Effects of grazing vs. confinement on first lactation performance of dairy replacement heifers
Previous university farm research indicates that heifers in managed intensive grazing show improved first lactation performance as compared to heifers in confinement. The project manager will do a controlled study working with two commercial dairies to see if these results persist in real-world conditions. Outreach will be through workshops and pasture walks targeted at contract heifer grazers and commercial dairy farms. If this study supports the previous research it will encourage large confinement dairies to see grazing of their dairy replacements as a viable option. This will increase the need for Contract Heifer grazers, which will be a new business opportunity for rural land owners/farmers to graze these animals, which will help the rural economy. Another result will be healthier animals raised in an ecologically friendly manner.
The project leader will contact the 2 dairies April 1st 2005 or before. Breeding records will be reviewed to select 50 recently bred heifers from each farm. 25 randomly selected heifers will be designated the “MIG” group and 25 will be designated the “Confinement” group. All animals will be weighed and a body condition score will be determined for each animal. The animals will be put in their designated raising regime by apx. May 1st. The project leader and/or SWCD cooperators will visit both the groups throughout the grazing season. A 6-month grazing season is expected. At the completion of the grazing season both groups at both farms will be again weighed and a body condition assigned. The MIG groups and the Confinement groups will then be housed in the normal manner for the participating farms. With the help of Dr Stone and John Conway, the animals will be assigned a special code on the host farms computer system. Both farms use Dairy One’s Dairy Comp 305 software. The protocol for compiling health information will be synchronized on both farms. At freshening, calving ease will be noted and any calving difficulties will be entered. The production and any metabolic problems will be compiled.
2005: Bad year for grazing, good year to study grazing.
As the summer turned into one of the hottest and driest summers on record, we weren’t sure how good a year it was to look at grazing in general, since temperature and heat negatively affect the growth rate of the northeast’s cool season grasses. While comparing the rate of gain between the two grazing systems, we realized that there was a significant difference in the rate of gain of the animals being grazed (.4 lbs/animal/day vs 2 lbs/animal/day). The theory that we used to explain the difference was that there were different management practices taking place on the two grazing systems, which resulted in the difference in performance. During a normal year there is sufficient grass growing to be forgiving of any poor management decisions. The hot, and dry weather magnified management practices, giving us a unique opportunity to look at what practices may or may not be beneficial. In order to test our theory, we will look at weather data collected near each of the two sites, since they are 45 miles apart and there was a wide variation of precipitation this year. We will also look at the difference in soils to factor in their production capabilities. We will then compile a summary of management factors and compare the two grazing systems. The results of this comparison will be placed on the SARE web site early in 2006.
We weighed and measured the heifers from the two farms and put each of the groups into their raising regimes by May 11,2005. At Bergen Farm we kept the 25 confinement animals in their freestall barn, and the 25 pasture animals were moved to a heifer grazer near Watkins Glen who I will refer to as the Schuyler Grazing System. The Pine Hollow animals were divided also into the two groups of 25, with the pasture animals being put in Pine Hollow’s grazing system that they have been using for the past three years, and the confinement animals being sent to a custom heifer operation in Geneva. This was an added expense for Pine Hollow which we were able to help off-set with an additional grant from The Grazing Lands Conservation Initiative (GLCI).
On a visit to the Schuyler grazing system 4 days after their introduction to the pastures, the animals were all grouped together near the fence and were obviously waiting for a mixer wagon to feed them. This period of adjustment to learning to graze affected this group. The Pine Hollow group had experienced grazing the summer before, so were not affected as much. There was no structure on the Pine Hollow grazing system, which kept the animals on the pastures. On the Schuyler grazing system an old barn was available to the animals from all the paddocks. On my visits the animals were quite often in the barn. I suggested closing the barn to the animals, but the grazier assured me they were spending early mornings, evenings, and nights on the pasture. The grazing management summary will include more variables between the two grazing systems.
Growth Results (attached seperatly)
*1 The Bergen animals had to be removed from the pasture 30+ days early due to poor performance. Pasture animals and confinement animals were weighed the same day.
*2 The Pine Hollow animals were removed from the pasture system on two different dates. This allowed reducing the number of animals per acre since there was less grass available. The first group contained 7 of the study animals, so I weighted the “Days in System” to reflect the average.
Animal Nutritionist w/ Cornell Pro-Dairy
Ithaca, NY 14850
Dairy System Specialist
Ithaca, NY 14850