Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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Fosforbenutting bij biologisch gehouden vleesvarkens
Bikker, Paul ; Tije, Naomi ten; Tijkorte, Achim - \ 2017
Wageningen : Wageningen Livestock Research (Wageningen Livestock Research rapport 1069) - 22
varkenshouderij - biologische landbouw - fosfor - varkensvoeding - slachtdieren - proeven - proefopzet - pig farming - organic farming - phosphorus - pig feeding - meat animals - trials - experimental design
Dit rapport beschrijft een praktijkstudie naar de mogelijkheden om het verteerbaar fosfor (vP) gehalte in het rantsoen van biologisch gehouden vleesvarkens te verlagen. De verlaging van het berekend vP-gehalte met 0,4 g/kg (15% in startvoer, 20% in vleesvarkensvoer) had geen negatieve invloed op de gezondheid en groei van de varkens. Deze verlaging ten opzichte van het controlevoer draagt bij aan een hogere fosforbenutting. De gerealiseerde vP-gehalten, gebaseerd op analyse van voer en feces, waren echter aanzienlijk hoger dan vooraf berekend op basis van tabelwaarden. Hierdoor kan niet vastgesteld worden of een verlaging van het vP-gehalte ten opzichte van de norm voor regulier gehouden varkens mogelijk is zonder invloed op de dierprestaties.
Nutrition of pigs kept under low and high sanitary conditions : effects on animo acid and energy metabolism and damaging behaviour
Meer, Yvonne van der - \ 2017
University. Promotor(en): Walter Gerrits, co-promotor(en): Alfons Jansman; Aart Lammers. - Wageningen : Wageningen University - ISBN 9789463431972 - 181
pigs - feeds - pig feeding - animal nutrition - amino acid metabolism - animal health - energy metabolism - abnormal behaviour - behaviour disorders - immune system - nutrition physiology - varkens - voer - varkensvoeding - diervoeding - aminozuurmetabolisme - diergezondheid - energiemetabolisme - abnormaal gedrag - gedragsstoornissen - immuunsysteem - voedingsfysiologie

It is economically and environmentally important to match the nutrient supply to the nutrient requirements in pig production. Until now, the effects of different sanitary conditions on energy and nutrient requirements are not implemented in recommendations for nutrient composition of pig diets. The current nutrient requirement data are based on studies with pigs in experimental settings, which can be regarded as rather optimal. Changes in nutrient requirements caused by differences in sanitary conditions are poorly documented. As in the pig production sector farm conditions are variable it is of major importance to determine the effects of low sanitary conditions (LSC) on requirements for amino acids and energy in growing pigs. Pigs under LSC have an increased risk of clinical and subclinical infections, resulting in a chronic stimulation of their immune system. Immune system stimulation is known to influence energy and amino acid metabolism. However, most studies in pigs evaluating the relationship between immune system stimulation and nutrient requirements often use specific experimental challenge models. Whereas such models have the obvious advantage of reproducibility and allow mechanistic insight in the effects of stimulating specific parts of the immune system, these models often induce clinical illness, rather than subclinical infections. Results obtained with such models may therefore be difficult to translate to practical situations. Therefore the objective of the present thesis was to study the effect of low and high sanitary conditions (HSC) on amino acids and energy metabolism in pigs. Also interactions between the immune system, nutrient metabolism and damaging behaviour of pigs were considered in this thesis.

The experiment described in Chapter 2 was designed to study the effect of different dietary crude protein levels and extra amino acid supplementation on the growth performance of pigs kept under different sanitary conditions. In a 2×2×2 factorial arrangement, 68 groups of 9 pigs were allocated to either LSC or HSC, and were offered ad libitum access to two different diets, a normal crude protein concentration diet or a low crude protein concentration diet, each having either a basal dietary amino acid profile or supplemented dietary amino acid profile containing 20% more methionine, threonine, and tryptophan compared with the basal profile. The pigs were followed from 10 weeks of age until slaughter. Haptoglobin concentrations in serum and IgG antibody titers against keyhole limpet heamocyanin, collected in the starter, grower, and finisher phases, and pleuritis scores at slaughter were greater for LSC pigs compared with HSC pigs, illustrating that sanitary conditions affected health conditions. The average daily gain and gain to feed ratio were greater for HSC pigs compared with LSC pigs. A 20% increase in dietary supplementation of methionine, threonine, and tryptophan relative to lysine increased gain to feed ratio more in LSC than in HSC pigs. The results therefore illustrated that dietary requirements for methionine. threonine, and tryptophan were greater for LSC compared with HSC pigs.

In Chapter 3 the damaging behaviour of 576 pigs from the experiment in Chapter 2 was evaluated. At 15, 18, and 24 weeks of age, prevalence of tail and ear damage, and of tail and ear wounds was scored. At 20 and 23 weeks of age, frequencies of biting behaviour and aggression were scored by behaviour sampling. The prevalence of ear damage during the finisher phase and the frequency of ear biting were increased in LSC compared with HSC pigs. The frequency of ear biting was increased in low protein fed pigs compared with normal protein fed pigs. The supplemented AA profile reduced ear biting only in LSC pigs. The prevalence of tail wounds was lower for pigs in LSC than for pigs in HSC in the grower phase. Regardless of dietary amino acid profile or sanitary status, pigs fed low protein diets showed more ear biting, tail biting, belly nosing, other oral manipulation directed at pen mates, and aggression than pigs fed normal protein diets, with no effect on ear or tail damage. In conclusion, both LSC and a reduction of dietary protein increased the occurrence of damaging behaviours in pigs and therefore may negatively impact pig welfare.

