Location: Reproduction Research2013 Annual Report
1a. Objectives (from AD-416):
1. The primary objective of this project is to determine the effects of dietary manipulation (energy and amino acid level) on gilt development and sow lifetime productivity. 2. Survey colostrum and other litter of origin effects on gilt development and sow lifetime productivity. 3. Assess the contribution of gilt social structure on gilt development and sow lifetime productivity. 4. Assess relationships between gilt development, sow lifetime productivity and mammary gland development and function.
1b. Approach (from AD-416):
This experiment will evaluate gilts from birth until they complete third parity in a commercial setting. The animals will be housed at Circle 4 farms in Milford Utah. Circle 4 farms, a part of Murphy Brown LLC, is an 80,000 sow commercial operation that also has dedicated research facilities and research staff, which will facilitate the execution of this experiment. The experiment will be conducted in their sow research barn. The experimental design employs three diets. Each diet will be applied to 50 pens consisting of 20 gilts each pen (pen is the experimental unit, total 1000 gilts per diet). Gilts will enter the trial at the rate of 3 pens per week (one pen each treatment) for 50 weeks. Beginning on day 100 of age, the dietary treatments will be applied to the pens of gilts until they are mated and enter the breeding herd. Dietary treatments will be chosen from the results of a preliminary trial that is already contracted by NPB to examine the effects of 6 diets on aspects of gilt development up to 260 days of age. The preliminary gilt trial is a two by three factorial design, with two levels of lysine (100% and 85%) and 3 levels of metabolizable energy (85%, 100%, 115%) according to the table below: Metabolizable energy 85% Metabolizable energy 100% Metabolizable energy 115% Lysine 85% Low protein, low energy Low protein, control energy Low protein, high energy Lysine 100% Control protein, low energy Control protein, control energy Control protein, high energy From the results of the preliminary trial, three diets will be chosen for this trial, including: (1) a control diet; (2) a diet that results in reduced growth rate/decreased fat to lean ratio; and (3) a diet that results in increased growth rate/increased fat to lean ratio. For each of these three diets, two diet formulations will be used, including a grower diet and a finisher diet, similar to the design for the preliminary trial. The three grower diets will be fed from 100 days of age until gilts reach 200 lbs. The three finisher diets will be fed to gilts in the experiment from a weight of 200 1bs until mating and entry of the gilts into the breeding herd. From there, sows will receive the normal gestation and lactation diets and feeding regime used at Circle 4 farms. The gilts will be followed in the breeding herd until they reach third parity or are culled. Although dietary manipulation beginning at day 100 is the primary objective, we propose that the females for this experiment be evaluated from birth until third parity to provide information on all aspects of gilt development and their productivity as sows.
3. Progress Report:
This project was developed by the Sow Lifetime Productivity consortium of researchers set up by the National Pork Board. Numerous discussions have taken place to fully define the experimental details of the project. A great deal of progress has been made and an experimental protocol has been generated. Further discussions and results from the 5438-31000-091-02T project are needed to define a few additional details of this project before it is implemented. Gilts for this trial are expected to be born in January of 2014 and will go on diets in April of 2014. Additional funding is needed to complete the experiments proposed, and an additional proposal will be submitted to the National Pork Board by October 2013 to obtain this additional funding.