THIS ARTICLE IS SPONSORED BY THE MINNESOTA DAIRY HEALTH CONFERENCE.

THIS ARTICLE IS SPONSORED BY THE MINNESOTA DAIRY HEALTH CONFERENCE. ST. PAUL, MINNESOTA UNITED STATES OF MINNESOTA

Studies in Dairy Cow Calving Behavior Jerome Carrier!, Sandra Godden!, John Fetrow!, Steve Stewart\ Paul Rapnicki\ Marcia Endres 2 and Petra Mertens! College of Veterinary Medicine! and College of Agricultural, Food and Environmental Sciences 2 University of Minnesota Introduction: management of the parturient cow in freestall herds In a typical setting for freestall-housed dairy cattle, pregnant heifers and dry cows are transferred to a close-up pen 2 to 4 weeks prior to expected calving date in order to receive a transition ration in preparation for the coming lactation (Cook and Nordlund, 2004). However, if the parturition itself were to happen in the freestall pen, the newborn calf would be exposed to large amounts of fecal pathogens and may be injured by mechanical equipment like automatic manure scrapers, may suffer from cold stress during winter months or may be trampled by the cows. Because freestall pens are not a good environment for the newborn calf, cows are usually transferred to a maternity pen for calving. The challenge is in deciding when the transfer to the maternity pen should occur. It is difficult to precisely predict the moment of calving based on external physical signs like udder enlargement, vulvar swelling and relaxation of the pelvic ligaments (Berglund et ai., 1987; Metz and Metz, 1987; Cook and Nordlund, 2004). This is why moving cows to the maternity pen based on the external signs may result in some animals spending up to 3 to 7 days (or more) in the pen instead of the desired 1 or 2 days (Cook and Nordlund, 2004). With such long stays for some animals, the maternity pens will tend to become dirtier and require more maintenance. Dirtier pens may increase the risk of mastitis or metritis for the cow and the risk of infectious diseases for the calf. Moreover, cows spending longer periods in a maternity pen may tend to have more metabolic problems after calving due to larger depression of dry matter intake, as suggested by field data on non-esterified fatty acids concentrations (NEF A), displaced abomasum and ketosis in transition cows from the University of Wisconsin (Cook and Nordlund, 2004). To decrease the amount of time spent by preparturient cows in the calving pen, it is now often recommended that they be moved to a nearby individual calving pen only when the parturition process is initiated and birth is imminent (Bickert et ai., 2000; Cook and Nordlund, 2004). The move occurs either during stage 1 of parturition (cervix relaxation and dilation), or at the beginning of stage 2 (expulsion of the calf) (Youngquist, 1997). Although the standard textbook recommendation is to avoid moving cows during calving (Mee, 2004), it is.not exactly known how moving cows during parturition may affect its course. Parturition studies for dairy cattle have been conducted under management systems that are different than what is described above, and oftentimes with different breeds. For example, in a study by Berglund and others (1987), Swedish Red and White, Swedish Friesian, Red and White x Friesian cross as well as Swedish Jersey cows and heifers calved in the tie-stalls to which they were accustomed. In another report, Polish 105

