The effect of stocking density and a blind on the behavior of Holstein dairy cows in group maternity pens. Part II: Labor length,lying behavior,and social behavior

In natural settings, dairy cows separate from the herd to give birth. When kept indoors, seeking isolation before calving may be restricted and may depend on space and resources provided in maternity housing. The effect of group maternity pens on behavior around calving and labor progress is unknown. Therefore, the objective of this study was to determine the effects of stocking density and provision of a blind in group bedded pack maternity pens on lying and social behavior as well as length of labor of preparturient dairy animals. The study was conducted as a complete randomized block design with a 2 × 2 factorial arrangement of treatments including stocking density and presence or absence of a blind, resulting in a total of 4 treatments: (1) high stocking density (7.7–12.9 m² lying space/cow) with a blind, (2) low stocking density (15.4–25.8 m²) with a blind, (3) high stocking density without a blind, and (4) low stocking density without a blind. A total of 127 primiparous heifers and 247 multiparous cows were housed in mixed-parity groups from approximately 3 wk before and immediately after calving. During the 4 h before calving, lying behavior (lying time and bouts) was collected automatically using accelerometers, and social behavior (agonistic interactions, allogrooming, and attention from other cows), stage II labor duration, and frequency of position change during stage II labor were collected using video. Lying behavior was collected with accelerometers. Regardless of treatment, lying time and bouts increased as calving approached. Cows and heifers performed more lying bouts in low stocking density pens compared with high stocking density pens. Agonistic interactions and allogrooming were not different between treatments. Other cows spent more time paying attention to focal animals regardless of stocking density as calving approached, but time spent paying attention was reduced by the presence of a blind during h ?2 before calving. The hazard of calving unassisted was greater for cows and heifers in low stocking density pens with a blind compared with all other treatments. Further, animals in pens with a blind tended to change positions fewer times during stage II labor. These results suggest that providing a blind in group maternity pens may improve the calving environment for cows and heifers and, in combination with low stocking density, may reduce the amount of time spent in labor.     

Effects of prepartum stocking density and a blind on physiological biomarkers,health, and hygiene of transition Holstein dairy cows

Many dairy cows succumb to disease after calving. Disease risk may be affected by the cows' social environment and ability to perform maternal behaviors. In nature, cattle isolate from others and find seclusion to give birth; these behaviors may be limited in indoor group pens and could potentially affect the cows' ability to cope. The aim was to determine whether stocking density and a physical blind in prepartum bedded-pack group pens affected physiological biomarkers, disease risk, and hygiene of peripartum dairy cows. A randomized complete block designed with a 2 × 2 factorial arrangement of treatments was used. Approximately 3 wk before calving, 374 cows (primiparous = 127; multiparous = 247) were assigned randomly to 1 of 4 treatment pens with the following 2 factors: (1) high versus low stocking density (7.7 to 12.9 m² vs. 15.4 to 25.8 m² lying space per cow), and (2) presence or absence of a blind. The blind was created using plastic road barriers and plywood, a steel gate, and shade cloth. After calving, cows were moved into a freestall pen and milked 3 times per day. Blood was sampled on the day of enrollment (baseline; ?24 d) and approximately ?14, ?7, 3, 7, 10, and 14 d relative to calving, to measure inflammatory (haptoglobin) and metabolic (nonesterified fatty acids and β-hydroxybutyrate) biomarkers. β-Hydroxybutyrate (≥1.2 mmol/L) was used to diagnose subclinical ketosis. Vaginal discharge was scored 3, 7, 10, and 14 d after calving, to diagnose metritis (none, mild, or severe). Hygiene was scored on ?24, ?14, and ?7 d before calving. Before calving, haptoglobin was lower in pens with a blind. After calving, cows in pens with low stocking density before calving tended to be at greater odds of being diagnosed with metritis. Cows were more likely to have poorer hygiene scores in high stocking density pens. No treatment effects were detected for pre- and postpartum nonesterified fatty acids, β-hydroxybutyrate, postpartum haptoglobin, or subclinical ketosis. Results suggest that the provision of a blind and lower stocking density may be beneficial for reducing inflammation before calving. However, low prepartum stocking density might increase the odds of metritis after calving. Although the reason for this paradox is unclear, the effects of prepartum stocking density may require further exploration.     

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.     

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.     

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.     

