Competition at the feed bunk changes the feeding, standing, and social behavior of transition dairy cows

Transition dairy cows are vulnerable to the negative consequences of depressed feed intake around calving. Competition can decrease feeding activity in midlactation cows, but the effects of competition on the transition cow are not well understood. The objective was to test the effect of competition on the behavior and feed intake of transition cows. Standing behavior, feeding behavior, and dry matter intake were monitored from 1 wk before to 2 wk after calving for 36 Holstein dairy cows. Displacements at the feed bins were recorded the week before calving. Cows were assigned to either competitive (2:1 cows:feed bin) or noncompetitive (1:1 cow:feed bin) treatments. Treatment groups were balanced for parity and baseline feeding measures, resulting in 8 primiparous and 10 multiparous cows per treatment. Competition increased the number of displacements at the feed bins for both primiparous and multiparous cows. Primiparous cows had no change in feed intake or standing time when fed in a competitive environment, but did increase the time spent for each meal during the week before calving (28 ± 1.5 vs. 24 ± 1.5 min/meal). In the week before and after calving, competitively fed multiparous cows had a lower feeding time per visit than noncompetitively fed cows (4.2 ± 0.5 vs. 5.8 ± 0.5 kg/visit and 5.3 ± 0.7 vs. 7.0 ± 0.7 kg/visit, respectively). Multiparous cows ate at a faster rate 2 wk after calving (142 ± 11 vs. 105 ± 11 g/min). Multiparous cows in the competitive treatment increased the time they spent standing (without eating) during the week after calving compared with cows in the noncompetitive treatment (820 ± 44 vs. 649 ± 44 min/d). Feeding rate was correlated with a displacement index in multiparous cows, whereby cows with lower displacement indices ate more rapidly. Results indicate that restricting access to feed increases displacements regardless of parity, and alters the feeding and standing behavior of primiparous and multiparous cows differently.     

Exposure to an unpredictable and competitive social environment affects behavior and health of transition dairy cows

Social factors are important determinants of disease in humans and and laboratory animals, but less research has been done using farm animals. The objective of this study was to determine if an unpredictable and competitive social environment affects behavior and health during the transition period when dairy cows are at high risk of disease. Five weeks before calving, 64 cows were assigned to a predictable and noncompetitive social environment (predictable) or an unpredictable and competitive social environment (unpredictable) using 8 groups of 4 animals per treatment. Each group consisted of 3 multiparous and 1 primiparous cow. At first enrollment (baseline; 5 wk before calving), all groups had access to 4 electronic feed bins. At 4 wk before calving, cows in the predictable groups were given access to 6 feed bins, and cows in the unpredictable groups were moved into a new pen with 4 resident cows each trained to consume feed from one bin. Each cow in the unpredictable group was then provided access to only 1 of the 4 feed bins which they shared with 1 resident cow (resulting in 2 cows/bin), creating a competitive feeding environment. To create an unpredictable environment, access to morning feed was delayed 0, 1, 2, or 3 h every other day. On alternate days, the cows in unpredictable groups were assigned to feed from a new feed bin (and thus had to compete with a new resident partner). Feeding and social behavior were collected electronically from the feed bins. Blood was sampled at baseline (wk ?5), wk ?2, wk ?1, and wk +1 relative to calving to measure inflammatory (haptoglobin and tumor necrosis factor-α) and metabolic (nonesterified fatty acids, β-hydroxybutyrate, calcium, and glucose) biomarkers. Uterine cytology was performed 3 to 5 wk after calving to diagnose cytological endometritis. Data were analyzed using mixed models including baseline data as a covariate, week as a repeated measure, treatment as a main effect, and a treatment by week interaction. The probability of cytological endometritis at the group level was analyzed using Mann-Whitney U tests. Parity was included in separate models to determine any parity × treatment interactions. Cows from both treatments consumed the same amount of feed, but cows in the unpredictable group spent less time feeding and had a higher rate of feed intake. Cows in the unpredictable groups also visited the feed bins less often, consumed more feed during each visit, and were involved in more social replacements at the feed bin compared with predictable groups. Cows in the unpredictable groups had higher serum concentrations of nonesterified fatty acids and tumor necrosis factor-α, but lower β-hydroxybutyrate compared with predictable groups. Multiparous cows in unpredictable groups were more likely to be diagnosed with cytological endometritis after calving compared with cows in the predictable groups, but primiparous cows in unpredictable groups showed a tendency for the opposite response. These results suggest that an unpredictable and competitive social environment before calving causes changes in feeding and social behavior, some physiological indicators of metabolism and inflammation, and increases the risk of uterine disease in multiparous cows after calving.     

