Changes in Photoperiod During the Dry Period Impact Colostrum Production in Holstein and Jersey Cows.

Multi-parous Holstein cows exposed to short day photoperiod (SDPP) of 8 h of light per day during their dry period produced up to 3.2 kg more milk per day compared with cows exposed to long day photoperiod (LDPP) of 16 h of light per day; it is unknown if a similar response would be observed for Jersey cow milk production. The objective of this study was to determine the effect of photoperiod during the dry period on subsequent colostrum and milk production in Holstein and Jersey cattle.

Associations between preweaning calf feeding behaviors with age at first calving and lactational performance using an automatic calf feeder.

The objective of this retrospective observational study was to determine whether preweaning calf behaviors and milk replacer (MR) intake from an automatic calf feeder were associated with age at first calving and first-lactation performance. Calves were housed in groups with access to an automatic calf feeder for 7 wk with a maximum milk allowance of 1,800 g/d of MR (12 L/d). Outcomes of interest included age at first calving (n = 137), first-lactation mature-equivalent 305-d (ME305) milk yield (n = 132), and first-lactation ME305 energy-corrected milk (ECM) yield (n = 132).

The effects of dexamethasone administration on physiological, behavioral, and production parameters in dairy cows after a difficult calving.

Dairy cows are predisposed to diseases during the postpartum period. Dystocia has been associated with increased risk for disease, which is likely the result of increased tissue trauma and stress during the prolonged parturition. To attenuate the inflammatory response seen in dystocic animals and improve well-being, we assessed the effects of a glucocorticoid, dexamethasone administered within 12 h after calving.

Practical challenges and potential approaches to predicting low-incidence diseases on farm using individual cow data: A clinical mastitis example.

Clinical mastitis (CM) incidence is considerable in terms of cows affected per year, but cases are much less common in terms of detections per cow per milking. From a modeling perspective, where predictions are made every time any cow is milked, low CM incidence per cow day makes training, evaluating, and applying CM prediction models a challenge. The objective of this study was to build models for predicting CM incidence using time-series sensor data and choose models that maximize net return based on a cost matrix.

Short Communication: Association between neonatal calf diarrhea and lying behaviors.

The objective of this study was to determine the association of neonatal calf diarrhea (NCD) with step activity and lying behaviors in pre-weaned dairy calves. Calves were housed in individual hutches for the first 6 days of life, and then moved into a group pen. On the day of birth, calves (n = 30) were fitted with an accelerometer, and step activity and lying behaviors were recorded.