Sows feeding

As the nutritional requirements of sows continue to be refined, are there opportunities to achieve next-level precision sow feeding?

Traditionally, sows have been fed once per day, which has been shown to increase the efficiency of energy utilization but decrease the efficiency of protein utilization, says Ryan Samuel, South Dakota State University Extension swine specialist.

There may be a trio of “rights” in precision feeding modern, prolific sows — the right diet, in the right quantity, at the right time, Samuel says in an Extension news release.

Work is ongoing at South Dakota State University that will better define the right diet and the right quantity with respect to dietary amino acid requirements and phase or transition feeding sows over multiple parities.

Previous research has not demonstrated any significant advantage in productivity to feeding sows more than once per day. For example, it has been observed that pigs fed a single meal gained weight at a similar rate as pigs fed frequent small meals.

In fact, feeding sows once per day appeared to result in greater efficiency of energy storage compared to sows fed more than a single meal per day.

The improvement in energy utilization efficiency has also been attributed to reduced energy expenditure related to consuming a single meal compared to multiple meals. On the other hand, reducing feeding frequency has an effect on lipid metabolism.

Whereas single-meal fed animals tend to retain excess energy primarily as fat, frequently fed animals tend to store excess carbohydrates as glycogen, rather than converting them to lipid. As a result, it can be predicted that the composition of the body weight gain between frequently fed and single-fed animals would be different.

Animals fed once per day appear to retain more energy as fat, compared to animals consuming meals that are more frequent. However, animals fed once per day appear to oxidize more amino acids due to the inability to deal with the large influx of nutrients.

Work conducted at the University of Alberta investigated the energy and protein metabolism of non-pregnant sows and pregnant sows through gestation. Simultaneous measurements of energy and protein metabolism demonstrated that the periodicity of eating had opposite impacts on sow metabolism.

Therefore, while single-meal feeding improved the efficiency of energy retention, the efficiency of protein utilization was reduced in those sows.

Recently, the University of Minnesota reported that when sows were fed in the afternoon, instead of the morning, alterations in energy and nutrient metabolism improved backfat gain.

A goal within the swine industry is to achieve precision feeding. One of the objectives in this vein is lowering the crude protein content of swine diets. Potential advantages of low crude protein diets include savings on expensive protein ingredients, reductions in nitrogen emissions and improvements in gut health, thereby improving the production efficiency. However, the results of feeding sows diets with low crude protein formulations have been mixed.

Perhaps the dietary requirements for amino acids are greater due to single-meal feeding, where protein utilization is reduced, than if sows were fed more frequent, smaller meals.

Furthermore, reductions in dietary crude protein content will require greater levels and mixtures of synthetic amino acids in the diets.

Within one gestation cycle, feeding sows more than once per day has not been shown to provide an advantage in measures of sow productivity such as the number of pigs born, born alive, strength of the piglets or daily feed cost per sow.

However, research has demonstrated that feeding frequency impacts metabolism and, consequently, dietary nutrient requirements. Ideally sows are not kept in the breeding herd for a single gestation; therefore, it is imperative that sow research be carried out over at least two parities.