Prepartum behavior and dry matter intake identify dairy cows at risk for metritis

Metritis is a disease of particular concern after calving because of its profound negative effects on the reproductive performance of dairy cows. Cows at risk for metritis have shorter feeding times in the days before calving but prepartum dry matter intake (DMI) and water intake may also be useful in identifying cows at risk for this disease. Feeding, drinking, and intake measures may also be affected by social interactions among group-housed cows. The objective of this study, therefore, was to measure intake, feeding, drinking, and social behavior to determine which measures could identify cows at risk for metritis after calving. Feeding and drinking behavior and intake measures were collected from 101 Holstein dairy cows from 2 wk before until 3 wk after calving using an electronic monitoring system. Social behavior at the feed bunk was assessed from video recordings. Metritis severity was diagnosed based on daily rectal body temperature as well as condition of vaginal discharge that was assessed every 3 d after calving until d +21. In this study, 12% of cows were classified as severely metritic and 27% as mildly metritic. Prepartum feeding time and DMI were best able to identify cows at risk for metritis. Cows that developed severe metritis spent less time feeding and consumed less feed compared with healthy cows beginning 2 wk before the observation of clinical signs of infection. For every 10-min decrease in average daily feeding time during the week before calving, the odds of severe metritis increased by 1.72, and for every 1-kg decrease in DMI during this period, cows were nearly 3 times more likely to be diagnosed with this disorder. During the week before calving, cows that were later diagnosed with severe metritis had lower DMI and feeding times during the hours following fresh feed delivery. During this period these cows also engaged in fewer aggressive interactions at the feed bins compared with cows that remained healthy. This research is the first to show that social behavior may play an important role in transition cow health. Research is now required to determine how management should be changed to reduce or prevent illness in transition dairy cows.     

Short communication: Effect of a stable pen management strategy for precalving cows on dry matter intake, plasma nonesterified fatty acid levels, and milk production

During the close-up transition period, dairy cows are at risk for negative energy balance due to increasing energy demands and decreasing feed intake. This can result in postparturient health problems and decreased milk production after calving. Cows are frequently regrouped during this period, which can negatively affect feeding and resting behavior. The hypothesis was that housing in a stable pen during the close-up transition period should result in a more settled environment resulting in fewer displacements from the feed bunk, which would result in improved feed intake, energy balance [lower nonesterified fatty acid (NEFA) concentrations], and lactation performance. This study addresses precalving pen grouping strategies, which have the potential to affect feed intake and energy balance. A randomized complete block design with pen as the experimental unit was used to compare a stable (S) housing strategy (cows with similar calving dates added to a precalving pen at once) to the more traditional dynamic (D) housing strategy (cows added up to 2 times per week to a precalving pen). Twice-weekly blood samples were collected for NEFA analysis and cow interactions within the pen were observed. Dry matter intake (DMI), milk production, and postparturient health problems were recorded. Mean DMI for the duration of the 28 d of the study was not different (S: 25.5 ± 1.6 vs. D: 25.7 ± 1.0 kg/d), and when examined over time relative to calving, no treatment by time interaction was observed. Concentrations of NEFA were not different when cows initially entered the pens (S: 0.21 ± 0.10 vs. D: 0.18 ± 0.04 mEq/L) and remained not different for the time intervals closer to calving (d −9 to −14: S: 0.28 ± 0.09 vs. D: 0.21 ± 0.04; d −3 to −6: S 0.36 ± 0.10, D 0.32 ± 0.05 mEq/L). Pen grouping strategy did not affect DMI, plasma NEFA concentrations, or milk production.     

Effects of replacing inorganic salts of trace minerals with organic trace minerals in pre- and postpartum diets on feeding behavior,rumen fermentation,and performance of dairy cows