The experiment of Chapter 4 was designed to quantify the difference in energy requirements for maintenance, and in incremental efficiencies for deposition of dietary energy and protein in the body of clinically healthy pigs kept under LSC or HSC, fed a basal diet either or not supplemented with additional methionine, threonine and tryptophan.

In a 2 × 2 factorial arrangement, 24 groups of 6 pigs each were allocated to either a LSC or HSC, and were offered two different diets having either a basal or a dietary amino acid profile supplemented with methionine, threonine, and tryptophan. For each group of pigs, complete energy and nitrogen balances were determined during two consecutive weeks, during which feed was available ad libitum or at 70% of ad libitum. Fasting heat production was determined over a 25 h period of fasting after a period of restricted feeding. Low sanitary conditions increased fasting heat production from 696 to 750 kJ/(kg BW0.6 . d), regardless of the dietary amino acid supplementation. The incremental efficiency of ingested nitrogen for retention in the body was reduced in LSC pigs from 73 to 53%, but incremental efficiencies of digestible energy intake for fat deposition in the body were unaffected by the experimental treatments. These findings showed that the effects of continuous immune stimulation by introducing LSC, was affecting energy and nutrient efficiencies of pigs both at maintenance level and at a feeding level close to ad libitum intake.

In Chapter 5 diurnal patterns for heat production, respiratory quotient, and carbohydrate and fat oxidation of the pigs studied in the experiment of Chapter 4 were evaluated to get more insight in the mechanisms behind the effects found in Chapter 4. The LSC pigs had reduced activity compared with HSC and a higher resting metabolic rate during the period of restricted feeding, especially during the light parts of the day. Therefore the diurnal energy expenditure pattern of LSC and HSC pigs can be considered as different. Fat and carbohydrate oxidation patterns were not different for LSC and HSC pigs, indicating that protein and fat deposition during the day was similar for LSC and HSC pigs.

Overall, the results of this thesis indicate that both energy and AA requirements are greater in LSC pigs compared with HSC pigs. It is questionable, however, whether it is nutrient and cost effective and biologically possible to satisfy these increased nutrient requirements in LSC pigs, as the incremental efficiency of N for retained protein is low, and ADFI is reduced for LSC pigs compared with HSC pigs. The present thesis demonstrates that care should be taken in reducing dietary protein concentrations to improve protein efficiency in pigs, as it incurs a risk to increased damaging behaviours, particularly when pigs are kept under LSC.

Protein quality of pig diets : processing effects on amino acid digestibility and post-absorptive utilization
Hulshof, Tetske - \ 2016
University. Promotor(en): Wouter Hendriks, co-promotor(en): Paul Bikker; Thomas van der Poel. - Wageningen : Wageningen University - ISBN 9789462579026 - 175
pigs - protein quality - pig feeding - feeds - feed processing - amino acids - protein digestibility - digestive absorption - protein utilization - nutrition physiology - animal nutrition - varkens - eiwitkwaliteit - varkensvoeding - voer - voedermiddelbewerking - aminozuren - eiwitverteerbaarheid - verteringsabsorptie - eiwitgebruik - voedingsfysiologie - diervoeding

The increasing world population and per capita income imposes a risk for protein scarcity. It is, therefore, necessary to use current ingredients more efficiently which includes the accurate assessment of protein quality before inclusion in animal diets. Protein quality is defined in this thesis as the capacity of a dietary protein to meet a pig’s requirement for nitrogen (N) and amino acids (AA) to meet a particular production target. Protein quality is influenced by processing applied to feed ingredients which may lead to the formation of Maillard reaction products (MRP) or cross-link products. The Maillard and cross-link reactions mainly involve lysine (Ly)s and their products may decrease ileal crude protein (CP) digestibility. During the acid hydrolysis step used to analyze AA, part of the early MRP revert back to Lys. This reverted Lys is not bioavailable for animals. Therefore, methods that specifically analyze Lys with a free ε-amino group (that is, not bound to other nutrients) have been developed. The guanidination reaction with O-methylisourea (OMIU) is one such method. The initial aim of this thesis was to evaluate the ileal digestible reactive Lys assay as a more accurate measure for protein quality of processed protein sources than the ileal digestible total Lys assay. Soybean meal (SBM) and rapeseed meal (RSM) were used as sole protein sources throughout this thesis. Processing of SBM and RSM by toasting at 95°C for 30 min in the presence of a sugar-rich lignosulfonate was used as model for over-processed protein sources.

