Effect van een kruidenextract op berengeur, agressief en seksueel gedrag bij biologische varkens

An experiment with 273 entire males was conducted on an organic pig farm. Half of these males received a herbal extract in the drinking water to reduce mounting behaviour and boar taint. The herbal extract did not affect sexual behaviour and boar taint. Only two carcasses (0,7%) had a typical boar taint. However a complete change towards non castration for organic pigs is not yet applicable partly because of international trade difficulties. A follow up study will be prepare

Voorkeur voor verhoogde rustplaats bij vleeskuikenouderdieren

In dit rapport worden de resultaten gepresenteerd van een studie naar de rustplaats preferentie van vleeskuikenouderdieren tijdens de legperiode, waarbij de dieren konden kiezen tussen roosters en zitstokken. Daarnaast konden de dieren op het strooisel, de drinklijn of in het legnest overnachten. Dit experiment is uitgevoerd in opdracht van het Consortium Breeders In Balance en het Ministerie van Landbouw, Natuur en Voedselkwaliteit. Uit de preferentietest met verschillende rustplaatsen blijkt dat ouderdieren een duidelijke voorkeur hebben voor een rooster in vergelijking met een zitstok om ’s nachts op te rusten. Daarnaast verbleef een groot deel van de dieren door de tijd heen ’s nachts consistent op hun geprefereerde rustplaats. De rustplaats blijkt ook invloed op het welzijn van de dieren te hebben. Bij de dieren op de zitstokken en drinklijn werden, t.o.v. het rooster meer en grotere borstblaren aangetroffen

Split-feeding en twice a day-feeding voeren bij vleeskuikenouderdieren

In dit rapport worden de resultaten gepresenteerd van een studie naar het toepassen van split-feeding (= apart ochtend- en middagvoer) en twice a day-feeding (standaard voer) t.o.v. eenmaal daags voeren (standaard voer) bij vleeskuikenouderdieren tijdens de late legperiode (van 50 - 60 weken leeftijd). Dit experiment is uitgevoerd in opdracht van het Consortium Breeders In Technology (BITe) en het Ministerie van Landbouw, Natuur en Voedselkwaliteit. Uit het onderzoek blijkt dat dieren die split-feeding kregen een hogere productie hadden tussen 51 en 55 weken leeftijd. Verder gaf het toepassen van tweemaal daags voeren (twice a day-feeding en split-feeding) nauwelijks effecten op productie en broedeikwaliteit. Wel werd bij de verschillende voerstrategieën een duidelijk ander gedragspatroon gedurende de dag waargenomen. De tweemaal daags gevoerde dieren (twice a day-feeding en split-feeding) vertoonden t.o.v. eenmaal daags gevoerde dieren meer eet en rust gedrag en minder foerageer en pik gedrag. Verder onderzoek met een aangepaste opzet van het experiment is wenselijk om uit te zoeken wat de voordelen op reproductie, broedeikwaliteit en gedrag zijn van split-feeding en twice a day-feeding

Weinig verschil in verteerbaarheid

De verteringscoëfficiënten van gangbare grondstoffen voor leghennen kunnen ook worden toegepast op biologische grondstoffen. In onderzoek vonden Schothorst Feed Research en Wageningen Livestock Research slechts kleine verschillen in de verteerbaarheid van fosfor, stikstof en omzetbare energie tussen biologische en gangbare mengvoergrondstoffen voor leghennen

Weinig verschil in verteerbaarheid

De verteringscoëfficiënten van gangbare grondstoffen voor leghennen kunnen ook worden toegepast op biologische grondstoffen. In onderzoek vonden Schothorst Feed Research en Wageningen Livestock Research slechts kleine verschillen in de verteerbaarheid van fosfor, stikstof en omzetbare energie tussen biologische en gangbare mengvoergrondstoffen voor leghennen

Effect of solid feed level and types of roughage on passage kinetics of milk replacer, concentrates, and roughage in veal calves