Our objectives were to evaluate the effects of complete replacement of supplementary inorganic salts of trace minerals (STM) by organic trace minerals (OTM) in both pre- and postpartum diets on feeding behavior, ruminal fermentation, rumination activity, energy metabolism, and lactation performance in dairy cows. Pregnant cows and heifers (n = 273) were blocked by parity and body condition score and randomly assigned to either STM or OTM diets at 45 ± 3 d before their expected calving date. Both groups received the same diet, except for the source of trace minerals (TM). The STM group was supplemented with Co, Cu, Mn, and Zn sulfates and Na selenite, whereas the OTM group was supplemented with Co, Cu, Mn, and Zn proteinates and selenized yeast. Treatments continued until 156 days in milk and pre- and postpartum diets were formulated to meet 100% of recommended levels of each TM in both treatments, taking into consideration both basal and supplemental levels. Automatic feed bins were used to assign treatments to individual cows and to measure feed intake and feeding behavior. Rumination activity was monitored by sensors attached to a collar from wk ?3 to 3 relative to calving. Blood metabolites were evaluated on d ?21, ?10, ?3, 0, 3, 7, 10, 14, 23, and 65 relative to calving. Ruminal fluid samples were collected using an ororuminal sampling device on d ?21, 23, and 65 relative to calving, for measurement of ruminal pH and concentration of volatile fatty acids. Cows were milked twice a day and milk components were measured monthly. Cows supplemented with OTM tended to have longer daily feeding time (188 vs. 197 min/d), and greater dry matter intake (DMI; 12.9 vs. 13.3 kg), and had a more positive energy balance (3.6 vs. 4.2 Mcal/d) and shorter rumination time per kg of dry matter (DM; 40.1 vs. 37.5 min/kg of DM) than cows supplemented with STM during the prepartum period. In the postpartum period, OTM increased DMI in multiparous cows (24.1 vs. 24.7 kg/d) but not in primiparous cows (19.1 vs. 18.7 kg/d). The difference in DMI of multiparous cows was more evident in the first 5 wk of lactation, when it averaged 1 kg/d. Milk yield was not affected by treatment in multiparous cows (44.1 vs. 44.2 kg/d); however, primiparous cows supplemented with OTM had lesser yields than primiparous cows supplemented with STM (31.9 vs. 29.8 kg/d). Cows supplemented with OTM had a greater percentage of protein in milk (3.11 vs. 3.17%), reduced concentration of nonesterified fatty acids in serum (0.45 vs. 0.40 mmol/L), and rumination activity (30.1 vs. 27.8 min/kg of DM) than cows supplemented with STM. At the end of the transition period, cows supplemented with OTM had reduced molar proportion of acetate, reduced pH, and tended to have a greater concentration of total volatile fatty acids in ruminal fluid. In conclusion, complete replacement of STM by OTM caused modest changes in rumen fermentation, feeding behavior, energy metabolism, and performance of dairy cows, improving postpartum DMI in multiparous cows and reducing circulating levels of nonesterified fatty acids. The pre-absorptive effects of TM source and the parity specific responses on performance warrant further research.     

The effect of transition cow housing on lying and feeding behavior in Holstein dairy cows

The present study investigated the effect of straw yard housing during the dry period and 2 d of additional maternity pen housing postcalving on lying and feeding behavior and calving difficulty in Holstein dairy cows. In this study, 122 multiparous cows were moved to either a straw yard or into freestall housing 4 wk before their expected calving date. Cows that had been housed in straw yards stayed in the maternity pen for an additional 2 d after their calving day, but cows that had been housed in freestalls were moved to the general lactation group the morning after calving. Lying time, lying bouts, feeding time, number of feeder visits, feed intake, feeding rate, and assisted calvings were recorded. Observations were divided into 2 periods: precalving (the 4-wk dry period before calving) and postcalving (the day of calving and the 2 d after). During the precalving period, cows housed in straw yards showed a higher number of lying bouts but no difference in lying time compared with cows housed in freestalls. Cows that were housed longer in the straw-bedded maternity pen postcalving spent more time lying during the 2 d postcalving and had a higher number of lying bouts on the day of calving than cows moved to the freestall area on the day postcalving. Additionally, cows that were housed longer in the maternity pen had a slower feeding rate and longer total feeding time during the 2 d after calving than cows with a shorter stay in the maternity pen. We found no difference in the number of assisted calvings. This study suggests that straw yard housing during the dry period may facilitate the transition between standing and lying. Furthermore, the extended stay in the maternity pen postcalving increased lying time, the number of lying bouts, and feeding time, but decreased feeding rate compared with cows that were moved to the general lactation group on the day postcalving. These results suggest potential recovery benefits with an extended stay in a maternity pen postcalving. However, further studies are needed to separate the effects of housing in the dry period and the effects of an extended housing in individual maternity pens.     

Performance and feeding behavior of primiparous cows loose housed alone or together with multiparous cows

Lactating Holstein cows (52 multiparous and 90 primiparous) were monitored over a period of 10 mo to observe effects of grouping primiparous cows (PPC) separately from multiparous cows (MPC) on performance, feeding behavior, feed intake, feed efficiency, and milk production of PPC. Cows were kept in 2 symmetrical pens each equipped with a robotic milking unit, 2 waterers, and 28 feeding spaces. Typically, 100 lactating cows were present at a time, thereby ensuring 1.78 cows per feeding place in each pen. One pen (PP) was composed exclusively of PPC whereas the other pen (PM) included 30% PPC and 70% MPC. Primiparous cows were evenly distributed to each pen by days in milk and daily milk production. As they calved, additional primiparous cows were assigned sequentially to each of the 2 treatment groups; multiparous cows calving during the study were allocated to the PM group. Both PP and PM groups were managed equally and were fed the same basal ration twice daily plus 3 kg/d of concentrate during milking. Individual eating behavior and feed consumption at each visit were monitored electronically. Milk production was recorded daily, and milk composition monthly. Observed arithmetic means and standard errors are presented but application to other management situations is limited because animals within pen were not independent. Total dry matter intake (18.7 vs. 18.1 ± 0.9 kg/d) and milk production (25.9 vs. 25.6 ± 0.8 kg/d) of PPC were similar in both the PM and PP groups, respectively. Primiparous cows in the PP group had numerically more visits to the robotic milking unit (3.26 vs. 2.68 ± 0.15) and to the feed troughs (4.91 vs. 4.02 ± 0.43), but apparently spent less time eating (2.72 vs. 3.22 ± 0.1 h/d) than did PPC in the PM group. Differences in feed efficiency were low but PPC in the PP group had numerically higher feed efficiency at times through 200 d in milk. Alternative grouping strategies illustrate potentially important differential responses among primiparous cows that warrant further study.     