Effect of prepartum exercise on lying behavior,labor length,and cortisol concentrations

The objective of this study was to assess the effect of exercise and pasture turnout on lying behavior, labor length, and cortisol concentrations around the time of parturition in dairy cows. Twenty-nine primiparous and 31 multiparous, pregnant, nonlactating Holstein (n = 58) and Jersey × Holstein cross (n = 2) dairy cows were assigned to control (n = 20), exercise (n = 20), or pasture (n = 20) treatments at dry-off using rolling enrollment. Control cows remained in the dry cow group pen. Exercise cows were removed from the dry cow group pen 5 times per week and walked for 1.4 ± 0.1 h at 1.88 ± 0.58 km/h. Pasture cows were moved to an outdoor paddock 5 times per week for 1.8 ± 0.3 h/d. Cows were housed in deep-bedded sand freestalls in a naturally ventilated, 4-row freestall barn. Cows were moved into maternity pens on the day of projected calving or when cows displayed signs that calving was imminent (restlessness, raised or lifted tail, ruptured amniotic sac, or swollen vulva), and treatments were discontinued. Cameras continuously recorded cows from entry into the pen until farm staff noted a calf, and one observer continuously watched video for two visually observable periods throughout the calving process: time from initial observation of amniotic sac to initial observation of calf's feet, and time from initial observation of calf's feet to full expulsion of calf. Assisted calvings were excluded. Accelerometers were attached to the rear fetlocks of cows 3 d before dry-off and removed 14 d postpartum. Activity was summarized by day for the 7 d before and after delivery time recorded from video observation into lying time (hours per day), lying bout frequency (bouts per day), lying bout duration (minutes per bout), and steps (number per day). Plasma total cortisol concentration was measured on d 0 and 3 postpartum and determined by a radioimmunoassay procedure using a commercially available kit. Data were analyzed using mixed linear model. During calving, time from appearance of the amniotic sac to appearance of the calf's feet was longer for pasture cows compared with control. Control cows engaged in fewer lying bouts and less overall lying time compared with pasture and exercise cows. Cortisol concentrations were higher on the day of calving compared with 3 d later, regardless of treatment. Understanding the effects of lying alterations around calving and increases in labor period length may allow for physical activity recommendations for late-gestation dairy cows.     

Short communication: Flooring preferences of dairy cows at calving

The present study investigated the flooring preference during the 30 h before parturition in Holstein dairy cows housed individually in a maternity pen. Seventeen multiparous cows were moved, on average, 2 d before expected calving date into an individual maternity pen with 3 different flooring surfaces: 10 cm of sand, pebble-top rubber mats, or concrete flooring, each covered with 15 cm of straw. Calving location, lying time, and total time and number of lying bouts on each of the floor types were recorded during 2 periods: precalving (24 to 29 h before calving) and at calving (0 to 5 h before calving). Ten cows calved on sand, 6 on concrete, and 1 on the rubber mat. Lying bouts increased during the hours closest to calving, regardless of flooring. The number of lying bouts did not differ between flooring types precalving but cows had more lying bouts on sand and concrete compared with rubber at calving. Cows spent more time lying down on sand and concrete compared with rubber precalving, but lying times did not differ between treatments at calving. Cows that calved on sand spent more time lying on sand at calving compared with the other 2 flooring types. Cows that calved on concrete did not show a flooring preference at calving. These results indicate that rubber mats are the least preferred by dairy cows in the maternity pens, even when covered with a deep layer of straw.     

Transition cow nutrition and management strategies of dairy herds in the northeastern United States: Part I—Herd description and performance characteristics