Digestibility, post-absorptive utilization, and pig growth performance

In Chapter 2, protein quality in processed protein sources was determined using the content of AA, OMIU-reactive Lys, MRP, and lysinoalanine (LAL; as cross-link product), the standardized ileal digestibility (SID) of AA and OMIU-reactive Lys and pig growth performance. The SBM and RSM diets contained furosine and carboxymethyllysine (CML) as MRP, and LAL indicating that the Maillard and cross-link reactions had taken place in SBM and RSM, presumably during the oil extraction/desolventizing process. The amounts of furosine, CML, and LAL were elevated in the pSBM and pRSM diets due to further processing. Processing resulted in a reduction in total and OMIU-reactive Lys contents, a decreased pig growth performance as determined by the gain to feed ratio (G:F), and the SID of CP, AA, and OMIU-reactive Lys. The SID AA contents of the protein sources from Chapter 2 were used to formulate the diets of the main in vivo experiment (Chapters 3 and 4). In this experiment, six experimental diets were used of which four contained either SBM, pSBM, RSM, or pRSM as sole protein source. The remaining two experimental diets contained pSBM or pRSM and were supplemented with crystalline AA to the same SID AA levels as the SBM or RSM diet. These supplemented diets were used to verify that processing affected AA digestibility rather than post-absorptive AA utilization. The effects of processing on CP digestibility and N solubilization along the small intestine, metabolic load as assessed by organ weight, and nutrient composition of the empty body of growing pigs are described in Chapter 3. The small intestine was divided in three segments of similar length and digesta was collected from the last 100 cm of each segment. The amount of insoluble N as a fraction of N in digesta at each small intestinal segment was not affected by processing. Thus, the reduced SID of CP and AA reported in Chapter 2 was not caused by a reduced N solubility but by a general increase of N in digesta. Processing reduced the SID of CP, CP content in the empty body, and G:F. Supplementing crystalline AA to diets containing pSBM or pRSM increased the CP content and G:F to the level of the SBM and RSM diets. Processing also reduced the weight of several organs and supplementing crystalline AA restored organ weight. The effects of processing on whole body AA composition, nutrient retention, and post-absorptive utilization of AA in growing pigs are described in Chapter 4. Post-absorptive AA utilization was calculated as percentage of SID AA intake used for AA retention. Processing affected the AA composition of protein in the organ fraction (that is, empty organs and blood), carcass, and empty body. The Lys concentration in body protein was mainly reduced by processing. Supplementing crystalline AA restored the AA composition of body protein for SBM and RSM. Processing reduced AA retention and again supplementing crystalline AA restored AA retention for both SBM and RSM. Since crystalline AA were supplemented on an SID AA basis, the results indicated that processing affected AA digestibility but not post-absorptive AA utilization. Thus, correcting AA retention for SID AA intake would result in a similar post-absorptive AA utilization which was found for most AA for the RSM diets. However, the post-absorptive AA utilization was lower for the pSBM diet than for the SBM diet which might be related to an imbalanced AA supply after absorption in the first diet.

The assessment of ileal digestibility and utilization is expensive and laborious. Therefore, two alternative in vitro methods for determining protein digestibility for processed protein sources were evaluated (Chapter 5). The protein digestibility determined using the pH-STAT method and a 2-step enzymatic method was compared with the in vivo SID of CP reported in Chapter 2. Initial pH and the degree of hydrolysis assessed in the pH-STAT method were positively correlated to SID of CP. Protein digestibility determined with the 2-step enzymatic method, simulating digestion in the stomach and small intestine, tended to correlate to SID of CP. Both the 2-step enzymatic method and pH-STAT method were suitable alternatives for the assessment of SID of CP. However, only four ingredients were tested. The suitability of the methods should be further studied using multiple (processed) feed ingredients before they can be used as alternatives for in vivo assays.

Reactive Lys analysis

O-methylisourea was reported to bind specifically to the ε-amino group of Lys. The results of Chapter 2, however, cast doubt on the specificity of OMIU to react only with the ε-amino group of Lys. A series of experiments was conducted to study this specificity (Chapter 6). Incubating crystalline L-Lys with OMIU under standard conditions (OMIU pH of 10.6, OMIU to AA ratio of 1000:1, and reaction time of 7 d) resulted in a low homoarginine (that is, Lys with OMIU bound to its ε-amino group) recovery. The reaction of OMIU with the α-amino group of Lys was confirmed by mass spectrometry analysis with double derivatized Lys being identified. Several reaction conditions (OMIU pH, OMIU to Lys ratio, and reaction time) were studied but none of these resulted in 100% recovery of homoarginine. Binding of OMIU to the α-amino group of Lys could result in an underestimation of the reactive Lys content when significant levels of Lys with a free α-amino group (that is, crystalline L-Lys (HCl), free and N-terminal Lys) are present in food/feed ingredients, diets, and ileal digesta. The free Lys content in food/feed ingredients was on average 1.3% of total Lys. The free Lys content can be substantial in certain diets and was reported to be 13% of total Lys in ileal digesta. The latter might result in an overestimation of the OMIU-reactive Lys digestibility. The reaction of OMIU with α-amino groups may necessitate analysis of free Lys to accurately quantify reactive lysine in samples containing a large proportion of Lys with a free α-amino group.

