M. Tarantola

Studies of apparent digestibility in horses and the use of internal markers

Abstract The digestibility of horse feeds and rations can be determined by means of different techniques: calculations from the chemical composition of feeds, in vitro and in vivo methods. The aim of this research is to compare indigestible internal markers (acid-insoluble ash (AIA) and acid detergent lignin (ADL)) and total collection techniques for apparent digestibility estimation in horses. Analyses were carried out on two diets, different in concentrate quality, for dry matter, crude protein, crude fiber, ether extract, ash, fiber fractions NDF and ADF, AIA, nitrogen-free extract, organic matter and gross energy. Digestibility of all the parameters, excluding AIA and ash, were calculated on the basis of the total faeces collection and using alternatively AIA or ADL markers. Analysis of variance (ANOVA) was performed to study the different digestibility coefficients. The digestibility coefficients obtained using AIA are very close to those obtained with total collection. Both methods can then be used for digestibility trials in horses. The two diets involved different digestibility levels. Apparent digestibility cannot be estimated using ADL as an internal marker, because of the lack of recovery and consequent great underestimation of digestibility rates.

Acute phase proteins and heterophil:lymphocyte ratio in laying hens in different housing systems

IN most developed countries, approximately 90 per cent of laying hens are kept in cages ([Tauson 1998][1]). From 2012, European Council Directive 1999/74/EC will prohibit the use of conventional cages within the EU, but will permit the use of modified ‘enriched’ cages and non-cage systems.

Effects of housing and short-term transportation on hormone and lymphocyte receptor concentrations in beef cattle

The experiment was designed to evaluate the effects of housing system and short-term transportation on the pituitary and adrenal response and on blood progesterone concentrations of beef cattle. Since the use of steroid hormones in farm animals has been banned in the EU (Council Directive 96/22/EC), it seems important to study the possible modifications in serum progesterone concentrations induced by stress in cattle. Thirty-two, 6 months old male Piedmontese beef cattle (16 reared in a littered loose house, Group A, and 16 housed in a littered tying stall barn, Group B) were blood sampled at T1 (6 months old), T2 (12 months old), T3 (18 months old, before transportation to the slaughterhouse) and T4 (after transportation to the slaughterhouse) in order to measure hormonal concentrations and lymphocyte glucocorticoid (GR) and β-adrenergic (β-AR) receptor concentrations. Circulating hormone concentrations were measured using commercial radioimmunoassay kits, whereas lymphocyte receptor density was determined through binding assays. In beef cattle housed in tie stall barn a significant increase in serum cortisol concentration was observed at T3, whereas there was no effect of the housing system on blood progesterone concentrations. Short-term transportation caused a significant increase in blood cortisol and catecholamine concentrations in both groups, whereas lymphocyte GR and β-AR significantly decreased in Group A. Our data confirm the activation of the hypothalamic-pituitary-adrenal axis and the catecholaminergic system in short-term transportation and suggest that the stress-induced increase in circulating progesterone concentrations does not exceed the limit established by pending legislation.

Effects of low doses of dexamethasone on productive traits and meat quality of veal calves

An experimental administration of dexamethasone was carried out on 15 veal calves in order to assess the rôle of low doses of exogenous glucocorticoids on productive traits and meat quality. Three groups, of five veal calves each, were formed : one group received oral dexamethasone (0·4 mg per calf per day for 25 days), another intramuscular (i. m.) dexamethasone (2 mg at days 14 and 21), and the third was the control. Calves were slaughtered at 165 days of age (day 31). Food conversion ratio (FCR), hot dressing percentage (HDP), chilled dressing percentage (CDP) and shrinkage were determined. From all carcasses, samples of m. longissimus thoracis (between the 8th and 10th rib) were taken in order to evaluate the chemical composition and some organoleptic characteristics : meat colour, waterholding capacity and tenderness. The animals treated with oral dexamethasone showed the lowest daily weight gain ( P < 0·05) and the poorest FCR ( P < 0·05). Hot dressing percentage, cold dressing percentage and shrinkage were not affected by the oral treatment. The i. m. injections of dexamethasone did not influence the overall performance. Muscle chemical composition and pH were not affected by the treatments; the meat of calves treated with oral dexamethasone was significantly lighter ( P < 0·05) and tended to be paler, while i. m. treatment induced intermediate characteristics. The shear force of the meat was rather low. Shear force of cooked meat from animals treated with dexamethasone (both oral and i. m.) was significantly lower than the control (P < 0·05). Treatment with dexamethasone i. m. induced a decrease in water-holding capacity; the oral treatment had no effect on this parameter.

