The key focus of nursery nutrition programmes is to transition pigs from lactation where they are consuming a highly digestible liquid diet to a low-cost grain soybean meal-based diet. Critical components of this transition are to phase feed expensive protein and carbohydrate sources. However, these alternative protein and carbohydrate sources have dramatically increased in cost over the last few years. This has led to using lower cost alternative sources and reducing feed budgets of expensive diets. Many of these alternative sources are lower quality. Therefore, these strategies can result in disappointing performance.

A successful nursery feeding program contains several components, but the most important are to:

1. match dietary nutrient levels and ingredients with weight and age of the nursery pig
2. maximise feed intake, because newly weaned pigs are in an extremely energy deficient state and early intake helps maintain a healthy intestine, and
3. appropriately adjust pigs (based on age, weight, health status, etc.) to lower cost diets (usually grain-soybean meal diets) as quickly as possible after weaning to reduce total feed cost.

The concepts are relatively simple and can be applied in a variety of situations around the world. Detailed specifications that have been used successfully are detailed elsewhere (DeRouchey et al., 2010; Tokach et al., 2007). However, significant modifications of these diets have occurred in the last two years. These modifications will be the focus of this paper.

Recent research at Kansas State University has focused on further defining the amino acid requirements during the nursery phase (Nemecheck 2011). One significant finding that has changed our diet formulation strategy has been the lowering of dietary lysine levels in diets for pigs less than 15lb or in the first one or two diets after weaning while maintaining high dietary lysine levels during the later nursery phase (Nemecheck et al. 2010). This has allowed for maintaining excellent performance level while altering the amount of specialty protein sources needed in diets for young pigs. Recommendations for dietary lysine levels are listed in Table 1.

Also, due to expense of fat sources relative to corn, we have reduced or removed fat levels in nursery diets. The low feed intake of young pigs often leads nutritionists to feed high levels of fat to increase the energy density of the diet. Unfortunately, fat utilisation from the diet is limited in the pig before approximately 35 days of age. Poor utilisation of dietary fat is not well understood and may be due to a combination of factors including low digestibility during the initial period from changing fatty acid type compared to milk fat after weaning. Also, newly weaned pigs have limited ability to catabolise fat from body stores. However, added dietary fat is extremely important from a feed manufacturing standpoint because it helps lubricate the pellet mill die, and, thus, improves pellet quality of starter diets that contain high levels of milk products. The bottom line is that fat utilisation increases with age and fat should be used strategically in the first diets after weaning as an aid in pelleting rather than as a main energy source.

Traditionally in the US, fish meal sources such as select menhaden fishmeal have provided a large portion of the specialty protein sources in nursery diets. However, in the US availability of high quality fish meal has declined and the price has become more expensive relative to other sources. Therefore, there are three main strategies being employed to eliminate fish meal from nursery pig diets. The first and with a longest history of research data is to replace the fish meal with spray dried blood meal or cells. When switching to spray dried blood meal differences in digestible amino acid profile need to be accounted for in diet formulation, especially methionine and isoleucine requirements (Table 2). Also stringent monitoring to ensure some other source of blood meal such as ring or flash dried. These products typically are more variable in quality and can have lower amino acid availability.

The second strategy is to replace all or some of the fish meal with dried porcine enteric mucosal products such as DPS 50 (Nutraflow, Sioux City IA) or PEP (Techmix, Stewart, MN) products. These products are by products of heparin collection from porcine intestine. Recent research indicates that these can be excellent replacements for fish meal in nursery pig diets (Meyers, 2011).

The final strategy is to use supplemental synthetic amino acids to minimise the amount of soybean meal in nursery pig diets. Synthetic lysine, threonine and methionine are widely available for supplementation in swine diets. In addition, synthetic tryptophan, valine and isoleucine are available and may be used in nursery pig diets depending on the protein sources available. Reducing the amount of fishmeal in diets for 15- to 25-lb pigs and increasing the amount of synthetic amino acids have been shown to increase growth rate in nursery pigs (Nemecheck et al. 2011). This method requires setting minimum ratios for amino acids relative to lysine (Table 2.)

Dried distillers grains with solubles (DDGS) also have been used successfully in nursery pig performance (Stein and Shurson, 2009). Certainly as with the growing pig the quality of the source can have an influence on the dietary value. Also, the fermentation process leaves mycotoxins unchanged. Thus, with the removal of starch during fermentation and the concentration of other components of the corn kernel by approximately three times the mycotoxin level in the DDGS will be approximately three times of the corn used in the fermentation process. However, the amino acid profile of DDGS can be used successfully to reduce the need for specialty protein sources like fish meal. In addition, the price of DDGS in the Midwest US is approximately 80 to 85 per cent of corn price while having the additional amino acids and higher phosphorus availability. Moderate levels of DDGS have been used successfully in the first diets after weaning (10 to 20 per cent) and in concentrations as high as 40 per cent in the later nursery diets to reduce feed cost, without negative effects on growth performance.

