Joint Models to Predict Dairy Cow Survival from Sensor Data Recorded during the First Lactation.

Early predictions of cows' probability of survival to different lactations would help farmers in making successful management and breeding decisions. For this purpose, this research explored the adoption of joint models for longitudinal and survival data in the dairy field. An algorithm jointly modelled daily first-lactation sensor data (milk yield, body weight, rumination time) and survival data (i.e., time to culling) from 6 Holstein dairy farms. The algorithm was set to predict survival to the beginning of the second and third lactations (i.e., second and third calving) from sensor observations of the first 60, 150, and 240 days in milk of cows' first lactation. Using 3-time-repeated 3-fold cross-validation, the performance was evaluated in terms of Area Under the Curve and expected error of prediction. Across the different scenarios and farms, the former varied between 45% and 76%, while the latter was between 3.5% and 26%. Significant results were obtained in terms of expected error of prediction, meaning that the method provided survival probabilities in line with the observed events in the datasets (i.e., culling). Furthermore, the performances were stable among farms. These features may justify further research on the use of joint models to predict the survival of dairy cattle.

Individual antimicrobial treatments in veal calves: Effect on the net carcasses weight at the slaughterhouse and relationship with the serostatus of the calves upon arrival to the fattening unit.

In recent years, the scientific community, institutions, and public opinion have shown a growing awareness towards the problem of antimicrobial resistance. Guidelines from the European Union aim at significantly reducing (even avoiding) the antimicrobial use for prophylactic and metaphylactic purposes in veterinary medicine and this represents an important issue for several intensive farming systems, such as the veal industry. This retrospective observational cohort study analyzed net carcass weight data at the slaughter of 618 veal calves belonging to 6 batches of animals fattened in an Italian commercial farm according to the number of individual antimicrobial treatments administered during the fattening cycle. Sixty-eight percent (419 animals) of the overall sample of calves received at least one individual antimicrobial treatment due to a disease event during the fattening, and 280 of these (45 % of the overall sample) had more than one treatment. On average, the net carcass weight of calves individually treated more than once was about 10 kg lower than that of untreated calves or treated only once. Moreover, the carcasses of calves that received more than one treatment were 16 times more at risk of being severely penalized in payment at the slaughterhouse due to a net weight below 110 kg than those of untreated calves. Serum analysis data of a subsample of 105 calves belonging to 3 out of the 6 batches collected within 5 days after their arrival to the veal farm identified 3 persistently infected animals by bovine viral diarrhea (BVD) virus and a prevalence of calves with serum immunoglobulin concentration below 7.5 g/L of 37 %. The presence of specific antibodies against infectious bovine rhinotracheitis (IBR) and bovine respiratory syncytial virus (BRSV) and a serum immunoglobulin level above 7.5 g/L at the onset of the fattening were the most important factors associated with a decreased risk of multiple individual antimicrobial treatments (and thus, disease development) or with a delay in disease onset during the fattening, thus leading to better performances at the slaughter. The outcomes of this study suggested that a relationship could exist between calf serostatus upon arrival to the veal farm and the possibility to avoid multiple individual antimicrobial treatments during fattening. Further research is needed to deeply study this association, as such knowledge would allow for planning effective preventing strategies to reduce the antimicrobial use in veal calves.

Renal function in patients with intestinal failure receiving home parenteral support.

BACKGROUND: Progressive renal impairment, given by an annual decline in estimated glomerular filtration rate (eGFR), has been described in patients with intestinal failure (IF) receiving home parenteral support (HPS). The objective of this study was to examine changes in eGFR over 5 years following initiation of HPS treatment and to identify potential risk factors for loss of renal function. METHOD: This retrospective database study investigates eGFR changes in nonmalignant IF patients discharged with HPS from Rigshospitalet, Copenhagen, in an 8-year period. RESULTS: One year after HPS initiation, mean eGFR decreased by 15.3 ml/min/1.73 m2 . Paired t-test showed a decline of 15.0 ml/min/1.73 m2 (95% CI, -18.3 to -11.6; P < .0001). Over the following years, eGFR continued to decrease but at insignificant lower rates. Decreased eGFR was associated with increasing age, female sex, increasing body weight, diabetes at HPS initiation, and a high requirement of HPS volume. CONCLUSION: In nonmalignant IF patients, the decrease of eGFR was mainly seen during the first year of HPS. This may be due to a higher risk of dehydration and possibly secondary hyperaldosteronism leading to renal damage following the onset of IF. However, the decrease in eGFR may also represent a higher production of creatinine due to a beneficial increase of muscle mass in the initial recovery phase. In general, once the patients were stabilized, the eGFR decline followed a physiological course resembling the background population. Patients with diabetes or high HPS volume needs seem to be more vulnerable and may require special attention.