The results presented in this thesis indicate that the effects of processing on SID of CP and AA, body composition, nutrient retention, post-absorptive AA utilization, and growth performance could be substantial. These effects should, therefore, be taken into account when using processed feed ingredients in diets for growing pigs. The extent of protein damage in feed ingredients can be assessed by the analysis of OMIU-reactive and total Lys, MRP, and cross-link products. However, OMIU-reactive Lys only provides accurate results when samples contain small levels of Lys with a free α-amino group (that is, crystalline L-Lys (HCl), free and N-terminal Lys). When samples contain significant levels of Lys with a free α-amino group, it is recommended to use standard guanidination conditions (OMIU pH of 10.6, OMIU to AA ratio of 1000:1, and reaction time of 7 d) to convert protein-bound Lys to homoarginine and to separately analyze such samples for free Lys.

Geraffineerd voeren : naar een sluitende mineralenkringloop door raffinage van lokaalgeteeld veevoer
Sanders, J.P.M. ; Liere, J. ; Wilt, J.J. de - \ 2016
Utrecht : Innovatie Agro & Natuur - Netwerkorganisatie voor grensverleggende vernieuwingen - ISBN 9789050595278 - 32 p.
veevoeding - melkveevoeding - varkensvoeding - bioraffinage - grasmaaisel - maïs - mineralenboekhouding - livestock feeding - dairy cattle nutrition - pig feeding - biorefinery - grass clippings - maize - nutrient accounting system
Raffinage van in Nederland geteeld voer kan bijdragen aan het verminderen van de import van voer en daarmee van de nutriënten fosfor en stikstof. Die verminderde import aan nutriënten is het gevolg van het verbeteren van de voerbenutting van de geraffineerde producten en dan met name van in gras en snijmais aanwezige eiwitten. De import van eiwit is immers de belangrijkste bron van onze fosfor- en stikstofoverschotten. In deze rapportage worden het raffinage proces beschreven, alsmede de stromen die bij de verschillende bewerkingen vrijkomen. De mogelijkheden voor inzet van deze stromen als voer voor runderen dan wel varkens passeren de revue. Tevens wordt een globale kosten- en opbrengstenberekening gemaakt. Tenslotte volgt een schets van de implicaties van de verschuivingen in eiwitbenutting op nationaal niveau. Zijdelings wordt aandacht besteed aan de productie van eendenkroos als eiwitbron.
Het effect van aminozuuraanbod en -samenstelling van het voer op zoötechnische prestaties van beren gehuisvest onder verschillende sanitaire condities
Meer, Y. van der; Gerrits, W.J.J. ; Jansman, A.J.M. - \ 2016
Wageningen UR Livestock Research (Livestock Research rapport 938) - 32 p.
beren (varkens) - aminozuren - eiwit - voedselsamenstelling - varkensvoeding - mestresultaten - hygiëne - varkenshouderij - zoötechniek - dierlijke productie - boars - amino acids - protein - food composition - pig feeding - fattening performance - hygiene - pig farming - zootechny - animal production
Dit experiment was opgezet om het effect van eiwitniveau (normaal versus verlaagd) en aminozuursamenstelling in het rantsoen te evalueren op de technische prestaties van beren gehuisvest onder een tweetal sanitaire condities.
IAG ring test feed composition 2015
Raamsdonk, L.W.D. van; Rhee, N.E. van de; Pinckaers, V.G.Z. ; Vliege, J.J.M. - \ 2015
RIKILT Wageningen UR (RIKILT report 2015.017) - 25 p.
feed formulation - pig feeding - ring test - microscopy - voersamenstelling - varkensvoeding - ringtest - microscopie
A ring test was organized for the microscopic determination of botanic composition in animal feed in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the ring test was RIKILT Wageningen UR, The Netherlands. The aim of the ring study was to provide the participants information on the performance of the local implementation of the method for composition analysis of feed.
IAG ring test animal proteins 2015
Raamsdonk, L.W.D. van; Rhee, N.E. van de; Scholtens-Toma, I.M.J. ; Prins, T.W. ; Vliege, J.J.M. ; Pinckaers, V.G.Z. - \ 2015
Wageningen : RIKILT Wageningen UR (RIKILT report 2015.016) - 31 p.
ring test - microscopy - animal proteins - cattle feeding - pig feeding - animal health - ringtest - microscopie - dierlijke eiwitten - rundveevoeding - varkensvoeding - diergezondheid
A ring test was organized for the detection of animal proteins in animal feed by microscopy in the framework of the annual ring tests of the IAG - International Association for Feeding stuff Analysis, Section Feeding stuff Microscopy. The organizer of the ring test was RIKILT - Wageningen UR, The Netherlands. The aim of the ring study was to provide the participants information on the performance of the local implementation of the detection method for their local quality systems. A further aim was to gather information about the application of the microscopic method. The current 2015 version of the IAG ring test for animal proteins is the first one in the IAG series of ring tests applying the full new method for microscopy as published in Regulation (EC) 51/2013 amending Annex VI of Regulation (EC) 152/2009 together with accompanying SOPs.
Linking early life conditions to osteochondrosis prevalence in gilts
Koning, D.B. de - \ 2015
University. Promotor(en): Bas Kemp, co-promotor(en): Ilse van Grevenhof; Wouter Hazeleger. - Wageningen : Wageningen University - ISBN 9789462575042 - 234
gelten - osteochondritis - varkensvoeding - vloertypen - bouw (dier) - voortbeweging - antilichamen - koolhydraatrijk voedsel - arginine - voedersupplementen - diergezondheid - gilts - pig feeding - floor type - conformation - locomotion - antibodies - carbohydrate-rich foods - feed supplements - animal health