Technical note: validation of a system for monitoring individual feeding and drinking behavior and intake in group-housed cattle

The objective of this study was to validate a system for monitoring individual feeding and drinking behavior and intake in group-housed cattle. A total of 42 Holstein cows were tested with access to 24 feed bins and 4 water bins. For the purposes of this validation experiment, we focused our observations on 4 water bins and 13 feed bins. When the cow approached the feed or water bin, an antenna detected the cow's unique passive transponder and lowered the barrier, allowing the cow access to the feed or water. For each visit to the bin, the system recorded the cow number, bin number, initial and final times and weight and calculated the visit duration and intake. Bins were also monitored by direct observation and time-lapse video recording for 2 d per bin, with observations for 4 and 6 h/d for the feed and water bins, respectively. Data from direct observations were compared with the electronic data recorded by the system. Feed disappearance over 24 h was assessed by using an external scale over 3 consecutive 24-h periods, and these values were compared with the sum of intakes across all visits to that bin for the same time periods. The system showed a high specificity (100%) and sensitivity (100 and 99.76% for the feed and water bins, respectively) for cow identification. The duration of the feeding and drinking visits and the feed and water intake per visit, as estimated by the monitoring system, were highly correlated with those obtained by direct observation (R² ≥ 0.99 in all the cases). The comparison of the total feed that disappeared from each bin in 24 h with the sum of the feed cows consumed from that bin during the same period differed by less than 1 kg (29.92 ± 0.90 kg and 29.24 ± 0.90 kg as estimated by manual weighing and by the electronic system, respectively). This difference could be attributed to changes in feed moisture during the 24-h period. In conclusion, this electronic system is a useful tool for monitoring intakes and feeding and drinking behavior of loose-housed cows.     

Short communication: Decrease in rumination time as an indicator of the onset of calving

The aim of this study was to investigate whether rumination time (RT) is affected by the onset of calving. The relationship between both feeding time and dry matter intake (DMI) to the onset of calving was also examined. In addition, the correlation between feeding behavior characteristics, described here as RT, feeding time, and DMI, was evaluated. Under test conditions, the feeding behavior of pregnant Holstein cows was recorded from the time when they were moved into calving pens (usually 7 to 5 d prepartum) until the onset of calving. Feeding time and DMI were recorded by automatic feed bins; RT was measured continuously by a measuring halter based on electromyography (DairyCheck; BITSz Engineering GmbH, Zwickau, Germany), which constitutes a new approach regarding feeding behavior detection. Data analysis related to the final 72 h, before the onset of calving, which were divided into twelve 6-h blocks. The last 6 h (one 6-h block) before calving were compared with the 72- to 7-h time frame (11 times 6-h blocks) before calving, which was defined as the reference period. For this time period, feeding behavior data for 17 cows was fully available, which was the precondition for data analysis. In the final 6 h before imminent birth, RT was significantly reduced. During this time, it was found that the mean minimum RT was 69.9 ± 28.5 min/6 h compared with the mean RT of 95.5 ± 30.8 min/6 h in the reference period. The average decrease in RT was 27% (25.6 min/6 h). In addition, feeding time and DMI were significantly reduced. The average decrease in feeding time was 57% (20.8 min/6 h), and in DMI it was 56% (1.9 kg/6 h). High correlation coefficients between feeding behavior characteristics were only found between feeding time and DMI. Values of feeding behavior among cows were characterized by high variability. Recording RT can serve as a use ful tool for predicting the timing of birth for dairy cows, but further research is necessary.     

