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.     

Dairy cows with prolonged calving seek additional isolation

In modern calving facilities, dairy cows either calve in a group pen or are moved to a separate individual pen when calving is imminent. In practice, cows are often moved too close to calving, which poses a health risk to cow and calf. Thus, a need exists for new calving facility designs and management practices that better align with the motivations of the cow. This study examined dairy cow preferences for individual calving pens by offering 3 different levels of isolation (tall and narrow, low and wide, and tall and wide) by analyzing the association between precalving behavior, choice of degree of isolation, and the progress of calving. The hypotheses were that cows would prefer the highest level of isolation when giving birth, and that calving in a high level of isolation would be associated with less restlessness and a shorter calving duration. Contrary to these hypotheses, no specific preference between degrees of isolation or difference in calving behavior in the different calving pens was found. However, cows experiencing a longer calving duration chose to calve in the most secluded calving pen (tall and wide). These results cannot determine cause and effect, but may suggest that interactions between motivation for isolation seeking and calving behavior exist.     

The effect of stocking density and a blind on the behavior of Holstein dairy cattle in group maternity pens. Part I: Calving location,locomotion, and separation behavior

In a more natural setting, dairy cows separate from herdmates and seek a secluded area to give birth. However, on many dairy facilities, cows calve in barren group pens with limited space, which may limit their ability to perform these behaviors. The objective of this study was to determine the effect of stocking density and provision of a blind (a single-sided solid partition) in group bedded pack maternity pens on the behavior of dairy cattle. The study included 4 experimental treatments: (1) high stocking density (7.7–12.9 m² of 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. We analyzed the effect of these treatments on locomotor and separation behavior as well as blind use during the 24 h before calving. A total of 127 primiparous heifers and 247 multiparous cows were housed in 16 mixed-parity groups (4 groups per treatment) from approximately 3 wk before to immediately after calving. Locomotor behavior increased from 24 to 2 h before calving regardless of treatment but increased the most in high stocking density pens without a blind. Additionally, heifers performed more locomotion than cows. Animals increased their distance from other cows beginning approximately 4 h before calving. Animals in low stocking density pens had a greater distance from other cows compared with those in high stocking density pens. Additionally, heifers had a greater distance from penmates during the 4 h before calving than cows. More animals calved in the area of the pen that contained a blind compared with the same respective areas of high and low stocking density pens that did not contain a blind. These results suggest that periparturient dairy cattle in group maternity pens are motivated to seek seclusion at calving, but increased stocking density may impede their ability to do so. Providing additional space and a blind may benefit periparturient dairy cows and heifers by facilitating natural calving behaviors.     

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 degree of visual cover and location of birth fluids affect dairy cows' choice of calving site

Under natural conditions, cows seek isolation and visual cover when calving becomes imminent, but the degree of visual cover necessary to provide an attractive calving site is not known. When calving indoors, preparturient cows are attracted to other cows' birth fluids, and this may influence their isolation seeking. Therefore, we aimed to investigate the effect of degree of visual cover of secluded areas and the location of birth fluids on dairy cows' calving site selection. One hundred twenty-four Danish Holstein cows were moved in groups of 8 to 12 to a group pen with access to 6 areas secluded by a barrier of either 3 m (wide barrier) or 1.5 m (narrow barrier). Sixty cows calved within 14 d of having been moved to the group pen and were included in the study. From 3 h before partition and until the cow and calf were removed from the pen within 3 h after parturition, the location and posture of cows were recorded, along with the location of where their birth fluids were discharged. In addition, location and posture of calves were recorded during and up to 3 h after calving. All data were collected from continuous video recordings. Continuous data for location and behavior were analyzed by mixed models, binary data were analyzed by chi-squared analysis, and location of calving relative to where the cow's own or alien birth fluids were discharged was analyzed using logistic regression models. Ten percent of the cows calved in a secluded area, with no effect of barrier width. However, before calving, cows with access to secluded areas with a wide barrier spent more time in a secluded area (22 vs. 7 min/3 h), and more cows were observed lying there (58 vs. 28%) than cows with access to secluded areas with a narrow barrier. Secluded areas with a wide barrier were used by more cows and calves during the first hour after calving (36 vs. 10%). Among the cows that entered a secluded area after calving, the latency to enter correlated with their calf's latency to enter, suggesting that the 2 sought seclusion together. Seventy-nine percent of the cows calved in proximity (within a 1.25-m radius) to their own or an alien cow's birth fluids. There was no effect of barrier width on the probability of calving in proximity to their own or alien birth fluids. However, the probability of calving in proximity to their own or alien birth fluids was higher than the probability of not doing so. The greater use of secluded areas with a 3-m-wide barrier before and after parturition suggests that these are preferred over areas with a 1.5-m-wide barrier. Only a few cows calved in a secluded area, and more research is needed to explore the environmental and social factors affecting parturient cows' use of designated calving areas. The majority of cows calved close to where their own or alien birth fluids were discharged, suggesting that cows are attracted to these before calving. This may have affected the use of secluded areas as calving sites.     