The other main ingredient in nursery diets that has increased dramatically in price in the last few years is lactose source. Procuring high-quality lactose sources at an economical cost continues to be a challenge. The high lactase enzyme levels at birth and high digestibility of lactose make crystalline lactose or one of several lactose sources (dried whey, deproteinized whey, whey permeate, etc.) an excellent carbohydrate source for young pigs. As long as the diet contains a basal level of lactose, several other carbohydrate sources can be used for the remainder of the diet while achieving acceptable performance. However, the lactose source along with complementary carbohydrate sources is probably one of the most important dietary factors for influencing variability in nursery performance in the period immediately after weaning. Unfortunately, there are few indicators of lactose source quality. Traditionally, the best way to ensure lactose quality is to specify human edible grades of lactose sources and minimize sources to those that have demonstrated consistent quality.

Traditionally, we have used diets in pellet form in the immediate period after weaning. Diets fed in meal form in the immediate period after weaning have been shown to increase feed intake and reduce removal rates (Groesbeck et al. 2009). However, due to the increases in feed cost and increased economic value of feeding diets in pellet form we are observing a move to feeding pellets in other phases during the nursery. As with finishing pigs a critical factor for maintaining the performance benefits is the quality of the pellet with a minimum amount of fines or without an excess of heat that denatures the specialty protein and carbohydrate sources.

Over the last 10 years, one significant change in US swine production has been an increase in weaning age and has lead us to reexamine creep feeding practices (Sulabo, 2009).

Things we have learned:

• The main effect of creep feeding is to help get pigs started on feed in the early period after weaning in the nursery. There is not going to be any benefit in increasing weaning weight or reduction in weight loss of the sows.
• Based on our research, the authors recommend the following creep feeding protocol:
  • Use the round creep feeder with the reservoir that has a cover
  • Put the creep feeders in three to four days prior to weaning>
  • Fill one time with 2lb per feeder
  • Use the first phase nursery diet and not simple diets
  • Ensure feeders are adequately cleaned between use

Also the reduction in weaning age, this has led to a reduction of the amount of diet fed to pigs less than 15lb and consolidation of the traditional two-diet programme for pigs fed less than 15lb in to a single diet phase. Various versions of the single phase nursery diet and examples of diet formulations using the concepts outlined in this paper are available online [click here].

Although there has been evolution in weaning ages, changes in production practices and increases in ingredient costs in the last few years, the objective of nursery feeding programmes remain unchanged. This objective is to transition the pig as rapidly as possible from a liquid to dry diet with the staging of specialty protein and carbohydrate sources to economical grain and soybean meal based diets.

Literature Cited

DeRouchey, J.M., R.D. Goodband, M.D. Tokach, J.L. Nelssen and S.S. Dritz. 2010. Nursery swine nutrient recommendations and feeding management. National Swine Nutrition Guide.

Groesbeck, C.N., J.M. DeRouchey, M.D. Tokach, R.D. Goodband, S.S. Dritz and J.L. Nelssen. 2009. Effects of irradiation of feed ingredients added to meal or pelleted diets on growth performance of weanling pigs. J. Anim. Sci. 87:3997-4002.

Nemechek, J.E., M.D. Tokach, S.S. Dritz, R.D. Goodband, J.M. DeRouchey and J.L. Nelssen. 2010. Does lysine level fed in one phase influence performance during another phase in nursery pigs? J. Anim. Sci. 88 (Suppl. 3): (Abstr.).

Meyers, A.M. 2011. The effects of porcine intestinal mucosa products on nursery pig growth performance and feeder adjustment on finishing pigs. M.S. Thesis.

Nemechek, J.E. 2011. Evaluation of compensatory growth, standardized ileal digestible lysine, and replacing specialty protein sources on growth performance of nursery pigs. M.S. Thesis.

Nemechek, J.E., M.D. Tokach, S.S. Dritz, R.D. Goodband, J.M. DeRouchey and J.L. Nelssen. 2011. Evaluation of SID lysine level, replacement of fish meal with crystalline amino acids, and lysine:CP ratio on growth perfromance of nursery pigs from 6.8 to 11.3 kg. J. Anim. Sci. 89 (E-Suppl. 2):220 (Abstr.).

Stein, H.H. and G.C. Shurson. 2009. The use and application of distillers dried grains with solubles in swine diets. J Anim Sci 87:1292-1303.

Sulabo, R.C. 2009. Influence of creep feeding on individual consumption characteristics and growth performance of neonatal and weanling pigs. PhD Dissertation.

Tokach, M.D., S.S. Dritz, R.D. Goodband, J.M. DeRouchey and J.L. Nelssen. 2007. Starter Pig Recommendations. Kansas State University Research and Extension Publication MF-2300.

Further Reading You can view other papers presented at the 2012 Kansas State University Swine Profitability Conference by clicking here.

January 2013