Heifer care and management
Feeding strategies for post-weaned dairy heifers, 2 to 6 months of age
The general guideline out of Cornell University is to have a growth goal for dairy calves of doubling their birth weight by 56 days of age. For example, a heifer calf that weighs 100 lb at birth should be fed a balance of nutrients in order to reach a weight of 200 lb by day 56. This means the calf must have an average daily gain (ADG) of 1.78 lb/day over that time period.
Let’s assume with a group of calves that the ADG goal has been met, the calves are strong and healthy, and now it’s time to wean them. How does the dairy heifer grower keep the momentum going? How does the grower take these replacement heifer calves into the next stage of development to attain a target goal for frame size and body weight by 25 weeks of age without excessive body condition? How can the grower produce heifers that will provide consistent performances across all seasons of the year?
This article will discuss three feeding strategy options that were evaluated at the U of M Southern Research and Outreach Center (SROC) in Waseca from 2003-2005 on feeding dairy heifers based on limit or full-fed concentrate mixtures, with or without access to long hay, during part of the feeding period from 2 to 6 months of age. All heifers were from three commercial dairies and housed in grower barns in 4 or 5 replicated group pens (6 heifers/pen) per dietary treatment. Studies included 72 to 96 Holstein dairy heifers with treatments lasting 84 to 112 days.
1. Concentrate diets containing alternative protein sources. 90 Holstein heifers, 84-day trial. All three diets contained an 18% crude protein concentrate mix (DM basis) with cracked corn, fed up to a maximum of 5 lb/head/day with access to long hay (16.7% CP). Protein alternatives included: soybean meal-based pellet (CCP); dried distillers grain (CCDDG); and, urea partially replacing soybean meal (CCUP).
Results (Table 1) – Overall heifer performance was not affected by concentrate mix fed. Limit feeding a concentrate mix to 5 lb/day with free choice hay for post-weaned dairy heifers supported good growth rates and is a very acceptable program. The addition of dried distillers grain (3.2 lb/day) or urea (0.03 lb/day) as alternative protein sources in concentrate mixes to help feed utilization are acceptable options.
2. Full vs. limit fed whole-shelled corn and protein pellet diets with differing fiber levels. 96 Holstein heifers, 112-day trial. Diets formulated used either a 16% or 18% concentrate mix with free-choice hay vs. no hay.
Results (Table 2) – Limit fed with corn and pellet mix (LFWCP); full fed with corn and pellet mix (FFWCP); full fed with high fiber (FFHF); full fed with low fiber (FFLF). Limit-feeding concentrate grower diets with access to free choice hay (avg. 6.25 lb/day) in group pens from 9 to 25 weeks of age resulted in a more consistent heifer performance without excess body condition when compared to full fed concentrates without hay followed by a period of limit feeding concentrates with full fed hay.
3. Conventional (GM) vs. whole shelled corn and pellet (WCP) vs. complete pellet (CP) diets. 72 Holstein heifers, 112-day trial. All diets were formulated for 16% crude protein and fed for 16 weeks. Grain mixes were limit fed to 6 lb/heifer daily with free choice hay (16.9% crude protein).
Results (Table 3) – Heifers fed the whole shelled corn and pellet diet had a 3.6 and 5% higher total gain than those fed the grain mix and complete calf grower pellet, respectively. Heifers fed the whole shelled corn and pellet diet used their feed 2.6 and 7.3% more efficiently than those fed the grain mix and complete calf grower pellet diets, respectively. Limit-fed concentrate diets, with access to free-choice hay, fed to heifers performed at a higher growth rate than anticipated. Feed dry matter intake averaged 2.9% of body weight for the 112-day feeding period.
In conclusion, these three feeding trials resulted in very acceptable average daily gains, hip heights and body weights to produce good quality six-month-old heifers. They show various options the heifer grower can consider for developing a nutritional management plan for group-fed dairy heifers between 2 to 6 months of age that will provide consistent performance with considerations for economic efficiencies.
Dairy Heifer Feeding Strategies Performance Tables
| |
Table 1. Protein sources |
Table 2. Full/limit fed, differing fiber levels |
Table 3. Conventional/ |
|
CCP |
CCDDG |
CCUP |
LFWCP |
FFWCP |
FFHF |
FFLF |
GM |
WCP |
CP |
|
| Initial BW, lb |
223 |
223.3 |
219.8 |
205.1 |
204.1 |
203.8 |
205.6 |
192.8 |
187.7 |
189 |
| Final BW, lb |
398.3 |
406.2 |
396.4 |
457.6 |
482.9 |
485.9 |
483.4 |
457.3 |
462 |
449.5 |
| Total Gain, lb |
175.3 |
182.9 |
176.6 |
252.5 |
278.8 |
282.1 |
277.8 |
264.5 |
274.3 |
260.5 |
| Final Hip Ht, in |
43.9 |
43.8 |
43.7 |
44.8 |
45.0 |
45.4 |
44.9 |
45 |
45.1 |
44.6 |
| Feed/gain, lb |
4.4 |
4.1 |
4.3 |
4.8 |
3.9 |
4.1 |
4.1 |
3.9 |
3.8 |
4.1 |
| ADG, lb |
2.1 |
2.2 |
2.1 |
2.3 |
2.5 |
2.5 |
2.5 |
2.4 |
2.5 |
2.3 |
CCP: soybean meal-based pellet (cracked corn based diet)
CCDDG: dried distillers grain
CCUP: urea partially replacing soybean meal
LFWCP: limit fed with corn and pellet mix
FFWCP: full fed with corn and pellet mix
FFHF: full fed with high fiber
FFLF: full fed with low fiber
GM: conventional diet (grain mix)
WCP: whole shelled corn and pellet
CP: complete pellet diet
by Hugh Chester-Jones and Neil Broadwater - Dairy Connection Articles, University of Minnesota Extension
