Search

The effects of formulating broiler diets that contain sources of either rapidly or slowly digestible protein and 2 different dietary fiber sources on growth performance were studied in broilers chickens from 0 to 36 d of age. A total of 1,920 one-day-old, male Ross 708 broiler chickens were randomly allocated and housed in 48 floor pens (40 birds/pen) to one of 4 dietary treatments. Birds were allotted according to a completely randomized block design using a factorial arrangement of treatments with 2 protein digestion rates (rapidly or slowly) and 2 dietary fiber sources [3% oat hulls (OH) or 3% sugar beet pulp (SBP)] from 0 to 36 d of age. All diets were formulated to be isocaloric and isonitrogenous. The pen was the experimental unit for all variables studied (12 replicates/treatment). Data were analyzed using the MIXED procedure of SAS, and the model included the main effects of the protein digestion rate, dietary fiber source, and their interaction. There were 3 experimental feeding phases; starter (from day 0-14), grower (from day 14-28), and finisher (from day 28-36). Results indicated that broilers fed diets containing sources that supplied more rapidly digestible protein had 4% greater (P < 0.01) ADG and improved (P < 0.01) the feed conversion ratio (FCR) by 5% throughout the experiment, most notably after the starter phase. Diets containing 3% OH increased (P < 0.05) the ADFI and ADG (P < 0.05) in the starter phase compared with broilers fed diets containing 3% SBP, without affecting the FCR. The ADG and FCR of broilers fed diets containing sources of slowly digestible protein were improved (P < 0.05) to the level of broilers fed rapidly digestible protein containing diets with the addition of 3% OH. It is concluded that broiler diets should be formulated to contain a high concentration of ingredients that supply rapidly digestible protein, but if this is cost-prohibitive, then 3% OH could be used to increase the ADFI and ADG and potentially protein digestion rates to reduce the FCR.

This paper presents the results of the research on the use of fish oil (FO) in combination with soybean oil (SO) in laying hens diet on physical and chemical properties of fresh eggs and those stored in a refrigerator for 28 d at + 4°C. Fatty acids (FA) profile, as well as thiobarbituric acid reactive substances (TBARS) values in yolks are also presented. The following feeding treatments have been used: C (control, without FO), E1 (0.3% FO + 4.7% SO), E2 (0.6% FO + 4.4% SO), E3 (0.9% FO + 4.1% SO), E4 (1.2% FO + 3.8% SO) and E5 (1.5% FO + 3.5% SO). Laying hens diets were balanced at the level of 176.10 g/kg crude protein and 11.50 MJ/kg ME. The results of the study showed that feeding treatments affected the relative shares of the eggs basic parts (P < 0.05). The egg storage duration significantly reduced Haugh units (HU), egg and albumen egg weight, and increased the yolk color intensity (P < 0.001). Fish oil share increment in the diets resulted in the EPA (eicosapentaenoic FA) content increase from 10.27 to 20.10 mg/100 g egg; DHA (docosahexaenoic FA) from 105.44 to 236.87 mg/100 g egg and ∑ n-3 PUFA (polyunsatureated FA) from 204.59 to 327.35 mg/100 g egg. The ∑ n-6 PUFA/∑ n-3 PUFA ratio decreased from 8.69 (C group) to 4.54 (E5 group). TBARS values were affected by feeding treatments as well as treatment-storage interactions (P < 0.01).

To meet the growing consumer demand for chicken meat, the poultry industry has selected broiler chickens for increasing efficiency and breast yield. While this high productivity means affordable and consistent product, it has come at a cost to broiler welfare. There has been increasing advocacy and consumer pressure on primary breeders, producers, processors, and retailers to improve the welfare of the billions of chickens processed annually. Several small-scale studies have reported better welfare outcomes for slower-growing strains compared to fast-growing, conventional strains. However, these studies often housed birds with range access or used strains with vastly different growth rates. Additionally, there may be traits other than growth, such as body conformation, that influence welfare. As the global poultry industries consider the implications of using slower growing strains, there was a need for a comprehensive, multidisciplinary examination of broiler chickens with a wide range of genotypes differing in growth rate and other phenotypic traits. Tomeet this need, our team designed a study to benchmark data on conventional and slower-growing strains of broiler chickens reared in standardized laboratory conditions. Over a 2-year period, we studied 7,528 broilers from 16 different genetic strains. In this paper, we compare the growth, efficiency, and mortality of broilers to one of two target weights (TW): 2.1 kg (TW1) and 3.2 kg (TW2). We categorized strains by their growth rate to TW2 as conventional (CONV), fastest-slow strains (FAST), moderate-slow strains (MOD), and slowest-slow strains (SLOW). When incubated, hatched, housed, managed, and fed the same, the categories of strains differed in body weights, growth rates, feed intake, and feed efficiency. At 48 d of age, strains in the CONV category were 835 to 1,264 g heavier than strains in the other categories. By TW2, differences in body weights and feed intake resulted in a 22 to 43-point difference in feed conversion ratios. Categories of strains did not differ in their overall mortality rates. Global Animal Partnership, Canada First Research Excellence Fund, Ontario Agri-Food Innovation Alliance, and Protekta