Study of soil-plant (potato and beetroot)-animal cycle of nutritive and hazardous minerals in a rabbit model

Potato and beetroot were grown on soils previously treated with heavy metal salts. Each particular microelement had a high concentration in both potato and beetroot [cadmium (Cd) 3.7 and 55.4, lead (Pb) 8.1 and 3.0, and mercury (Hg) 5.8 and 6.8 mg/kg dry matter, respectively]. In a metabolic balance trial 16 New Zealand White rabbits were fed 50 grams of basal diet and potato or beetroot ad libitum. The apparent digestibility of major nutrients and the accumulation of the microelements in different organs were investigated. Both potato and beetroot samples of high Pb and Hg content had the significantly (p < 0.05) lowest digestibility of organic matter and nitrogen-free extract. The Cd ingested from both potato and beetroot accumulated in the kidneys and liver (2.85 and 1.48 as well as 0.459 and 0.265 mg/kg, respectively). All the microelements (Cd, Pb and Hg) accumulated in the testicles (0.196, 0.32 and 0.199 mg/kg, respectively), reducing the rate of spermatogenesis. The tissue retention ofheavy metals depends not only on the element itself, but also upon the ‘carrier’ feedstuff

Influence of feeding intensity on corporeal development, body composition and sexual maturity in female rabbits

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

Reduction in primary production followed by rapid recovery of plant biomass in response to repeated mid-season droughts in a semiarid shrubland

The frequency and severity of extreme weather events, including droughts, are expected to increase due to the climate change. Climate manipulation field experiments are widely used tools to study the response of key parameters like primary production to the treatments. Our study aimed to detect the effect of drought on the aboveground biomass and primary production both during the treatments as well as during the whole growing seasons in semiarid vegetation. We estimated aboveground green biomass of vascular plants in a Pannonian sand forest-steppe ecosystem in Hungary. We applied non-destructive field remote sensing method in control and drought treatments. Drought treatment was carried out by precipitation exclusion in May and June, and was repeated in each year from 2002. We measured NDVI before the drought treatment, right after the treatment, and at the end of the summer in 2011 and 2013. We found that the yearly biomass peaks, measured in control plots after the treatment periods, were decreased or absent in drought treatment plots, and consequently, the aboveground net primary production was smaller than in the control plots. At the same time, we did not find general drought effects on all biomass data. The studied ecosystem proved resilient, as the biomass in the drought-treated plots recovered by the next drought treatment. We conclude that the effect of drought treatment can be overestimated with only one measurement at the time of the peak biomass, while multiple within-year measurements better describe the response of biomass

Effect of ingested heavy metals (Cd, Pb and Hg) on haematology and serum biochemistry in rabbits

In order to investigate the effects of exposure to possible environmental pollutants such as Cd, Pb and Hg on haematological and serum biochemistry values, New Zealand White female rabbits were treated orally with distilled water solutions of CdSO4·H2O, Pb(NO3)2 and HgCl2 (n = 4/treatment) in concentrations of 2.3, 4.1, and 30 mg/kg dry matter, respectively, for 28 days. The initial concentrations of Cd, Pb, and Hg in serum were significantly increased by the treatment. Exposure to Pb significantly decreased the red blood cell (RBC) count, haemoglobin (Hgb) concentration and the haematocrit (Hct) value. The Zn-protoporphyrin concentration did not change as a result of Pb exposure. Pb and Hg loading significantly increased the aspartate aminotransferase (AST) activity. Alanine aminotransferase (ALT) activity was also increased by both Hg and Cd exposure. Comparing the treated and the control rabbits, all the trace elements studied significantly reduced the activity of enzymes in the pancreatic tissues. The haematological results indicate that hyperchromic macrocytic anaemia developed in rabbits treated with Pb. The increased activities of both AST and ALT indicate pathophysiological changes of the liver parenchyma, which was verified by focal fatty infiltration seen histopathologically. Cd exposure could exert a toxic effect on the kidneys, although the slight tubulonephrosis developed would not possibly affect the renal function. The reduced activities of amylase, trypsin, protease and lipase induced by Cd, Pb and Hg suggest toxicity to the pancreas

Study of the energy and protein balance of pregnant rabbit does using two comparative methods