Our objective was to describe management and herd characteristics of the transition period on freestall dairy herds in the northeastern United States using an on-farm survey and prospective cohort design. Enrolled herds (n = 72) had a median of 900 milking cows (range: 345–2,900) and a rolling herd average of 12,674 kg (standard deviation ± 1,220 kg), and 87.2% (n = 82/94) of fresh pens were milked at least 3×/d. The prevalence of herds with ≥15% of sampled cows with elevated concentrations of nonesterified fatty acids prepartum (≥0.27 mmol/L, 2–14 d before parturition) and postpartum [primiparous: ≥0.60 mmol/L, multiparous: ≥0.70 mmol/L, 3–14 d in milk (DIM)], β-hydroxybutyrate postpartum (≥1.2 mmol/L, 3–14 DIM), and haptoglobin postpartum (≥1 g/L, 0–12 DIM) was 51%, 51%, 51%, and 57%, respectively. In most herds, cows were moved to a calving pen when showing signs of labor (73.6%; n = 53/72) instead of 0 to 3 d before expected calving (26.4%, n = 19/72). Cows remained in the calving or maternity pen for a median (range) time of 2 (0–24) h after parturition before moving to the next pen. Primiparous cows remained in the first pen moved to after parturition for a longer period than multiparous cows [median (range) days: 12 (1.5–25) vs. 6 (1.5–22)]. Approximately 20% of herds had routine vaccinations administered in the maternity or calving pen, first pen after parturition, or both. Almost all herds (n = 69/72) performed fresh cow health checks; however, only 53% (n = 38/72) locked up all fresh cows daily. More herds housed primiparous and multiparous cows in separate pens during the far-off dry (65.3%; n = 47/72) and high-lactation (81.9%; n = 59/72) periods compared with the close-up dry (31.9%; n = 23/72) and fresh periods (27.8%; n = 20/72). At least half of the pens observed during the far-off dry, close-up dry, and fresh periods had a stocking density <100%. Approximately one-third of pens observed during the far-off dry period had feed pushed up ≤4×/d compared with approximately 15 to 20% of pens observed during the close-up dry, fresh, and high-lactation periods. More than half of the total mixed ration samples acquired from the far-off and close-up dry period visits had greater than the recommended proportion of particles in the 19-mm screen of the Penn State Particle Separator. The results of this observational study illustrated the range of management practices used in freestall herds in this region and lay the groundwork for future hypothesis-driven studies using this sampled population.     

Effect of alternative models for increasing stocking density on the short-term behavior and hygiene of Holstein dairy cows

The primary objective of this study was to evaluate short-term responses in lying behavior and hygiene of Holstein dairy cows housed at a stocking density of 100 (1 cow per stall and headlock) or 142% imposed by 1) the denial of access to freestalls and headlocks, 2) the denial of access to freestalls, headlocks, and 26.6 m(2) of alley space, or 3) the addition of a rotating group of 14 cows to the resident group of 34 cows. The secondary objective was to determine the bioequivalence of the 3 methods of experimentally increasing stocking density. Cows (n=136) were assigned to 1 of 4 pens in a 4-row freestall barn and treatments were allocated using a 4×4 Latin square with 14-d periods. Lying time (h/d) and number of bouts/d for 12 focal cows per pen were determined using dataloggers recording at 1-min intervals during the final 5 d of each period. Dry matter intake (DMI) was established from the pen mean over the final 4 d of each period. Feeding and rumination activities on focal cows were determined by direct observation at 10-min intervals for 24h on d 11. Hygiene of focal cows was assessed from the difference in the scores after the legs and udder were cleaned on d 2 of each period and those on d 14. Lying time was greater for 100% stocking density (13.0 h/d) than the 142% stocking density treatments (11.8 h/d), which did not differ. Lying bouts (12.3/d) and bout duration (64.8 min/bout) did not differ among treatments. Short-term responses in DMI (24.6 kg/d) did not differ in response to the treatments. The 3 stocking density treatments decreased, or tended to decrease, the time spent feeding compared with 100% (4.4 versus 4.2 h/d). The stocking density treatments decreased the percentage of rumination occurring within a stall (92.3 versus 85.3%). A treatment effect on udder and leg hygiene scores was not evident on d 14 of each period or in the change from d 2 to 14 of each period. With the exception of rumination time (h/d), the 3 methods for experimentally imposing stocking density were bioequivalent for responses in behaviors, DMI, and hygiene. Future stocking density experiments in 4-row barns should simply deny resting and feeding space to simulate overcrowded housing conditions for lactating dairy cows because it is bioequivalent to more complicated, and potentially confounding, research models.     

