Effects of concentrate allowance and individual dairy cow personality traits on behavior and production of dairy cows milked in a free-traffic automated milking system.

The primary objective of this study was to determine whether the level of concentrate allowance in an automated milking system (AMS) affects the feed intake, eating behavior, milking activity, and performance of lactating dairy cows. The secondary objective of this study was to describe how the response to concentrate allocation, specifically in feeding and milking behavior, varies with cow personality traits. Fifteen Holstein cows were used in a crossover design with two 28-d periods, each including 14 d of adaptation and 14 d of data collection. The cows were housed in a freestall pen with free-traffic access to the AMS. Treatments consisted of a basal partial mixed ration (PMR) common to both treatment groups, with a concentrate allowance (on dry matter basis) of (1) 3.0 kg/d in the AMS (L-AMS) or (2) 6.0 kg/d in the AMS (H-AMS). Between the 2 treatment periods, each cow was assessed for personality traits using a combined arena test consisting of exposure to a novel environment, novel object, and novel human. Principal component analysis of behaviors observed during the novel environment and object tests revealed 3 factors (interpreted as active, social, and alert-curious) that together explained 76% of the variance, whereas principal component analysis of the novel human test revealed 2 factors (interpreted as active-vocal and fearful of novel humans) that together explained 77% of the variance. When on the H-AMS treatment, PMR dry matter intake (DMI) was less (24.5 vs. 26.0 kg/d) and AMS concentrate delivery was greater (5.9 vs. 3.1 kg/d), as per design. Consequently, total DMI was greater on the H-AMS treatment (30.4 vs. 29.1 kg/d). When on the H-AMS treatment, cows who were more alert-curious consumed more PMR, whereas cows who were more fearful of the novel human were less likely to receive the maximum amount of AMS concentrate available, limiting their total DMI and increasing the day-to-day variability of that intake. Although this was a preliminary study, these data suggest an association between dairy cow personality traits and how cows respond to increased AMS concentrate allowance.

Effects of concentrate location on the behavior and production of dairy cows milked in a free-traffic automated milking system.

The objective of this study was to determine whether the amount of concentrate allowance in an automated milking system (AMS) affects partial mixed ration (PMR) sorting behavior, milking activity, and production of lactating dairy cows fed isocaloric diets. Fifteen primiparous Holstein cows were used in a crossover design with 28-d periods, including 14 d of adaptation and 14 d of data collection. The cows were housed in a freestall pen with free-traffic access to the AMS. Treatments consisted of a higher-concentrate PMR (H-PMR) with a pelleted concentrate allowance of 3.0 kg/d on a dry matter (DM) basis in the AMS, or a lower-concentrate PMR (L-PMR) with a pelleted concentrate allowance of 6.0 kg/d in the AMS. As designed, cows on the L-PMR had greater AMS concentrate intake (6.3 vs. 3.1 kg/d of DM) compared with the H-PMR. The standard deviation for mean concentrate intake among days increased from 0.38 to 1.0 kg/d with greater targeted AMS concentrate intake. When fed the L-PMR diet, PMR intake was reduced compared with when cows were fed the H-PMR diet (17.1 vs. 19.1 kg/d of DM). The reduction in PMR intake was compensated for by greater AMS concentrate intake; thus, cows on the L-PMR had greater total dry matter intake (DMI; 23.6 vs. 22.3 kg/d). Cows sorted against long (>19 mm) and fine (<4 mm) PMR particle fractions, and in favor of medium (8 to 19 mm) and short (4 to 8 mm) PMR fractions when on the H-PMR treatment, but only sorted against the medium and in favor of the short PMR fractions on the L-PMR treatment. PMR eating rate and total time spent eating PMR did not differ significantly between the 2 treatments; however, meal size tended to be larger when cows were fed the H-PMR compared with the L-PMR (2.2 vs. 2.1 kg DM/meal). Cows tended to spend 30.8 min/d more time lying down when fed the L-PMR. On the L-PMR treatment, cows tended to have more voluntary AMS visits (5.9 vs. 4.6 visits/d), were fetched less (0.1 vs. 0.5 times daily), and had a greater milking frequency (3.5 vs. 3.0 milkings/d) compared with when they were on the H-PMR treatment. However, milk yield was not affected by treatment. These data suggest that allocating a greater proportion of total dietary concentrate to the AMS, in a free-traffic setup, may improve milking activity and decrease the need for fetching, as well as promoting greater amounts of and maintaining consistency in total dry matter consumption.