The effect of hides and parity on behavior of periparturient dairy cows at pasture

Under natural conditions, most parturient cows seek visual cover or seclude themselves from the herd when calving becomes imminent. Studies on calving site selection of dairy cows housed indoors show that predominantly older and dominant cows calve in secluded areas. This study aimed to investigate whether cows distance themselves further from herd members under spacious outdoor conditions and whether artificial hides on a pasture motivate cows to seek visual isolation from the herd. One hundred eighty-two Danish Holstein cows were allocated to 1 of 13 groups of 14 cows according to expected calving date. In 2 paddocks (each 75 × 150 m), 5 zones (75 m × 30 m) were defined; zone 0 contained the feeding and shade area, and zone 4 bordered an area with trees. Weekly and according to calving date, a group of 14 cows was moved either to a paddock that had 12 hides distributed evenly throughout zones 1 to 4 (7 groups) or to a paddock without hides (6 groups). The hides were wooden structures (3.3 m long × 1.0 m wide × 1.2 m high) that the cows could hide behind. One hundred seven cows calved within 14 d of having been moved to the paddock, and 82 of these (38 primiparous and 44 multiparous), and their calves, were included in the study. From 3 h before until 3 h after calving, the location, posture, and behavior of cows were recorded continuously from video recordings. In addition, location, posture, and behavior of the calves were recorded for the first 3 h after birth. Continuous variables were analyzed by linear mixed effects models, whereas binary data were analyzed using mixed effects logistic regression. The presence of hides did not affect selection of calving location in the paddock, but more primiparous than multiparous cows calved in zone 4; that is, furthest away from the feeding area. Before calving, primiparous cows were more likely to be positioned in zone 4 and less likely to approach and contact herd members. After calving, primiparous cows and their calves tended to be more likely to be positioned in zone 4. The more cows present in the paddock, the less likely the cows were to isolate (i.e., be further than 30 m away from any other cow) at the time of calving. In addition, the more cows in the paddock when a calf was born, the less time these calves spent in a lying posture. The results show that primiparous cows move further away from herd members at calving than multiparous cows and suggest that primiparous cows prefer to isolate themselves through distance rather than seeking artificial cover. Contrary to expectation, the hides did not make more cows select a calving site away from the feeding area.     

Survey of calf and heifer housing on Pennsylvania dairy farms

Research has established a link between calf and heifer housing and calf health. To determine current calf and heifer housing practices in Pennsylvania, 329 dairy farms were surveyed. The study was designed to increase awareness on the part of dairy farmers in housing and management and to develop education programs and materials in the area of calf and heifer management. All surveys were conducted on the farm by personal interviews. Results showed 24.9% of the farms had maternity pens in a building separate from the milking herd, although half of these farms used maternity pens in conjunction with facilities of lesser quality for the health and management of the animals. The same number of farms used calf hutches as those keeping calves in dairy barns with cows. A high percentage of the farms weaned calves (moved from milk diets to dry feed diets) to recommended types of facilities that included group pens, loose housing, and group or superhutches. However, 49.5% of the facilities used for weaned calves were in conjunction with other dairy animals. Animal restraint facilities have also been identified as an area that needs more emphasis on dairy farms. Many areas of dairy replacement housing on commercial dairy farms were determined to be unsatisfactory according to recommended Pennsylvania standards.     

