EFFECT OF HEADLOCKS ON MILK PRODUCTION AND FEED INTAKE OF DAIRY CATTLE

headlocks increase milk production or feed when headlocks were removed. Two-year-old and older cows did not differ in response to headlocks and neckrails. use of headlocks increases labor efficiency of a commercial dairy.


Introduction
Headlocks or self-locking stanchions have been utilized for animal restraint necessary for many routine dairy husbandry procedures for several decades. Headlocks allow a single person to restrain a group of cows, increasing the labor effic iency of routine animal care including breeding, pregnancy exam, vaccination, injections, and other procedures. Within the last decade, so me concerns have been raised about the effects of headlocks on milk production and feed intake. Several studies showed that extended lockup time (4 hr) did not affect feed intake or milk production. One study showed a decrease in milk with extended lock-up time, but similar feed intake. Another study found a decrea se in int ake withou t a difference in milk production. Therefore, a study was conducted during the summer of 2000 to determine the effect of headlocks and neck rails on milk production and dry matter intake of lactating dairy cows on a commercial d airy.

Procedures
Mid-lactation Holstein cows were housed in head-to-head 2-row freestall buildings equipped with 100 freestalls and identical cooling fans located over the freestalls and low-pressure feedline sprinkling systems. brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by K-State Research Exchan The two barns were located on a northeast Kansas dairy and s to cked wit h 108 mid lactation Holstein cows ( 55 2-year-o lds and 53 cows). Each barn contained 220 ft of bunk space with 110 headlocks and 100 freestalls. A total of 108 cows were allotted to each barn, resulting in an overstocking of sta lls by 108% and headlocks stocked at 98% of capacity. Headlocks were manufactured by a loc al co mpany a nd utilized 2 linear ft per lock. Headlocks when locked provided a neck area of 8 × 32 in. When o pen, headlocks provided a top opening of 13.5 in.
Cows were blocked by lactation number, days in milk, and production, then randomly assigned to each of two treatments. Initial milk production and days in milk for each treatment are illustrated in Figures 1 and 2. Treatments were headlocks or neckrails. A switchback design was used and the treatments (headlocks and neckrails) were switched between the buildings. The study was done in two 4-week periods. Cows were milked three times and amounts recorded electronically for each milking, using an aut omat ic identification system. Bot h barns received an identical TMR and the amounts fed and r efused were recorded daily. Dry matter of the feed and refusals were determined twice weekly. Milk production data were averaged by lactation number and week within per iod for each tr eat ment. Feed intake dat a were a veraged by we ek within each period fo r each treatment. Averaged data were then analyzed fo r the effects of treatment, period, parity, and week.

Results
Average dry matter intakes (Figure 3) were similar for bo th treat ments aver aging 51.8 and 50.4 lb/c/d for neckr ail and headlock treatments, respectively. Average milk production (Figure 4) was similar for both neckrail and headlock treatments. Firstlactation and older cows produced similar amounts of milk when exposed to either treatment ( Figure 5). Results from this study indicated tha t o n a commercial da iry, headlocks did no t adver sely affect milk production or dry matt er intake o f cat tle trained to headlocks. Removal of the headlocks did not increase milk production or feed intake.
In summary, it does not appear that headlocks adversely affect milk production or feed intake on commercial dairy farms. It should be emphasized that the cows involved in this study had been previously trained to headlocks.