Effects of supplementing a Saccharomyces cerevisiae fermentation product during the periparturient period on performance of dairy cows fed fresh diets differing in starch content

The objective of this study was to evaluate the effects of supplementing a Saccharomyces cerevisiae fermentation product (SCFP; NutriTek, Diamond V, Cedar Rapids, IA) during the periparturient period (d ?28 ± 3 to 44 ± 3 relative to calving) on dry matter intake (DMI), milk production, apparent total-tract nutrient digestibility, and postpartum ovarian activity of dairy cows fed fresh diets varying in starch content. From d 28 ± 3 before the expected calving date until d 44 ± 3 after calving, 117 Holstein cows were fed diets with SCFP (SCFP; n = 59) or without (control, CON; n = 58). A common, basal, controlled-energy close-up diet (net energy for lactation: 1.43 Mcal/kg; 13.8% starch) was fed before calving. Cows within each treatment (CON or SCFP) were fed either a low- (LS; 22.1% starch) or high-starch (HS; 28.3% starch) diet from d 1 to 23 ± 3 after calving (fresh period), resulting in 4 treatment groups: LS-CON (n = 30), LS-SCFP (n = 29), HS-CON (n = 28), and HS-SCFP (n = 30). All cows were fed the HS diets from d 24 ± 3 to 44 ± 3 after calving (post-fresh period). Cows were assigned to treatment balanced for parity, body condition score, body weight, and expected calving date. Milk yield was higher for cows fed the LS diets compared with those fed the HS diets during the fresh period (34.1 vs. 32.1 kg/d), whereas DMI and 3.5% fat-corrected milk yield (FCM) were not affected by dietary starch content, and LS cows tended to lose more body condition than HS cows (?0.42 vs. ?0.35 per 21 d) during the fresh period. Overall DMI during the close-up and fresh periods did not differ between SCFP and CON cows. However, SCFP supplementation transiently increased DMI on d 1 (13.0 vs. 11.9 kg/d) and 5 (15.5 vs. 14.1 kg/d) after calving compared with CON. During the post-fresh period, SCFP cows tended to eat less than CON cows (19.8 vs. 20.6 kg/d) but had similar 3.5% FCM (44.9 vs. 43.6 kg/d), resulting in greater feed efficiency for SCFP cows (FCM/DMI; 2.27 vs. 2.13). Neither starch content of fresh diets nor SCFP supplementation affected the interval from calving to first ovulation or the incidence of double ovulation. These findings suggest that feeding low-starch diets during the fresh period can increase milk production of dairy cows during the fresh period, and that supplementation of SCFP may increase feed intake around calving and feed efficiency in the post-fresh period.     

Dairy cows seek isolation at calving and when ill

Dairy cows are typically gregarious, but isolate themselves in the hours before calving when kept on pasture. Self-isolation is also a common behavior of ill animals. The objectives of this study were to determine if dairy cows would (1) isolate to calve when housed indoors in an individual maternity pen and (2) continue to isolate when ill after calving. We selected individuals from a pool of 79 multiparous Holstein dairy cows based on inclusion criteria created to address each objective. Cows were moved from a group pen to 1 of 10 adjacent maternity pens. Half of these individual pens were partially covered with plywood, creating a secluded corner as well as a window that provided visual access to the group pen. The other individual pens were uncovered on all sides. For our first objective, we selected 39 cows that were moved into the maternity pens >8 h before calving (partially covered: n = 19; uncovered: n = 20). For our second objective, we selected 18 cows housed in the partially covered pens: 9 cows with high rectal temperature after calving and signs of an infectious disease (mastitis, metritis, pneumonia, or some combination), and 9 healthy cows paired with ill cows based on the amount of time they spent in the maternity pen before calving. Ten-minute scan sampling was used to record the location and lying time from 6 h before to 72 h after calving. Individual feed intake was measured after calving. Binomial tests were used to determine if cows in both pen types were more likely to calve in the corner or window side of the pen. Repeated-measures ANOVA were used to determine if cows used the corner more as calving approached and if ill cows spent more time lying or more time in the corner compared with healthy cows in the 72 h after calving. Cows in the uncovered pens were equally likely to calve on both sides of the pen (10 vs. 10), but 79% of cows in the partially covered pens calved on the corner side of the pen (15 vs. 4). Cows in the partially covered pens used the corner side of the pen more in the 1 h before and after calving compared with those housed in the uncovered pens. Ill cows housed in the partially covered pens ate less, tended to spend more time lying down, and spent more time in the corner of the pen compared with healthy cows. These results indicate that periparturient dairy cows seek seclusion to calve and when ill, which suggests that adding a secluded area to maternity and hospital pens may be beneficial.     

