Performance and carcass characteristics of free-range broiler chickens fed diets containing alternative feedstuffs

Abstract

The present study was carried out to evaluate the effects of alternative feedstuffs as partial substitutes of corn and soybean in free-range broiler diets on performance, carcass yield and technical-economic viability. A total of 400 Pescoço Pelado broilers were distributed in a completely randomized experimental design (CRD), with four treatments (treatment 1:Control; treatment 2: 10% rice bran inclusion; treatment 3: 10% ground cassava leaves; and treatment 4: 10% ground lead tree hay) with four replicates per treatment. Each replicate consisted of a group of 25 birds per paddock, separated per sex. Initial weight (IW), final weight (FW), body weight (BW), daily weight gain (DWG), feed intake (FI) and feed conversion ratio (FCR) were evaluated. Carcass, cuts (breast, thigh, drumstick, back, neck, leg and wings), abdominal fat and giblets (gizzard, heart and liver) yields were determined. The technical-economic viability of each treatment was assessed by determining the cost of feed per kg body weight, economic efficiency index and cost. The highest final weights were obtained with the use of rice bran. Rice bran and cassava leaves promoted higher carcass yield, as well as lower back and abdominal fat yields. The use of cassava leaves showed better economic efficiency among the treatments with alternative feedstuffs. The use of alternative feedstuffs at 10% inclusion in substitution of corn and soybean meal did not not result in major changes in performance and carcass parameters, and economic efficiency, and therefore, their use is recommended when the availability or the price of key ingredients, such as soybean meal and corn, increase

Effect of the supplementation of biocomplexed minerals in diets for free-range chickens on performance and carcass characteristics

“…Regarding the feed conversion index, males presented better values throughout the production period (1 to 90 days), which indicates that they are more efficient in converting the consumed feed into weight gain. This result is in agreement with those of Santos et al (2005), Faria et al (2011), andDel Castilho et al (2013), who observed better indices of feed conversion for males.…”

“…The results of the present study are in agreement with those of Santos et al (2005), Faria et al (2011), andDel Castilho et al (2013), who observed higher average weight gain for males, and with Santos et al (2005) and Dourado et al (2009), in which males presented higher values of feed intake.…”

“…In addition, female hormones, especially estrogen, increase body fat deposition (Kessler and Silva, 2017). With similar results, Santos et al (2005), Faria et al (2011), Mitrovic et al (2011), Sarica et al (2014), and Cruz et al (2018) found higher values of abdominal fat yield for females.…”

“…The fact of that females present higher mean of breast yield and males higher thigh yield and drumstick weight may be related to the effect of sexual dimorphism, and this behavior has been observed in other studies (Dourado et al, 2009;Faria et al, 2011;Del Castilho et al, 2013;Sarica et al, 2014;Cruz et al, 2018). Males presented greater development of the secondary parts of the carcass, such as wing, back, head plus neck, and feet.…”

“…Next, the division of the cuts was carried out, separating the breast, thigh, drumstick, wing, back, neck plus head, and feet. For carcass analysis, live weight at slaughter, weight and carcass yield, the weights and yields of the above-cited cuts, the weights and yields of edible viscera (liver, heart, and gizzard), and abdominal fat were evaluated according to the methodology of Faria et al (2011).…”