Schothorst Feed Research
  • Lelystad, Netherlands
Recent publications
The effect of a biosynthetic bacterial 6-phytase (PhyG) on the digestibility and excretion of crude protein (CP), phosphorus (P) and phytate-P (PP) in mid-lactating dairy cows was investigated. Thirty Holstein-Friesians were assigned to three treatments with 10 cows per treatment in a randomized block design. Cows were fed forage (grass and corn silage) provided ad libitum, and a concentrate (without added inorganic phosphate) administered separately in amounts individualized per cow according to milk production, supplemented with phytase according to treatment. The formulated forage-to-concentrate-ratio was ~65:35%. Dietary treatments comprised the control diet (CON) and CON supplemented with 2,000 (PhyG2,000) or 5,000 (PhyG5,000) phytase units (FTU)/kg DM in the total diet. The experiment comprised an 18-d pre-period for the collection of data to facilitate the allocation of cows to the treatments, followed by a 19-d experimental period comprising a 14-d diet adaptation period and 5 days of twice daily feces collection. Fecal samples were analyzed for the determination of apparent total tract digestibility (ATTD) of chemical constituents in the diet. The ATTD of PP was 92.6% in CON suggesting a high but incomplete degradation of phytate by ruminal microbial phytases. Cows fed PhyG2,000 exhibited increased ATTD of CP and PP [68.4% (2.7% points above CON) and 95.1% (2.5% points above CON), respectively] whilst PhyG5,000 further increased ATTD PP and also increased ATTD P [54.1% (7.8% points above CON)]; ATTD of Ca tended to be increased in PhyG5,000 vs CON. Linear dose-response relationships were observed for ATTD of DM, CP, P, Ca and PP. In addition, fecal excretion of P, and PP linearly reduced and that of Ca and CP tended to linearly reduce with increasing PhyG dose level. No difference was observed for DM intake and milk composition was unaffected except for milk protein which tended to be higher in cows fed PhyG5,000 than CON. In summary, the addition of exogenous phytase at 2,000 FTU/kg or higher to diets of lactating dairy cows improved P, PP, Ca and CP digestibility and reduced fecal excretion of P, PP and CP in a dose-dependent manner.
This study evaluated the effect of limestone solubility on the capacity of a novel consensus bacterial 6-phytase variant (PhyG) to improve phosphorus (P) and calcium (Ca) digestibility, retention and utilization in low-Ca broiler diets containing no added inorganic phosphate (Pi). Male Ross 308 broilers (n = 1,152) were fed one of 16 experimental diets from 11 to 21 d of age in a randomized complete design (12 birds/cage, 6 cages/treatment). Diets comprised three positive controls (PC3, PC2 and PC1) containing 1.8, 1.2 or 0.6 g/kg MCP-P and 7.7, 7.0 or 6.2 g/kg Ca, respectively, and a negative control (NC) containing no added Pi (4.4 g/kg P; 2.8 g/kg phytate-P) and 5.5 g/kg Ca from either low or high solubility limestone (LSL or HSL respectively [with 42 and 97% solubility after 5 min at pH3.0]), supplemented with 0, 250, 500, 1,000 or 2,000 FTU/kg of PhyG. Fecal samples collected on d 18 to 20 and ileal digesta collected on d 21 were analyzed for titanium dioxide, Ca, P, and phytate (IP6, inositol hexakisphosphate). Tibias (d 21) were analyzed for ash content. Data were analyzed by factorial analysis (2 limestone solubilities × 4 MCP-P levels and 2 limestone solubilities × 5 phytase dose levels) and exponential regression. Increasing dose levels of PhyG resulted in an exponential increase (P < 0.01) in the apparent ileal digestibility (AID) of P, ileal digestible P content of the diet, ileal IP6 content and IP6 disappearance in birds fed either HSL or LSL diets, but AID Ca and ileal digestible Ca were exponentially increased by the phytase only in HSL diets (P < 0.01). Relative to HSL, the LSL increased AID P, ileal digestible P and IP6 disappearance (P < 0.05) but reduced AID Ca, ileal digestible Ca and retainable Ca (P < 0.05), resulting in reduced retainable P and tibia ash. Phytase exponentially increased the apparent total tract digestibility of P, retainable P and tibia ash in HSL and LSL diets, but at or above 500 FTU/kg values were higher in HSL than LSL (interaction P < 0.05). The findings highlight that phytase dose-response effects on mineral digestibility and utilization are different for high- and low-solubility limestones and it is therefore recommended to use digestible rather than total Ca content during diet formulation to ensure an optimal balance of Ca and P, especially in low-Ca diets. In diets containing HSL, higher phytase dose levels may be needed to compensate for the low digestible P content of the basal diet.