Rumination and its relationship to feeding and lying behavior in Holstein dairy cows

The objective of this study was to describe the relationship between rumination and feeding and lying behavior in dairy cows. Rumination time was monitored electronically using HR-Tags (SCR Engineers Ltd., Netanya, Israel). Feeding time and dry matter intake (DMI) were monitored using Insentec feed bins (Insentec BV, Marknesse, the Netherlands). All measures were collected in 2-h periods for 42 mature Holstein cows for a minimum of 9 d in the early dry period. Pearson correlation was used to describe associations, among 2-h periods within cow, first examining the relationship within a single period, and then modeling how this relationship changes when a lag of 2, 4, or 6h was imposed. Periods when cows spent more time ruminating were associated with lower feeding times and lower DMI (r = -0.71 and r = -0.72, respectively), likely because cows were unable to feed and ruminate simultaneously. The correlations with rumination time changed from negative to positive when lags of 2, 4, and 6h were modeled (r = -0.09, 0.24, and 0.15, and r = -0.16, 0.23, and 0.17 for feeding time and DMI at lags of 2, 4, and 6h, respectively). These results indicate that following periods of high feeding times and intakes, cows spent more time ruminating. This relationship peaks at approximately 4h after feeding. Periods of rumination were also associated with time spent lying down. Cows that spent more time ruminating per day, spent less time feeding (r = -0.34) and rumination times did not relate to DMI (r = 0.11). These data indicate that rumination time can be used to estimate within-cow variation in feeding behavior and intake, but daily summaries of rumination behavior are a poor indicator of DMI.     

Short-term effects of regrouping on behavior of prepartum dairy cows

The objectives were to determine the effect of regrouping during the dry period on feeding, social, rumination, and lying behavior for cows that were moved to a new pen and cows that remained in their home pen but had new cows introduced. Forty-eight prepartum Holstein dairy cows were housed in groups of 6 and regrouped in groups of 3 (16 triads) with 1 triad moving to another pen and 1 triad staying in the same pen; the triad was considered the experimental unit. For 7 d before and 8 d after regrouping, cows were continuously monitored for feeding, rumination, and lying behavior by means of an electronic feeding system, a rumination logger on each cow's neck, and a data logger attached to 1 of the hind legs, respectively. Video recording was used to monitor displacements at the feeder for 3 h following the afternoon fresh feed delivery before regrouping and for the 2 subsequent afternoon feed deliveries after regrouping. Cows that were moved to a new pen after regrouping decreased DMI by approximately 9% on the day of regrouping compared with baseline values, but cows that remained in their home pen showed no significant decrease in intake after regrouping. Feeding rate decreased in both treatments by 10% after regrouping. Rumination times also decreased by approximately 9% in both treatments, reaching the lowest values on the day of regrouping for cows that stayed in the home pen and on the day after regrouping for the moved cows. Cows that were moved to a new pen displaced other cows at the feeder twice as frequently after regrouping, but no such effect of regrouping on cows that stayed in the home pen was observed. These results indicate that regrouping can affect behavior of prepartum dairy cows, especially those cows that are moved to a new pen.     

Effects of metritis on stall use and social behavior at the lying stall

Metritis in dairy cows has been associated with changes in behavior at the feed bunk, but little is known about the effects on behavior at the lying stall. The aim of this study was to investigate stall use by primiparous dairy cows diagnosed with metritis, specifically time spent in the stall, social interactions at the stall, and lying-related behaviors. After parturition, primiparous cows were housed in a mixed-parity pen with a constant group size of 20. Cows had access to 12 electronic feed bins, 2 electronic water bins, and 24 lying stalls. Four cameras installed above the experimental pen allowed for observation of cows in the feeding and lying area. Every 3 d after parturition, cows were examined for metritis by evaluation of the visual appearance and olfactory character of vaginal discharge. Cows diagnosed with metritis (n = 16) were compared with healthy individuals (i.e., cows without metritis or other clinical disease, n = 16). Healthy individuals were selected based on data availability, body weight, and calving date and, based on these criteria, paired with metritic cows. Video of the 3 d before diagnosis (d ?3 to d ?1) in the metritic animals (and video from the corresponding days in milk for paired healthy cows) were used to measure behavior. Behaviors assessed included those in the stall (lying, perching, and standing fully in the stall), social behaviors (when a cow either displaced or was displaced by another cow; i.e., actor and reactor replacements), and lying-related behaviors (including visits when the cow entered and left the stall without lying down, aborted lying events when behaviors indicative of the onset of a lying bout were not followed by the cow lying down, and latency to lie down, defined as the time between an aborted lying event and the first lying bout). Cows with metritis spent more time standing fully in the stall on all 3 d, resulting in more time spent standing on d ?2 and ?1. Cows with metritis tended to have more aborted lying events on d ?2, and significantly more on d ?1. Cows with metritis tended to be replaced more often at the lying stall on d ?3 and tended to have a longer latency to lie down on d ?2. We observed no differences between health groups in the number of actor replacements or the number of visits to the stall. In summary, cows with metritis spent more time standing fully in the lying stall and had more aborted lying events. These results suggest that primiparous cows with metritis may be identified by altered behavior at the lying stall.     

Effects of induced parturition and estradiol on feed intake, liver triglyceride concentration, and plasma metabolites of transition dairy cows.