The aims of this study were (1) to determine the effect of solid feed (SF) level and type of roughage on passage kinetics of milk replacer (MR), concentrates, roughage in veal calves, and (2) to compare passage kinetics of concentrates measured by the fecal excretion curves of indigestible markers with the non-invasive 13C tracer breath test. In total, 48 Holstein-Friesian calves (6 weeks of age; 68 ± 7.7 kg of BW) were assigned to 1 of the 4 dietary treatments. Three treatments contained chopped straw as roughage in the SF mixture in a concentrate to roughage ratio of 90:10 (as fed). The SF level varied, being 20 g/kg BW0.75/d (LowSF), 30 g/kg BW0.75/d (MiddleSF), or 40 g/kg BW0.75/d (HighSF). The fourth treatment (Hay) contained long hay as roughage in the SF mixture in a concentrate to roughage ratio of 70:30 (as fed). The SF level of the Hay treatment was similar to the HighSF treatment, viz. 40 g/kg BW0.75/d. The quantity of MR was fixed for the HighSF treatment (i.e., 39 g/kg BW0.75/d) and during the adaptation period, the amount of MR for the other treatments was calculated based on a pair gain strategy, to achieve comparable body weight gain (BWG) across treatments. Passage kinetics were estimated using the recovery of 13C from a pulsed-dose [1-13C]octanoate with the concentrate or a pulsed-dose low-enriched bacterial protein in the concentrate, in breath measured in respiration chambers. The estimated time to peak enrichment was corrected for the time to peak enrichment following an intravenous injection of [13C]sodium bicarbonate. Passage kinetics were estimated from fecal excretion curves obtained after ingestion of the chromium-mordanted straw (i.e., for LowSF, MiddleSF, and HighSF treatments) or hay (i.e., for Hay treatment) as a marker for the roughage, 2 g of Ytterbium(II)Oxide as a marker for concentrate, and 9 g of cobalt(II)EDTA as a marker for the MR. The results of the fecal excretion curves show that the total-tract retention of MR was, on average, 12.4 h, and that the passage kinetic of MR was not affected by the level of SF. Additionally, the total-tract retention of concentrates was shorter (on average 21.4 h) than that of both straw (59.1 h) and hay (36.8 h), and was not affected by the level of SF. Furthermore, the passage of roughage, both through the rumen and through the total digestive tract, was affected by level of SF as well as type of roughage. Long hay increased time to peak by (on average) 22.3h (P = 0.004) relative to the chopped straw containing treatments. Hence, the passage rate of long hay is higher and subsequently the mean retention time in the gastro-intestinal tract shorter than that of chopped straw. Additionally, the fractional passage rate of the slowest compartment was related with SF level (r = -0.32, P = 0.049), suggesting that the fractional passage rate of the rumen decreases with increasing SF level likely due to the effect of SF level on rumen volume. The results of the 13C breath test show that [1-13C]octanoate cannot serve as an alternative to measure passage kinetics of concentrates through the digestive tract of veal calves. Overall, this study provides estimates of digesta passage kinetics of MR, concentrates and roughage that can be used in digestion modelling. It is concluded that the potential interactions between MR and SF occurring in the gastro-intestinal tract, do not complicate the prediction of the nutritional value of these ration components, and that the non-invasive 13C tracer breath test approach cannot serve as an alternative to the fecal excretion curves of indigestible markers to determine passage kinetics of concentrates in veal calves

Effect of solid feed level and types of roughage on nitrogen and energy balance and circadian activity patterns in veal calves

Het effect van de hoeveelheid ruw- en krachtvoer en van het type ruwvoer op de energie- en stikstof huishouding en circadiane activiteit patronen van vleeskalveren

Effect of Feeding 0.8% Dried Powdered Chlorella vulgaris Biomass on Growth Performance, Immune Response, and Intestinal Morphology during Grower Phase in Broiler Chickens