The development of the carbon footprint (CF) of raw cow milk over time has been scarcely researched. The objectives of this study are (1) to determine the annual raw cow milk CF in the Netherlands between 1990 and 2019 and (2) to identify the factors explaining the development of the raw cow milk CF over time. We applied Life Cycle Assessment (cradle to farm gate) to the average Dutch dairy system and used data collected from national statistics and from the farm accountancy data network. The CF of raw cow milk produced in the Netherlands in 2019 was 992 g CO2-eq. per kg Fat and Protein Corrected Milk (FPCM), while in 1990 it was 1522 g CO2-eq. (kg FPCM)⁻¹. This represents a reduction of 35%. The reduction rate of the CF is affected by the scope of the CF study, i.e. reduction rate is smaller if direct land use change (dLUC) (32%) and soil organic carbon (SOC) balance (29%) are included in the total CF. Methodological choices affect the absolute level of the CF by up to 27%, but the impact on the reduction rate over time is negligible. The results show that continuous improvement in agricultural practices (increased milk and roughage yields, improved feed efficiency and decreased nitrogen application) has played an important role in reducing the CF of milk over the years. Along with this process, the Dutch dairy system has evolved into less grazing and less land devoted to permanent grasslands which decreased carbon sequestration. In order to achieve climate targets, the annual reduction rate needs to be increased and additional efforts are required if the Dutch dairy sector is to play its part in limiting global warming to 1.5 °C. Special attention is needed for the reduction of greenhouse gas (GHG) emission from enteric fermentation and manure storage. However, the main challenge for the future is to find a balanced set of measures to integrally reduce all the sources of GHG emission within the carbon footprint of milk.
Background The palatine tonsils are part of the mucosal immune system and stimulate immune responses through M cell uptake sampling of antigens and bacteria in the tonsillar crypts. Little is known about the development of the tonsillar microbiota and the factors determining the establishment and proliferation of disease-associated bacteria such as Streptococcus suis. In this study, we assessed tonsillar microbiota development in piglets during the first 5 weeks of life and identified the relative importance of maternal and environmental farm parameters influencing the tonsillar microbiota at different ages. Additionally, we studied the effect sow vaccination with a bacterin against S. suis on microbiota development and S. suis colonisation in their offspring. Results Amplicon sequencing of the 16S rRNA gene V3-V4 region revealed that a diverse tonsillar microbiota is established shortly after birth, which then gradually changes during the first 5 weeks of life without a large impact of weaning on composition or diversity. We found a strong litter effect, with siblings sharing a more similar microbiota compared to non-sibling piglets. Co-housing in rooms, within which litters were housed in separate pens, also had a large impact on microbiota composition. Sow parity and prepartum S. suis bacterin vaccination of sows had weaker but significant associations with microbiota composition, impacting on the abundance of Streptococcus species before and after weaning. Sex and birthweight had limited impact on the tonsillar microbiota, and none of the measured factors had consistent associations with microbiota diversity. Conclusions The piglet tonsillar microbiota is established shortly after birth. While microbiota development is associated with both environmental and maternal parameters, weaning has limited impact on microbiota composition. Intramuscular vaccination of sows pre-partum had a significant effect on the tonsillar microbiota composition of their piglets. These findings provide new insights into the mechanisms shaping the tonsillar microbiota.
