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1. Lighting is a crucial environmental factor in poultry production. This study evaluated the effects of light-emitting diodes (LED) on performance and several bone characteristics, including bone mineralisation, morphometry, histology and selected gene expression in broiler breeders.2. A total of 800 one-d-old female broiler breeder chickens (Ross 308) were randomly allocated to one of 20 light-proof pens and reared under green (GL) or white (WL) LED light for two photophases (8 or 12 h) in a 2 × 2 factorial experiment and compared to a control group (incandescent lamp at 8 L:16D duration; CON). Weight gain, feed consumption and feed conversion ratio (FCR) were calculated. Femoral and tibial characteristics were measured.3. The LED colour affected feed intake during the rearing period, being higher for birds under white compared to green light. Tibial calcium (Ca) concentration in WL birds was lower than for green LED lighting regimens but not different from the CON group (p ≤ 0.05). Birds under 12 h lighting had greater tibia bone dry matter and trabecular separation (mm) than those in the 8 h groups. However, bone volume fraction and trabecular number per mm in 8 h birds were higher than in 12 h groups (p ≤ 0.01). There was greater expression of the osteocalcin gene under WL compared with CON. Osteopontin expression in WL8 was 4.63 times greater than in the CON group (p ≤ 0.05). The alkaline phosphatase gene expression in WL12 was higher than in the CON group (p ≤ 0.05).4. Exposure to white and green LED spectra enhanced bone gene expression and mineralisation, respectively, without adverse effects on bird performance. Thus, LED light may be beneficial to broiler breeder bone traits. [ABSTRACT FROM AUTHOR]

We studied the effect of lighting during 19 days of incubation on embryonic bone characteristics, gene expression, thyroid hormones, and glucose in Cobb broiler hatchlings. Eggs (2160) were incubated under darkness (control) and green and white lighting (16D:8L and 12D:12L). On 19th day, tibiotarsal length increased under eight hours of white light, and femoral ossified length was longer under eight hours of white and green light. In femur, expression of Alp, Col10a1, and Spp1 increased by 12 h white and 8 h green lighting, and Bglap expression decreased under white. In tibiotarsus, expression of Alp decreased by 8 h lighting (green or white) while Bglap increased by 12 h lighting (green or white). Tibiotarsal expression of Col10a1 increased by 12 h lighting (white and green), and in 8 h green lighting, and Spp1 expression was higher under light illumination. The hatchling blood triiodothyronine concentration in 8 h green lighting was higher than that in control, whereas, thyroxine concentration was lower under 12 h white lighting compared with other treatments. Femoral organic matter to mineral (OM:M) ratio and calcium concentration were higher in the eight-hour white light group than in the control, but tibiotarsal OM:M ratio and calcium and phosphorus concentrations were higher under 12 h white light. The findings indicated that lighting during incubation may impact, both positively and negatively, bone morphology and gene expression. More studies are needed to find the most beneficial lighting system during incubation in chickens. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the nitrogen requirements of Holstein suckling calves at 2, 6 and 8 weeks of age. Newborn healthy calves, randomly divided into 2 groups (n=16 per group), were fed with either a starter based on corn or barley. The calves received pasteurized cow's milk in accordance to the herd schedule. The calves were housed in individual metabolic cages and urinary and fecal nitrogen contents were measured in samples collected for four days at 2, 6 and 8 weeks of age. Nitrogen requirement was estimated using the regression analysis. Nitrogen requirement for maintenance at week 2 significantly (P=0.037) differed between the starters, but not at 6 and 8 weeks. However, the nitrogen requirement for maintenance at 8 weeks of age tended to be differ between male and female calves (P=0.075), but not at weeks 2 and 6. Daily nitrogen requirements for maintenance based on the metabolic weight decreased as the calves aged. Nitrogen requirement for growth was affected by the type of grain in the diet at weeks 2 (P=0.068), 6 (P<0.05) and 8 (P<0.05). No effect of sex was found on nitrogen requirements for growth (P>0.05). [ABSTRACT FROM AUTHOR]

Adding corn silage (CS) instead of alfalfa hay (AH) to the finely ground starter diet would improve calf performance if feed intake or feed efficiency is increased. We investigated the effects of replacing AH with CS in the starter diet on nutrient intake, digestibility, growth performance, rumen fermentation and selected blood metabolites in Holstein calves. Newborn male calves (n = 30; 3 days of age; 40.2 ± 1.28 kg BW) were assigned randomly to three groups receiving starter diets containing chopped AH (10% dry matter (DM) basis; AH diet), CS (10% DM, CS diet) or their combination (each at 5% level; AHCS diet). The starter diets had the same nutrient composition but differed in DM content (91.2%, 87.5% and 83.8% for AH, AHCS and CS, respectively). The calves were weaned on day 50, and the study continued until day 70. Nutrient intake, BW (at weaning and at the end of the study) and body measurements were not affected by the diet. During the post-weaning period, average daily gain tended to be greater on CS than on AH diet. Feed efficiency was greater in CS than in AH or AHCS calves during the post-weaning period. Digestibility of neutral detergent fiber was greater in AHCS and CS compared with AH during the post-weaning period. Concentration and profile of volatile fatty acids and ruminal fluid pH were not affected by the diet. Replacing AH with CS in the starter diet had no effect on feed intake, growth performance and general health of the calves. These results indicate that AH and CS can be used interchangeably in dairy calf starter diets until 70 days of age, allowing dairy producers more choices in selecting the feed ingredients. [ABSTRACT FROM AUTHOR]

Summary: Mutations in keratin genes underlie a variety of epidermal and nonepidermal cell‐fragility disorders, and are the genetic basis of many inherited palmoplantar keratodermas (PPKs). Epidermolytic PPK (EPPK) is an autosomal dominant disorder that can be due to mutations in the keratin 1 gene, KRT1. Epidermolytic ichthyosis (EI), the major keratinopathic ichthyosis, is characterized by congenital erythroderma, blistering and erosions of the skin. Causative mutations in KRT1 and KRT10 have been described, with PPK being present primarily in association with the former. We report four unrelated cases (one with sporadic EI and three with autosomal dominant PPK), due to two novel and two recurrent KRT1 mutations. Mutations in KRT1 are not only scattered throughout the keratin 1 protein, as opposed to being clustered, but can result in a range of phenotypes as further confirmed by these mutations, giving a complex genotype/phenotype pattern. [ABSTRACT FROM AUTHOR]