Osteochondrosis (OC) involves the development of necrotic growth cartilage near the surface of a joint and is suggested to be associated with lameness in sows. Development of OC in pigs occurs at young age in a relatively short time frame of several weeks around 10 weeks of age. Due to this time dependency, one may wonder whether there are time dependent effects of factors or conditions associated with OC. The aim of this thesis was to assess whether OC prevalence is associated with conditions encountered in early life such as dietary restriction, floor type, conformation and locomotive characteristics (CLC), natural (auto-) antibodies (N[A]Ab), and carbohydrate levels. Indications for time dependent effects were found for dietary restriction on OC prevalence. This indicated that gilts receiving restricted feeding from 4 to 10 weeks of age and switched to ad libitum feeding until 26 weeks of age had a significantly higher prevalence of OC when compared to gilts receiving restricted feeding after 10 weeks of age. Time dependent effects of floor type were not clearly present, but gilts housed on a deep litter type system using wood shavings after weaning had a higher prevalence of severe OC when compared to gilts kept on a concrete partially slatted floor. Feed with a lower carbohydrate level increased OC prevalence compared to feed with a higher carbohydrate level. We hypothesized that the effects of dietary restriction, floor type, and dietary carbohydrate levels were mediated through loading of the joints either by, respectively, a short rapid increase in weight gain, higher incidence of play behaviors, or by an overall increased body weight. Although OC has been suggested to be associated with various CLC such as lameness, a consistent association of CLC at young age with OC at slaughter could not be found. This is likely due to CLC and OC both varying over time, making associations between the 2 entities complicated. There were indications that a component of the immune system is associated with OC as N(A)Ab against several antigens were found after weaning in association with OC. However, as with the CLC, associations with OC were not consistent over time, making it difficult to discern the exact associations between N(A)Ab and OC. To conclude, several early life conditions were found to affect or be associated with OC prevalence in gilts. This indicates that if one wants to reduce OC prevalence, one needs to start early after weaning. However, the exact implications of OC on CLC such as lameness and, therefore, welfare remain uncertain and require further studies into the long term welfare effects of OC.

Immuunsysteem sturen met voer
Have, H. ten; Smits, M.A. - \ 2015
V-focus 12 (2015)4. - ISSN 1574-1575 - p. 20 - 21.
varkens - varkenshouderij - diergezondheid - varkensvoeding - voedertoevoegingen - immuunsysteem - antigenen - darmen - pigs - pig farming - animal health - pig feeding - feed additives - immune system - antigens - intestines
Het onderzoeksprogramma Feed4Foodure werkt aan een meetlat om te voorspellen wat het vermogen is van een dier om adequaat te reageren als het wordt blootgesteld aan ziekteverwekkers. Dit wordt de immuuncompetentie van het dier genoemd. Deze immuuncompetentie is te beïnvloeden door onder andere diervoeding en voederadditieven, vertelt onderzoeker Mari Smits van Wageningen UR.
Proficiency test for aflatoxin in pig feed
Elbers, I.J.W. ; Nijs, W.C.M. de - \ 2015
Wageningen : RIKILT Wageningen UR (RIKILT report 2015.010) - 27
aflatoxinen - varkensvoeding - vergelijkend warenonderzoek - laboratoria - betrouwbaarheid - evaluatie - aflatoxins - pig feeding - comparative testing - laboratories - reliability - evaluation
Proficiency testing is conducted to provide laboratories with a powerful tool to evaluate and demonstrate the reliability of the data that are produced. Next to validation and accreditation, proficiency testing is an important requirement of the EU Additional Measures Directive 93/99/EEC [1] and is required by ISO 17025:2005 [2]. The aim of this proficiency test was to give laboratories the possibility to evaluate or demonstrate their competence for the analysis of aflatoxins in pig feed.
Impact of health status on amino acid requirements of growing pigs : towards feeding strategies for farms differing in health status
Kampman-van de Hoek, E. - \ 2015
University. Promotor(en): Wouter Hendriks, co-promotor(en): Walter Gerrits; Alfons Jansman. - Wageningen : Wageningen University - ISBN 9789462573437 - 184
varkens - afmesten - diergezondheid - aminozuren - voedingsstoffenbehoeften - voedingseiwit - aminozuurmetabolisme - stikstofretentie - immuniteitsreactie - immuunsysteem - varkensvoeding - diervoeding - pigs - finishing - animal health - amino acids - nutrient requirements - dietary protein - amino acid metabolism - nitrogen retention - immune response - immune system - pig feeding - animal nutrition

Abstract

There is large variation in the production performance of commercial growing-finishing pig farms. This variation even exists when pigs have a similar genetic background and fed similar diets. The health status is one of the major factors contributing to this large variation in pig performance, as activation of the immune system can decrease feed intake, body weight gain and increase nutrient utilisation for immune system functioning. As a consequence, amino acids (AA) are repartitioned from skeletal muscle deposition towards utilisation for immune system functioning. Current requirement estimates for growing-finishing pigs are formulated to maximize protein deposition for growth and do not take into account the increased utilization of AA for immune functioning as induced by health challenging conditions. This lack of knowledge hampers the ability of feed manufacturers to optimize diets and improve pig performance. The main objective of the present thesis was to quantify the effect of health status on AA requirements for body protein deposition and for immune system functioning of growing pigs.

