Effect of macronutrient ratio of the pre‐starter diet on broiler performance and intermediary metabolism

The aim of this study was to investigate the influence of isoenergetic substitution between the three energy delivering macronutrients in pre‐starter diets on performance and intermediary nutrient metabolism in broiler chickens. From hatch until 5 days of age, 600 chicks, collected during peak of hatch, were fed one of the three experimental pre‐starter diets with isoenergetic (13 MJ metabolisable energy/kg) substitutions between fat (43 vs. 108 g/kg), protein (126 vs. 240 g/kg) and carbohydrates (391 vs. 510 g/kg). After 5 days, commercial grower and finisher diets were provided. Pre‐starter composition influenced body weight until slaughter age, although not statistically verifiable. Broilers fed the low protein (LP) pre‐starter had the lowest body weight in relation to chickens on the low carbohydrate or low fat pre‐starter diet. After hatch, chicks on the LP pre‐starter diet were able to use the residual yolk sac more rapidly to fulfil their protein requirement, which is reflected in small intestine and liver development. Also, plasma metabolite levels were influenced mostly by the LP pre‐starter, indicating that the main focus for the requirements of newly hatched chicks should be on proteins. Furthermore, optimal nutrition during the first day’s post‐hatch should take into account the contribution of the yolk.     

Spreading of West Nile virus infection in Croatia

West Nile virus (WNV) is an emerging zoonotic pathogen with rapid global expansion. The virus circulation is confirmed in many countries of Mediterranean Basin and Southern and Central Europe. In our study detection of specific WNV antibodies was performed in horses and cattle sera samples collected from October 2010 to April 2011. Serum samples were randomly taken from different parts of Croatia and tested by IgG and IgM ELISA. Positive serological results were confirmed by virus neutralization assay (VN-assay) and plaque reduction neutralization test (PRNT). Results showed that WNV antibodies were present in 72 out of 2098 horse sera (3.43%) and 3 of 2695 cattle sera (0.11%). The highest seroprevalence was found in Eastern Croatia in counties next to Hungarian, Serbian and Bosnia and Herzegovinian state borders. In Adriatic part of Croatia positive animals were found only in the westernmost county, near Slovenian and Italian borders. Geographic distribution and number of positive horses indicated that WNV is highly present in Croatia and spreading from East to West. However, positive horses in westernmost part of country indicate possible second origin of spreading. Location of serological positive cattle supports the hypothesis that seropositive cattle could be indicators of high WNV activity in the respective geographic regions.     

A new approach to recording plumage deterioration

1. Recording methods for the scoring of plumage wear are reviewed. 2. A new technique, distinguishing between feather tracts, the surface to which damage occurs and the degree of degradation to the feathers themselves is elaborated: a 5 step scale for degradation is applied to all appropriate fractions of 6 feather regions. After correcting for the normal feather weight in the respective areas, all 6 area values are summed to constitute an overall index of body plumage wear (IBPW).     

Haematological characteristics predicting susceptibility for ascites. 2. High haematocrit values in juvenile chickens

1. Male broilers of two different genetic stocks, a pure broiler sire line (A) and commercially available Ross broilers (B), were used to study the effect of differences in haematocrit values in 12-d-old chickens on the development of ascitic symptoms. Body weight gain (BWG), feed intake (FI) and feed conversion ratio (FRC) were measured from 2 to 5 weeks of age. Mortality was recorded from 2 to 6 weeks. The birds were kept at a low ambient temperature to stimulate the incidence of ascites. 2. From each stock 32 birds with the highest (High Ht) and 32 birds with the lowest (Low Ht) haematocrit values in venous blood were selected at 12 d of age for an examination on susceptibility for the ascites syndrome at 5 weeks. 3. At 2 weeks 448 birds per stock (including High Ht and Low Ht birds) were allotted to 32 floor pens (1 High Ht and 1 Low Ht in each pen). Venous blood samples were taken weekly in High Ht and Low Ht birds for haematocrit measurements and at week 5 also thyroid hormone (T3, T4) concentrations in plasma were measured. At 5 weeks all High Ht and Low Ht birds were examined post-mortem and arterial pressure index, heart weight, lung weight and liver weight (all relative to body weight) were recorded. High values for arterial pressure index, relative heart and liver weights and low values for relative lung weights and plasma thyroid hormone were considered to be indicators for ascites susceptibility. 4. Stock A, with the highest ascites mortality, had lower values for BWG and FCR than stock B. Throughout, a clear difference in Ht values between High Ht and Low Ht birds was maintained. No significant effects of 12-d haematocrit values were found on the incidence of ascitic symptoms until week 5. High Ht values tended to correlate with low relative lung weights and low plasma T3 concentrations in High Ht birds. 5. Within the groups of selected birds, there was an effect of stock on ascitic symptoms (arterial pressure index, relative heart weight and T3 values) at week 5. This is consistent with a higher ascites mortality in flock A than in flock B, over the whole period up to 6 weeks. Until 4 weeks both A and B were similar with respect to mean Ht values of High Ht and Low Ht groups. After 4 weeks Ht values were very high in the High Ht birds of stock A, possibly as a result of the susceptibility for ascites of stock A. There was a significant interaction between stock and Ht values on the ascites-related variable arterial pressure index. Only in stock A was high arterial pressure at 5 weeks related to high Ht values at d 12. 6. Overall it was concluded that a high Ht in blood of juvenile chickens has limited practical value in predicting incidence of ascites at 5 weeks of age.     

