Igino Andrighetto

Effect of type of housing on veal calf growth performance, behaviour and meat quality

A study compared the traditional housing of veal calves in individual crates (IC) with group pen housing (GP). Thirty-four pure Holstein male calves (67.6±4.9 kg LW) imported from Poland were used, of which 16 were kept tethered in IC while the remaining animals were housed in six pens of three calves each. The growth trial lasted 142 days during which the calves were fed only a milk replacer diet. Calves health, average daily gain (ADG) and feed efficiency (FE) were similar between types of housing throughout the trial. However, GP calves had higher ADG (1387 vs. 1317 g/day; P<0.05) and better FE (1.83 vs. 1.94; P<0.05) than IC calves in the last 72 days of the trial. Behavioural measurements were taken at the 10th week of the study. The GP calves were allowed to adopt more comfortable resting postures and displayed increased social behaviour than the IC calves. Haemoglobin in samples taken at the end of the growing cycle was higher in GP than in IC calves (10.9 vs. 7.7 g/100 ml; P<0.01). At slaughter, the dressing percentage was unaffected by the housing system, but GP calves showed a better carcass conformation than IC calves. Meat quality evaluation was carried out on the Longissimus thoracis muscle. The meat of GP calves had lower intramuscular fat content (3.92 vs. 6.85% DM; P<0.01) and showed a better tenderness and flavour than that of the IC calves. Consistent with the haemoglobin data, the calves reared in group pens produced carcasses and meat with a darker colour than calves in individual crates.

Identification of undeclared sources of animal origin in canine dry foods used in dietary elimination trials.

Failure to respond to commercial limited antigen diets can occur in dogs kept on a dietary trial for the diagnosis of adverse food reaction (AFR). The aim of this study was to assess twelve canine dry limited antigen diets (eleven novel protein diets and one hydrolysed diet) for potential contamination by ingredients of animal origin not mentioned on the label. The validity of the two methods adopted for the detection of such food antigens was also evaluated. Each dietary product was analysed by microscopy analysis using the official method described in Commission Regulation EC 152/2009 with the aim of identifying bone fragments of different zoological classes (mammalian, avian and fish) and by polymerase chain reaction (PCR) for the identification of DNA of animal origin. Discrepancies between the results obtained by PCR and/or microscopy analysis and the ingredients listed on pet food packages were found. Only in two pet foods did the results of both analyses match the ingredients listed on the label. In the remaining ten samples, microscopy detected bone fragments from one or two unpredicted zoological classes, revealing avian fragments in six of ten samples followed by those of fish in five of ten and mammalian fragments in four of ten. In two samples, microscopy analysis identified a contamination that would have otherwise passed unobserved if only PCR had been used. However, PCR confirmed the presence of all the zoological classes detected by microscopy and also identified the DNA of an additional unexpected zoological class in two samples. Dogs might fail to respond to commercial limited antigen diets because such diets are contaminated with potential allergens. Both PCR and microscopy analysis are required to guarantee the absence of undeclared animal sources in pet foods. Before ruling out AFR, a novel protein home-made diet should be considered if the dog is unresponsive to a commercial regimen.

Effects of feeding propylene glycol to mid-lactating dairy cows

Propylene glycol (PG) is a gluconeogenic precursor widely used to prevent and treat ketosis postpartum. The study has investigated the effects of PG administration to dairy cows at mid stage of lactation. According to a 3 × 3 latin square design, three Italian Brown lactating cows (125 ± 7 days in milk) fitted with rumen cannula were fed a corn silage based diet (CP 14.7%, NDF 41.1% DM) with 0, 200 or 400 g day−1 PG added. Dry matter intake was increased by feeding PG with a significant quadratic component per dose (16.2, 17.2 and 16.5 kg day−1 for 0, 200 and 400 g PG day−1, respectively). Milk yield was not affected by PG, averaging 17.1 kg day−1. Average daily gain increased from 64 to 206 and 302 g day−1 when cows received 200 and 400 g day−1 of PG (linear component per dose P < 0.05). Digestibility of the diet did not differ among treatments, whereas repeated rumen fluid samples, taken 0, 2, 4, 6 and 8 h after the meal, showed a consistently lower acetate to propionate ratio when feeding PG. Blood insulin was not affected by PG administration. Except for therapeutic treatments, PG administration to dairy cows at mid stage of lactation should be advised against. Despite the positive effect on intake, administration of the additive, increasing the molar percentage of rumen propionate, contributes to shift the energy partition from milk production to liveweight gain.