A health status web was developed as a tool to categorize growing-finishing pig farms on the basis of their health status. The health status web can be of use for feed manufacturers to develop targeted strategies to accommodate the nutritional requirements of pigs belonging to particular groups of farms sharing a common health status. A dose-response technique was developed, which is a simple, accu­rate technique to quantitatively estimate changes in AA requirements of individual meal-fed pigs. Nevertheless, a minimum time period of 21 days is required for each individual, which makes the technique inappropriate for studying the effect of immune system activation on AA requirements. The combined measurements of whole body N retention, plasma irreversible loss rate (ILR, i.e. the amount of free AA that disappears per unit of time from the plasma pool for protein synthesis or oxidation), urea entry and appearance of 13C into plasma proteins, provided insight into the consequences of immune system activation on AA metabolism.

Pigs selected from a farm with a suboptimal health status had greater serum haptoglobin, lower serum albumin concentrations, and greater leukocyte counts in blood at the start of the experiment than pigs selected from a farm with a high health status, indicating a higher level of immune system activation. The occurrence of compensatory gain in pigs from a farm characterized as having a suboptimal health status proves, however, that it is difficult to maintain a contrast in health status, and that pigs can adapt quickly to a change in housing conditions. In the absence of effects on feed intake, health challenging conditions may affect performance due to alterations in post-absorptive AA metabolism, as also indicated by increased urinary N losses, and a tendency for a reduced N retention and a lower utilization of digestible N for N retention in pigs with a systemic inflammation, or by a reduction in faecal nutrient digestibility as indicated for dry matter and N in pigs from a farm with a suboptimal health status. The observed changes in protein and AA metabolism after immune stimulation imply that especially tryptophan may become limiting during immune system activation, whereas lysine becomes excessive. Furthermore, the utilization of methionine, tyrosine, and valine for immune system functioning seems to increase in pigs with a systemic lung inflammation. In addition, the dietary AA or protein supply was able to modulate the acute phase response pre- and post-challenge, stressing the importance of an adequate dietary AA supply for appropriate functioning of the immune system of growing-finishing pigs.

Before implementing targeted feeding strategies for farms sharing a common health status, future research should be conducted to study the possible beneficial effects of increasing the dietary supply of particularly tryptophan, methionine, tyrosine, and valine relative to lysine for immune system function and for body protein deposition in pigs from farms with a different health status.

