Management during the transition period, i.e. three weeks before and after calving, is highly associated to the cow’s milk yield at peak and consequently for the full lactation. Also, 70-80% of disease incidence occurs during the transition period. The key management factors related to fresh cow health and milk yield are: to provide sufficient bunk space so that cows can eat simultaneously when fresh feed is delivered, increase cow comfort by providing ample space to lie down and facilitate rising and minimizing lameness with soft deep bedded stalls or packs in this period. An effective routine to promptly detect fresh cows in need of medical attention, and minimizing social stress during the last 3-10 days prior to calving is also important.
Housing factors and management, not transition feed rations, have shown to have a major influence on the success rate of the transition cow management. To be able to objectively evaluate the effectiveness of transition cow management at the herd level, a measurement tool, Transition Cow Index, TCI, was developed. Key management factors associated with improved herd average TCI scores will be presented here.
Recommendations for housing transition cows
Bunk space in the close-up and fresh pen: Lactating Holstein cows need minimum 76 cm (30 inches) of bunk space in pre- and post-fresh pens so that they can eat simultaneously when feed is delivered. Pregnant prepartum cows are likely to take even more space than lactating cows. These recommendations assume that the pens are equipped with lockups or other vertical dividers between feeding spaces. If the cows are fed at a post-and-rail feeder, additional space should be provided in this situation as dominant cows clear subordinates more quickly.
To determine feeding space/cow, it is important to focus on length of bunk as opposed to counting self-locking stanchions or headlocks. In the US, headlocks come in a number of widths including 61, 69, and 76 cm (24, 27, and 30 inch) intervals between each unit. Video studies show that lactating Holstein cows fill a row of 61 cm (24 inch) headlocks to a maximum of 80% at peak feeding periods. This 80% maximal fill rate occurred in two and three row pens, each with various stall-stocking densities, suggesting that the finding was independent of the number of cows per headlock.
Number of cows in the close-up and fresh pens changes frequently, so number of cows in the pens vary widely every week. There will also be seasonal changes in stocking pressure. It is therefore useful to focus on the longer term capacity of the pens. Traditionally the sizing of close up and fresh pens is calculated by multiplying average number of calvings per week (divide number of calvings previous year with 52) with target number of weeks in pen. A dairy with a 20 calvings/week average and a 3-week planned duration in the close up pen should have a close up pen for 60 cows. These pens will be overstocked half of the time. Special needs pens should preferably be built to accommodate the surges in numbers of special needs cows. Based on a review of Midwestern herd records, recommended sizing for close-up and fresh pens is 140% of the average population, i.e. 140% of 60 in the example above, and the recommendation would be not 60, but 84 stalls in the pre fresh pen with an available bunk that is 73 meters (240 feet) in length. Sizing these pens on this basis will mean that they are overstocked less than 10% of the time. There are also times when pens sized on this basis appear to be substantially understocked. An estimate of the impact of this practice suggests that it makes economic sense.
Amply sized free stalls, packs, and shades: A deeply bedded pack is probably the preferred housing for close-up cows in confinement housing. The guideline of 9.3 sq. meters (100 sq ft.) of space/cow includes the bedded area only and assumes that cows have access to an external feeding alley or outside lot. If the feeding area is continuous with the bedded pack, the space should provide a minimum of 11.2 sq. meters (120 sq ft.) per cow with good bedding covering most of the area. The pack should be sized to accommodate surges in cow numbers as discussed in the section on bunk space above.
There is increasing evidence that locomotion scores increase for a substantial proportion of transition cows, i.e. their ability to walk normally decreases, and physiological mechanisms have been proposed where the same physiological changes that are associated with the loosening of the pelvis to accommodate parturition also relax the suspensory apparatus of the digit in the hoof. The study of sand and mattress free stalls by Cook et al showed that cows with elevated locomotion scores change their behavior on mattress stalls, but not on sand, may explain the substantial improvement in fresh cow performance on sand surfaces. Any deep, loose surface will be an improvement over a hard surface. Mattresses covered with modest quantities of shavings or other materials are viewed as average, and any stall surface such as concrete or other firm packed materials covered with modest bedding should be considered a high risk to successful transitions.