Periparturient climatic, animal, and management factors influencing the incidence of milk Fever in grazing systems

The objective of the present study was to quantify the climatic, animal, and management factors influencing incidence of milk fever (MF) in cows exposed to grazing systems. Data were extracted on 4,469 calvings of multiparous cows in a seasonal calving research herd between 1970 and 2000. Climatic data during the calving period also were extracted for these years. Poisson regression was used to investigate the effect of climate on frequency of MF within year; the offset variable was the number of cows at risk for MF at that time. Generalized estimating equations, with cow included as a repeated effect, were used to quantify the effect of parturition-associated cow and management factors on the logit of the probability of MF. Both univariate and multivariate analyses were performed. Explanatory variables investigated included time of calving relative to the herd-year calving period, parity, body weight, breed of cow, body condition score at calving, weight and gender of the calf, incidence of twin calves, calving inductions, and calving assistance. Odds of recurring MF within cow, as well as the timing of MF relative to day of calving, was quantified using generalized estimating equations with cow included as a repeated effect. Results show significant effects of evaporation, minimum grass temperature, difference between ambient maximum and minimum temperature, and rainfall on the odds of MF occurring, with a greater incidence at greater evaporation, larger diurnal variation in air temperature, greater rainfall, and lesser grass minimum temperature. Cow factors, such as age, excessive or poor body condition score, and requirement for calving assistance increased the odds of MF; a lesser odds ratio was observed in cows hormonally induced to calve and those that had twin births. Results indicate that herd managers may identify the day of greatest risk for MF and cows that are at greatest risk of MF based on climatic, cow, and management factors.     

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.     

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.     

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.     

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.     

On-farm deaths of dairy cows are associated with features of freestall barns

On-farm death (OFD) of a dairy cow is always a financial loss for a farmer, and potentially a welfare issue that has to be addressed within the dairy industry. The aim of this study was to explore the associations between OFD of dairy cows, housing, and herd management in freestall barns. To achieve the goal, we followed 10,837 cows calving in 2011 in 82 herds. Data were gathered with observations and a structured interview during farm visits and from a national dairy herd improvement database. The hazard of OFD was modeled with a shared frailty survival model, with SAS 9.3 PHREG procedure (SAS Institute Inc., Cary, NC). The study population was 58% Ayrshire and 42% Holstein cows. The median herd size and mean milk yield in the study herds were 116 cows and 9,151 kg of milk per cow per year. The overall probability of OFD was 6.0%; 1.8% of the cows died unassisted and 4.2% were euthanized. Variation in OFD percentage between individual herds was large, from 0 to 16%, accounting for 0 to 58% of all removals in the herds. Keeping close-up dry cows in their own group was associated with higher hazard of OFD [hazard ratio (HR) = 1.37] compared with keeping them in the same pen with far-off dry cows. Higher hazard on OFD was observed when barns had only one kind of calving pen; single (HR = 2.09) or group pens (HR = 1.72), compared with having both of those types. The hazard of OFD was lower if the whole herd was housed in barns or pens that had only 1 type of feed barrier at the feed bunk, namely post-and-rail (HR = 0.51) or a type with barriers between the cow's heads (HR = 0.49), compared with having 2 types. Lower OFD hazard was observed with wider than 340 cm of walking alley next to the feeding table (HR = 0.75), and with housing a whole herd in pens with only 1 type of walking alley surface, specifically slatted (HR = 0.53) or solid (HR = 0.48), compared with having both types. The hazard of OFD was higher with stalls wider than 120 cm (HR = 1.38) compared with narrower stalls. The hazard of OFD was also associated with breed, parity, and calving season. This study identified many factors that contribute to the incidence of OFD of dairy cows. The solutions for reducing on-farm mortality include housing, management, and breeding choices that are most probably herd specific.     