Effect van voerniveau bij drachtige lacterende zeugen op reproductie en conditie = Effect of feeding level in gestating lactating sows on reproduction and condition
Peet-Schwering, C.M.C. van der; Rommers, J.M. ; Troquet, L.M.P. ; Soede, N.M. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research report 861) - 39
zeugen - voeropname - varkensvoeding - varkenshouderij - lichamelijke fitheid - zogen - voortplantingsvermogen - biggen - lactatie - sows - feed intake - pig feeding - pig farming - physical fitness - suckling - reproductive performance - piglets - lactation
Op VIC Sterksel is onderzocht wat het effect is van het voerniveau van zeugen tijdens de laatste 8 dagen van een zes weekse lactatie waarin ze ook drachtig zijn op de gewichts- en spekdikte ontwikkeling van de zeugen, de resultaten van de biggen en het aantal levend en dood geboren biggen in de volgende worp. De resultaten van het onderzoek zijn in dit rapport beschreven.
Pilot inkuilen Grote waternavel ten behoeve van veevoeding
Hoving, I.E. ; Schooten, H.A. van - \ 2015
Wageningen : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 853) - 26
veevoeding - varkensvoeding - conservering - varkens - voeropname - voedingswaarde - kuilvoer - hydrocotyle - kuilvoerbereiding - ingekuilde planten - livestock feeding - pig feeding - conservation - pigs - feed intake - nutritive value - silage - silage making - silage plants
This report describes the results of a practical ensiling experiment with Greater water pennywort, in which the processing of the plant material and the effect of drying on the ensiling result and nutrition value has been investigated. The conservation of the ensiled product was very poor (even after drying) due to the high water content, low sugar content and soil contamination. The intake of the wet product by pigs seem to be good. The poor preservation proved no obstacle. Greater water pennywort has potential as fodder for pigs given the nutritional and good intake. What is needed are methods to harvest cleaner and to ferment the product better.
Grass silage in diets for organic growing-finishing pigs
Bikker, P. ; Binnendijk, G.P. ; Vermeer, H.M. ; Peet-Schwering, C.M.C. van der - \ 2014
In: Proceedings of the 4th ISOFAR Scientific Conference ‘Building Organic Bridges’, at the Organic World Congress. - - p. 815 - 818.
graskuilvoer - varkens - varkenshouderij - ruwvoer (roughage) - groei - prestatieniveau - biologische landbouw - varkensvoeding - grass silage - pigs - pig farming - roughage - growth - performance - organic farming - pig feeding
In this study, organically raised pigs received an increasing proportion of grass silage up to 10 and 20% dry matter in the daily ration in the grower and finisher period, respectively, to determine the effects of grass silage on feed intake and growth performance. The pigs receiving a mixture of grass silage and compound feed ingested 0.3 kg DM/d (13% of their daily ration) as grass silage and realised a similar daily net energy intake as pigs fed compound feed only. However, the silage fed pigs realised a lower daily gain (37 g/d) and a lower calculated net energy utilisation (1.6 MJ/kg) for gain and a lower dressing percentage (1.1%) of the carcass. The optimal feeding system and the nutritive value of grass silage for growing pigs requires further investigation to improve the silage intake and clarify and minimise the loss in animal performance.
Extra snijmais goed voor welzijn varkens.
Bracke, M.B.M. ; Aarnink, A.J.A. ; Rotgers, G. ; Vermeer, H.M. - \ 2014
V-focus 11 (2014)6. - ISSN 1574-1575 - p. 34 - 35.
varkenshouderij - vleesvee - vleesproductie - varkensvoeding - dierenwelzijn - proefboerderijen - maïs - maïskuilvoer - varkensstallen - krachtvoeding - varkens - dierlijke productie - pig farming - beef cattle - meat production - pig feeding - animal welfare - experimental farms - maize - maize silage - pig housing - force feeding - pigs - animal production
Vleesvarkens hebben graag een emmer snijmais. Dat blijkt uit praktijkonderzoek op Varkens Innovatie Centrum Sterksel, onderdeel van Wageningen UR. In vergelijking met stro heeft snijmais meer voederwaarde en het leidt minder snel tot verstoppingen in de mestput.
Weetjes en praktische tips over de aanpak van Brachyspira pilosicoli bij biologische varkens
Bokma-Bakker, M.H. ; Kluivers-Poodt, M. ; Peet-Schwering, C.M.C. van der; Eijck, I.A.J.M. ; Kolpa, B. ; Kleijer, G. ; Willems, E.M. ; Leejen, J. - \ 2014
varkenshouderij - brachyspira pilosicoli - varkensziekten - biologische landbouw - diergezondheid - dierziektepreventie - stress - dierenwelzijn - varkensvoeding - varkensstallen - varkens - dierlijke productie - pig farming - swine diseases - organic farming - animal health - animal disease prevention - animal welfare - pig feeding - pig housing - pigs - animal production
In deze flyer wordt een aantal weetjes en praktische tips over de aanpak van Brachyspira pilosicoli bij biologische varkens samengevat. De kennis is zowel afkomstig uit onderzoek als uit praktijkervaringen.
Unveiling causes for growth retardation in piglets
Paredes Escobar, S. - \ 2014
University. Promotor(en): Leonard den Hartog, co-promotor(en): Martin Verstegen; Walter Gerrits. - Wageningen : Wageningen University - ISBN 9789462571204 - 168
biggen - groei - mestresultaten - geboortegewicht - speengewicht - voer - groeivertraging - inslineresistentie - varkensvoeding - diervoeding - voedingsfysiologie - piglets - growth - fattening performance - birth weight - weaning weight - feeds - growth retardation - insulin resistance - pig feeding - animal nutrition - nutrition physiology

The evolution of hyper‐prolific sow breeds has led to a higher number of piglets born per sow per year. This increase in litter size has enlarged the number of light weight (or growth retarded) piglets, increased pre‐weaning mortality and heterogeneity at the end of the nursery phase (ten weeks of age). These poorly performing piglets represent a challenge to the swine industry as their presence in the herd has economic and welfare implications.

Reducing the heterogeneity at the end of the nursery phase is relevant, as it influences the efficiency of use of the grower and finisher facilities, and/or it reduces penalties for delivering underweight piglets to the slaughterhouse. The focus of this thesis was the end of the nursery phase, as this is the time point where piglets are transferred to the grower and finisher facilities.

The aim of this thesis was to identify and describe the causes of growth retardation in the nursery phase to provide a basis to look for alternative nutrition or management solutions.

The database analysis described in Chapter 2 provides a phenotypic definition of growth retardation based on the risk factor analysis approach, and describes season of birth, body weight at birth, at weaning and at six weeks of age as the main factors to predict piglet BW at the end of the nursery phase.

Based on the algorithm developed to predict piglets’ BW at the end of the nursery phase, our target population was defined as piglets with a birth weight above the mean ‐2 times the SD from the total population and a predicted BW at the end of the nursery phase below the mean ‐1 time the SD from the mean of the total population, considered Low Performing

piglets LP). We aimed to characterize differences between LP piglets and their heavier counterpart (piglets with a predicted BW at the end of the nursery phase above the mean +1 time the SD from the mean of the total population HP).