Impact of age at calving on lactation, reproduction, health, and income in first-parity Holsteins on commercial farms

The objective was to examine milk production, health, and economic performance among Holstein heifers during first lactation on 3 commercial dairy farms in California. Heifers (n = 1905) were moved to the breeding group between 360 and 390 d of age and grouped retrospectively according to age at first calving (AFC) as low (< or =700 d), medium (701 to 750 d), and high (> or =751 d). Within farm, growing heifers were managed similarly, as were lactating primiparous cows, for the first 310 d in lactation. Heifers were fed to gain 0.70 to 0.80 kg/d from 4 mo of age to breeding, and 0.8 to 0.9 kg/d from breeding to 252 to 258 d of pregnancy. First calving at <700 d was associated with reduced yields of milk and milk components. Cows in the high age group produced more milk fat and true protein than medium and low cows. Incidence of stillbirths was highest for cows in the low group (19.8%), but stillbirths were also a concern for those calving at medium (16.1%) or high age groups (13.5%). Both low and high cows had lower conception rates at first postpartum AI, and abortions averaged 9.8% across groups. Days open and number of inseminations were lower for medium than low cows. Incidence of mastitis and lameness was lowest for cows in the medium group. Culling and mortality rates were not affected by AFC, but among those that died, cows in the low group tended to die earlier postpartum than cows in the high group. Heifers in the medium group had an adjusted income value numerically higher by 138.33 dollars and 98.81 dollars compared with those in the low and high groups, respectively. First calving at <700 d compromised first lactation yields of milk and milk components and impaired reproductive performance. However, extending AFC beyond 750 d did not improve lactation, reproduction, or health of primiparous cows. Although not preassigned to age groups before start of breeding, Holstein heifers managed as in this study had the highest economic return when calving between 23 and 24.5 mo of age.     

Successful control of Johne's disease in nine dairy herds: Results of a six-year field trial

The objective was to evaluate if a standardized Johne's disease control program significantly reduced the prevalence of cattle infected with Mycobacterium avium ssp. paratuberculosis in dairy herds with a moderate to high initial infection prevalence of ≥10% ELISA-positive adult cattle. Nine Wisconsin dairy herds of diverse sizes and management styles completed the 6-yr study. The control program involved changes to heifer rearing practices in combination with a routine testing program. For heifers, the program specifically required 1) segregated maternity pens for ELISA-positive and ELISA-negative cattle; 2) removal of calves from the maternity pen in <2 h; 3) use of colostrum only from individual ELISA-negative cows (no colostrum pooling); 4) hygienic collection of colostrum; 5) feeding of pasteurized milk as milk replacer or on-farm pasteurized milk until weaning; and 6) minimizing contact with manure from the adult cattle until weaning. The testing program was designed to detect the most infectious cattle by using a commercial ELISA once on every adult during each lactation. Producers were required to cull cows with strong-positive ELISA results before the next calving and to label cows with low- to medium-level ELISA results and manage them to limit infection transmission. Outcomes were measured by comparing the apparent prevalence based on ELISA or fecal culture in the whole herd and in first-lactation cohorts at 2 time points: before implementation of the control program and at the end of the trial. The combined results from the 9 herds showed a significant reduction in ELISA-positive cows, from 11.6% at the start of the trial to 5.6% at conclusion of the trial. The apparent prevalence decline among first-lactation cows was greater and was evident by ELISA (10.4 vs. 3.0%) and by fecal culture (17.0 vs. 9.5%). Although variations among farms were observed, the collective results demonstrated that bovine paratuberculosis can be controlled in dairy herds through effective heifer husbandry practices in combination with diagnostic testing to identify, for culling or management, cows most likely infectious.     

The relationship between oxidative damage and vitamin E concentration in blood, milk, and liver tissue from vitamin E supplemented and nonsupplemented periparturient heifers

