Effect of decreasing dietary crude protein on growth performance, feed efficiency and meat quality of finishing Charolais bulls

This study aimed to evaluate the effect of decreasing dietary crude protein (CP) on the performance of finishing Charolais bulls in the Italian rearing system. Animals were fed two diets, differing only in the CP level (low protein (LP), 13.5% CP versus control (CON), 15.0% CP). Dry matter (DM) intake (DMI) and animals\u2019 weights were recorded to obtain average daily gain (ADG) and feed conversion rate (FCR). Feed and fecal samples were collected to evaluate digestibility of diet components. Daily cost of the ration (DRC), feed cost per kg of daily weight gain (CDG) and daily gross margin (DGM) were calculated to analyze the possible benefits of decreasing the protein level. Meat quality analyses were also conducted. Higher DMI (10.6 versus 10 kg/d; p < 0.05) and ADG (1.47 versus 1.36 kg/d; p < 0.05) were observed for CON. No differences in FCR or digestibility were found. Even if the DRC was lower (p < 0.05) for the LP diet (2.26 versus 1.97 \u20ac; CON versus LP), no difference was reported for CDG and DGM. Meat lightness and redness were significantly lower and higher in the LP, respectively. To conclude, the CP requirement in these rearing conditions appeared to be higher than 13.5%

Effect of different formulation of oligoelements on the health and the performance of beef cattle during conditioning phase

To improve the efficiency of lifestock production it is important to focus on the conditioning phase, after the arrival of the animals. One of the major problem is related to stressors, such as regrouping and movements of animals, which can affect the development of the immune profile. The aim of this study was to assess the effect of two different vitamin and mineral integration on the performance and the health of beef cattle during the first period of breeding The study was conducted on 107 young charolaise bulls during the first 46 days of breeding. Animals were grouped according to weight. (407 \ub1 23 kg), and age (300\ub153) in 11 pens; 5 pens (47 animals in total), were fed with a standard integration and 6 pens (60 animal in total) with an experimental integrator. Feed intake for group, rumination time and activity of each animal were measured daily. Total mixed ration (TMR) samples and residual samples were collected weekly, submitted to chemical analyses and shieved with a modify Penn State separator. Temperature Humidity Index (THI) was measured weekly. The trial was divided into 2 periods Weight, average daily gain, activity and rumination time data were analyzed by ANOVA and PROC GLM (SAS). Mineral integration (Control vs Experimental), pen (within diet) and period were used as fixed factors, while the initial weight was used as a covariable. A Z test was conducted in order to establish the different risks between groups on the onset of Bovine Respiratory Distress syndrome (BRD). The control and experimental group (C vs SP) had a Dry Matter Intake (DMI) of 8,14 and 7,70 kg/d during the first period and 8,44 and 8,31 kg/d during the second period.( P=0,291) The average mean value of the C and SP group for both periods were of 8,29 and 8,00 kg/d respectively, and no significant differences were found between groups (P=0,567). In addition, no significant effects were observed for weight due to different integration (464 kg vs 468 C vs SP; P= 0.562), though significant effects were found due to period (447,5 vs 485 C vs SP; P< 0.001), with a higher weight in the second phase. The subjects of the SP group showed an Avarage Daily Gain (AVG) 10% higher than the control (1.72 vs. 1.56 kg/d) and this difference was statistically significant (P = 0.05). There were no statistically significant differences in feed efficiency and rumination time between C vs SP group. This can be related to the high individual animal variability. A tendency to significance were reported for the activity (P=0,085). Five animals were found to be affected by BRD (six cases in total), two in the SP group and 4 in the C group, but no significance evidence emerged.(2 vs 4, respectively; P=0.492). The outcomes of the study suggest that the experimental integration resulted more efficient in improving the average daily gain, probably due to a major oligoelement biodisponibily, and that can lead to an increase of cattle performances. More studies are needed to investigate the effects on rumination time and activity

Machine learning to detect posture and behavior in dairy cows: Information from an accelerometer on the animal’s left flank

The aim of the present study was to develop a model to identify posture and behavior from data collected by a triaxial accelerometer located on the left flank of dairy cows and evaluate its accuracy and precision. Twelve Italian Red‐and‐White lactating cows were equipped with an accelerometer and observed on average for 136 ± 29 min per cow by two trained operators as a reference. The acceleration data were grouped in time windows of 8 s overlapping by 33.0%, for a total of 35133 rows. For each row, 32 different features were extracted and used by machine learning algorithms for the classification of posture and behavior. To build up a predictive model, the dataset was split in training and testing datasets, characterized by 75.0 and 25.0% of the observations, respectively. Four algorithms were tested: Random Forest, K Nearest Neighbors, Extreme Boosting Algorithm (XGB), and Support Vector Machine. The XGB model showed the best accuracy (0.99) and Cohen’s kappa (0.99) in predicting posture, whereas the Random Forest model had the highest overall accuracy in predicting behaviors (0.76), showing a balanced accuracy from 0.96 for resting to 0.77 for moving. Overall, very accurate detection of the posture and resting behavior were achieved

Effect of total mixed ration processing time on ration consistency and beef cattle performance during the early fattening period

The aim of this study was to assess the effect of processingtime ofthe total mixed ration (TMR) on its physical and chemical characteristics, consistency over time, dry matter intake (DMI), rumination, activity, feed conversion ratio(FCR) and performance of beef cattle. The trial was conducted on 98 charolais bulls (476 \ub1 36 kg) which were randomly assigned to two groups (1: 54 animals in 6 pens; 2: 44 animals in 5 pens).The two groupswere fed rations with the same composition, but that were mixed for a short (20 min)mixing time (SMT) or for a 10 minutes longer mixing time (LMT). The trial lasted 60 days and was divided into 2 periods (P1 and P2). After P1 the Journal Pre-proof 2diets were exchangedbetween groups according to a cross-over design. Animals were assessed for average daily weight gain (ADG), DMI,FCR, rumination and activity. All data were submitted to a mixed ANOVA model using the pen as random effect and period, mixing time and their interaction as fixed effects. The differences on TMR composition betweenpens andconsecutive days within each diet,were tested througha GLM model using pen and day as fixed effects. A One-way ANOVA model was used to test the significance of the differences in activity and rumination between pens, within each diet, using the pen as fixed effect. The LMT rationhad a lower particle geometric mean length (GML) compared with SMT (4.12 vs. 5.08 mm; P< 0.001). Bulls raised withthe LMT showed a significantly higher ADG (1.96 vs. 1.87 kg/day; P=0.035) and a lower conversion ratio (4.97 vs. 5.39; P=0.036) compared with animals raised with SMT. Average daily rumination time and activity level did not differ between mixing time and were 381 minutes and 494 binary digits, respectively, but LMT bulls showed a lower (0.083 vs. 0.095; P=0.012) index of dishomogeneity in activity (DA) and a lower sorting activity against long particles (99.8 vs. 96.3%; P= 0.005). The variation of TMR composition between one day and another was significant (P< 0.001) for both neutral detergent fibre (aNDF) and starch in SMT, whereas in LMT it showed a tendency to significance (P=0.056)only for neutral detergent fibre.These results indicate that LMT improved consistency of TMR over time, ADG, FCR and reduced feed sorting