The National Swine Nutrition Guide, launched early this year in the USA, is a Herculean effort in which the latest scientific views as to pig nutrition have been included. The guide, available online and in print, offers in-depth information and fact sheets. This review captures the new NSNG, using a few of these fact sheets.
By Dr Ioannis Mavromichalis, Ariston Nutrition, Madrid, Spain
In the United States of America, new nutritional information regarding pig nutrition originates in private and public research institutions, and it is published annually in the form of abstracts and papers usually in the Journal of Animal Science. From this knowledge base of raw data, roughly each decade, a group of experts under the auspices of the National Research Council reviews data and publishes their estimates under the title of ‘Nutrient Requirements of Swine’. The last edition of this ‘bible’ for nutritionists was published in 1998. Today, this publication is accepted as the starting point for any discussion regarding pig nutrition, almost worldwide.
However, these purely scientific publications alone are not enough for field nutritionists and producers to properly feed pigs under a varied range of commercial conditions. Thus, in the past and to some limited extent even today, the extension services of a few universities have published what has come to be known as the ‘nutrition guides’. The first that comes to mind is the well-known ‘Swine Nutrition Guide’ by Kansas State University. These popular guides combine scientific evidence with practical experience and local practices to offer clear-cut advice for commercial pig production. Of course, even these guides are adapted by field nutritionists as any publication cannot possibly be suitable for all possible scenarios. To this end, articles in popular technical magazines, such as the National Hog Farmer, come to clarify and add to existing knowledge.
To the above list, it would be amiss to forget books such as the one published in 1998 by a group of experts under the title ‘Swine Nutrition’. This is a tome of over 1,000 pages and it is now in its second edition (2001) under the editorship of Lewis and Southern. Sadly, no more USA nutrition books regarding pigs come easily to mind.
Swine Nutrition Guide
In 2010, a new form of publication has come to join this impressive list of reference material. With a publication title such as the ‘National Swine Nutrition Guide’, it is evident that it aims high to combine together all such practical information (below the level of the National Research Council publication) into one comprehensive guide. When it was first announced in late 2009, many expected one more nutrition guide along the lines of those published by the few remaining extension services. But, we were to be happily disappointed!
The National Swine Nutrition Guide, or NSNG, is a massive piece of work. With over 350 pages of content and more than 40 contributing authors and reviewers, it is indeed a national work encompassing a wide base of knowledge providing in-depth information and practical guidelines for all interested parties. From researchers to nutritionists to producers, there is a part in the NSNG that interests all. So, let’s have a quick review of the major attributes of this new source of information.
The guide is divided into 35 chapters, or fact sheets, with each chapter being several pages long. Each chapter is written by leading experts on the subject and it is also reviewed by equally well versed professionals, often from the industry providing a more wide coverage. All major universities active in swine nutrition research are represented and authors range from recently hired professionals having the edge of knowledge to well-established names giving more depth and authority.
In contrast to most previous publications, this guide is also available on the Internet. Each chapter can be easily downloaded in a PDF format. And it is free of charge to all, courtesy of the US Pork Center of Excellence. This organisation was established in 2005 to bring about a higher level of cooperation and collaboration among universities, the pig production industry, and government.
Quite unique in its approach, the NSNG also includes software to formulate simple diets for all classes of pigs. The NSNG Diet Formulation and Evaluation CD performs two distinct functions. First, it allows the formulation of swine diets on a least-cost basis. Second, it allows evaluation of existing diets for nutritional adequacy. These functions can be applied to diets for sows, breeding boars, nursery pigs, growing/ finishing pigs, and replacement gilts and boars. A separate review of this software will appear on www.allaboutfeed.net.
Example fact sheets
With such wide reach, it would be impractical to cover here each single chapter of the guide. Instead, a few representative fact sheets will be briefly outlined.