This study investigated the relationship between oxidative damage and the effect of vitamin E supplementation in blood, milk, and liver tissue in 16 periparturient heifers. The question is whether measurements of oxidative and vitamin E status in blood of a periparturient cow are representative of the total body, given that blood concentrations of both vitamin E and oxidative stress products change around this period. The daily vitamin E intake of the vitamin E-supplemented Holstein-Friesian heifers (n = 8) was 3,000 international units and was started 2 mo before calving; the control heifers (n = 8) were not supplemented. Oxidative damage was determined on the basis of malondialdehyde (MDA) concentrations. Blood was sampled 9 times before calving, on calving day, and twice after calving. Liver biopsies were taken at wk −5, −1, and 2 relative to calving day. Milk was obtained from all heifers immediately after calving, the first 2 milkings and on d 3, 7, and 14 at 0600 h. Serum and liver tissue were analyzed for vitamin E, cholesterol, and MDA; and milk samples were analyzed for vitamin E, MDA, fat, protein, and somatic cell count. The results showed that vitamin E supplements increased both absolute vitamin E concentrations and the ratio of vitamin E to cholesterol in blood and liver tissue. Absolute vitamin E concentration in milk tended to be greater in supplemented cows. Based on the increased MDA blood concentrations at calving, it seems that dairy heifers experience oxidative stress. The effect of vitamin E on MDA differs between the blood, liver, and mammary gland. Vitamin E supplementation could not prevent the increase in blood MDA at calving, but the significantly lower MDA blood concentrations of supplemented cows in the 2 wk after calving suggest that vitamin E has a role in recovery from parturition-related oxidative stress. Vitamin E supplementation reduced oxidative damage in liver, whereas no obvious effect was found on milk MDA concentrations. A strong relationship was found between blood and liver vitamin E and the ratio of vitamin E to cholesterol. Concentrations of MDA in blood and milk were also strongly related. The results show that the relationship between oxidative damage and vitamin E differs within blood, liver tissue, and milk. This implies that oxidative and vitamin E status calculated on the basis of blood values alone should be interpreted with caution and cannot be extrapolated to the whole animal.     

The effect of lameness on the resting behavior and metabolic status of dairy cattle during the transition period in a freestall-housed dairy herd

The objective of this observational study was to examine the effect of lameness on the resting behavior of dairy cattle through the transition period in a mattress-bedded commercial freestall facility, and explore the relationships between lameness, behavior, and metabolic indicators of disease. A convenience sample was used, comprised of 40 multiparous and 17 primiparous Holstein cows that were recruited as they entered the close-up pen and tracked through the maternity, hospital, and fresh pens. At recruitment, 87.5% of multiparous cows and 23.5% of primiparous cows showed evidence of abnormal gait. Lying time decreased from 16 d before calving from a least squares means ± standard error of 13.5 ± 0.6 h/d to a nadir of 10.6 ± 0.38 h/d on the day of calving. After a period of increased rest after calving, lying time stabilized by d 6 to between 9.8 and 10.8 h/d. This change was accompanied by an increase in the number of lying bouts per day from least squares means (95% confidence limits) of 11.2 (10.0 to 12.4) bouts per day to a peak of 17.7 (16.5 to 18.8) bouts per day on the day before calving, and a decrease in the duration of each lying bout. Resting behavior was influenced by calving month, temperature humidity index, body condition, parity, and lameness. Moderate and severely lame cows had significantly longer lying times throughout the transition period before and after calving, but most notable was a dramatic increase in the number of lying bouts observed 3 d before and after calving. In the straw-bedded, loose-housed maternity pen, moderate and severely lame cows had 20.3 (19.1 to 21.5) bouts per day, compared with 15.6 (14.3 to 16.8) bouts per day for nonlame cows. We hypothesized that this alteration in behavior may be associated with hypersensitivity to pain due to lameness. A total of 26.3% of cows tested above a threshold of 1,400 μM β-hydroxybutyrate. Moderate and severely lame cows had a least squares means (95% confidence limits) β-hydroxybutyrate concentration of 1,165 (1,037 to 1,291) μM that was significantly greater than 697 (560 to 834) μM for slightly lame cows and 687 (551 to 824) μM for nonlame cows. In summary, lameness significantly altered the resting behavior of cows during the transition period and was associated with elevated risk for ketosis in the study herd.     

Direct-fed microbial supplementation and health and performance of pre- and postpartum dairy cattle: a field trial

