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Two short-term grazing experiments were conducted with Norwegian Red cows. In Exp 1, 24 cows were randomly assigned to one of the following three pasture allocation methods (PAM): weekly pasture allowance (7RG), grazing 1/7 of 7RG each day (1SG), or grazing as 1SG but had access to grazed part of the paddock within one week (1FG). In Exp 2, 7RG was shortened to 5 days (5RG). We hypothesized that PAM will affect sward quality, quantity, intake and production differently. Pasture chemical composition changed with advancing grazing days but were not different between treatments. Pasture intake, milk yield, and methane emission were not affected by PAM. In Exp 1, 7RG cows spent less time on grazing, whereas in Exp 2, 1FG cows spent longer on grazing than others. Patterns observed in sward quality, and behavioural and physiological adaptations of cows to short-term changes in nutrient supply may explain the observed effects. [ABSTRACT FROM AUTHOR]

The main objective of this study was to investigate the effect of supplementing a pasture diet with crushed rapeseed on enteric methane (CH4) emissions from lactating dairy cows. The experiment was conducted as a crossover design using eight multiparous lactating Norwegian red dairy cows [(means ± s.d.) 548 ± 52 kg bodyweight, 38 ± 14 days in milk and 35 ± 3.7 kg milk/day, at the start of the experiment] maintained in two groups and fed two diets in two periods with the second period extended (18 days) to investigate the persistence of the CH4 response. Four of the eight cows were fitted with a rumen cannula with two cannulated cows assigned to each group. Cows were maintained on pasture (24 h/day) with access to 9 kg/day of concentrate containing 10% crushed rapeseed (RSC) or a control concentrate (CC). Dietary fat content was 63 g/kg dry matter for RSC and 42 g/kg dry matter for CC. The CH4 production was measured for five consecutive days in each period using the sulfur hexafluoride tracer gas technique. Compared with CC, RSC caused a reduction in enteric CH4 emission (221 vs 251 g/day and 8.1 vs 9.0 g/kg of energy-corrected milk), and this response persisted in the extension period. Cows fed RSC had higher milk yield compared with cows fed CC (31.7 vs 29.6 kg/day). However, milk fat and protein content were lower in milk from cows fed RSC than CC. Therefore, energy-corrected milk was not affected by treatment. Feeding RSC lowered milk fat content of palmitic acid compared with CC. The study showed that adding crushed RSC to the diet can be an effective means of reducing CH4 emissions from lactating dairy cows on pasture, without negatively affecting milk production. [ABSTRACT FROM AUTHOR]

Dairy milk samples from 37 milk tours in 15 areas of Norway were collected during indoor feeding or on pasture in 2008 and analyzed with respect to 6 major elements (Ca, P, K, S, Na, Mg) and 28 trace elements (As, Ba, Be, Bi, Cd, Ce, Co, Cr, Cs, Cu, Dy, Fe, I, La, Li, Mn, Mo, Nd, Pb, Rb, Sb, Se, Sm, Sr, V, Y, Yb and Zn). Surprisingly, the least-square means of major and trace elements in milk did not vary much from one region to another. The concentration levels of iodine, copper, manganese and lithium in milk from the northern region were higher compared with milk from other regions. Milk from the south was enriched with respect to selenium, yttrium, cerium and bismuth, while milk from the western region was enriched with respect to rubidium. [ABSTRACT FROM AUTHOR]

To evaluate the iodine (I) level in Norwegian milk, the I concentration was determined in 104 dairy tanker milk samples collected from 19 milk tours in different areas of Norway, throughout the year 2008. The I concentration in milk from indoor feeding was 122 µg L−1and higher than in milk from the summer season, being 92 µg L−1. The weighted average mean I concentration throughout the year was 114 µg L−1milk. The results showed that the I concentration in milk from the winter season 2008 has been reduced to nearly the half during the last decade, from 232 µg I L−1in milk collected in the winter season in 2000. The I concentration in milk from the summer season is at the same level as a decade ago. The reason for the reduction in I in milk produced during the winter season is not known. [ABSTRACT FROM PUBLISHER]

Production of animal feed pellets with uniform, predictable, and good technical pellet quality is challenging. The objective of this work was to investigate water adsorption in dry ingredients and in mixture of dry ingredients commonly used in animal feed. Rehydration at 20 and 80°C and water adsorption in moist air at 80°C were studied. Ingredients studied were soybean meal, wheat, barley, dehulled oats, rapeseed cake, sugar beet pulp, maize, and wheat bran. The ingredients were milled fine (< 0.5 mm) or coarse (> 0.5 mm). Results show that the chemical composition of ingredients and the physical state of water affect water adsorption. A combination of steam and water should be used to optimize production of pelletized feed. The combination of a fine degree of milling, high temperature, and a long residence time favor the water adsorption process for most of the dry ingredients. For mixtures of dry ingredients, the individual chemical composition of each ingredient could be as important as physical factors such as particle size, temperature, and residence time in water. [ABSTRACT FROM AUTHOR]