Systematic early obstetrical assistance at calving: II. Effects on dairy heifer calf growth,health, and survival to weaning

Good calving management should not only ease the transition of cows into lactation, but also contribute to providing healthy replacement animals for the herd. Difficulty during parturition has been found to be detrimental to the offspring. Because of the association of obstetrical intervention with undesirable outcomes, the general management recommendation for calving is to let cows give birth unassisted whenever possible. Unfortunately, very few studies have investigated the effects of planned early assistance during calving, regardless of whether or not another problem exists. To investigate the effects of early assistance during apparently normal calvings, a clinical trial was conducted on 257 Holstein cows. They were observed through the second stage of calving, and before calving they were divided randomly between 2 assigned interventions: not assisted or early assistance during the second stage of parturition. After calving, the animals were classified into 4 actual calving intervention groups: too quick to be assisted, not assisted, early assistance, and late assistance (for cows in the not assisted group that did not calve unassisted within the 1 h maximum time allowed). Early assistance was given 15 min after first sight of both front hooves of the calf and done using human force only. Heifer calves (n = 129) born from enrolled dams were followed until weaning to assess the effect of assigned and actual calving interventions on their growth, health, and survival. Heifer calves’ weight at birth was positively associated with weight at 7 wk, but the effect varied by assigned and actual intervention. As a routine management practice, giving early assistance during calving to dairy cows did not influence average daily gain, health, or survival in dairy heifer calves up to weaning at 7 wk of age.     

Calf mortality in Virginia Dairy Herd Improvement herds

Information concerning heifer calf mortality and dairy herd management practices was obtained by survey of 407 Virginia Dairy Herd Improvement herds. Dairy producers, with the assistance of Dairy Herd Improvement supervisors, accounted for mortality of all heifer calves born from October 1, 1978 to March 31, 1979. Calf mortality was compared among herd sizes, fat and milk production, cow and calf housing systems, calving locations, and calf feeding practices. Average herd size was 82 cows with 87% of herds containing fewer than 120 cows. Mortality at birth and from birth through 3 mo of age averaged 1.2 and 6.5%. Mortality at birth was correlated .10 with herd size. Losses from birth through 3 mo of age were correlated .10 with age at weaning and -.16 with rolling yearly average milk and fat production. Relationship of mortality with other herd characteristics or management practices was negligible.     

Calf Management Practices and Health Management Decisions on Large Dairies

Calf raising practices were studied to obtain a picture of managers approaches to calf management. Ten categories outlining calf management practices were used to formulate questions for on-farm surveys of 46 dairies. To assess consistency in management, managers decisions were scored to indicate whether they coincided with currently accepted recommendations for effective calf management.Results indicate that calving area sanitation is often not maintained with cows in the maternity area for long periods. Most calving areas are near constant activity with few scheduled observations performed. Treatment of the calf's navel is not universal nor is automatic supplementation of colostrum. Colostrum intake is often left to the calf with most operators unsure of the quantity being consumed. Veterinary advice or services are seldom used for calves; treatments are performed primarily by calf raisers.Large dairy operations showed inconsistency in calf management practices, inadequate use of calf records, and use of labor sources outside the operator's family. Large herd size often dictated labor-intensive calf management practices.     