The effect of induced parturition and estradiol on feed intake, liver triglyceride, plasma metabolites, and milk yield was evaluated in fifty-six Holstein cows and heifers. Cows were assigned to treatments on d 260 of gestation and were on trial until d 10 postpartum for measurement of dry matter intake (DMI), plasma metabolites, and liver triglyceride and until d 31 postpartum to measure milk yield. Fourteen animals per group (9 cows and 5 heifers) received either a placebo, 1 mg of fenprostalene, 50 mg of estradiol-17 beta benzoate, or both on d 276 of gestation. Cows that received fenprostalene consumed more dry matter (DM) for the last 8 d prepartum than did cows that did not receive fenprostalene (9.6 kg/d vs. 8.5 kg/d, respectively) but consumed less DM for the first 10 d postpartum (10.9 kg/d vs. 13.1 kg/d, respectively). Cows injected with estradiol-17 beta benzoate tended to consume less DM postpartum than did cows not injected with estradiol-17 beta benzoate (11.3 kg/d vs. 12.7 kg/d, respectively). There was no effect of treatment on milk yield; however, a fenprostalene by day interaction resulted from lower milk yield on d 3, 4, 5, 7, and 10 relative to calving in cows that received fenprostalene. Administration of fenprostalene resulted in a delay in the peak plasma nonesterified fatty acid (NEFA) concentration until 2 d after calving. Plasma glucose concentrations were greatest 1 d prior to calving for cows that received fenprostalene, whereas plasma glucose concentrations peaked on the day of calving for cows that did not receive fenprostalene. Liver triglyceride increased over time; however, there was no effect of treatment on liver triglyceride. Calving induction improved DMI for the last 8 d prepartum, but a concomitant decrease in liver triglyceride after calving did not result. Estradiol-17 beta benzoate had no effect on plasma metabolites or liver triglyceride, indicating that the physiological rise in estradiol prior to calving does not have a primary role in lipolysis or hepatic fatty acid metabolism in the dairy cow.     

Changes in feeding, drinking, and standing behavior of dairy cows during the transition period

The aims of this study were to determine how measures of feeding, drinking, and standing behavior change over the period around calving, to derive objective meal and drinking bout criteria for transition cows, and to describe the within-cow consistency of these behavioral measures. Fifteen transition dairy cows were monitored from 10 d before until 10 d after calving. Meal criteria were calculated for each cow in both the pre- and postcalving periods and varied among cows from 5.3 to 105.2 min. There was a tendency for the average number of meals per day to be higher after calving than before calving, but time spent eating declined from 87 to 62 min/d from the precalving to the postcalving period. Time spent drinking before calving averaged 5.5 min/d and increased gradually after calving to an average of 6.8 min/d. Total daily standing times remained reasonably similar over the transition period but were highest at around calving (14.4 h) and lowest during the precalving period (12.3 h). On the day of calving, there was a dramatic increase in the number of standing bouts (21.8 bouts) compared with the pre- and postcalving averages of 11.7 and 13.1 bouts, respectively. In summary, changes in feeding behavior may help account for the well-documented changes in feed intake during transition. Documented changes in standing behavior suggest that cow comfort may be particularly important during the time around calving.     

Effect of prepartum dry matter intake on liver triglyceride concentration and early lactation.

Depression in feed intake during the final week before calving was hypothesized to be a major factor in the etiology of fatty liver development near parturition. Eleven cows were allowed to eat for ad libitum intake prior to calving (control), and 11 cows were maintained at the same level of DMI recorded during d 21 to 17 prior to calving by force feeding the feed refusals via rumen cannulas. Feed intake by control cows decreased 28% during the final 17 d prior to calving. Lipid triglyceride increased 227 and 75% for control and force-fed cows between d 17 prior to parturition and d 1 following calving. Dry matter intake prior to calving was correlated negatively with liver triglyceride immediately after calving (r = -.80). Plasma glucose concentrations for control and force-fed cows were 63 and 76 mg/dl 2 d prior to calving and also were related closely to liver triglyceride immediately after calving (r = -.50). By d 28 after calving, there were no differences in liver triglyceride between treatments. Cows that were force-fed prior to calving tended to yield milk with greater fat percentage (4.22 vs. 3.88%) and to yield more 3.5% FCM (46.1 vs. 41.7 kg/d) during the first 28 d postpartum.     

