Reza Akbari Moghaddam Kakhki

(1) Background: this study compared hydroxychloride and traditional oxide/sulfate sources of zinc (Zn), manganese (Mn), and copper (Cu) in ISA Brown pullet diets, focusing on growth, tibia strength, egg production, and eggshell quality. (2) Methods: in total, 120 pullets were divided into two groups, each with six replicates of 10 birds, receiving diets with hydroxychloride or oxide/sulfate sources of Mn, Zn, and Cu (65, 50, and 5 mg/kg, respectively) during rearing. At 16 weeks, 18 pullets per group transitioned to individual cages and were fed a standard diet with Mn-oxide, Zn-oxide, and Cu-sulfate until 50 weeks. (3) Results: pullets fed hydroxychloride minerals exhibited a higher feed conversion ratio (p = 0.023) and a trend toward higher average daily feed intake (p = 0.059) compared to those on oxide/sulfate sources during the rearing phase. During the laying phase, while no significant differences were observed in egg production until 24 weeks, hens previously fed hydroxychloride minerals demonstrated increased average daily feed intake and egg weight from 25 to 50 weeks of age (p < 0.05). (4) Conclusions: rearing diets supplemented with hydroxychloride minerals influenced feed intake and efficiency, with carryover effects that enhanced laying-phase performance.

(1) Background: This study assessed the efficacy of hydroxychloride sources of zinc (Zn), manganese (Mn), and copper (Cu) compared with organic sources in the rearing diets of Lohmann brown pullets, focusing on pullet performance, tibia quality, egg production, and eggshell quality. (2) Methods: A total of 120 birds (six replications and 10 birds each) received diets with Mn, Zn, and Cu from organic or hydroxychloride sources during the rearing phase. After the onset of lay, birds were fed diets containing oxide/sulfate sources up to 50 weeks of age. (3) Results: no significant differences were observed in growth performance and tibia quality during the rearing phase (p > 0.05). From 18 to 24 weeks of age, no carryover effect on egg production performance was observed. However, from 25–50 weeks, pullets fed hydroxychloride sources showed lower feed intake and egg mass compared to the organic group (p < 0.05), whereas egg production and eggshell quality remained similar between groups (p > 0.05). (4) Conclusions: These findings suggest the potential of hydroxychloride sources in rearing diets without compromising overall growth in the pullet phase and feed efficiency in the laying cycle.

Eggshell and bone quality were investigated at 72 wk of age (WOA) using Lohmann Brown and Dekalb White hens raised with a rearing spacing allowance (SA) of 247 and 299 cm²·bird⁻¹ from days 0 to 16 before being transferred to a common SA (755 cm²·bird⁻¹) for lay cycle. Eggshell thickness, breaking strength, along with tibia and femur weight, breaking strength, length, and ash were measured at 72 WOA. Strain and SA did not interact on any above parameter (P > 0.05). Hens reared in high SA during the pullet phase had heavier tibia and more femur ash, indicating rearing environment during the pullet phase influences the bone quality of hens in the late laying stage (P < 0.05).

1. The impact of feeding sources of n-3 fatty acids (FA) to ISA Brown and Shaver White breeders and their offspring on antibody titres and plasma FA profile was examined. 2. Breeders were fed either a control diet (CON); CON + 1% microalgae (DMA: Aurantiochytrium limacinum) as a source of docosahexaenoic acid; or CON + 2.6% of a co-extruded mixture of full-fat flaxseed (FFF) as a source of α-linolenic acid. Day-old female offspring were assigned to diets (breeder-offspring): 1) CON-CON, 2) CON-DMA, 3) CON – FFF, 4) DMA – CON, 5) DMA – DMA, 6) FFF – CON or 7) FFF – FFF, followed by a standard layer diet through 18 weeks of age (WOA) to 42 WOA. 3. Antibody titres against infectious bronchitis (IBV) and Newcastle disease (NDV) were measured at six days and six WOA, and plasma FA profile was measured at 18 and 42 WOA. 4. Pullets from FFF-fed breeders had higher antibody titres against IBV and NDV than pullets fed DMA (P < 0.05). Feeding FFF to offspring increased plasma ∑n-3 FA at 18 and 42 WOA, whereas feeding DMA to offspring reduced ∑n-6 FA at 18 WOA. 5. In conclusion, independent of breeder strain, alpha linoleic acid (ALA) and DHA sources showed varied responses. Feeding breeders FFF increased plasma concentration of antibody titres and n-3 FA whereas DMA reduced plasma concentration of ∑n-6 FA.

Coccidiosis induced necrotic lesions impair digestive capacity and barrier function in concurrence with increased risks for secondary bacterial infections. The industry has been successful in controlling coccidiosis with anticoccidials and vaccination. However, concerns over Eimeria species resistant to anticoccidials, gaps in vaccination and restriction on antibiotics is stimulating research and application of alternative and/or complimentary strategies for coccidiosis control. The aim of this paper is to appraise literature on the utility of feed enzymes and yeast derivatives in modulating coccidiosis. Feed enzymes can complement endogenous enzymes (protease, amylase, and lipase) that may become insufficient in coccidiosis afflicted birds. Coccidiosis in the upper small intestine creates conditions that enhances efficacy of phytase and there are reports indicating supplemental phytase can mitigate the negative impact of coccidiosis on bone quality. Increase in intestinal short chain fatty acids due supplemental fiber degrading enzymes has been linked with reduced survivability of Eimeria. There is evidence whole yeast (live or dead) and derivatives can modulate coccidiosis. Immunomudulation properties of the yeast derivatives have been shown to enhance cellular and humoral immunity in Eimeria challenge models which is critical for effectiveness of coccidial vaccination. Moreover, yeast nucleotides have been shown to be beneficial in stimulating healing of intestinal mucosal surface. Other novel work has shown that certain yeast cells can produce derivatives with anticoccidial compounds effective in attenuating oocysts shedding. Yeast cell surface has also been shown to be an effective oral Eimeria vaccine delivery vehicle. Overall, while further refinement research is warranted to address inconsistencies in responses and commercial application, there is evidence feed enzymes and yeast derivatives could complement strategies for maintaining intestinal function to bolster growth performance in broilers compromised with coccidiosis. However, broilers receive diets containing several feed additives with distinct mode of actions and yet there is dearth of empirical data on the expected responses.Future evaluations should consider combinations of additives to document animal responses and potential synergies.