Effect of dietary transition at dry off on the behavior and physiology of dairy cows.

This study (1) investigated the effect of dietary transition at dry off on the behavior and physiology of Holstein dairy cows and (2) evaluated the efficacy of utilizing reductions in dietary nutrient density and milking frequency to mediate the dry-off process. Forty-eight cows were dried off over a 5-d period approximately 60 d before their expected calving dates. At the start of dry off (d 1), cows were randomly assigned to 1 of 2 total mixed rations that differed in nutrient density: higher nutrient density (HND; n = 24) and lower nutrient density (LND; n = 24). During dry off, cows were milked 1×/d on d 1, 2, and 3 and a final time on d 5. Milk yield, feeding behavior, rumination, lying behavior, and reticulorumen pH were monitored electronically and feed samples were collected to determine feed sorting. Blood samples, body condition scores, and body weights were taken periodically. Across treatments, milk yield was reduced by approximately 10 kg/d during dry off, with cows fed the LND diet producing 0.9 kg less milk at the time of dry off compared with cows fed the HND diet. Cows fed the LND diet consumed 2.2 kg less dry matter per day, fed at a slower rate, spent 15.7 min more feeding, and sorted to a greater extent for the smaller, more nutrient dense components of the diet compared with cows fed the HND diet. Despite sorting activity, cows fed the LND diet ruminated 3.3 min more per kilogram of dry matter consumed and had a mean reticulorumen pH 0.07 units higher compared with cows fed the HND diet. Following the start of dry off, cows spent approximately 5% more of their free time lying down. Dietary transition and dry off similarly affected the energy balance and inflammatory response of cows, although these parameters varied by day after the start of dry off. The results of this study indicate that the LND diet more effectively reduced milk production before dry off compared with the HND diet while not substantially altering cow physiology.

Deviations in behavior and productivity data before diagnosis of health disorders in cows milked with an automated system.

To explore potential changes in behavior and productivity useful for early detection of health disorders in cows milked with automated milking systems (AMS), we collected longitudinal data throughout lactation of 57 dairy cows housed in a freestall barn with an AMS. Health problems were recorded, including subclinical ketosis (SCK; n = 19), metritis (n = 11), hoof disorders (n = 14), pneumonia (n = 7), and displaced abomasum (DA; n = 5). Data on rumination, activity, milking frequency and yield, and lying behavior were recorded electronically. Using repeated-measures mixed linear regression models, these data were analyzed for the days before the day of diagnosis/treatment (d 0) for each disorder separately, controlling for days in milk and parity. Analyses were performed between the day on which each outcome variable deviated significantly from baseline (up to d -14) and the day before diagnosis (nadir at d -1, before treatment and recovery). Outcomes tested were 3-d rolling averages of milk yield, milking frequency, and AMS supplement intake, in addition to daily rumination time (DRT), body weight, milk temperature, activity (measure of head/neck motion), and 3 lying behavior variables. From d -8, -6, and -5 before diagnosis of DA, SCK, or pneumonia, respectively, DRT declined by 45, 25, and 50 min/d. From d -14 to -1 before diagnosis of hoof disorders, DRT declined by 3 min/d. Body weight declined from d -4 before pneumonia (-14 kg/d) and metritis (-13 kg/d), from d -6 before SCK (-10 kg/d), and from d -5 before hoof disorders (-5 kg/d). Milk yield declined by 4.4 and 4.1 kg/d from d -4 before DA and pneumonia diagnoses, respectively, and by 1.2 kg/d from d -5 before SCK diagnosis. Activity levels declined before diagnosis of DA, pneumonia, SCK, or metritis. Lying behavior changed before diagnosis of DA, pneumonia, or metritis. Our results provide evidence that rumination behavior often deviated before milk yield and that several variables could contribute to earlier or automated identification of disorders. Behavior and productivity changed differently in association with various health disorders, suggesting the potential to distinguish among health problems. These variables merit further investigation in larger studies of cows milked with AMS.