A double-blind field trial was conducted on a commercial dairy to study the effects of feeding a direct-fed microbial (DFM) product consisting of 2 strains of Enterococcus faecium plus Saccharomyces cerevisiae yeast on prepartum and postpartum performance of Holstein cows. Treatments consisted of the normal pre- and post-fresh TMR supplemented with the DFM (2 g/cow per d) or a placebo. Treatments started approximately 10 d prepartum and continued until about 23 d in milk (DIM). A total of 366 Holstein cows were enrolled in 1 of 2 placebo groups or 2 DFM-supplemented groups. Groups were enrolled consecutively, starting with the placebo treatment. Sample size was limited to 4 groups because the cooperating dairy prematurely terminated the study due to increased health problems in one of the groups. Blood samples were taken during the prefresh period between 2 and 10 d prior to calving and at weekly intervals from 3 to 23 DIM. Blood concentrations of nonesterified fatty acids before calving and β-hydroxy-butyrate after calving were not affected by treatment. Supplementation with the DFM product increased milk fat percentage for the first lactation cows and increased milk protein percentage for the second and greater lactation cows during the first 85 DIM. Second-lactation cows fed the DFM product received fewer antibiotic treatments before 85 DIM than cows receiving the placebo. This validated the dairy producer's concern that cows consuming one of the diets (revealed to be the placebo diet after the study was completed) were experiencing more health problems. Most measures of milk yield were numerically increased by supplementation with the DFM product. However, differences in milk yield were not significant. Key covariates for main study outcomes included milk yield in the previous (first) lactation, body condition score prior to calving, days spent in the maternity pen, and stocking density of the pre-fresh pen.     

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.     

Short-term increases in stocking density affect the lying and social behavior, but not the productivity, of lactating Holstein dairy cows

Reduced access to resources because of increased stocking density may have a detrimental effect on the behavior of the lactating dairy cow. The objective of this study was to determine the short-term responses in behavior, productivity, fecal cortisol metabolites, and udder and leg hygiene of lactating Holstein dairy cows housed at stocking densities of 100 (1 cow per freestall and headlock), 113, 131, and 142%. Multiparous cows (n=92) and primiparous cows (n=44) were assigned to 1 of 4 pens (34 cows per pen) in a 4-row freestall barn. Pens were balanced for parity, milk production, and days in milk. Stocking densities were imposed for 14 d using a 4 × 4 Latin square design. Time spent feeding and time spent ruminating were quantified by 24 h of direct observation of focal cows (n=12 per pen) beginning at 0800 h on d 11 of each period. Data loggers recorded lying behavior (time and bouts) from the same focal cows per pen at 1-min intervals during the final 5 d of each period. Fecal cortisol metabolites were quantified from samples collected on d 13 and 14 of each period from the same focal cows. Displacements from the feed barrier were recorded on a pen basis after 9 milkings over the last 4 d of each period. Productivity was assessed on a pen basis from milk yield (recorded from d 10 to 14 of each period) and milk components (quantified from composite samples collected on d 12 of each period). Milk composition was further analyzed for milk fatty acid profiles, which were determined from a subset (n=6 per pen) of the focal cows. Data were analyzed using the MIXED procedure of SAS, with the pen (n=4 per treatment, except displacements where n=3 per treatment) as the experimental unit. Feeding and ruminating (h/d) did not differ among treatments. Lying time was reduced at stocking densities of 131 and 142%, relative to 100 or 113%. Lying bouts were not affected by treatment. Stocking densities of 131 and 142% reduced the percentage of time cows spent ruminating within a freestall relative to 100%. Displacements from the feed bunk increased linearly across treatments. Fecal cortisol metabolites, udder hygiene score, milk yields, milk composition, and milk fatty acids did not differ among treatments. Decreased lying time and increased aggression at the feed bunk suggest that an alteration of the time budgets of lactating dairy cows may occur at higher stocking densities, but it is unclear at what point these changes might have further biological consequences.     

Abundance of mRNA of apolipoprotein b100, apolipoprotein e, and microsomal triglyceride transfer protein in liver from periparturient dairy cows

Limited secretion of very low density lipoproteins (VLDL) in dairy cows is strongly related to fatty liver and other metabolic disorders in the early postpartum. Currently, there is limited information on which roles apolipoprotein B(100) (ApoB(100)), apolipoprotein E (ApoE), and microsomal triglyceride transfer protein (MTP) play in that VLDL limitation. To our knowledge, no studies have simultaneously measured ApoB(100), ApoE, and MTP mRNA in periparturient dairy cows. Therefore, a trial was conducted to assess liver gene expression of these proteins in transition dairy cows and to evaluate the relationships between their expression and metabolic status. Eight multiparous Holstein cows were monitored during the transition period. To evaluate metabolic and nutritional status, body condition score was registered, and plasma indexes of energy metabolism and VLDL were determined from 35 d before to 35 d after calving. Liver biopsies were performed on d -35, 3, and 35 relative to day of calving, and gene expression of ApoB(100), ApoE, and MTP were determined on liver tissue. Body condition, plasma glucose and VLDL decreased, and plasma NEFA and BHBA increased after calving. Compared with values of d -35, on d 3 after calving the ApoB(100) mRNA synthesis was lower, whereas MTP and ApoE mRNA abundance were higher. Negative correlation (r = -0.57) between plasma NEFA concentration and ApoB(100) mRNA abundance, and positive correlation between ApoB(100) mRNA abundance and plasma cholesterol (r = 0.65) and plasma albumins (r = 0.52) were detected at 3 d postpartum. Data on changes of gene expression of the 3 main proteins involved in the regulation of synthesis and secretion of VLDL in the liver suggest that decreased mRNA for ApoB(100) may be consistent with decreased synthesis and/or secretion of VLDL from liver during the periparturient period.     