The total body composition of 4×10 female, 5-month-old New Zealand White rabbits was determined, using direct chemical analysis and computerised tomography (CT). Ten non-pregnant rabbits (control) and 3 × 10 pregnant rabbits at days 14, 21 and 28 of gestation, respectively, were included in the study. With the advancement of pregnancy, the body weight (BW) of does significantly (P < 0.05) increased (control: 3255 g, day 28: 3938 g), while the dry matter, DM (control: 43.02%, day 28: 40.94%), ether extract, EE (control: 20.15%, day 28: 18.13%), crude protein, CP (control: 20.15%, day 28: 18.13%), and energy concentration decreased (control: 12.41 MJ/kg BW, day 28: 11.81 MJ/kg BW). During pregnancy the protein content of uteri (control: 12.24%, day 28: 49.45% of DM) and the retained energy in the form of uterus with fetuses (day 14: 0.824 MJ, day 28: 2.189 MJ) increased, while the dry matter (control: 82.39%, day 28: 28.96%) and ether extract content (control: 86.05%, day 28: 45.92% of DM) of uteri decreased. With the advancement of pregnancy the dry matter (day 14: 39.70%, day 28: 18.65%) and crude protein (day 14: 75.74%; day 28: 63.63% of DM) content and the number of fetuses (day 14: 8.8; day 28: 6.4) decreased, while their fat concentration (day 14: 10.13%, day 28: 24.34% of DM) increased. According to the equations created from the CT pictures, body fat (R2 = 0.871) and energy (R2 = 0.926) content can be predicted with high accuracy. The accuracy of predicting body protein content is much lower (R2 = 0.356), which can be improved by introducing the body weight as a new dependent variable (R2 = 0.797). It can also be concluded that, in contrast to other animal species, rabbit fetuses show considerable development not only in the last trimester of gestation but already from the second half of pregnancy

Effect of inorganic and organic manganese supplementation on the performance and tissue manganese content of broiler chicks

The effects of dietary levels of manganese (Mn) in inorganic (MnO) and organic (Mn fumarate) forms were evaluated on cockerel chicks. A basal corn-soybean diet with 23 mg/kg Mn was supplemented with levels of 0, 30, 60 and 240 ppm Mn from both Mn sources. Each treatment was replicated in five pens of 10 chicks. The chicks were fed diets ad libitum from 14 to 49 days of age, after which five birds per treatment were sacrificed for pathomorphological examinations and analysis. The treatments did not exert significant effects on the body weight (BW), the feed/gain (F/G) ratio or the mortality rate. According to the necropsy findings, no growth retardation or emaciation occurred in either of the groups and the differences in the average absolute and relative organ weights were not significant (P ? 0.05). Tissue analysis indicated that the tibia showed the greatest response to Mn, followed by the liver and kidney. Accumulation in the tibia was higher (P < 0.05) with supplements of 30, 60 and 240 mg/kg from both Mn sources (3.71, 3.78, 4.44, and 3.68, 4.00, 4.36 mg/kg DM, MnO and Mn fumarate, respectively) compared to the control group (3.21 mg/kg). Accumulation in the liver increased significantly (P < 0.05) only with supplements of 60 and 240 ppm independently of the Mn source (12.7, 14.2, and 14.0, 14.9 mg/kg, respectively) compared to the control (9.8 mg/kg). Similarly, kidney tissue Mn was higher (P < 0.05) only with supplements of 60 and 240 ppm (12.8, 12.8, and 13.1, 12.5 mg/kg, respectively) compared to the control (10.2 mg/kg). At the same level of supplementation of the two Mn sources there were no significant differences (P ? 0.05) between the Mn concentrations of organs and tissues. Droppings sensitively reflected the intake, whereas blood plasma and feathers showed only the extreme Mn loading

Effects of nickel supply on the fattening performance and several biochemical parameters of broiler chickens and rabbits

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 non-significant beneficial effects on the growth performance of broiler chickens and rabbits

Long-chain polyunsaturated fatty acid status in obesity: a systematic review and meta-analysis

Long-chain polyunsaturated fatty acid (LCPUFA) status has recently been related to the pathogenesis of obesity. Our aims were to systematically review observational studies investigating LCPUFA status from different blood compartments in overweight or obese subjects and to assess the relationship between LCPUFA profile and obesity. The Ovid MEDLINE, Scopus and Cochrane Library CENTRAL databases were searched from inception to January 2014. The meta-analysis showed significant differences in the LCPUFA composition of total plasma lipids, plasma phospholipids and plasma cholesteryl esters between overweight or obese subjects and controls. Dihomo-\u3b3-linolenic acid (DGLA) values were significantly higher in overweight or obese subjects compared with controls in all the investigated biomarkers. In addition, the DGLA/linoleic acid ratio (surrogate parameter for \u3946 desaturase activity) in plasma phospholipids was significantly elevated (mean difference [MD]: 0.05; 95% confidence interval [CI]: 0.02, 0.08; n\u2009=\u2009280), while the arachidonic acid/DGLA ratio (surrogate parameter for \u3945 desaturase activity) was significantly decreased (MD: -0.55; 95% CI: -0.71, -0.39; n\u2009=\u2009347) in overweight or obese subjects compared with controls. The results of the present meta-analysis confirm that LCPUFA profile is altered in obesity and suggest that the differences observed in desaturase activities may be responsible for the disturbed LCPUFA metabolism in obesity