By Will Fombelle, Carthage Veterinary Service LTD
The gilt development unit, or “GDU” is oftentimes an area of the breeding herd that does not get a lot of publicity or attention. However, as we think toward the future of an individual sow unit, the GDU may be the most influential area in regards to improving future sow farm production. It is very important that our production teams pay great attention to the growing gilts in order for these animals to progress through their growing period without interruption.
Growing gilts are the lifeline of a sow herd. It is very important that we maximize the performance of these growing gilts, so that we give our sow herd the best possible chance of improving genetic potential and overall production. As most of us have heard multiple times before, the three basics to growing pig performance is feed, air and water. These basics make no exception to gilt developer units. Most successful sow units are using the metric of 85-90% selection rate for an individual group of replacement gilts, which includes gilt mortality. Our production teams must buy-in to this metric and push each other in order to reach this goal.
Future gilt performance is thought to be affected as early as weaning age. Any un-due stress may influence certain benchmarks such as sow longevity or total born. The same principles that we follow in commercial finishing apply to producing a high-quality mature gilt.
Gilt developer units across the industry greatly differ in size, set-up and gilt delivery schedules. As different as they all may be, the care required of our production teams remains the same. Putting forth the hard work in the first few weeks of placement will prove its benefits as pigs grow up and move through the production system. Providing accurate pen stocking densities, feed and water space, and comfort mat space is essential. The newest data from the 2014 PIC wean-to-finish manual shows that optimal feeder space to nursery pigs would be 1.0 inch per pig on conventional dry feeders. In finishing pigs, 2.0 inches per pig is recommended This manual also encourages water availability to be maximized at one cup drinker per 10 pigs. Comfort mat square footage is recommended at 0.4 square feet of mat per pig.1
Mat feeding is also essential for getting gilts started onto feed adequately. A common practice in the industry is to provide supplemental mat feed to all pigs three to five times per day for the first week. The goal would be to provide enough feed so that pigs consume all supplemental feed in one hour of time and then begin to acclimate themselves to the self-feeders in each pen.
Proper ventilation of a gilt developer is essential to provide adequate amount and quality of air to each pig. If barns are able to keep air in the range of 50-65% relative humidity, air quality will be sufficient. When setting up ventilation controllers and curves as gilts are placed, it is important to keep in mind the proper benchmarks of air volume and speed. Wean pigs require 1-2 cubic feet per minute or “cfm” at minimum ventilation. Proper air speed at minimum ventilation is approximately 650 feet per minute. Work with your ventilation expert to set up your fans and air inlets to reach these values.
Health and vaccination protocol
As we have discussed previously, all gilt developers and situations are different. By working with your herd veterinarian, you should be able to work up a medication and vaccination protocol that is specific to your operation’s needs. A proper vaccination protocol should take into account the area risk for disease transmission and also provide protection against routine reproductive diseases that we commonly face. Vaccinating against porcine circovirus type 2, parvovirus, leptospirosis and Erysipelothrix rhysiopathiae is highly recommended in growing gilt populations.
The selection of replacement gilts may be one of the most important tasks in gilt development units. Gilt selection involves individually evaluating each gilt to decide if she is of good enough quality to be entered into the breeding herd population. We must heavily focus time and training in this area, as these gilts are the life-blood of the sow unit.
Selecting gilts involves evaluating several key maternal traits including: bone and muscle structure, skeletal confirmation, body condition score, feet and leg quality, mammary gland quality and overall walking ability. We must heavily train our staff to be comfortable with our expectations of our replacement gilts. Remember, a gilt with poor muscle structure at a body weight of 250 pounds is heavily prone to poor structure at 500 pounds. These animals will be the early removals from the breeding herd at young parities.
Boar exposure and heat checking
Heat checking with vasectomized teaser boars should begin at approximately 23 weeks of age. Boars should be turned out into the pens so that each gilt receives one minute of boar exposure. For example, in a pen of 50 gilts, the boar should be in the pen for 50 minutes. Our GDU technicians should be walking these pens and applying side and back pressure to gilts, as to mimic the boar’s natural movements. By stimulating gilts early with boars, we give ourselves the best chance to hit our gilt breeding targets and maximize total born in our future gilt litters.
As we have discussed in this column, gilt development units are arguably the most crucial aspect of a sow unit. Gilts are the future and life-blood to our breeding herds. If we do not adequately care for and manage our gilt populations, we will greatly deter future sow farm productivity. Great gilt management gives us the best chance of managing a successful breeding herd.
1PIC 2014 Wean to Finish Manual