Prepartum free stalls, in particular, need to accommodate the ample dimensions of pregnant cows and allow for some clumsiness in their rising and lying motions. Stalls for prepartum Holsteins and Jerseys should be at least 127 and 115 cm (50 and 45 inches) wide respectively. Length is the distance between the outer corner of the rear curb to the point where the stall surface touches the brisket locator. If there is no brisket locator, the total stall length is the stall resting length. This distance should be greater than 178 and 160 cm (70 and 63 inches) for Holstein and Jersey cows respectively. Appropriate dimensions have been developed for cows of other breeds and various sizes.
Evaluating the potential for lunge, bob, and rise should reflect assessments of 3 separate items in a free stall: a brisket locator that does not restrict rising motions including the forward swing of the front foot, freedom from impediments to the forward lunge of the head and shoulder, absence of bob zone obstructions, and the neck rail being sufficiently high and forward. For a stall to be considered low risk for Holstein cows, the total stall length should be at least 2.75 m (9 ft.) long, and preferably 3.0 m (10 ft.), with no obstructions to forward lunge and bob. If the stall is less than 2.75 m (9 ft.), the lower rail of the divider loop must be less than 28 cm (11 inches) above the stall bed or less. If the lower rail of the loop divider is higher than 28 cm, it will inhibit side lunging and is considered to be a moderate risk for transition cows. If the stall is less than 2.45 m (8 ft.) and has obstructions to side lunging such as lower divider rails greater than 30 cm (13 inches) above the stall bed, the stalls present major risks to successful transition performance. Finally, the neck rail should be approximately 122-127 cm (48-50 inches) above the stall surface.
Pen moves and social stress versus stable social groups
The first two days after entry into a new social group are characterized by a dramatic increase in the number of agonistic interactions, most of them physical. If no additional new cows enter the pen, the group becomes relatively stable. More recent work with mid-lactation cows has shown reduced time spent eating, increased feed evictions, and reduced milk yield following a pen move. Minimizing the number of regroupings through the transition period is consistent with successful transition programs.
Dry and Close-Up Pens
The traditional close-up pen is based upon cows entering the pen approximately three weeks prior to due date. For reasons of convenience, cows are separated from the far-day pen and moved to the close-up pen once or twice each week. In some systems, the cows deliver their calves in the close up pen, while in other systems they are removed to calving pens at various times relative to delivery.
Movement of single animals should be avoided as it is believed that familiarity and social bonds among 3 to 5 moved animals may reduce the social stress of integrating within a larger group. A weekly move policy would appear to be preferable to more frequent entries.
Calving pens can refer to either a pen to which a cow is moved hours before delivering her calf or it could be a close-up pen where cows enter several weeks before their anticipated calving date and deliver the calf within the pen. If the calving pen has a stable social structure (no additions), extended stays are fine. If new cows are continually being added, we recommend that the duration of stay be limited to 48 hr. maximum. Clinical data from field investigations show dramatic increases in ketosis and displaced abomasums and early lactation culling of cows that stay 3-10 days in daily-entry group calving pens.
Effective screening program for cows needing attention
The main factor determining the fresh cow screening and treatment program is the quality of the people and how much they care for the cows. Facilities that allow easy restraint without exciting the cows is also critical to these programs. The optimal screening programs appear to use some form of appetite assessment. Efficient screening practices involve: delivery of fresh TMR while fresh cows were being milked, palpation of udders for fullness while being milked, observation of cow behaviour as the cows returned to the pen, i.e., does she go to feed bunk or does she lie down, and an assessment of appetite and attitude. Effective screening requires both special people and facilities. The procedure needs to be efficient and not interfere significantly with the daily time-budget of the fresh cows. Screening procedures that lock cows up for a period of 1 hr or less/day are considered optimal.
Key management factors related to fresh cow health and improved herd average TCI scores:
- Provision of sufficient bunk space so that transition cows can eat simultaneously when fresh feed is delivered
- Increasing cow comfort and minimizing lameness with deeply bedded stalls or packs and provision of ample space within the stall to lie down and facilitate rising
- Minimizing social stress or the need to establish social rank during last 3-10 days prior to calving
- Provision of an effective process to promptly detect fresh cows in need medical attention