When it comes to litters, size matters. Larger numbers of pigs per litter have a direct correlation with an operation’s total pigs marketed; however, for these pigs to meet their full potential, adequate birth weights are necessary.
“No matter the genetics, the management or the facilities, birth weight plays a big factor in a pig’s lifetime productivity,” says Dr. Gawain Willis, director of nutrition services for Purina Animal Nutrition LLC.
Willis explains that measuring birth weights is especially important as genetics allow sows to produce larger litters. Unfortunately, this trend also can result in lower birth weights. In fact, research shows the average birth weight of each pig drops an average of 0.10 pound for each additional pig in the litter.
“As the industry evolves and larger litters become more common, producers must pay close attention to birth weights in their farrowing units,” he says.
“In our research birth weights played a significant role in pre-weaning mortality rates,” adds Willis, citing research studies at Purina Animal Nutrition Center in Gray Summit, Mo. “Almost all of our pre-weaning mortality occurred in the smaller birth weights. Growth rates, feed efficiency and piglet vitality also were noticeably improved with higher birth weights.”*
In the trials, heavier-born pigs were able to get off to the proper start and also reached weaning and market weights more quickly; with 2.8 pounds higher weaning weights. In terms of finishing, pigs born between 3.1 and 3.5 pounds reached a marketable weight of 270 pounds seven days sooner than pigs with birth weights of 1.6 to 2 pounds.
Increased nutrients through gestation and lactation are one major factor required to allow sows to produce heavier litters. Willis explains that higher-producing sows often require increased nutrients to achieve long-term production or they may fall out of the herd too soon.
“Feeding sows properly can result in greater efficiency for both piglets and sows,” he says.“Lifetime productivity of sows and the pigs they produce begins with feeding the sows the quality and quantity of nutrients they require.”
 Willis, Gawain. “Sow nutrition, health and management.” Purina Animal Nutrition LLC. Swine VIP Presentation, Sept. 4, 2013. Gray Summit, Mo.
De Rodas, Brenda and Gawain Willis. “Litter size and birth weight and its impact on long-term production.” Purina Animal Nutrition LLC Research Study, Purina Animal Nutrition Center.2006-2012.
*Because of factors outside of Purina Animal Nutrition LLC’s control, individual results to be obtained, including but not limited to: financial performance, animal condition, health or performance cannot be predicted or guaranteed by Purina Animal Nutrition LLC.