Systematic early obstetrical assistance at calving: I. Effects on dairy calf stillbirth,vigor, and passive immunity transfer

A critical time for dairy cattle is the perinatal period. Good calving management is critical to reduce periparturient losses and ensure the health of the offspring. Generally, it has been recommended that cows be allowed to calve unassisted when possible, but very few studies have been published that support or refute this general guideline. To investigate the effect of early assistance, a clinical trial enrolled 257 Holstein cows that were observed through the second stage of calving and assigned randomly to 1 of 2 calving interventions: not assisted (NA) or early assistance (EA) during the second stage of parturition. Early assistance was given 15 min after the first sight of both front hooves of the calf and done using only human force. After calving, the animals were classified into 4 actual calving intervention groups: too quick to be assisted (TQ), NA, EA, and late assistance (LA; for cows in the NA group that did not calve unassisted within the 1 h maximum time frame allowed). Giving early assistance to cows during calving as a routine management practice (assigned intervention) did not negatively influence calves’ stillbirth risk, vigor at birth, or transfer of passive immunity. Calves in the LA intervention group had significantly greater odds of stillbirth than calves in the NA and EA groups, respectively. Calves in the LA group also had significantly worse vigor at birth than calves in the TQ, NA, or EA groups. Early assistance given at calving to cows that did not present signs of calving difficulties did not adversely affect calves’ likelihood of being stillborn, vigor at birth, or transfer of passive immunity.     

Effect of group size and health status on behavior and feed intake of multiparous dairy cows in early lactation

Dairy cows in early lactation are often housed in a large group, where they may have to compete for access to feed and space. However, a cow's ability to compete may be impaired due to production disease, and housing in a small group with minimal competition may be beneficial for cow welfare. The aim of this study was to investigate the effect of group size and health on social and feeding behavior of cows during the first 3 d after introduction to a new group. Data included 54 multiparous Holstein-Friesian cows that were moved from an individual maternity pen and individually joined an existing group pen for 6 (N6) or 24 cows (N24) on d 4 after calving. Cows were considered sick if they were diagnosed with and treated for milk fever, mastitis, or retained placenta, diagnosed with subclinical ketosis or metritis within 3 d of calving, or were diagnosed and treated for any other infection (n = 22; balanced across treatments). Stocking density of both pens was 100% at the feeding and lying areas. Behavioral data were collected from video recordings during the 1 d after introduction to the group pen, as well as via electronic feed bins and leg-attached accelerometers during the first 3 d after introduction to the group pen. No interactions between health status and group size were discovered. During the 1 d after introduction, N6 cows displaced other cows from feed less frequently than N24 cows (1.22 vs. 5.76 times/24 h), were less likely to access feed after a displacement (replacement; 0.29 vs. 1.67 times/24 h), and were less frequently being butted by another cow (0.42 vs. 1.69 times/24 h). Second-parity cows received more head butting than later-parity cows. Data obtained from feed bins showed that the number of replacements peaked on d 2 after introduction to the group pen. During the first 3 d we observed no effect of group size on DMI, but sick cows ate less than cows that were not sick (15.2 vs. 16.6 kg of DM/d). However, cows in N6 visited the feeder less often (42.4 vs. 55.6 times/d). Over the 3 d after introduction DMI and feeding time increased, whereas feeding rate decreased. Lying time and the number of lying bouts increased from d 1 to 2. The number of steps decreased over days, but the number of steps was higher among N24 than N6 cows on d 1 and d 2. Results suggest that cows experience less competition when moved to a smaller group after calving regardless of health status. Thus, minimizing competition by housing dairy cows in a small group for the first days after calving may improve cow welfare under commercial conditions.     

Effect of serum calcium status at calving on survival,health, and performance of postpartum Holstein cows and calves under certified organic management