With an increased knowledge of the mechanism of action of Fusarium mycotoxins, the concept that these substances are deleterious only for monogastric species is obsolete. Indeed, most mycotoxins can be converted into less toxic compounds by the rumen microflora from healthy animals. However, mycotoxin absorption and its conversion to more toxic metabolites, as well as their impact on the immune response and subsequently animal welfare, reproductive function, and milk quality during chronic exposure should not be neglected. Among the Fusarium mycotoxins, the most studied are deoxynivalenol (DON), zearalenone (ZEN), and fumonisins from the B class (FBs). It is remarkable that there is a paucity of in vivo research, with a low number of studies on nutrient digestibility and rumen function. Most of the in vitro studies are related to the reproductive function or are restricted to rumen incubation. When evaluating the production performance, milk yield is used as an evaluated parameter, but its quality for cheese production is often overlooked. In the present review, we summarize the most recent findings regarding the adverse effects of these mycotoxins with special attention to dairy cattle.
Reducing dietary crude protein (CP) level is recognised to reduce postweaning (PW) diarrhoea in piglets but it should not limit growth performance. The objective of this study was to explore the effects of reducing dietary CP level at two standardized ileal digestible lysine (SIDLys) levels on the growth performance of weaned piglets. Our hypothesis is that, as soon as the amino acids (AA) profile is balanced, reducing the dietary CP level does not affect growth performance, regardless of the SIDLys level. At weaning (29 days old, ∼8.3 kg), 432 piglets were allocated to six treatments (12 pens of six piglets per treatment) during a prestarter (d0-d14) and a starter (d15-d35) period. A 2×3 factorial arrangement aimed at testing two levels of SIDLys (1.07% or 1.25% SIDLys in prestarter, 1.0% or 1.17% SIDLys in starter) and three levels of CP, designed to maintain the SIDLys:CP ratio for each of the two SIDLys levels at 6.4%, 6.7% or 7.0% in prestarter, and 6.2%, 6.4% or 6.6% in starter. All diets were isoenergetic (9.8 MJ NE/kg in prestarter, 9.2 MJ NE/kg in starter) and with a balanced AA profile. Piglets were weighed individually at the start, at feed change, and at the end. The average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) were calculated per pen. The SIDLys ×CP interaction was not significant for any parameter. For the complete PW phase, increasing SIDLys yielded a significant gain of 80 g/d in ADG (P<0.01) and −0.17 in FCR (P< 0.01), resulting in +2.8 kg live weight at d35 PW (P<0.01). Dietary CP reduction had no effect on ADFI, ADG, FCR or final weight. In conclusion, growth performance are maintained when dietary CP level is reduced with a balanced AA profile, regardless of the SIDLys level.
This study evaluated the effects of different concentrations (10, 20, or 40 μM) of eugenol (EUG 10, EUG 20, or EUG 40), ascorbic acid (50 μg/mL; AA) or anethole (300 μg/mL; ANE 300) on the in-vitro survival and development of goat preantral follicles and oxidative stress in the cultured ovarian tissue. Ovarian fragments from five goats were cultured for 1 or 7 days in Alpha Minimum Essential Medium (α-MEM+) supplemented or not with AA, ANE 300, EUG 10, EUG 20 or EUG 40. On day 7 of culture, when compared to MEM, the addition of EUG 40 had increased the rate of follicular development, as observed by a decrease in the proportion of primordial follicles alongside with an increase in the rate of normally developing follicles. Furthermore, EUG 40 significantly increased both follicular and oocyte diameters. Subsequently, ovarian fragments from three goats were cultured for 1 or 7 days in α-MEM+ supplemented or not with AA, ANE 300 or EUG 40. All tested antioxidants, except ANE 300, were able to significantly decrease the levels of reactive oxygen species in the ovarian tissue, but EUG 40 could most efficiently neutralize free radicals. All ovarian tissues cultured in the presence of antioxidants, especially EUG 40, presented a significant decrease in H3K4me3 labeling, indicating a silencing of genes that play a role in the inhibition of follicular activation and apoptosis induction. When compared to cultured control tissues, both EUG 40 and ANE 300 significantly increased the intensity of calreticulin labeling in growing follicles. The mRNA relative expression of ERP29 and KDM3A was significantly increased when the culture medium was supplemented with EUG 40, indicating a response to ER stress experienced during culture. In conclusion, EUG 40 improved in-vitro follicle survival, activation and development and decreased ROS production, ER stress and histone lysine methylation in goat ovarian tissue.
