Footpad dermatitis (FPD), damage and inflammation of the plantar surface of the foot, is of concern for poultry because FPD affects the birds' welfare and production value. Footpad dermatitis is painful and causes costly chicken paw downgrades, carcass condemnations, and reduced live weights. However, a universal preventative has not been found. The hypothesis was that diets containing orange corn, when compared with diets containing yellow or white corn, would reduce the severity of footpad dermatitis in broiler chickens on wet litter. When compared with yellow and white corn, orange corn contains higher quantities of carotenoids, antioxidant pigments, believed to play a role in skin and feather health. This experiment was a randomized block, 3 × 2 factorial design: orange, yellow, and white corn diets with birds raised on wet or dry litter (control group). Female Ross 708 broilers (n = 960) were used to create 4 replicates of each diet x litter treatment combination. Footpads were scored at day 19, 27, 35, and 42, following the Global Animal Partnership standard's 0-2 scale of visual increasing severity: 0 indicates minimal damage and 1 and 2 indicate mild to severe lesions and ulceration, dark papillae, and/or bumble foot. At 42 d of age, birds on the wet litter had greater severity of FPD, scores 1 and 2, compared with the control group (88 vs. 13% respectively; P < 0.0001). At 42 d of age, prevalence of more severe footpad scores, 1 or 2, was lowest on the orange corn diet (33%), followed by white corn (56%) and yellow corn (63%). Birds fed the orange corn diet had higher BW throughout the study (P = 0.004) and had fat pads and livers with higher yellow pigment deposition (P < 0.005). Litter moisture content altered microbiome composition but corn type did not. In conclusion, the main determinant of FPD in this study was exposure to wet litter. When compared with yellow and white corn, orange corn was associated with improved bird growth and reduced severity of footpad dermatitis, especially at later time points.
The process of skin healing was studied in thin sections of adult mirror‐carp, superficially wounded with a razor blade in a scaleless region. Shortly after wounding, epidermal cells from both sides of the wound moved towards the wound cavity. The cells moved as compact groups, without severing the normal intercellular desmosomes. The moving cells displayed phagocytotic activity of cellular debris during the migration. The phagosomes reacted with diaminobenzidine, revealing strong peroxidase content. The normally abundant pinocytotic vesicles from the basal layer of filament cells vanished during the first hour after wounding, and reappeared after 2 days; 24 h after wounding, desmosomes interconnected the filament cells from both sides of the wound. Due to profuse mucus secretion, the number of mucous cells from the epidermal stratum was markedly reduced. Rodlet cells appeared 1 h after wounding in the external region of the epidermis. There was pronounced increase in alkaline phosphatase content of the pavement cells 10 min after wounding; this enzyme appeared around the ridges of the pavement cells and inside the mucous cells 20 min later. In the dermis, the region surrounding the wound was darkened, blood cells extravasated, and penetrated partially into the epidermis. After 2 days, dermal fibroblasts displayed intense phagocytosis; after 8 days they were particularly abundant in the region of regenerating tissue and were secreting large quantities of collagen. Marked changes in the relative frequency of the different types of leucocyte occurred during the post‐wounding days.
Keel bone fractures and osteoporosis are prevalent and damaging skeletal issues in the laying hen industry. There is a large interest in improving bone quality parameters to reduce or eliminate these conditions, thus improving bird welfare. Both essential fatty acids (EFA) and vitamin D can play a role in bone metabolism. The hypothesis of this study was that birds supplemented with lower n-6:n-3 EFA ratio or vitamin D would have improved bone properties compared to a control diet. A total of 3,520 Lohmann Brown-Lite pullets were used in this study. Pullets were housed on the floor from 0-17 weeks of age and then moved to an aviary (17-52 weeks of age). Starting at 12 weeks of age, birds were split into diet treatments- control, flax, fish, or vitamin D diets with n-6:n-3 ratios of 6.750, 0.534, 0.534, and 6.750, respectively. Diets were formulated to be isonitrogenous and isocaloric. Basal vitamin D3 levels were formulated to be 2,760 IU/kg across all diets; for the vitamin D diet, the vitamin D3 level was increased to 5,520 IU/kg. Hens on fish and vitamin D diets had greater bone density, keel bone volume, digital bone mineral content, and keel condition compared to flax and control hens. Additionally, birds fed the vitamin D diet had the heaviest body weights compared to birds fed fish or control diets. Birds fed the flax and vitamin D diets had improved feather coverage across multiple body regions. Feeding an n-3 EFA- or vitamin-D enriched diet decreased mortality by 1.6-3.3% compared to the control. The fish and vitamin D diets generated mixed production performance. Compared to the other treatments, the vitamin D diet generated higher case weights but lower hen day percentage throughout the study. When compared to the other treatments, the fish diet had the lowest case weights but had a greater hen day percentage after 36 weeks of age. Results indicate that a fish-based EFA and vitamin D-supplementation show promise in improving skeletal health but require further investigation.
