Performance Evaluation of Two Slow-Medium Growing Chicken Strains Maintained under Organic Production System during Different Seasons

Abstract

A total of 160 1-day-old medium-growing male chicks (Gallus gallus domesticus) were raised for 120 days in a certified organic farming system. A total of two strains were studied (Coloryield, CY; RedBro, RB). Overall, two weather periods were considered based on the outdoor temperature, being S1 colder than S2. In total, 40 chicks per strain were assigned to each period (n = 80). Chickens were fed ad libitum with the same organic feeds. In the first month, chickens were kept indoors and, from day 30, they had access to the pasture. Slaughter live weight (LW), average daily gains, (ADG), the feed conversion ratio (FCR), and mortality rates did not differ between the two strains. LW was (p < 0.05) higher in the S1 and a trend (p = 0.084) was observed for ADG, which was higher in S1. No differences were found for feed intake, FCR, and mortality rates between weather periods. There were no differences for coefficient of variation (CV) between the strains studied, nevertheless, CV for LW in S2 was increased. Differences in the productive performance between these strains raised in organic production systems were slight. However, chickens raised in S1 had a better performance. It would be preferable to raise chickens in these weather conditions whenever possible.

Use of Maca Powder (Lepidium meyenii) as Feed Additive in Diets of Laying Quails at Different Ages: Its Effect on Performance, Eggshell Quality, Serum, Ileum, and Bone Properties

“…There are many factors such as reproductive hormones, age, stress, and coop conditions that adversely affect performance, egg quality, bone structure, and digestive activities in laying birds [1][2][3]. The age of the bird is one of the most important factors affecting egg production, egg quality, and bird health in the egg industry.…”

An analysis of the welfare of fast-growing and slower-growing strains of broiler chicken

“…As above, there were occasional exceptions with Ranger Classic and Ranger Gold birds generally having better welfare outcomes than two slightly slower-growing JA87 or JA57 crosses (Mancinelli et al, 2020). A few studies found no differences between strains in fearfulness (Eleroglu et al, 2015), HB or FPD (Nielsen et al, 2004) or mortality (Sarmiento-Garcia et al, 2021). But whether or not differences between strains are detected will depend on study power (studies are not always replicated at the flock level, Supplementary Table 1), and on how similar the SG strains are in terms of origin and growth rate.…”

“…perfect plumage and dermatitis scores were found by Nielsen et al (2004) and Horsted et al (2005)) or very high (e.g. mortality, Sarmiento-Garcia et al, 2021), this could also mask subtle strain effects.…”

“…Louton et al (2019) similarly found gait score, plumage soiling and scratches to be positively correlated with strain ADG (Supplementary Table 1, Table 1) again with one exception, as heavier Ranger Gold birds had lower HB scores than Rowan Rangers. Other diverse studies have examined the suitability of various SG-slow and SG very-slow strains for extensive or organic rearing production (Almeida et al, 2012;Eleroglu et al, 2015;Castellini et al, 2016;Mancinelli et al, 2020;Sarmiento-Garcia et al, 2021), with observations continuing until slaughter at between 81 and 120 days of age. Castellini et al (2016) compared the performance of seven SG strains (Supplementary Table 1) and found that an "adaptability index", calculated from 49 separate indicators, was negatively correlated with growth rate.…”

Effects of different inorganic selenium levels in laying quails (Coturnix coturnix Japonica) diets on performance, egg quality, and serum biochemical parameters

“…Several factors such as environmental conditions, feed, or breed could affect the performance and egg quality in birds. (1) Among that, mineral composition, such as differences in selenium concentration, may affect a bird's performance and the chemical composition of its eggs. (2)(3)(4)(5) Selenium (Se) is an essential trace element for human and animal health, and it plays an important role in the performance, (2,(5)(6)(7) reproductive system, (8) and antioxidant defense system.…”