Effects of oilseed supplements on milk production and quality in dairy cows fed a hay-based diet

Abstract The influence of rapeseed (Brassica napus L.) and linseed (Linum usitatissimum L.) on feed consumption, milk yield, composition and fatty acid (FA) profile was investigated in lactating dairy cows. According to a Latin square design, twelve cows were assigned to three experimental settings which received a hay-based diet supplemented with one of the following mixtures: cracked barley (1.0 kg) and cracked maize (0.5 kg) as Control diet (C-diet); full fat ground rapeseed (1.0 kg), cracked barley (1.0 kg) and cracked maize (0.5 kg) as Rapeseed diet (R-diet) and extruded linseed (1.2 kg), cracked barley (1.0 kg) and cracked maize (0.5 kg) as Linseed diet (L-diet). Diet supplemented with rape- and linseed did not affect dry matter intake. As result of the high amount of dietary ether extract R- and L-diet showed higher crude fat intake as compared to the control. Despite the higher intake of crude fat and, in particular, of the polyunsaturated fraction, milk yield and composition resulted similar among treatments. Compared to C-diet, R-diet resulted in milk containing significantly lower amounts of saturated fatty acids (SFA) (60.9 vs 66.9% of total detected SFA) as well as higher amounts of monounsaturated fatty acids (MUFA) (30.6 vs 24.2%). However, R-diet had no effect on polyunsaturated fatty acid content (PUFA). With respect to C-diet, L-diet also significantly reduced the content of SFA (59.8 vs 66.9%) and increased both MUFA (29.1 vs 24.2%) and PUFA (4.7 vs 4.1%) contents. Feeding about 1 kg of whole oilseeds per head per day had no clear effects on milk vaccenic acid and conjugated linoleic acid contents. The inclusion of rapeseed in the diet significantly reduced the content of n-6 FA in the milk, whereas the linseed-supplemented diet significantly increased the content of n-3 FA. In comparison to C-diet, n-6/n-3 ratio was lower in L-diet milk and intermediate in R-diet milk. Feeding lactating dairy cows with oilseeds rich in unsaturated fatty acids (UFA) did not exert any effects on productive performance. Considering the increase in PUFA and the reduction of n-6/n-3 ratio as a desirable enrichment of milk fat for human health, under our experimental condition feeding linseed appears to improve the nutritional value of milk better than rapeseed.

Effects of yeast culture addition on digestion in sheep fed a high concentrate diet

Abstract Effects of yeast culture on intake, rumen parameters, digestibility and passage rate were studied in 12 sheep (average BW 59±3.5 kg). A high concentrate diet was supplemented with 0 (control), 20 (Y20) or 40 (Y40) g/d of yeast. DMI tended to be higher (P

Administration of dexamethasone per os in finishing bulls. II. Effects on blood parameters used as indicators of animal welfare.

A set of hormonal, haematological and biochemical parameters was used to evaluate the physiological response and welfare status of 14 finishing Marchigiana bulls treated for 49 days with a low daily dosage (0.75 mg/head per day) of dexamethasone per os. Compared to the Control group, dexamethasone decreased cortisol concentrations (42.3 v. 5.7 nmol/l; s.e.d. = 4.17; P < 0.001), and led to the reversal of the leukocyte formula in the animals treated (P < 0.05). Total serum proteins (70.2 v. 73.9 g/l; s.e.d. = 1.55; P < 0.05), in particular β1 globulins (7.5 v. 9.1 g/l; s.e.d. = 0.24; P < 0.01) and fibrinogen (199 v. 258 mg/dl; s.e.d. = 32.70; P < 0.05), increased as a consequence of treatment. Prolonged dexamethasone administration led the bulls to an apparently chronic stress condition. Moreover, the study indicated various blood parameters that might be used by health officials as effective tools in identifying beef cattle suspected of being illegally treated with dexamethasone.

Effect of induced ruminal acidosis on blood variables in heifers

BackgroundRuminal acidosis is responsible for the onset of different pathologies in dairy and feedlot cattle, but there are major difficulties in the diagnosis. This study modelled the data obtained from various blood variables to identify those that could indicate the severity of ruminal acidosis. Six heifers were fed three experimental rations throughout three periods. The diets were characterised by different starch levels: high starch (HS), medium starch (MS) and low starch, as the control diet (CT). Ruminal pH values were continuously measured using wireless sensors and compared with pH measurements obtained by rumenocentesis. Blood samples were analysed for complete blood count, biochemical profile, venous blood gas, blood lipopolysaccharide (LPS) and LPS-binding proteins (LBP).ResultsThe regression coefficient comparing the ruminal pH values, obtained using the two methods, was 0.56 (P = 0.040). Feeding the CT, MS and HS led to differences in the time spent below the 5.8, 5.5 and 5.0 pH thresholds and in several variables, including dry matter intake (7.7 vs. 6.9 vs. 5.1 kg/d; P = 0.002), ruminal nadir pH (5.69 vs. 5.47 vs. 5.44; P = 0.042), mean ruminal pH (6.50 vs. 6.34 vs. 6.31; P = 0.012), haemoglobin level (11.1 vs. 10.9 vs. 11.4 g/dL; P = 0.010), platelet count (506 vs. 481 vs. 601; P = 0.008), HCO3- (31.8 vs. 31.3 vs. 30.6 mmol/L; P = 0.071) and LBP (5.9 vs. 9.5 vs. 10.5 μg/mL; P < 0.001). A canonical discriminant analysis (CDA) was used to classify the animals into four ruminal pH classes (normal, risk of acidosis, subacute ruminal acidosis and acute ruminal acidosis) using haemoglobin, mean platelet volume, β-hydroxybutyrate, glucose and reduced haemoglobin.ConclusionsAlthough additional studies are necessary to confirm the reliability of these discriminant functions, the use of plasma variables in a multifactorial model appeared to be useful for the evaluation of ruminal acidosis severity.