Body condition loss during the dry period: Insights from feeding behavior studies

Body condition change during the dry period (ΔBCS) has been associated with a myriad of transition cow diseases. We used data from 3 studies to assess the relationship between ΔBCS, feeding behavior, and body condition score (BCS) at dry-off. We also studied the mediation effect that dry matter intake (DMI) has on ΔBCS and the association between dry period feeding time and DMI. A total of 100 parous cows were enrolled in 3 studies to investigate differences in dry period diet on behavior, health, and performance pre- and postcalving. Body weight was measured and BCS was assessed by the same trained observer after dry-off and 1 wk from calving date. The ΔBCS was calculated by subtracting the BCS at calving minus the BCS at dry-off. The BCS at dry-off was categorized as overconditioned (≥3.5) or not overconditioned (<3.5); no cows had a BCS <2.75. Feeding behavior data were collected using electronic feed bins. Parity at dry-off (median = 2; min = 1, max = 6) and 305-d milk production (mean = 10,235 kg, SD = 1,625 kg) from the previous lactation were considered. Data sets were split into 2 time periods: d ?56 to ?22 (early) and ?21 to 0 (late) in relation to calving. Selected feeding behaviors (DMI, DMI as a percentage of body weight, and feeding time) were used to evaluate the associations between each feeding behavior and BCS at dry-off in each period using mixed linear regression models. Each model included the following covariates: parity, previous 305-d milk yield, and trial treatment. Experimental day was included as random slope, and cow was included as random intercept. A mediation analysis was used to evaluate the potential causal direct effect of BCS at dry-off on ΔBCS and the potential indirect effect mediated by differences in DMI. The BCS at dry-off was associated with changes in feeding behavior, such that overconditioned cows had lesser daily DMI and feeding time during the early and late dry periods compared with not overconditioned animals. We also noted an effect of previous 305-d milk yield on DMI; cows that produced more milk had greater DMI throughout the dry period. The ΔBCS was only partially mediated by DMI, and BCS at dry-off still had a direct effect on ΔBCS. This result indicated that mechanisms other than DMI were associated with BCS loss during the dry period. Feeding time correlated weakly and moderately with DMI during the early and late dry periods, respectively. To conclude, strategies to improve intake during the dry period should take dry-off BCS into account or, preferably, efforts should be made to minimize the number of overconditioned cows at the end of lactation.     

Short communication: Calving site selection of multiparous,group-housed dairy cows is influenced by site of a previous calving

A calving cow and her newborn calf appear to have an attracting effect on periparturient cows, which may potentially influence the functionality of future motivation-based calving pen designs. In this pilot study we examined whether calving site selection of group-housed Holstein dairy cows was affected by the site of a previous calving. Ten multiparous cows moved to 1 of 2 group pens 11 (range = 4–27) d before calving were included. Each pen consisted of an open area (9 × 9 m) connected to 6 secluded areas (4.5 × 3 m each), where cows could move freely between all areas. Time of calving, location of the breaking of the amniotic sac, as well as the place of birth were recorded. In all but 1 case cows calved within a distance of 1 cow length from where the previous calving took place, suggesting that the cows did not select calving site at random. These preliminary observations indicate that choice of calving site may be affected by the site of a previous calving, potentially explained by the presence of amniotic fluids.     

Secluded maternity areas for parturient dairy cows offer protection from herd members

Use of individual maternity pens for dairy cows is recommended to ensure undisturbed calving and postpartum transfer of colostrum to calves, but management of these pens is a challenge due to difficulty predicting the time of calving. If group-housed cows, however, have the opportunity to calve in a secluded area of a group pen, this may limit disturbance of the dam and her newborn, especially if this area is fitted with a gate preventing other cows from entering. The aims of this study were to assess effects of cows calving inside a secluded area versus cows calving in the group area on maternal behavior and social interaction between dam and herd members during the first postpartum hour, calf's latency to stand, number of calves suckling an alien cow, and the dam's acute response to separation from the calf. This was investigated in pens consisting of a central group area with access to 6 secluded areas with or without a mechanical push gate allowing only 1 cow access at a time. At least 2 wk before expected calving, 60 Danish Holstein multiparous cows were assigned alternately, in groups of 6, to a group pen with 6 gated secluded areas or a group pen with 6 ungated secluded areas. The effects of treatment (gated, ungated) and calving place chosen within treatment (secluded area, group area) on maternal behavior, interactions with herd members, maternal response to separation, and calf latency to stand were investigated. Irrespective of whether cows calved in a secluded area or not and whether the secluded area was gated or not, cows spent, on average, 39 (±7.9) min of the first hour after calving licking their calves. When calving in a gated secluded area, the cows interacted less with herd members than when calving in the group area (0.5, 28, 18, and 33 min/h for gated/secluded, gated/group, ungated/secluded, and ungated/group areas, respectively), and no calves suckled an alien cow within the first hour after birth. In addition, the longer the calf stayed with the dam, the longer the dam stood with her head out of the pen after removal of the calf. Calf's latency to stand after calving was unaffected by treatment and calving place (mean = 39 min; range = 8–243 min). The results show that dam and calf can be protected from disturbances when cows calve in a secluded maternity area, especially if the secluded maternity area is fitted with a gate preventing other cows form entering.