The study objective was to assess the effect of hypocalcemia (HYPO; ≤2.0 mmol/L) of the dam at calving on survival, health, and performance of lactating dairy cows and their calves under certified organic management. Prepartum dairy cows (primiparous, n = 445; multiparous, n = 328) from 1 dairy herd were monitored (prepartum pen) for imminent signs of parturition (appearance of amniotic sac outside the vulva) until birth. All calves were subject to the same newborn care, colostrum management, and failure of passive transfer assessment (serum total protein ≤5.5 mg/dL). Serum total calcium of cows was determined in samples taken within 2 h after calving. To define HYPO cows after calving, a cut-point of total serum Ca concentration with optimal sensitivity and specificity to predict metritis or calf diarrhea was established by using the receiver operator characteristic. The effect of HYPO on survival (died or culled within 60 DIM), health status, and pregnancy per artificial insemination (PAI) for first services of lactating cows were analyzed using the GLIMMIX procedure of SAS. Additionally, the effect of HYPO at calving on days in milk (DIM) at first service (DIMFS), milk yield (kg), milk components (percent fat and protein), and somatic cell count were analyzed for the first 3 Dairy Herd Improvement Association (DHIA) tests using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). The effect of parity (primiparous and multiparous), body condition score at calving, and manure hygiene score at calving were also included in the statistical models. The effect of HYPO at calving on calf survival, serum total protein, and diarrhea within 10 d of age were assessed using GLIMMIX procedure of SAS. The overall prevalence of HYPO was 14.6% (2.7% for primiparous and 30.8% for multiparous cows). Cows experiencing HYPO at calving had greater proportion of metritis (25.1 vs. 14.7%) and culling within 60 DIM (15.9 vs. 6.8%) compared with non-HYPO cows, respectively. For the first 3 DHIA tests, milk yield and components did not differ between HYPO and non-HYPO cows. The DIMFS as well as proportion of cows with dystocia, births of twins, mastitis, and PAI at first service were not different between HYPO and non-HYPO cows. The proportion of stillbirth, weaned calves, and serum total protein did not differ between calves born from HYPO or non-HYPO cows. However, calves born from HYPO cows had greater incidence of diarrhea (49%) than calves born (33.3%) from non-HYPO cows. Findings from the present study showed that HYPO at calving had significant health implications for both dams and calves under certified organic management.     

Short communication: the effects of supplementation of various n-3 fatty acids to late-pregnant dairy cows on plasma fatty acid composition of the newborn calves

The passage of long-chain fatty acids (FA) through the placenta in ruminants is limited. However, essential long-chain polyunsaturated FA, and especially n-3 FA, are crucial for normal development of the bovine fetus; therefore, uptake of these FA by the embryo must occur during pregnancy. The objectives of the present study were to examine the effects of enrichment of dam plasma with various n-3 FA during late gestation on newborn calf plasma FA composition. Twenty-seven multiparous cows at 256 d of pregnancy were divided into 3 groups and fed encapsulated fats as follows: 1) control: supplemented at 240 g/d per cow with saturated FA; 2) flaxseed oil (FLX): supplemented at 300 g/d per cow with fat that provided 56.1g/d per cow of α-linolenic acid (ALA) from flaxseed oil; and 3) fish oil (FO): supplemented at 300 g/d per cow with fat that provided 5.8 and 4.3g/d per cow eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil, respectively. Blood samples were taken from dams twice weekly and from calves immediately after calving before first colostrum. The FA composition in plasma was determined in dams at the last sample before parturition, on average 2d before calving. Feeding cows with FLX resulted in a 2.6-fold increase in the proportion of ALA in dam plasma as compared with the control. The proportion of EPA in cow plasma was not different between groups; however, the percentage of docosapentaenoic acid (DPA) was 1.4 and 2 times higher, respectively, in cows fed FLX and FO than in the controls. In addition, the plasma proportion of DHA was 15 times higher in FO cows than in controls. In calves, no differences between groups were observed in the plasma proportions of ALA and EPA; however, the proportion of DHA was 1.9 times higher in the FO calves than in controls. Across treatments, data showed no correlation between the proportions of ALA, EPA, and DPA in dam and calf plasma; however, positive correlation was demonstrated between dams and calves in DHA proportion (r=0.55). In conclusion, the distinct plasma FA profile in newborn calves compared with dams was apparently due to low permeability of the bovine placenta to polyunsaturated FA. Enriching late-gestation dairy cows with n-3 FA increased the proportion of DHA, but not ALA, in newborn calf plasma, probably because of the essentiality of DHA to fetal development.