Nonanoic acid (NA) is one of a group of straight-chain aliphatic aldehydes, acids and their derivatives with a long and established history of use as flavors in human food and animal feed. The use of this group of flavors in feed was evaluated by the European Food Safety Authority (EFSA) in 2013 and in the absence of data in the target species, maximum safe levels were derived from available toxicology studies of 12 mg for piglets and 20 mg for grower/finisher pigs and sows per kg complete feed containing 120 g/kg moisture. These established safe levels limit the practical use of NA as a flavoring in swine diets and the objective of this study was to evaluate the tolerance to piglets of NA at significantly higher dietary levels that are relevant to commercial feeding practices. Three hundred eighty four (192 males, 192 females), cross bred [Tempo x (Large White x Landrace)] post-weaned piglets with an initial body weight (BW) of between 6.5 and 8.5 kg and age of 26 days were used in a 42-day tolerance study. Piglets were randomly assigned to one of 64 pens containing either 6 males or 6 females. One of 4 dietary treatments were fed to the piglets containing NA at 0, 100, 300 or 1,000 mg/kg complete feed. General health and performance were monitored for the duration of the study. At day 42, blood samples were taken and piglets were sacrificed and necropsied for pathological examination of the digestive tract. NA supplementation had no effect (P > 0.05) on the daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) or fecal consistency over the 42-day period. No treatment related effects (P > 0.05) on hematology or blood biochemistry parameters were reported and all values fell within normal ranges. There were no treatment-related findings from macroscopic and microscopic examination of digestive tissues. The results of the study support the tolerance to piglets of NA in feed treated with 1,000 mg /kg complete feed of which 720 mg/kg was recovered, which is considerably higher than anticipated practical conditions of use as a feed flavoring.
Different combinations of gut health-promoting dietary interventions were tested to support broilers during different stages of Eimeria infection. One-day-old male Ross 308 broilers (n=720) were randomly assigned to one of six dietary treatments, with six pens per treatment and 20 birds per pen, for 35 days. At 7 days of age (d7), all birds were inoculated with 1000, 100, and 500 sporulated oocysts of E. acervulina, E. maxima, and E. tenella, respectively. A four-phase feeding schedule was provided. The dietary treatments (TRT) 1–4 included the basal diet supplemented with multi-species probiotics from d0–9 and coated butyrate and threonine from d28–35 but received four different combinations of prebiotics and phytochemicals from d9–18 and d18–28. The basal diet for the positive control (PC, TRT5) included diclazuril as a anticoccidial. The negative control (NC, TRT6) contained no anticoccidial. Performance was assessed for each feeding phase, and oocyst output, Eimeria lesion scores, cecal weight, litter quality, and footpad lesions were assessed at d14, d22, d28, and d35. Body weight gain (BWG) and feed intake (FI) were not affected by dietary treatment. PC broilers had the best feed conversion ratio (FCR) of all treatments from d0–35 (P < 0.001). None of the dietary treatments resulted in better litter quality or reduced footpad lesions compared to the PC. Moreover, the PC was most effective in reducing oocyst output and lesion scores compared to all other treatments. However, broilers that received the multispecies probiotics (d0–9), saponins (d9–18), saponins, artemisin, and curcumin (d18–28), and coated butyrate and threonine (d28–35) had the best FCR (P < 0.001) and lowest oocyst output and lesion scores compared to other dietary treatments. This study suggests that although the tested compounds did not perform as well as the anticoccidial, when applied in the proper feeding period, they may support bird resilience during coccidiosis infection.