Feeding a diet contaminated with ochratoxin A for chickens at the maximum level recommended by the EU for poultry feeds (0.1 mg/kg). 1. Effects on growth and slaughter performance, haematological and serum traits

The European Commission Recommendation 2006/576/EC, suggests that the maximum level of Ochratoxin A (OTA) in poultry feeds should be set at 0.1 mg OTA/kg. Thirty-six one-day-old male Hubburd broiler chickens were divided into two groups, a Control (basal diet) and an Ochratoxin A (basal diet + 0.1 mg OTA/kg) group. The growth and slaughter performance traits were recorded. The liver, spleen, bursa of Fabricius and thymus weights were measured. The erythrocyte and leukocyte numbers were assayed in blood samples, and the heterophils to lymphocytes (H/L) ratio was determined. Alpha-1-acid glycoprotein (AGP), lysozyme, the total protein and the electrophoretic pattern were evaluated in serum samples. Liver enzymes (alanino aminotransferase, ALT and aspartate aminotransferase, AST) and kidney function parameters (uric acid and creatinine) were quantified. The results revealed that feeding a 0.1 mg OTA/kg contaminated diet to chicks caused a decrease in the absolute thymus weight (p < 0.05) and a lower total protein (p < 0.01), albumin (p < 0.01), alpha (p < 0.05), beta (p = 0.001) and gamma (p = 0.001) globulins serum concentration in the Ochratoxin A group. Moreover, the albumin-to-globulin (A/G) ratio of the OTA-treated animals resulted to be higher (p < 0.05). Feeding broiler chickens, a diet contaminated with the maximum level admitted by the European Commission Recommendation (0.1 mg OTA/kg), did not affect the animal performance, slaughter traits, organ weights, haematological parameters, liver enzyme or renal function parameters concentrations but had an overall immunosuppressant effect, with reduction in the thymus weight and of the total serum protein, albumin, alpha, beta and gamma globulins concentration.

Effect of genotype and transport on tonic immobility and heterophil/lymphocyte ratio in two local Italian breeds and Isa Brown hens kept under free-range conditions

This study was undertaken to investigate the effect of transport and genotype on the welfare and fear response of laying hens through a comparison of three breeds reared in free-range conditions: a commercial strain, the Isa Brown (IBh), and two local chicken breeds, the Bionda Piemontese (BPh) and the Bianca di Saluzzo (BSh). After a journey of 67 km (75 min) from the farmhouse of origin to the experimental station, ninety hens, divided according to breed, were free-range reared for two months. Body weight (BW), tonic immobility (TI), red and white blood cells, heterophil to lymphocyte (H/L) ratio and 1-acid glycoprotein (AGP) were assessed at four different sampling times: at the farmhouse of origin (T1), at 1 day (T2), 15 days (T3) and at 2 months (T4) after arrival at the experimental station. No statistical differences were found between the four sampling times for BW, total red and white blood cells or for AGP. An increase in the H/L ratio (P<0.05) was recorded at time T2 for IBh and BSh, compared to BPh (P<0.05). TI was significantly higher (P<0.05) for the local breeds, BPh and BSh, than for the commercial strain IBh. The results of this study suggest that genetic and adaptive differences can affect both, physiological and ethological parameters.

Egg quality and blood parameters of “Bianca di Saluzzo” and Isa Brown hens kept under free range conditions

Abstract Egg quality traits and some blood parameters of Bianca di Saluzzo hen (BSh) were compared to Isa Brown hen (IBh). Birds were reared in free range conditions. Weight of the whole egg was higher (P≤0.01) for IBh, due to its higher amount of albumen (P≤0.01) whereas BSh egg showed the highest weight and relative percentage of yolk (P≤0.01). IBh and BSh egg chemical composition was similar. Total red cells did not show statistical differences between groups, while total leucocytes were lower (P≤0.05) for BSh Heterophyl/Lymphocyte (H/L) ratio of BSh was lower (P hens. than IBh (0.33 vs. 0.82). IBh α-1 acid glycoprotein (AGP) mean concentrations were affected by time: the values registered after 15 d (T1) and 2 months (T2) of observation were similar (345±132 and 279±58 μg/ml r while AGP value registered after 4 months (T3) were significantly higher espectively), (700±487 μg/ml); BSh did not display any AGP statistical variation over time. IBh albumin mean concentration (1.62 g/dL) was statistically lower than BSh values (1.89 g/dL); in both groups no effect of time of sampling was recorded. Acute phase protein (APP) values of BSh suggested a more adaptive attitude to free range conditions and appeared more constant over time. The present findings suggest genetic or adaptive differences affecting egg quality, physiological and immunological parameters. ≤0.01)

Effects of verbascoside supplemented diets on growth performance, blood traits, meat quality, lipid oxidation and histological features in broiler chickens