Black and White pluriparous cows were moved to individual calving pens one week prior to calving (Metz and Metz, 1987). In a third study, Holstein heifers were moved from loose housing to tie stalls 2 weeks prior to calving (Nogalski, 2002). Descriptions that apply to current management systems in large freestall facilities are lacking. Cattle isolated in unfamiliar environments have an increased incidence of high-frequency vocalization and of defecation/urination, increased heart rate and increased cortisol concentrations, all changes indicative of stress or fear (Grandin, 1997; Rushen et ai., 1999). Behaviors like pacing or trying to escape are sometimes observed when cows, particularly heifers, are brought from their transition freestall pen to an individual calving pen (personal observations). These may be related to the same stress of isolation. Research is needed to determine whether moving cows at parturition actually does delay parturition, and if so, by how much and with what consequences. Stillbirth is defined as the death of a calf immediately prior, during, or within 24-48 hours of parturition (Meyer et ai., 2000). Many risk factors for stillbirth have been identified. The most important is dystocia, but other risk factors identified include parity (1 st calf), gender of the calf (male), season of birth (winter), prepartum body condition score (fat) and birth weight of the calf (very small and very big calves) (Chassagne et ai., 1999; Meyer et ai., 2000; Meyer et ai., 2001; Johanson and Berger, 2003). An important mechanism involved in stillbirth is the severe acidosis caused by oxygen deprivation when parturition is delayed, whether forced extraction is required or not (Meijering, 1984). This raises the question whether or not behavioral factors during parturition may also influence the risk of stillbirth. Such association between behavior and stillbirth has not been described. The purpose of this study is first to describe the parturition process in Holstein cows and heifers moved to a calving pen when calving is imminent, then to describe the associations between selected risk factors (including behavioral factors) and duration of parturition, and finally to describe the association between the risk factors and the risk of stillbirth. Presentation of a research project on calving behavior and other risk factors for stillbirth An observational study was undertaken at a commercial transition management facility associated with the College of Veterinary Medicine of the University of Minnesota that manages cows and heifers in late pregnancy and early lactation for two large dairies (total 2500 cows). On this facility, pre-fresh heifers and dry cows are kept in two separate large freestall pens (96 stalls per pen) and are moved to individual pens for calving (13' by 13'). After calving, all fresh cows are processed in a special area before being sent to a fresh cow freestall pen (32 stalls). Calves are processed at the same time and put in a well-bedded group pen awaiting the daily pick-up by the calflheifer grower. To study the parturition process, four of the eight possible calving pens were equipped with video cameras and were used preferentially when possible. The animals of interest are the 106

cohort that calved from November 2003 to February 2004 and whose calving was videotaped. The variables measured for the cows were Imri!y, body weight (estimated using a weigh tape at fresh cow processing time), and body condition score within 2 weeks prior to parturition. Also, the stage of parturition immediately prior to moving was scored using the following scale: I) presence of only mucus or blood at the vulva, II) presence of a visible "water bag" (either allantochorion or amnion, whether intact or ruptured) or III) presence of protruding calf body parts (feet or head). The information was immediately noted on a log adjacent to the calving pens by the person moving the cow. On the calving pen log were also noted the cow ID, pen number and time of entry in the calving pen to facilitate matching of the video data with all the other recorded data. Blood samples were collected from all fresh cows at the time of fresh cow processing and were analyzed for total serum calcium concentration. All calves were weighed on a scale immediately after birth, prior to feeding. The number of calves for each calving (1 or 2), along with their ID, gender and weight was recorded at the time of processing. The dead or alive status was also recorded, and the reported calving ease score from 1 to 5 (from no assistance to extreme difficulty) was recorded as well. Many variables will be recorded from the video observations. The cow's time on feet will be defined as the interval from the entry in the calving pen to the 1 st lying bout observed before calving. As frequent changes in position may be associated with the degree of calving difficulty, the frequency of lying bouts (bouts per hour) will be calculated. The cow's favorite position for strong abdominal straining is usually lateral recumbency, with both back legs fully extended (Youngquist, 1997). The duration of labor will be defined as the duration from the first observed abdominal push in full lateral position to the expulsion of the calf. For cows that do not show abdominal straining in lateral recumbency but otherwise do strain, that first strong abdominal push will be noted instead, and the position of the cow will be recorded. The time of the expulsion will be noted, and the intervals entry-to-expulsion and I! lying-to-expulsion will be calculated. The presentation of the calf will be noted (anterior/posterior), as well as the observed life status of the calf. The occurrence and time of assistance, starting time of extraction, maximal means of extraction (i.e. manual force only, cable attached to the side ofthe pen, or calf puller) will be noted, and the duration of extraction will be calculated (min). The goal here is to adjust the other risks factors for the difficulty of the expulsion/extraction, not to evaluate the assistance as a causal factor for stillbirth (as assisting a cow will shown by the model as being detrimental versus not assisting her). Some features of the cow activity in the individual pen will be recorded for the 1 st hour to assess the apparent state of "nervousness" or "restlessness". Among those, data on gate pushing, lying, standing, or walking will be collected. 107

