Broiler chicken and rabbit experiments were carried out to study the effects of nickel (Ni) supplementation on growth performance and Ni metabolism. ROSS cockerels and New Zealand White female rabbits were fed a diet containing Ni in concentrations of 0, 50 and 500 mg/kg in dry matter (DM). Dietary supplementation of 50 mg Ni/kg slightly improved the body weight gain (BWG) and had a beneficial effect on the feed conversion efficiency (FCE) in broiler chickens. However, Ni added at a level of 500 mg/kg significantly (P < 0.05) reduced the BWG by 10% and resulted in significantly (P < 0.05) worse (2.3 ± 0.2 kg/kg) FCE. The relative weight of the liver in cockerels was significantly (P < 0.05) decreased by Ni as compared to the control group (1.7 and 2.1% vs. 2.6%). The activity of AST and CHE enzymes was increased insignificantly by dietary supplementation of 500 mg Ni/kg, indicating damage of the liver parenchyma. The results of serum biochemistry were confirmed by a mild or moderate form of pathological focal fatty infiltration of the liver in broilers. Supplemental Ni of 50 mg/kg concentration resulted in non-significantly increased BWG in rabbits. Ni added to the diet at a level of 500 mg/kg reduced the digestibility of crude protein by 3-4% and that of crude fibre by 20-25% in rabbits. Approx. 98% of the ingested Ni was lost from the body via the faeces, 0.5-1.5% via the urine and approx. 1% was incorporated into the organs of rabbits. As a result of dietary supplementation of 50 and 500 mg Ni/kg, Ni accumulated in the kidneys (4.9 ± 0.5 and 17.1 ± 3.1 vs. 1.9 ± 0.3 mg/kg DM), ribs (10.3 ± 0.4 and 10.4 ± 0.6 vs. 9.1 ± 0.6 mg/kg DM), heart (1.4 ± 0.2 and 2.5 ± 0.4 vs. 1.0 ± 0.1 mg/kg DM) and liver (1.3 ± 0.1 and 2.2 ± 0.2 vs. 0.9 ± 0.05 mg/kg DM), as compared to the control animals. It can be stated that supplementation of the diet with 50 mg Ni/kg had slight but nonsignificant beneficial effects on the growth performance of broiler chickens and rabbits.

No abstract

Twenty-six 6-week old female New Zealand White rabbits were divided into two groups: ad libitum (AL) and 70% restricted (RS) feeding. At the beginning of the experiment the liveweights were practically the same: 0.99 +/- 0.08 vs. 1.01 +/- 0.08 kg in group AL and RS, respectively. At 18 weeks of age the body weight of Group RS rabbits was 84.7% (3.14 +/- 0.24 kg) of the group AL (3.71 +/- 0.31 kg). The apparent digestibility of crude protein was significantly (p < 0.001) higher in Group RS than in Group AL (76.5 +/- 1.4 vs. 73.0 +/- 2.7%). The daily water consumption was significantly (p < 0.05) higher (3.5 ml/g DM intake) in Group RS as compared to Group AL (1.9 ml/g DM). Since the average body weight in Group RS at 18 weeks was the same as that of Group AL at 14 weeks of age (3.14 kg), the comparison of the live body measures and indices was based on these ages. Animals fed ad libitum or restricted show no differences at the defined age in most live body measurements except in heart girth and rump width, which were significantly (p < 0.05) shorter in Group AL than in Group RS (29.3 +/- 0.8, 5.7 +/- 0.5 and 30.7 +/- 1.0, 6.2 +/- 0.3 cm, respectively). Body capacity was significantly (p < 0.05) smaller in Group AL, as the head capacity-body capacity proportion was significantly (p < 0.05) higher in Group AL than in Group RS (1653.1 +/- 134.5, 22.0 +/- 2.5 and 1913.7 +/- 168.7, 17.7 +/- 1.9, respectively). Due to restricted feeding the growth of the head proved to be less intensive than that of the body at the same body weight. The body in these does tended to be wider. Since the head in comparison to length or capacity of the body was smaller in does fed 70% of ad libitum, it could be concluded that the development of body parts of restricted-fed does was unequal (allometric growth). The effect of feed restriction reflected in lower dry matter and fat, and a higher ash and protein content both in total body and in dry matter composition of rabbits at 18 weeks of age. Restricted feeding delayed sexual maturity (69 vs. 92% of rabbits) with later starting ovarian activity, weaker ovarian responsiveness, and a smaller number of tertiary follicles on the ovarian surface.

A retrotransposon insertion in the SILV gene is associated with a peculiar phenotype of dog, known as a merle. It is characterised by various areas of their coat colour becoming diluted due to a malfunction in the eumelanin-producing pigment cells. Recent studies have shown that the exact size of the short interspersed element (SINE) insertion is in correlation with specific phenotypic attributes, but was not able to absolutely confine dogs to a certain colour pattern. Our study focused on the merle variations occurring in the Mudi breed. Altogether, 123 dog samples from 11 countries were tested and genotyped. The exact length of the merle alleles were determined by automated fluorescent capillary fragment analysis. The most frequent merle genotype in this Mudi sample collection was the ‘classic’ merle (m/M: 61.8%), whereas other variants, such as atypical (m/Ma and m/Ma+: 5.7%), harlequin (m/Mh: 13.8%), double merle (M/M: 0.8%) and mosaic profiles (17.9%) were also observed. The practical significance of testing this mutation is that, phenotypically, not only merle dogs are carriers of this insertion, but also the so-called hidden merle individuals (where the merle phenotype is fully covered by the pheomelanin-dominated colouration) are potentially capable of producing unintentionally homozygous ‘double merle’ progeny with ophthalmologic, viability and auditory impairments.

Several animal carcasses were found in the paddocks of a Hungarian County Zoo during 1 week. The 14 animals killed were thought to be the victims of a dogfight training. The primary suspect was the security guard of the Zoo with his guard dogs. DNA tests were carried out on hairs and bloodstains and 10 canine-specific STR loci were analysed by fluorescently labelled multiplex PCR using the ABI PRISM 310 Genetic Analyzer. The results confirmed that the killer was a single animal and all of the guard dogs were excluded.