A trial has been performed to evaluate the effects of dietary verbascoside (VB) on the growth performance, blood traits, meat quality and histological features of broiler chickens. Seventy-two male broiler chickens (Ross 708) were divided into three experimental groups (8 replicates): a control group (C; basal diet), a low VB group (LVB; basal diet+2.5 mg VB/kg feed) and a high VB group (HVB; basal diet+5.0 mg VB/kg feed). The animals were kept in cages, three birds per cage. The trial lasted 35 days. Growth performance and carcass yield were recorded. Blood samples were collected at day 35 in order to evaluate the blood, serum and plasma parameters. As a result of this study, growth and slaughter performances were not affected by the dietary treatments. The LVB and HVB groups showed significantly lower concentrations of total protein (P=0.000), albumin (P=0.000), α-globulin (P=0.001) and β-globulin (P=0.023) than C group. The heterophil to lymphocyte ratio was higher in HVB group than in LVB and C groups (P=0.005). The thiobarbituric acid reactive substances results indicated lower lipid oxidation in the LVB group than in C group. The most relevant histological feature was the lymphoid depletion observed in the thymus and bursa of Fabricius in LVB and HVB. Other studies are still needed to identify the optimal dosage and exposure time of VB dietary supplementation and to further investigate the effects of VB on lymphoid tissue as well as to establish the VB antioxidant effect on broiler chickens.

Effect of urea treatment on the nutritive value of local sorghum and millet straw: a comparative study on growing performance of Djallonke rams

Abstract Two tons of and chopped millet and sorghum straws have been treated with an urea solution at 5% (100 kg of straw, sprinkled with 50 lt. of solution). Treated straws were used as basic diet (900 g day) associated to 100 g of cotton cake for 24 growing Djallonke rams in comparison to non treated straws. Four groups of animals were fed for 98 days with: urea treated sorghum (UTSS), not treated sorghum straw (NTSS), treated millet (UTMS), non treated millet straw (NTMS). Treated straws presented an increase of NDF of about 9%, of total nitrogen from 2 to 3 times while digestibility of dry matter increased respectively by 8,8% and 23,0% respectively in treated sorghum and millet. Also dry matter intake increased by 4,5% and 15,5% for treated sorghum and millet respectively compared to non treated. Mean weekly weight gain were significantly higher (P<0.05) for UTSS e UTMS compared to NTSS e NTMS. While the weekly weight gain, did not differed between UTSS vs. UTMS and NTSS vs. NTMS. At the end of the trial the UTSS and UTMS group presented a weight gain of about 40% and 38.7%, of their initial weight; while the gain for both NTSS and NTMS was respectively of 31.1% and 29.5%.

Yellow mealworm larvae (Tenebrio molitor) inclusion in diets for male broiler chickens: effects on growth performance, gut morphology, and histological findings

Abstract This study evaluated the effects of Tenebrio molitor (TM) larvae meal inclusion in diets for broilers. A total of 160 male broiler chicks (Ross 708) at one‐day of age were randomly allotted to four dietary treatments: a control (C) group and three TM groups, in which TM meal was included at 50 (TM5), 100 (TM10), and 150 (TM15) g/kg, respectively. The experimental diets were isonitrogenous and isoenergetic. Each group consisted of five pens as replicates (8 chicks/pen). After the evaluation of growth performance and haematochemical parameters, the animals were slaughtered at 53 days and carcass traits were recorded. Morphometric investigations were performed on duodenum, jejunum, and ileum and histopathological alterations were assessed for liver, spleen, thymus, bursa of Fabricius, kidney, and heart. The live weight (LW) showed a linear (12 and 25 days, P < 0.001 and P < 0.05, maximum with TM15 and TM10) and quadratic (53 days, P < 0.05, maximum with TM5) response to dietary TM meal inclusion. A linear (1 to 12 and 12 to 25 days, P < 0.001, maximum with TM15) and quadratic (12 to 25 days, P = 0.001, maximum with TM15) effect was also observed for the daily feed intake (DFI). The feed conversion ratio (FCR) showed a linear response (25 to 53 and 1 to 53 days, P = 0.001 and P < 0.05, maximum with TM15). Haematological and serum biochemical traits, carcass traits and histopathological findings were not affected by dietary TM meal inclusion (P > 0.05). TM15 birds showed lower villus height (P < 0.05), higher crypt depth (P < 0.05), and lower villus height to crypt depth ratio (P = 0.001) compared with C and TM5. In conclusion, increasing levels of dietary TM meal inclusion in male broiler chickens may improve body weight and feed intake, but negatively affect feed efficiency and intestinal morphology, thus suggesting that low levels may be more suitable. However, no effect on haematochemical parameters, carcass traits, and histological findings were observed in relation to TM meal utilization.