PhD, Norwegian University of Life Sciences
The European pig industry is heavily dependent on imported feed ingredients, especially soybean meal (SBM) as a protein source in commercial diets. Increased and more efficient use of local protein sources, such as rapeseed (RS), could improve the sustianibility and self-sufficiency of this sector. However, the use of RS co-products in pig diets can be associated with reduced nutrient utilization and performance. This has been attributed to the high fiber content and the presence of several antinutritional factors in RS, such as glucosinolates. Improvements in feed efficiency (FE) are crucial for a more economically and enviromentally sustainable pork production. The capacity of the pigs to digest and metabolize the nutrients and the energy in the diet is a major factor contributing to variation in FE. My research aims at providing knowledge about the effects of replacing SBM with RS co-products on nutrient and energy digestibility, energy metabolism, nitrogen retention, and subsequent FE. Also, by using different techniques such as histology, immunohistochemistry, enzyme activity assays, metagenomics, transcriptomics, and metabolomics, we aim at identifying some of the underlying biological mechanisms associated with variation in the parameters mentioned before, associated with FE. The idea is to use the identified biological markers (associated with FE) in future experiments with larger number of animals that will be genotyped in order to identify pigs that are genetically superior/robust towards RS diets.
Abstract: Feed efficiency represents the cumulative efficiency with which the pig utilizes dietary nutrients for maintenance, lean gain and lipid accretion. It is closely linked with energy metabolism, as the oxidation of carbon-containing components in the feed drive all metabolic processes. While much is known about nutrient utilization and tissue metabolism, blending these subjects into a discussion on feed efficiency has proven to be difficult. For example, while increasing dietary energy concentration will almost certainly increase feed efficiency, the correlation between dietary energy concentration and feed efficiency is surprisingly low. This is likely due to the plethora of non-dietary factors that impact feed efficiency, such as the environment and health as well as individual variation in maintenance requirements, body composition and body weight. Nonetheless, a deeper understanding of feed efficiency is critical at many levels. To individual farms, it impacts profitability. To the pork industry, it represents its competitive position against other protein sources. To food economists, it means less demand on global feed resources. There are environmental and other societal implications as well. Interestingly, feed efficiency is not always reported simply as a ratio of body weight gain to feed consumed. This review will explain why this arithmetic calculation, as simple as it initially seems, and as universally applied as it is in science and commerce, can often be misleading due to errors inherent in recording of both weight gain and feed intake. This review discusses the importance of feed efficiency, the manner in which it can be measured and reported, its basis in biology and approaches to its improvement. It concludes with a summary of findings and recommendations for future efforts.
Pub.: 08 Aug '15, Pinned: 27 Jul '17
Abstract: Energy digestibility in the growing pig increases with BW increase and may differ between breeds of pigs or between lines selected on criteria other than digestion. However, little is known about the variability in energy digestibility within a line or a breed of pigs, especially when fibrous diets are fed. For this purpose, 20 Large White castrated male growing pigs originating from four boars (five per boar), and three to four sows per boar, were fed a high dietary fibre (DF) diet (18% NDF) and measured over 10 consecutive weeks (30 to 95 kg BW range) for their apparent faecal energy, nitrogen and organic matter digestibility. Each week, faeces were totally collected over 5 days and the feed dry matter intake over the same days was recorded. All digestibility coefficients increased regularly (P < 0.001) over the experimental periods or with BW increase (+0.6 point/10 kg BW increase for energy); this rate of increase was not affected by boar origin (no interaction; P > 0.05). The digestibility coefficients were affected by boar origin (P < 0.005 for energy), with about 2 points for energy between the extremes (81.7% v. 79.5%), and there was no marked interaction between boar origin and period. These preliminary results suggest the possibility of selecting growing pigs for an increased digestive efficiency when fed high DF diets.
Pub.: 26 Mar '13, Pinned: 27 Jul '17
Abstract: Canola meal is derived from the crushing of canola seed for oil extraction. Although it has been used in swine diets for a long time, its inclusion levels have been limited due to concerns regarding its nutritive value primarily arising from results of early studies showing negative effects of dietary canola meal inclusion in swine diets. Such effects were attributable to the presence of anti-nutritional factors (ANF; notably glucosinolates) in canola meal. However, due to advances in genetic improvements of canola that have led to production of cultivars with significantly lower ANF content and improved processing procedures, canola meal with a superior nutritive value for non-ruminant animals is now available. Therefore, the aim of this paper is to review the recent studies in the use of canola meal as feedstuff for swine, the factors influencing its use and the strategies to overcome them. First a historical overview of the development of canola is provided.
Pub.: 18 Feb '16, Pinned: 27 Jul '17