A method for the enrichment of live thyrotrophic pituitary cells is described. Pituitary glands of young male rats were removed into Earle's solution and dispersed in a 0.1% trypsin solution containing 0.5% bovine serum albumin, pH 7.2. Nylon fibres (25 microgram) were used for the separation of the thyrotrophic cells, by stringing them across a plastic frame which fitted a plastic Petri dish containing the cell suspension. The fibres were washed with light petroleum (b.p. 60--80 degree C) and carbon tetrachloride, hydrolysed with 3 M-HCL for 30 min at room temperature and washed with distilled water and phosphate-buffered saline (pH 7.2). The fibres were treated with thyrotrophin releasing hormone (TRH) alone or in the presence of soluble carbodiimide solution. After incubation for 1 h at room temperature, the fibres were transferred to a new Earle's medium and cells were released from the fibres by plucking them with a needle. The separated thyrotrophic cells were identified by radioimmunoassay and by electron microscopy. Using the above-mentioned methods, enrichment of thyrotrophic cells was obtained. Thus, the amounts of TSH, prolactin, LH and GH released, during 2 h of incubation, by 1.5 x 10(6) unseparated cells were 6.8 +/- 0.65, 4.1 +/- 0.47, 4.8 +/- 0.52 and 5.2 +/- 0.68 microgram respectively, while the same number of purified thyrotrophic cells released 76.1 +/- 0.42, 1.2 +/- 0.3, 0.6 +/- 0.35 and 1.6 +/- 0.22 microgram of the same hormones (means +/- S.E.M.).
Since 1973, the treatment of sexually mature fish with brain hormones (i. e. neurohormones) in order to induce spawning activity has gradually been replacing the hypophysation, although the latter is still widely used. Some brain-hormone analogues have a hightened spawning-inducing effect. Since the discovery that dopamine inhibits gonadotropic hormone release, dopamine antagonists—pimozide or domperidone—are injected before or together with brain-hormone analogues. This double treatment, i. e. the suppression of dopamine inhibition followed by neurohormone stimulation, has become a current technique in aquaculture. The discovery of the pulsatile release of gonadotropic hormone from the pituitary hints at the possibility of using techniques in which exogenous hormones are injected in pulses. In the past few years, induction of spawning through the control of photoperiod and/or temperature has become increasingly important.
Management choices during the pullet phase can affect behavior, welfare, and health later in life, but few studies have evaluated the pullet phase, particularly in extensive housing systems. This study was a 2 × 2 factorial randomized complete block design (RCBD) with two strains and two stocking densities. The Lohmann LB-Lite and Lohmann LSL-Lite were housed on the floor at high-stocking density (619–670 cm2/bird) and low-stocking density (1249–1352 cm2/bird), which changed with age from 2 to 16 weeks of age (WOA). Bird-based measures of appearance, blood parameters, organ measurements, and production values were evaluated. Stocking density alone affected (p < 0.05) only relative bursal weight (% of body weight)—3.32% in the low-density versus 3.08% in the high-density group. High-stocking density was correlated with decreased uniformity (high—89.33 ± 0.24%; low—90.41 ± 0.24; p < 0.02) and worse feather coverage in the brown strain. High-stocking density was correlated with greater uniformity (High—90.39 ± 0.24%; Low—88.47 ± 0.24%; p < 0.001) and better feather coverage in the white strain. This study’s feed conversion ratio (FCR) was improved by 0.07 in the low-stocking density for both strains. The remaining parameters were affected by strain and age only. Thus, while stocking density effects vary slightly depending on the strain used, cage-free pullets had limited negative effects at both the high and low-stocking densities tested in this study; there were few to no changes in the numerous bird-based welfare parameters tested.