Dynamic tracheal collapse as a cause of exercise intolerance in a thoroughbred

A 2-year-old Thoroughbred filly was admitted to the hospital for evaluation of exercise intolerance. Resting videoendoscopic evaluation (i.e., while the horse was standing) of the nasopharynx and trachea revealed right arytenoid paresis and a tracheal defect that was 100 cm distal to the external nares. Surgery, consisting of a right prosthetic laryngoplasty, was performed. However, postoperative videoendoscopic evaluation revealed minimal abduction of the affected arytenoid cartilage. Dynamic videoendoscopic evaluation (i.e., while the horse was exercising) revealed the right arytenoid to be fixed in a submaximal position with no evidence of collapse into the airway. When the endoscope was positioned in the midcervical tracheal region, marked tracheal collapse was identified during exercise. Tracheal collapse can critically limit athletic function. Treatment of tracheal collapse depends on causative factors, the length of the trachea involved, and accessibility of the affected tracheal segment. The use of dynamic tracheal videoendoscopy should be considered in athletic horses with exercise intolerance in which the cause cannot be determined from resting or dynamic videoendoscopic evaluations of the nasopharynx.     

Probing structural periodicity (annual ring size) in Scots pine by NMR profiling

The water distribution along a direction normal to the annual rings of a water-saturated sapwood sample from Scots pine (9 mm of length) was determined using NMR one-dimensional imaging. The NMR profiles were obtained at a low-field NMR instrument using pulsed field gradients in Hahn echo experiments. Using a gradient pulse of 60 G/cm, a spatial resolution of 12 μm along the axis was obtained. A subsequent Fourier analysis of the signal intensity along the specified direction enabled the size distribution of the annual rings together with the relative amount of water within the rings to be estimated. The technique is a non-damaging way to determine the annual ring profile in wood, and can be further developed as a mobile technique for annual ring profiling of whole trees.     

EQUINE PARANASAL SINUSOGRAPHY

Contrast paranasal sinusography was a simple procedure that enhanced evaluation of the paranasal sinuses in the standing horse. Two techniques of positive-contrast paranasal sinusography were developed using cadavers and sedated horses. For both techniques, 37% organically bound iodine was used. For the first technique, the conchofrontal sinus was injected with 30 ml of contrast medium followed by an additional 100 ml and 70 ml. For the second technique, the rostral maxillary sinus was injected with 20 ml followed by an additional 50 ml. Each technique enhanced visualization of different paranasal sinuses, and each was necessary for complete positive-contrast radiographic evaluation of the paranasal sinuses. The techniques of positive-contrast radiographic evaluation of the paranasal sinuses are described.     

Insulin-like growth factors in the regulation of avian ovarian functions.

In the past three decades, overwhelming evidence has accumulated to show that insulin-like growth factor (IGF)-I and -II, their receptors and binding proteins (IGFBP) (the IGF system), have major roles to play in the regulation of ovarian function in mammals. Although studies in birds did not start until 5-6 years ago, the limited information thus far available suggests that the IGFs act as autocrine/paracrine regulators of follicular growth and differentiation, just as observed in mammals. The genes for IGF-I and -II, type-I IGF receptor, IGFBP-2, and IGFBP-5 are expressed in both granulosa and theca cells of the chicken ovary. The mechanisms by which the IGF system controls ovarian function in the avian species are complex and involve interactions with the gonadotrophins (LH and FSH), growth hormone, and even other growth factors. Effects are different between strains and nutritional status.