Rekentool voor het bepalen van de effecten van voer- en management-maatregelen op de ammoniakemissie bij varkens: ontwikkeling en validatie

A calculation model was developed to determine the effect of housing, dietary and management measures on the ammonia emission from houses for growing-finishing pigs, weaned piglets and pregnant sows. On Pig Innovation Centre Sterksel measurements were done for further development and validation of the model

Het effect van twice-a-day-feeding en splitfeeding op reproductie, eischaalkwaliteit en gedrag van vleeskuikenouderdieren

In dit rapport worden de resultaten gepresenteerd van een studie naar het toepassen van split-feeding (= verschillend ochtend- en middagvoer) en twice-a-day-feeding (= 2 keer per dag eenzelfde standaard voer) ten opzichte van eenmaal daags voeren (standaard voer) bij vleeskuikenouderdieren tijdens de late legperiode (van 45-65 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 de dieren die het split-feeding programma volgden tussen 45 en 65 weken leeftijd een hogere productie en lagere uitval hadden. Daarnaast werden bij de tweemaal daags gevoerde dieren (twice-a-day-feeding en split-feeding) een lagere wateropname en lagere water/voer-verhouding gevonden. Het toepassen van tweemaal daags voeren (twice-a-day-feeding en split-feeding) had nauwelijks effect op broedeikwaliteit en geen effect op de broederijresultaten. Bij de tweemaal ten opzichte van eenmaal daags gevoerde dieren werd een ander gedragspatroon gedurende de dag waargenomen. De tweemaal daags gevoerde dieren kregen tweemaal daags een halve portie voer, hetgeen de belangrijkste factor was voor de verschillen in het gedragspatroon. Het was niet helemaal eenduidig maar de tweemaal daags gevoerde dieren (twice-a-day-feeding en split-feeding) vertoonden in gemiddeld: minder drinken, meer staan, minder zitten, meer lopen en minder foerageren

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

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 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

Abomasal infusion of corn starch and β-hydroxybutyrate in early-lactation Holstein-Friesian dairy cows to induce hindgut and metabolic acidosis

The objectives of this study were to induce hindgut and metabolic acidosis via abomasal infusion of corn starch and β-hydroxybutyrate (BHB), respectively, and to determine the effects of these physiological states in early-lactation dairy cows. In a 6 × 6 Latin square design, 6 rumen-fistulated Holstein-Friesian dairy cows (66 ± 18 d in milk) were subjected to 5 d of continuous abomasal infusion treatments followed by 2 d of rest. The abomasal infusion treatments followed a 3 × 2 factorial design, with 3 levels of corn starch and 2 levels of BHB. The infusions were water as control, 1.5 kg of corn starch/d, 3.0 kg of corn starch/d, 8.0 mol BHB/d, 1.5 kg of corn starch/d + 8.0 mol BHB/d, or 3.0 kg of corn starch/d + 8.0 mol BHB/d. A total mixed ration consisting of 35.0% grass silage, 37.4% corn silage, and 27.6% concentrate (on a dry matter basis) was fed at 90% of ad libitum intake of individual cows. The experiment was conducted in climate respiration chambers to facilitate determination of energy and N balance. Fecal pH decreased with each level of corn starch infused into the abomasum and was 6.49, 6.00, and 5.15 with 0.0, 1.5, and 3.0 kg of corn starch/d, respectively, suggesting that hindgut acidosis was induced with corn starch infusion. No systemic inflammatory response was observed and the permeability of the intestine or hindgut epithelium was not affected by the more acidic conditions. This induced hindgut acidosis was associated with decreased digestibility of nutrients, except for crude fat and NDF, which were not affected. Induced hindgut acidosis did not affect milk production and composition and energy balance, but increased milk N efficiency. Abomasal infusion of BHB resulted in a compensated metabolic acidosis, which was characterized by a clear disturbance of acid-base status (i.e., decreased blood total CO2, HCO3, and base excess, and a tendency for decreased urinary pH), whereas blood pH remained within a physiologically normal range. Abomasal infusion of BHB resulted in increased concentrations of BHB in milk and plasma, but both remained well below the critical threshold values for subclinical ketosis. Induced compensated metabolic acidosis, as a result of abomasally infused BHB, increased energy retained as body fat, did not affect milk production and composition or inflammatory response, but increased intestinal permeability

Effect van voersamenstelling op bijtgedrag bij varkens

Op Varkens Innovatie Centrum Sterksel is onderzocht of bijtgedrag (staart-, oor- en flankbijten) en staart- en oorschade bij dieren met intacte (niet gecoupeerde) staarten verminderd kunnen worden door de dieren vanaf enkele dagen na geboorte tot afleveren naar het slachthuis voer met extra vezels (verzadigend voer) en/of voer met extra aminozuren (tryptofaan, threonine en methionine) te geven. De resultaten van het onderzoek zijn beschreven in dit rapport

Birth weight affects body protein retention but not nitrogen efficiency in the later life of pigs