For the first objective (to describe the parturition of cows and heifers moved at time of imminent calving), all the aforementioned variables will be described as a whole, as well as by age groups (primiparous versus multiparous). For the second objective (to describe the association between restlessness (and other potential risk factors) and the duration of parturition), time from entry-to-expulsion, lying-to-expulsion, and duration of labor will be modeled with a multivariate linear regression against the following explanatory variables (when applicable): parity, cow body weight, body condition score, stage of calving at time of pen move, serum calcium, calf weight and gender, calf presentation, time on feet (entry to 1 st lying), frequency of lying bouts and gate pushing and other activity measures in the 1 st hour. For the third objective (to describe the association between restlessness (and other potential risk factors) and the stillbirth risk), the occurrence of stillbirth will be modeled by multivariate logistic regression against the same explanatory variables as for the second objective, with a primary interest in the restlessness indicators (gate pushing and other activities, time on feet), with adjustment for the observed calving difficulty. This study will give us a better description of the course of parturition in dairy cattle managed in freestalls for the entire dry period and later moved to individual calving pens when calving is imminent. The analyses from objectives 2 and 3 will give a first assessment of the significance of the perceived restlessness or hyperactivity on the duration of calving and on the risk of stillbirth. If nervous or restless behaviors are identified as a risk factor for stillbirth, then further research can be done to develop new calving facilities or management protocols which may reduce the expression of these behaviors. References Berglund, B., J. Philips son, and o. Dane11. 1987. External signs of preparation for calving and course of parturition in Swedish dairy cattle breeds. Animal Reproduction Science. 15:61-79. Bickert, W. G., B. Holmes, K. Janni, D. Kammel, R. Stowell, and J. Zulovich. 2000. Milking herd facilities. Page 44 in Dairy Freestall Housing and Equipment - i h Edition - MWPS-7. MidWest Plan Service, Iowa State University, Ames, IA. Chassagne, M., J. Bamouin, and J. P. Chacomac. 1999. Risk factors for stillbirth in Holstein heifers under field conditions in France: a prospective study. Theriogenology.51:1477-1488. Cook, N.B., and K. V. Nordlund. 2004. Behavioral needs of the transition cow and considerations for special needs facility design, in Managing the transition cow to optimize health and productivity. Vet. Clin. North Am. Food Anim. Pract. 20:495-520. 108

Grandin, T. 1997. Assessment of stress during handling and transport. Journal of Animal Science. 75:249-257. Johanson, J. M. and P. J. Berger. 2003. Birth weight as a predictor of calving ease and perinatal mortality in Holstein cattle. Journal of Dairy Science. 86:3745-3755. Mee, J. F. 2004. Managing the dairy cow at calving time, in Managing the transition cow to optimize health and productivity. N. B. Cook and K. V. Nordlund, guest editors. Vet. Clin. North Am. Food Anim. Pract. 20:521-546. Meijering, A. 1984. Dystocia and stillbirth in cattle - a review of causes, relations and implications. Livestock Production Science. 11: 143-177. Meyer, C. L., P. J. Berger, and K. J. Koehler. 2000. Interactions among factors affecting stillbirths in Holstein cattle in the United States. Journal of Dairy Science. 83:2657-2663. Meyer, C. L., P. J. Berger, K. J. Koehler, J. R. Thompson, and C. G. Sattler. 2001. Phenotypic trends in incidence of stillbirth for Holsteins in the United States. Journal of Dairy Science. 84:515-523. Metz, J., and J. H. M. Metz. 1987. Behavioural phenomena related to normal and difficult deliveries in dairy cows. Netherlands Journal of Agricultural Science. 35:87-101. Nogalski, Z. 2002. Effect of selected factors on the course of parturition in Holstein Friesian heifers. Electronic Journal of Polish Agricultural Universities, Animal Husbandry. Volume 5, Issue 2. [online} Rushen, J., A. Boissy, E. M. C. Terlouw, and A. M. B. de Passille. 1999. Opioid peptides and behavioral and physiological responses of dairy cows to social isolation in unfamiliar surroundings. Journal of Animal Science. 77:2918-2924. Youngquist, R. S. 1997. Parturition and dystocia. Pages 309-324 in Current Therapy in Large Animal Theriogenology. W.B Saunders Company. Philadelphia, P A. 109