Several factors predisposing to necrotic enteritis (NE) have been identified, including diet and Eimeria spp. infestations. Coccidiosis vaccines are indicated to decrease the intestinal lesions caused by specific Eimeria species that are a known predisposing factor to NE and, consequently, these vaccines could be a holistic approach to the control of NE disease and an alternative solution to coccidiostats. Besides, feed additives have also gained special attention from the poultry industry as an alternative solution to antibiotics to prevent NE as well as other bacterial enteritis. Then, the combination of vaccination against coccidiosis and the supplementation of the diet with feed additives could be a composite approach to the control of NE problems triggered by Eimeria spp. infestation. The objective of this study was to test the efficacy of an attenuated coccidiosis vaccine (EVANT®) in combination with different feed additives to prevent the loss of production performance and intestinal lesions in broilers challenged with NE. Healthy day-old broilers (n=960) were randomly allocated to 6 groups (8 cages/group). Groups 1-2 were left unvaccinated. Groups 3-6 were vaccinated following the manufacturer’s instructions. Chickens were grown using a diet favoring the intestinal proliferation of Clostridium perfringens. Moreover, the diets of groups 4-6 were supplemented with Medium Chain Fatty Acids (MCFA), butyric acid or phytogenic feed additives (PFA) respectively. A NE infection model was used to challenge groups 2-6; chickens were orally infected with Eimeria maxima (4,500 oocysts) and then C. perfringens (108 CFU) at 15 and 20 days, respectively. Birds were monitored and productive parameters recorded until 42 days; intestinal lesions were scored. Results showed that coccidiosis vaccination, with or without the addition of feed additives, decreased intestinal lesions associated with NE and improved the performance of the birds. Besides, the addition of MCFA to the diet decreased intestinal lesions associated to NE in vaccinated animals compared to all treatment groups. Moreover, the same additive improved the feed conversion rate. Therefore, vaccination with a live attenuated coccidiosis vaccine together with in-feed inclusion of MCFA might be a solution to reduce NE in broilers raised antimicrobial- and coccidiostat-free.
Removal of inorganic phosphate (Pi) from broiler diets could improve sustainability in poultry production. Small-scale studies of total Pi replacement by a novel consensus bacterial 6-phytase variant have been promising but larger scale studies are needed. In this study, effects of four diets on growth performance and bone quality were evaluated: PC1, nutritionally adequate and containing Pi without enzyme supplementation; PC2, as PC1 but containing xylanase (2,000 units (XU)/kg) and 75 kcal/kg reduction in ME; IPF1 and IPF2, as PC1 and PC2, respectively, formulated without Pi and 1.5 g/kg reduction in Ca, containing phytase at 3,000, 2,000 and 1,000 phytase units (FTU)/kg during starter (1-10 d), grower (10-22 d) and finisher (22-37 d) phases. A randomized complete block design used 820 Ross 308 mixed-sex birds/pen and 8 pens/diet. The phytase in IPF diets maintained all growth performance parameters, per phase and cumulatively, equivalent to the respective PC. Contrast analysis of pooled PC vs. pooled IPF data showed that phytase in IPF diets reduced or maintained FCR during all phases and cumulatively (-5.0 points during 22-37 d and -3.0 points during 1-37 d; P < 0.05). Tibia ash at d 21 and 36 was not different in birds fed IPF and PC diets, but tibia breaking strength was higher in birds fed IPF diets (+6.6% and +1.3%, respectively; P < 0.05). Overall (0-37 d), total feed costs per kilogram BW gain were reduced (P < 0.05) in the phytase supplemented IPF diets vs. PC diets under commercial broiler production conditions.
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22 members
Regiane R. Santos
  • Research & Development
Hassan Taweel
  • Ruminants Nutrition
Wilfried van Straalen
  • Ruminant Research
Lelystad, Netherlands