates especially in cold months of the year. Méda et al. (2011) recorded similar findings to the current results; increases in ammonia volatilization due to increased litter moisture content was a result of increases in microclimatic relative humidity.
The poultry production witnessed great expansion, and within this expansion, the interest in using other bedding materials as slats and cages have been increased as they contributed fewer problems and enhanced poultry welfare. The most common recorded problems from using litter were footpad lesions, hock joint dermatitis, hock joint arthritis, and femoral head necrosis as reported by Dawkins et al. (2017). Çavuşoğlu et al. (2018) also investigated some welfare parameters in 210-day-old male broiler chickens raised on deep litter, a mix of litter and slat system, and a slatted floor, they recorded negative influences on the measured welfare parameters in broilers raised on deep-litter, while the high live body weights recorded in broilers raised on slat floor contributed to severe pathological affections of the breast and shoulder.
Meanwhile, Adam (2017) reported that a deep litter housing system provided an optimum environment for layers and egg quality in the presence of good managerial procedures compared to battery cages housing system in open-sided houses. Kaukonen et al. (2016) stated that litter abiotic conditions are the keystone for the development of many pathological conditions like footpad dermatitis, hock burns, and breast blisters. They also concluded that maintaining litter quality is not enough to minimize the incidence of these pathological affections.
The current research reported significantly higher weight gains, performance indices, and live body weights, as well as, lower feed intake and consequently lower and enhanced feed conversion ratio in broilers raised in slat and cage systems compared to deep litter systems. The results were consistent with those recorded by Dhaliwal et al. (2018) and Davasgaium and Boodoo, (2000) who revealed that rice husk, wheat straw, and the mustard stalk were more or less similar, although birds on saw consumed the lowest amount of feed. Al-Bahouh et al. (2012) and Santos et al. (2008) reported enhanced performance of broiler breeds (Indian River®, Cobb®500, and Ross®308) that were raised in cages than on floors. Chuppava et al. (2018) conducted an experimental trial using Ross®308 broiler breed to investigate the influence of different flooring systems (50% or 100% slatted floors) with reduced contact to the excreta on body weight, carcass weight, feed intake, they reported that final body weight was significantly increased by the end of the fattening cycle which lasts for day 36 by using fully-slatted floors compared to commonly littered floors. Broilers on the plastic slatted floor were observed to have relatively higher weight gains and higher feed conversion ratios than when raised on wood shavings, this may be attributed to the prohibited possibilities for the birds to peck and manipulate particles in case of a slatted floor, so feed pecking occurs rather than the slatted floor resulting in higher feed intake. Pereira et al. (2007) observed that the presence of air movement between the manure and perforated floor can reduce heat stress in the slat-floor system, which in turn increases the productivity of birds.
Samli et al. (2010) explained that advanced floor housing as cages can adventurously and positively influence the broiler’s performance and intestinal microbiota. On the other hand, Fouad et al. (2008) reported that chicks housed on wood shaving were more active, had higher metabolic rates, and increased walking and playing behavior (mixing of floor materials). While, Pedroso et al. (2006) recorded no differences in feed intakes and gain ratios neither on the floor nor on cages for broilers. Darwish et al. (2017) found that Evian broiler on litter floor had higher body weights, weight gains, and feed consumption in most of the studied intervals compared to those raised in battery cages (p≤0.05 and 0.01), and no significant differences for feed conversion ratios, carcass characteristics, some blood parameters, and some immunity between the littered floor and battery cage systems.
The current results reported declined carcass and organs’ weights like liver, heart, spleen, and bursa of Fabricius in broilers raised on the tested deep litter systems including wood shavings, rice husk, and wheat straw. The results were consistent with those reported by Dal Bosco et al. (2015) who concluded that housing broilers on a deep litter system contributed to lower meat pH values and color, as well as, the higher percentage of monosaturated fatty acids and long-chain polyunsaturated fatty acids. Also, Darwish et al. (2017) reported higher performance and increased carcass yield in Evian broilers raised on floor system in comparison with battery cages. Li et al. (2017) recorded no significant differences in productive performances and the incidence of pathological affections development in broilers raised on the conventional deep litter system and those raised plastic slats.
Our results revealed significant increases in serum concentrations of total immunoglobulin IgG and IgM in broilers raised in the battery system and on the slatted floor. The result was consistent to those of Taherparvar et al. (2019) who investigated the influence of litter (sand, wood shaving, and paper) on some blood parameters and immunity in 270 day-old male Ross®308 broiler chicken, they recorded significant increases in total immunoglobulin titer contributed to the significant increase in immunoglobulin M. The current results recorded a significant decline in total bacterial counts of intestinal (duodenal) swabs in broilers raised in battery and on slatted floors compared to the deep litter systems. The current results might be attributed to the maintaining action of strict hygienic measures on the slatted floor and battery cages compared to deep litter. De Almeida et al. (2017) concluded that using slat-floor systems can be more efficient and contribute to lower pathological affections, high-quality environment, and high live body weights. De Jong et al. (2016) who reported a necessity to maintain hygienic measure and management of floor system to maintain the optimum welfare conditions in broilers. They also found that the welfare parameters like cleanliness, hock burn, footpad dermatitis, and gait score on-farm are highly correlated with the development of hock burn and footpad dermatitis in a slaughter plant.