Example 1: Trace mineral and vitamins for swine diets
This fact sheet was authored by Reese and Hill, both well-established names in their profession. It was reviewed by Campbell and Hostetler. The first reviewer is an industry expert from the vitamin business, while the second reviewer is an expert on the physiological aspects of mineral nutrition.
The chapter begins by providing basic information such as why these micro-nutrients are required, how they are supplied by natural sources, and what happens when animals are deprived (deficiency) or overdosed (toxicity). Again, very useful information. Each nutrient is presented individually. The next section presents the commercial sources of vitamins and minerals, along with bioavailability (for minerals) and concentration, plus conversion factors (for vitamins). It then closes with practical recommendations for all classes of swine. Here, however, the guide takes an approach quite different than previous similar publications. Instead of providing an exact value, for example 0.2% sodium for breeding sows, the guide offers a range of acceptable values, in this case 0.15 to 0.25% sodium. As such, it correctly leaves the final decision to be taken by field nutritionists. The chapter closes with a few Frequently Asked Questions (a section most likely to expand in future editions) and some references for further consultation.
Example 2: Nursery swine nutrient recommendations and feeding management
This chapter was written by the Kansas State University extension team, which is well-known for its contributions to the subject, and it was reviewed by Spencer and Dean, both established industry professionals. Those aware of previous publications by this extension team will not be disappointed in that this fact sheet is written along the lines of the nutrition programme advocated by them and followed by many producers not only in the USA but also in other parts of the world. Again, the fact sheets start with the basics covering the topic, such as why pigs don’t eat post-weaning and why they should eat more. Then, guidelines follow on how to properly construct piglet diets, in terms of both nutrients and ingredients, along with helpful information on how to prepare a feed budget. In closing, a good number of questions are answered as above.
Example 3: Example diets for swine
In this fact sheet, the authorship is from a number of universities, all well-respected scientists. For some reasons and contrary to expectations, industry professionals have been excluded even from the role of reviewer. Nevertheless, this does not deduct from the educational value of this section as all diets are properly constructed.
This fact sheet provides what the title promises. Numerous example diets with a wide range of applications. Special diets with high fat, or dry distiller’s grains with solubles (DDGS), or with extra crystalline lysine are presented along with more common diets based on maize and soybean meal. Formulas are presented for all classes of swine and even commercial products, such as phytase and ractopamine are briefly covered. The diets are formulated on metabolisable energy, digestible lysine, and available phosphorus. This is considered adequate by most nutritionists in the USA today, especially for simple diets, such as those based on maize and soybean. It would have been quite progressive to use the more advanced net energy system and values based on digestible phosphorus, something perhaps to be considered in future editions, when these systems enjoy wider acceptance in the States.
Example 4: Feeding systems for swine
DeRouchey and Richert, the authors of this fact sheet, are both very active scientists with a great number of publications under their name each year. The reviewers, Brumm and Cera, are both well-known names, and both actively engaged in the swine industry having hands-on practical experience.
This chapter describes both conventional feeding systems, such as gind-and-mix, and more progressive modern systems, such as wet-dry feeding. Quite surprisingly, it also includes information on liquid feeding, giving it thus a much wider readership worldwide. Finally, the most common feeders are presented, closing with a special section on lactation and gestation feeding, something more of an art than science.
Like each publication, there are positive and negative aspects in the NSNG. Any nutritionist, especially one trying to review this massive work, can easily fall in the trap of looking for the negative parts, but this would be like trying to see the tree and missing the forest. What is important is that the NSNG is an excellent source of information and anyone who reads or consults it will not be left wanting. At the end, it should be kept in mind that this is intended to be a ‘guide’, and as such it can never provide the definitive answer (and clearly the NSNG does not try to do this) to each and every problem we face daily on the field. But, taken as a ‘guide’, the NSNG does an exemplary job.
Dr Ioannis Mavromichalis, nutritionist at Ariston Nutrition, Spain, is a regular contributor for Pig Progress. Read more of his work on www.pigprogress.net