An experiment was performed to study the effects of a low inclusion level of Chlorella vulgaris (CV) biomass in broiler diets on performance, immune response related to inflammatory status, and the intestinal histomorphology. The study was performed with 120 Ross 308 male broiler chickens from 0–35 days of age. The broilers were housed in 12 floor pens (1.5 m2) bedded with wood shavings. The broilers received a three phase diet program, either with 0.8% CV biomass (CV) or without CV (CON). Each diet program was replicated in six pens. The final body weight increased (p = 0.053), and the feed conversion ratio (FCR), corrected for body weight, was reduced (p = 0.02) in birds fed CV compared to birds fed CON. In addition, decreased haptoglobins (p = 0.02) and interleukin-13 (p < 0.01) responses were observed during the grower phase of birds fed CV compared to the birds fed CON. A strong correlation (r = 0.82, p < 0.01) was observed between haptoglobin response and FCR. Histomorphology parameters of the jejunum were not different between the groups. It was concluded that the inclusion of 0.8% CV biomass in broiler diets is effective in influencing immune responses related to inflammatory status and promoting broiler growth

Effect of solid feed level and types of roughage on passage kinetics of milk replacer, concentrate, and roughage in veal calves

This study aimed (1) to provide estimates of total mean retention times of milk replacer (MR), concentrates, and roughage in veal calves fed a mixed diet; (2) to determine the effect of level and type of solid feed (SF) on passage kinetics of MR, concentrates, and roughages in veal calves; and (3) to compare passage kinetics in veal calves using the fecal excretion curves of indigestible markers and a noninvasive 13C tracer breath test approach to determine whether the latter technique can serve as an alternative. At the start of the trial, 48 Holstein-Friesian calves (6 wk of age; 68 ± 7.7 kg of body weight; BW) were assigned to 1 of 4 dietary treatments (for statistical analysis, only 39 calf observations were used). Three treatments contained chopped wheat straw as roughage in the SF mixture in a concentrate:roughage ratio of 90:10 (dry matter basis). The SF level was 20 g/kg of metabolic BW per day (low straw), 30 g/kg of metabolic BW per day (middle straw), or 40 g/kg of metabolic BW per day (high straw). The fourth treatment (high hay) contained long perennial ryegrass hay as roughage in the SF mixture in a concentrate:roughage ratio of 70:30 (dry matter basis, at 40 g/kg of metabolic BW per day). The quantity of MR was fixed for the high straw treatment, whereas the amount of MR for the other treatments during the adaptation period was adjusted based on a pair gain strategy (i.e., exchanging ration components but keeping similar net energy). At the end of the adaptation period, calves ranged from 12 to 15 wk of age with an average BW of 123 ± 8.6 kg. Passage kinetics of concentrates were estimated by measuring 13C enrichment excess of CO2 in breath from a pulsed-dose of [1-13C]octanoate. Passage kinetics of roughage, concentrates, and MR were also estimated using fecal excretion curves obtained after ingestion of chromium-mordanted roughage, Yb2O3, and Co-EDTA, respectively. We conclude that [1-13C]octanoate cannot serve as a measure for oro-duodenal transit of concentrates because of unrealistic estimates. Based on the fecal excretion curves, we concluded that the total mean retention time of MR (i.e., time to peak; the moment that the excretion curve reaches peak concentration) was, on average, 12.4 h, and that the passage kinetics of MR was not affected by the level or type of SF. The mean retention time of concentrates was shorter (21.4 h) than that of both straw (59.1 h) and hay (36.8 h), and was not affected by the level or type of SF. Also, the mean retention time of the slowest compartment (i.e., the rumen) was shorter for concentrates (39.6 h) than that of straw (110.0 h) and hay (59.2 h). Contrary, the passage of roughage was affected by level and type of SF. Long hay increased time to peak by 22.3 h and decreased ruminal mean retention time by 50.8 h relative to chopped straw, indicating that the passage rate of long hay is faster than that of chopped straw. We conclude that the level and type of SF only affects the passage kinetics of roughage and not that of MR and concentrates