Effect of the partial replacement of fish meal and oil by vegetable products on performance and quality traits of juvenile shi drum (Umbrina cirrosa L.)

Abstract A four-month growth trial was carried out in order to evaluate performance and quality traits of juvenile shi drum fed with two isonitrogenous and isoenergetic diets having different amounts of vegetable products (Vegetable diet vs. Control diet). Compared to the Control diet, the Vegetable diet was formulated by increasing the replacement of fish meal (14%) with soybean and cereal products, and fish oil (12%) with a mixture of vegetable oil. On June, 4 groups of 225 fish (2 replicates per dietary treatment) were sorted according to live weight and reared in fibreglass tanks over a four- month long experimental period. Fish were hand fed to apparent satiety. Offered feed, growth parameters and feed efficiency were recorded as productive performance. At the end of the trial (October) biometric, chemical and reological traits were examined to assess fish quality. The dietary treatments showed similar productive performance. The relatively high inclusion of vegetable sources led to a significant modification of body shape, mesenteric fat and viscera weight. Among quality traits, Vegetable diet-fed fish demonstrated a significantly lower whole body and fillet crude protein content. Yellowness value of the cooked fillet was significantly lower in the Control diet-fed fish, whereas fillet texture was similar. The results of this research showed that shi drum is a suitable candidate for Mediterranean marine aquaculture and its dietary formulation might include at least the amount of vegetable sources used in this trial.

Effect of period of milk production and ripening on quality traits of Asiago cheese

Abstract After 6 and 12 months of ripening, samples of Asiago d’Allevo were analyzed for quality traits. Cheeses were produced during 3 periods using milk from cows fed a total mixed ration (TMR, May) or grazing on alpine pasture (AG) in early (July) and late (Sept.) summer. Data were submitted to ANOVA considering ripening, milk production period and farm as main effects, and whole cheese weight as covariate. During ripening, pH of AG-cheese was significantly lower than that of TMR-cheese; crude fat and protein significantly increased. According to period, July-samples showed the significantly lowest value of dry matter (DM), maybe due to a lower crude fat con-tent; however, variability in skimming method could have altered proximate composition. No texture differences were found, although increasing weight of whole cheese significantly reduced max shear force as result of a lower DM content. Lightness (L*) and yellowness (b*) significantly decreased during ripening. AG feeding system caused a lower L* and higher b* than TMR one, probably as a consequence of a different amount of milk pigments. Cheese varied also within AG season: Sept.-samples showed the lowest L* value and the highest b*.

Growth performance, behaviour, forestomach development and meat quality of veal calves provided with barley grain or ground wheat straw for welfare purpose

Abstract Two different feeding plans for veal calves were compared in the study: a traditional liquid diet supplemented with 250 g/calf/d of barley grain or with 250 g/calf/d of ground wheat straw. The two solid feeds had different chemical composition but a similar particle size obtained by grinding the straw in a mill with an 8-mm mesh screen. Twenty-four Polish Friesian male calves were used in the study and they were housed in individual wooden stalls (0.83 x 1.80 m). The health status of all the calves was satisfactory for the entire fattening period and no specific medical treatment was required during the trial. Calves fed wheat straw showed a greater intake of solid feed (196 vs. 139 g/d; P<0.01) and a higher average daily gain (1288 vs. 1203 g/d; P<0.05) than those receiving barley grain. The consumption of milk replacer was not affected by the type of solid feed and no milk refusal episodes were detected. The haemoglobin concentration was similar in calves receiving the two feeding treatments despite the higher iron intake provided by the wheat straw throughout the fattening period (2.12 vs. 1.15 g; P<0.001). It is likely that the iron in wheat straw was less available for the calves’ metabolism. Feeding behaviour was affected by the provision of solid feeds. Eating and chewing were prolonged in calves receiving ground wheat straw and the same solid feed reduced the frequency of oral stereotypies at the end of the fattening period. At the slaughterhouse, no differences were observed between the feeding treatments as regards carcass weight and dressing percentage. The calves fed ground wheat straw had a heavier weight of the empty omasum (518 vs. 341 g; P<0.01) whereas the empty weight of the reticulorumen and abomasum were similar to those of calves fed barley grain. The incidence of abomasal erosions, ulcers and scars was similar in both treatments; however the index of abomasal damage, which considers the number and the seriousness of different type of lesions, was higher in calves receiving barley grain. Therefore, the grinding of straw particles, as opposed to barley grain, can reduce the abrasiveness of roughage at the abomasum level. Visual evaluation of the carcass colour and instrumental measurement of meat colour did not show significant differences between diets. The study confirmed that in the veal calf, carcass and meat colour are not strictly correlated with the iron intake from solid feeds.