Prepartum milking of heifers influences future production and health

Transition heifers face multiple stressors during the periparturient period, including first exposure to milking, that may adversely impact dry matter intake (DMI), reduce milk production, compromise immune function, and increase susceptibility to disease. It was hypothesized that reducing the combined stressors experienced at calving would improve the periparturient performance, health, and well-being of heifers. The objective of this study was to determine the effect of initiating the milking procedure 3 wk before expected calving on production, DMI, body weight, energy balance, udder health, calving traits, and health status, as indicated by plasma acute phase protein concentrations. Twenty-two primigravid heifers, blocked by expected calving date, were assigned randomly either to a prepartum milking (PM) group or control group. The PM heifers were milked twice daily beginning at 21 d before expected calving, and control heifers were not milked until after calving. All heifers had access to the same precalving and post-calving diets. Results indicated that PM heifers produced more milk during the first 2 wk after calving and had greater DMI as a percentage of body weight during the first month after calving than did control heifers, although energy balance was more negative for PM heifers. The PM heifers had reduced somatic cell counts through the first month after calving and lower average somatic cell scores during lactation despite having more quarters with mastitis infection at calving. The PM heifers had less udder edema at the third milking postcalving, and had reduced concentrations of haptoglobin in blood sooner than did control heifers. These results indicate that prepartum milking is an alternative management practice that has beneficial effects on the production, health, and well-being of first-lactation cows.     

Phenotype analysis of peripheral blood mononuclear cells in periparturient dairy cows

Impaired immune function during the periparturient period contributes to the increased susceptibility of the cow to infectious disease around the time of calving. Changes in subpopulations of peripheral blood mononuclear cells during the immediate periparturient period can contribute to the observed immunosuppression in cows, but it is not known exactly when and what changes occur. Using a flow cytometer and monoclonal antibodies directed against antigenic markers on mononuclear cells, the populations of CD3, CD4, CD8, and gamma delta T-cell receptor positive cells were examined in eight periparturient Jersey cows during the 2 wk before and 2 wk after parturition. The percentage of cells that were positive for CD3, CD4, and gamma delta T-cell receptor markers exhibited a significant decline before calving and reached a nadir at calving. These percentages did not return to precalving levels until 2 wk after calving. These data are compatible with the hypothesis that declining T-cell populations may contribute to the immunosuppression reported for dairy cows at calving.     

Effects of preventing periparturient hypocalcemia in cows by parathyroid hormone administration on hematology, conglutinin, immunoglobulin, and shedding of Staphylococcus aureus in milk

The effects of hypocalcemia at parturition on concentrations of serum immunoglobulin and conglutinin, number of bacteria shed into milk, and leukograms of dairy cows were investigated from -4 wk prepartum to 4 wk postpartum. Ten healthy multiparous Holstein cows were fed a high calcium diet to induce hypocalcemia at parturition. Five cows received intramuscular parathyroid hormone to prevent hypocalcemia at parturition. All cows experienced a leukopenia (attributable to an absolute and relative neutropenia) during the 1st wk after calving, decreased serum conglutinin activity during the first 3 wk postpartum, and decreased concentration of serum IgG1 during the 3 wk before calving. At parturition, a large increase in organisms was found in foremilk (1000 to 10,000 times more than prepartum values). Neither the hematological changes nor the decreased immunoglobulin concentration was influenced by hypocalcemia or the development of milk fever. This implies that the degree of hypocalcemia observed did not have a large or irreversible influence on bacterial infection, hematological, or humoral immunity changes in periparturient cows.