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To characterise the main Italian dual-purpose breeds in terms of feed efficiency and behaviour, the dry matter intakes (DMI) of 890 young bulls were collected using automatic feeding systems in two Italian genetic centres. In Experiment 1, Italian Simmental (IS), Rendena (RE) and Alpine Grey (AG) young bulls were fed total mixed ration for 46 days. In Experiment 2, Valdostana Red Pied (VR) and Black Pied and Chestnut (VB) young bulls were fed hay and concentrate for 60 days. The IS and RE bulls grew faster than AG (1.6 vs. 1.3 kg/d, p <.01). The DMI was highest for IS and lowest for AG while all breeds had similar values for DMI expressed as relative to body weight. Overall, RE and AG bulls were more efficient than IS. Regarding feeding behaviour, the number of feeding events for IS and AG was higher than for RE, while the feeding time was not different between breeds. The IS bulls showed a higher value of feeding rate (FR) than RE and AG (98.2 vs. 83.1–86.5 g DM/min, p <.01). Overall AG breed, despite its high feeding activity, was particularly efficient. In addition, efficient animals showed a low FR compared to inefficient ones. In Experiment 2, VR and VB strains were quite similar in terms of growth capacity but VR was more efficient despite its higher daily activity. In conclusion, dual-purpose breeds can reach notable growths and feed efficiencies and FR is well related to feed efficiency. Rendena and Alpine Grey bulls are slightly more efficient than Italian Simmental bulls Valdostana strains differ for feed efficiency but not for growth capacity Feeding rate is a useful behaviour trait to consider in the study of feed efficiency [ABSTRACT FROM AUTHOR]

The aim of the trial was to evaluate the effect of dietary additions of Stevia rebaudiana Bertoni extract (SB) and Chestnut wood tannin (CWT) on the in vitro rumen fermentability, protozoal population and methane yield. Both plant products were tested at 3 different levels of inclusion (0.75, 1.50 and 3.00% of incubated dry matter, DM) in a total mixed ration (TMR) for ruminants by using rumen batch culture systems and a rumen inoculum collected from sheep. Total volatile fatty acid concentration, their proportions and gas production were not modified by the plant extracts inclusion, except a significant linear increment of gas production at 24 hr for SB (p =.049). Ammonia concentration decreased (p <.05) of about 17% when 1.50 or 3.00% of CWT were included into TMR. Rumen protozoa population was depressed by the SB inclusion (p =.002) with a maximum reduction of 40% at the highest SB dosage, whereas CWT negatively affected total protozoa counts (−19%) only at the dose of 3.00%. In vitro DM and NDF degradability were not affected by the supplementation of SB and CWT, as well as the methane yield. Thus, the addition of SB and CWT decreases the in vitro protozoa population of the rumen with different intensity and without effects on fermentation parameters, apart from a reduction of nitrogen degradability caused by CWT. Despite the effect on protozoa, no decreasing effect on methane production was detected. [ABSTRACT FROM AUTHOR]

This research aims at evaluating the effects of the dietary addition of a supplement containing 75% of chestnut tannins (CT) on growth performance, slaughter traits (Experiment 1) and on nutrient utilisation (Experiment 2) of Italian heavy pigs. Exp. 1 compared a control (C) diet with diets containing 0.15 or 0.30% of CT supplement. Forty-two barrows (91 ± 6 kg of BW) were divided into pairs and kept in 21 partially-slatted pens equipped with individual feeding (7 pens/diet). Animals were slaughtered at a BW of 174 ± 6 kg. The CT inclusion did not modify the performance and the slaughter traits but lowered the intensity of red colour (p <.05) and brightness (p <.05) of the gastric mucosa. Exp. 2 measured digestibility of nutrients, nitrogen (N) balance and energy utilisation of a C diet compared with low protein diets containing 0 or 0.53% of CT supplement (low protein, LP and low protein plus tannins, LPT, respectively). Eighteen barrows (BW 153 ± 4 kg) were housed in 6 metabolic cages in 3 periods of 14 days, with 6 animals per diet. LPT pigs produced less urine than LP (2132 vs. 2561 g/d, p <.05) and both were lower than C (2978 g/d, p <.05). LP and LPT diets had similar digestibility (87.6 vs. 87.8% for DM, and 85.1 vs. 83.9% for CP). N and energy balance were similar among all diets (34.8, 39.0, 39.2% retained N, and 37.6, 35.7, 37.3% retained energy, for C, LP and LPT, respectively). In conclusion, tannins do not exert anti-nutritional effect at the concentrations applied. Dietary chestnut tannin (CT) addition (at 1.5–5.3 g/kg) does not modify digestibility, metabolic use of nutrients and performance of heavy pigs. Dietary CT addition reduces urine volumes of animals with potential impact on farm slurry management. Changes of colour and hypertrophy of gastric mucosa of pigs fed CT are proxy indicators of metabolic reactions to be further investigated. [ABSTRACT FROM AUTHOR]