Exploring factors that might affect nitrogen (N) efficiency in pigs could support the development of precision feeding concepts. Therefore, an experiment was conducted to determine the effects of birth weight (BiW) on N retention, N efficiency, and concentrations of metabolites in plasma and urine related to N efficiency in male pigs of 14 wk of age. BiW of the low BiW (LBW) and high BiW (HBW) pigs was 1.11 ± 0.14 and 1.79 ± 0.12 kg, respectively. Twenty LBW and 20 HBW pigs were individually housed in metabolism cages and were subjected to an N balance study in two sequential periods of 5 d, after an 11-d adaptation period. Pigs were assigned to a protein adequate (A) or protein restricted (R, 70% of A) regime in a change-over design and fed restrictedly 2.8 times the energy requirements for maintenance. Nontargeted metabolomics analyses were performed in urine and blood plasma samples. The N retention in g/d was higher in the HBW than in the LBW pigs (P < 0.001). The N retention in g/(kg BW0.75·d) and N efficiency (= 100% × N retention / N intake), however, were not affected by BiW of the pigs. Moreover, fecal digestibility of N and urinary concentration of N and urea were not affected by BiW of the pigs. The concentration of insulin (P = 0.08) and insulin-like growth factor-1 (IGF-1;P = 0.05) in blood plasma was higher in HBW pigs, whereas the concentration of α-amino N tended to be lower in HBW pigs (P = 0.06). The LBW and HBW pigs could not be discriminated based on the plasma and urinary metabolites retrieved by nontargeted metabolomics. Restricting dietary protein supply decreased N retention (P < 0.001), N efficiency (P = 0.07), fecal N digestibility (P < 0.001), urinary concentration of N and urea (P < 0.001), and concentration of urea (P < 0.001), IGF-1 (P < 0.001), and α-amino N (P < 0.001) in blood plasma. The plasma and urinary metabolites differing between dietary protein regime were mostly amino acids (AA) or their derivatives, metabolites of the tricarboxylic acid cycle, and glucuronidated compounds, almost all being higher in the pigs fed the A regime. This study shows that BiW affects absolute N retention but does not affect N efficiency in growing pigs. Therefore, in precision feeding concepts, BiW of pigs should be considered as a factor determining protein deposition capacity but less as a trait determining N efficiency.</p

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

3-Nitrooxypropanol decreases methane emissions and increases hydrogen emissions of early lactation dairy cows, with associated changes in nutrient digestibility and energy metabolism

The aim of this study was to determine the methane (CH4) mitigation potential of 3-nitrooxypropanol and the persistency of its effect when fed to dairy cows in early lactation. Sixteen Holstein-Friesian cows (all multiparous; 11 cows in their second parity and 5 cows in their third parity) were blocked in pairs, based on actual calving date, parity, and previous lactation milk yield, and randomly allocated to 1 of 2 dietary treatments: a diet including 51 mg of 3-nitrooxypropanol/kg of dry matter (3-NOP) and a diet including a placebo at the same concentration (CON). Cows were fed a 35% grass silage, 25% corn silage, and 40% concentrate (on dry matter basis) diet from 3 d after calving up to 115 d in milk (DIM). Every 4 weeks, the cows were housed in climate respiration chambers for 5 d to measure lactation performance, feed and nutrient intake, apparent total-tract digestibility of nutrients, energy and N metabolism, and gaseous exchange (4 chamber visits per cow in total, representing 27, 55, 83, and 111 DIM). Feeding 3-NOP did not affect dry matter intake (DMI), milk yield, milk component yield, or feed efficiency. These variables were affected by stage of lactation, following the expected pattern of advanced lactation. Feeding 3-NOP did not affect CH4 production (g/d) at 27 and 83 DIM, but decreased CH4 production at 55 and 111 DIM by an average of 18.5%. This response in CH4 production is most likely due to the differences observed in feed intake across the different stages of lactation because CH4 yield (g/kg of DMI) was lower (on average 16%) at each stage of lactation upon feeding 3-NOP. On average, feeding 3-NOP increased H2 production and intensity 12-fold; with the control diet, H2 yield did not differ between the different stages of lactation, whereas with the 3-NOP treatment H2 yield decreased from 0.429 g/kg of DMI at 27 DIM to 0.387 g/kg of DMI at 111 DIM. The apparent total-tract digestibility of dry matter, organic matter, neutral detergent fiber, and gross energy was greater for the 3-NOP treatment. In comparison to the control treatment, 3-NOP did not affect energy and N balance, except for a greater metabolizable energy intake to gross energy intake ratio (65.4 and 63.7%, respectively) and a greater body weight gain (average 0.90 and 0.01% body weight change, respectively). In conclusion, feeding 3-NOP is an effective strategy to decrease CH4 emissions (while increasing H2 emission) in early lactation Holstein-Friesian cows with positive effects on apparent total-tract digestibility of nutrients.</p