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*1. In many countries, eggs are not refrigerated and must be stored at room temperature. The objective of this study was to explore the effects of dietary oregano oil (275 mg $/$ / kg; ORE) versus an unsupplemented control diet (CON) on laying hens on the shelf life and fatty acid profile of eggs. 2. Treatments were randomly distributed into 10 pens containing 27 birds each. A total of 200 eggs were collected from both groups on the same day and were stored for either 0, 10, 21 and 35 d. At each storage time, egg yolks were analysed for fatty acid profile and lipid peroxidation. 3. The main indicator of lipid peroxidation, malondialdehyde (MDA), was significantly lower in ORE eggs compared to CON eggs (p = 0.001). Storage time had a significant impact on MDA concentrations (p = 0.023), with the highest found after 35 d. Significant differences were found for individual fatty acids, saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid were significantly lower in ORE eggs compared to CON eggs (p < 0.05). Palmitoleic acid (p = 0.002), linolenic acid (p = 0.001) and docosahexaenoic acid (DHA, p = 0.001) were significantly higher in ORE eggs. 4. Storage only affected oleic, linolenic, linoleic, arachidonic and docosahexaenoic acids (p < 0.05). Total SFA, MUFA, n-6 and ratio of n-3 to n-6 (n-3:n-6) PUFA were significantly higher in CON eggs (p < 0.05). The ratio of SFA to PUFA (SFA:PUFA, p = 0.005) and total n-3 PUFA (p = 0.001) were significantly higher in ORE eggs. 5. The n-3:n-6 ratio was significantly impacted by treatment (p = 0.021) and storage (p = 0.031) with no significant interaction. This ratio is important for human health indication and could lead to the development of designer eggs. [ABSTRACT FROM AUTHOR]

Laying hens can experience a progressive increase in bone fragility due to the ongoing mobilization of calcium from bones for eggshell formation. Over time, this escalates their susceptibility to bone fracture, which can reduce their mobility and cause pain. The provision of perches as an exercise opportunity could potentially enhance bone strength, but the timing of exposure to perches during the birds' development may modulate its impact. The objective of this study was to investigate the enduring impacts of perch provision timing on the musculoskeletal health of laying hens. A total of 812 pullets were kept in different housing conditions (seven pens/treatment, 29 birds/pen) with either continuous access to multi-tier perches from 0 to 40 weeks of age (CP), no access to perches (NP), early access to perches during the rearing phase from 0 to 17 weeks of age (EP), or solely during the laying phase from 17 to 40 weeks of age (LP). At weeks 24, 36, and 40 of age (n = 84 birds/week), three birds per pen were monitored for individual activity level, and blood samples were collected from a separate set of three birds per pen to analyze serum levels of tartrate-resistant acid phosphatase 5b (TRACP-5b) and C-terminal telopeptide of type I collagen (CTX-I) as markers of bone demineralization. At 40 weeks of age, three birds per pen (n = 84) were euthanized for computed tomography scans to obtain tibial bone mineral density (BMD) and cross-sectional area (CSA) with further analysis including muscle deposition, tibial breaking strength, and tibial ash percent. During week 24, hens from CP, EP, and LP pens had the highest overall activity compared to hens from NP pens ( p < 0.05) with no differences between treatments for overall activity level during weeks 36 or 40 ( p > 0.05). During weeks 24, 36, and 40, hens from CP and LP pens showed greater vertical and less horizontal activity compared to hens from EP and NP pens ( p < 0.05). TRACP-5b and CTX-I concentrations did not differ between treatments at week 24 of age ( p > 0.05). Hens from CP pens had the lowest TRACP-5b and CTX-I concentrations at 36 weeks of age with EP and LP hens showing intermediate responses and NP hens having the highest concentration ( p < 0.05). At 40 weeks of age, CP hens had the lowest TRACP-5b and CTX-I concentrations compared to NP hens ( p < 0.05). Total bone CSA did not differ between treatments ( p > 0.05), but CP had greater total BMD than NP ( p < 0.05) with no differences between EP and LP treatments. CP and LP hens had larger biceps brachii, pectoralis major, and leg muscle groups as well as greater tibial breaking strengths than EP and NP treatments ( p < 0.05). CP hens had higher tibial ash percentages compared to EP, LP, and NP ( p < 0.05). Our results indicate that providing continuous perch access improves the musculoskeletal health and activity of laying hens at 40 weeks of age compared to no access and that late access to perches has a beneficial impact on activity, muscle deposition, and bone strength.

Technology, like body-worn sensors, enables data collection from similar-looking individuals in large groups but may alter behavior. We aimed to evaluate the impact of body-worn sensors on broiler behavior. Broilers were housed in 8 pens (10 birds/m 2 ). At 21 days-old, 10 birds/pen were fitted with a harness contained a sensor (HAR), while the remaining 10-birds were unharnessed (NON). Behaviors were recorded on days 22-26 using scan sampling (126 scans/day for 5 days). Percent of birds performing behaviors were calculated daily for each group (HAR-or-NON), and agonistic interactions were identified based on birds involved (two NON-birds (N-N), NON-aggressor to HAR-recipient (N-H), HAR-aggressor to NON-recipient (H-N), or two HAR-birds (H-H)). HAR-birds performed locomotory behavior and explored less often than NON-birds (p<0.05). Consummatory behavior was unaffected by treatment on any day (p>0.05). Agonistic interactions occurred more often between NON-aggressor and HAR-recipient birds than other categories on days 22 and 23 (p<0.05). HAR-broilers showed no behavioral differences when compared to NON-broilers after 2 days; thus, a similar acclimation period is required before using body-worn sensors to evaluate broiler welfare without altering behavior.