Compared to the HP, the LP piglets grew slower, ate less and were lighter but have an equal gain:feed ratio at ten weeks of age. The LP piglets tended to take more time to touch a novel object and spent more time eating. The LP and HP piglets have an equal macronutrient digestibility, with the exception of NSP. When fed a high fibre diet, both groups have a lower starch and fat apparent total tract digestibility. Yet, the LP piglets have a reduced fermentative capacity, which might place them in disadvantage. Also LP piglets are unable to engage into compensatory gain or compensatory feed intake, as efficiency of nutrient utilization and feed intake per kg BW0.75 was unaffected. In terms of skeletal muscle development, the LP piglets have a low muscularity (total fiber number and fiber cross sectional area), which might be of disadvantage for lean mass accretion in further life and for meat quality. The LP piglets exhibit insulin resistance and a lower pancreatic amylase activity, which might be related to the lower performance. Lastly, in the general discussion a comparison of the main findings with literature characterizing growth retarded piglets is presented. Also based on modelled data, the economic impact of growth retarded piglets is estimated from 10 weeks of age until slaughter weight (110 kg BW).

The studies reported in this thesis describe a novel method for selecting growth retarded piglets in the nursery phase and provide insight into possible mechanism for growth retardation in the piglet phase.

De in vitro verteerbaarheid van gewelde maïs en maïsbijproduct en de in vivo verteerbaarheid van maïsbijproduct gemeten bij vleesvarkens
Bikker, P. ; Krimpen, M.M. van; Dekker, R.A. ; Wikselaar, P.G. van; Diepen, J.T.M. van - \ 2014
Wageningen : Wageningen UR Livestock Research (Report / Wageningen UR Livestock Research 788) - 28
varkens - varkenshouderij - diervoeding - maïs - maïsbijproducten - verteerbaarheid - in vitro verteerbaarheid - in vivo experimenten - spijsvertering - voederconversie - voer - voederwaardering - varkensvoeding - pigs - pig farming - animal nutrition - maize - maize byproducts - digestibility - in vitro digestibility - in vivo experimentation - digestion - feed conversion - feeds - feed evaluation - pig feeding
In opdracht van PPO (PPS Kleinschalige Bioraffinage) is de in vitro verteerbaarheid van gewelde maïs en van het maïsbijproduct na fermentatie bepaald. Als referentiegrondstoffen zijn in deze studie sojaschroot en kuilgras meegenomen. Tevens is in deze studie de in vivo verteerbaarheid van het maïsbijproduct bij varkens onderzocht. Dit rapport beschrijft zowel de resultaten van het in vitro als van het in vivo onderzoek.
Literatuurstudie en in vitro onderzoek naar antibacteriële werking van voeradditieven ter vermindering van de Streptococcus suis problematiek = Desk study and in vitro analysis of antibacterial effects of feed additives to reduce Streptococcus suis in the field
Smith, H.E. ; Greeff, A. de; Faber, I. ; Peet-Schwering, C.M.C. van der; Kluivers-Poodt, M. ; Troquet, L.M.P. - \ 2014
Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 760) - 8
varkenshouderij - varkensziekten - varkensvoeding - voedertoevoegingen - antibacteriële eigenschappen - streptococcus suis - dierziektepreventie - pig farming - swine diseases - pig feeding - feed additives - antibacterial properties - animal disease prevention
In opdracht van het Productschap Vee en Vlees en het ministerie van Economische Zaken is een literatuurstudie uitgevoerd naar voeradditieven waarvan beschreven is dat zij een direct bacteriedodend effect hebben, bij voorkeur tegen Streptococcus suis. De top 5 voeradditieven, die uit deze studie naar voren kwam, te weten oregano, knoflook, kaneel, laurinezuur en monolauraat zijn vervolgens in vitro getest op de bacteriedodende werking tegen verschillende Streptococcus suis stammen van serotype 2 en 9.
Stalboekje varkens : natuurlijk gezond met kruiden en andere natuurproducten
Groot, M.J. ; Kleijer-Ligtenberg, G. ; Asseldonk, T. van - \ 2014
Wageningen : RIKILT - 168
varkenshouderij - varkensvoeding - antibiotica - dosering - biologische voedingsmiddelen - diergezondheid - dierziektepreventie - zeugenvoeding - biggenvoeding - dierenwelzijn - biologische landbouw - varkens - diervoeding - dierlijke productie - pig farming - pig feeding - antibiotics - dosage - organic foods - animal health - animal disease prevention - sow feeding - piglet feeding - animal welfare - organic farming - pigs - animal nutrition - animal production
Het streven om het gebruik van antibiotica terug te dringen vraagt om een ander management. Goede voeding, huisvesting en hygiëne zijn hierbij belangrijk. In dit boekje worden handvaten gegeven om met natuurlijke middelen de gezondheid van de dieren te bevorderen en zo ziektes te voorkomen. Tevens kunnen middelen worden ingezet om de ernst van de ziekte te reduceren. Doel is tevens om de dierenartsen te informeren over de mogelijkheden van natuurproducten en de wetenschappelijke onderbouwing hiervan inzichtelijk te maken
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