A three-step in vitro procedure was developed by Calsamiglia and Stern [J. Anim. Sci. 73 (1995) 1459] to estimate intestinal protein digestion after 16 h incubation in the rumen. The objective of our work was to modify this procedure to give an accurate estimation of N digestibility without the use of surgically modified animals by replacing the rumen incubation step by an in vitro protease enzyme incubation, and the use of small nylon bags for samples instead of the time-consuming filtration step. The results were compared with those from mobile nylon bag studies or ADIN determinations. In addition, the effect of heat treatment of grains and soybean on protein digestibility was investigated.Briefly, samples were weighed into small nylon bags, sealed, and a maximum of 30 bags were placed in a 2.4 l bottle containing borate–phosphate buffer at 39 °C. After 1 h, protease solution (protease type xiv, Streptomyces griseus) was added. After 4 h, the bags were removed and rinsed thoroughly. Half of the bags were dried at 50–55 °C for 48 h and the dry weight was recorded. The rest of the bags were incubated for 1 h in pepsin solution, then NaOH and pancreatin solutions were added and the bags were incubated for 24 h at 39 °C. Bags were rinsed thoroughly and dried at 50–55 °C for 48 h. The dry weight of the bags was recorded and the bag residue and the original feeds were analyzed for N. Samples were barley, oats, wheat and soybeans, heat-treated for various times, and were obtained from other trials for which mobile bag digestibility values were determined with or without 16 h rumen incubation. Mobile bag digestibility values without rumen incubation ranged from 77 to 97%.Regression analysis of the relationship of N digestibility (mobile bag) and N digestibility (in vitro) for all grain samples resulted in a highly significant relationship (r2=0.95, P<0.0001). When soybean samples were included in the analysis, the r2 was only 0.02. Residual trypsin inhibitor activity of some of the samples interfered with mobile bag digestibility (no rumen incubation), while there was no interference of trypsin inhibitor with the in vitro digestibility determinations, demonstrating a benefit of the proposed method. There was also no interference for mobile bag digestibility when the samples were first incubated in the rumen for 16 h. This in vitro procedure closely simulated the physiological conditions in the animal allowing a prediction of intestinal N digestibility without the use of surgically modified animals. The method was sensitive to heat damage of the samples and could be used to rapidly evaluate the nutritional value of grain and soybean feedstuffs for ruminants. [Copyright &y& Elsevier]

The main objective of this study was to investigate the effect of increasing dietary levels of heat treated low glucosinolate rapeseed expeller press cake (RSC) on the transfer of iodine from feed to cow milk. Eight cows of the Norwegian red cattle breed were split in two 4 × 4 Latin squares, using 4 treatments and 4 periods of 14 days each. The 4 different treatments were 1) Control, 0.0 kg RSC/day, 2) RSC-Low, 0.6 kg RSC/day, 3) RSC-Medium, 1.4 kg RSC/day and 4) RSC-High, 2.0 kg RSC/day. Irrespective of a planned constant dietary iodine content, the analysed concentration of iodine ranged from 1.4 mg/kg DM in the RSC-High diet to 1.9 mg/kg DM in the Control diet. From day 11–14 in each period, samples were collected and the total iodine concentrations in feed, milk and plasma were determined by inductively coupled plasma mass spectrometry. The iodohormones, triiodothyronine (T 3 ) and thyroxin (T 4 ) in plasma were determined by fluoroimmunoassay. No differences (P > 0.05) in total iodine as well as the T 3 and T 4 plasma concentrations were observed between the four treatments, even though the plasma iodine reflected the somewhat varying dietary iodine. Feed intake, milk production and milk composition was not affected by the different treatments (P > 0.05). Although the levels of glucosinolates were low and no glucosinolate metabolites (e.g., goitrin and indole acetonitrile) were found in the RSC, an increasing offer decreased the milk iodine concentration from 0.35 mg/kg in the Control to 0.25 mg/kg with RSC-Low, to 0.15 mg/kg with RSC-Medium and to 0.10 mg/kg with RSC-High treatments. The iodine transfer, i.e. the output of iodine via milk related to the iodine intake, amounted to 25, 19, 13 and 10% in the Control and the 3 groups with increasing dietary RSC level. This study indicates that milk iodine transfer is severely inhibited at considerably lower levels of glucosinolates in RSC than previously anticipated. [ABSTRACT FROM AUTHOR]

Abstract: An experiment was designed to determine the effect of hydrothermal treatment (HT) on the coefficient of apparent ileal digestibilities (CAID) of crude protein (CP), amino acids (AA), starch and phosphorous (P) in growing pigs (initial body weight (BW) of 29.5±2.4kg) fitted with a T-cannula in distal ileum. The mash, based on wheat, fishmeal and soybean meal, was subjected to four HT, giving diets: (1) unconditioned mash as control; (2) low-temperature steam conditioning before pelleting (SC-Low); (3) high-temperature steam conditioning before pelleting (SP-High); (4) expander conditioning before pelleting (EXP); and (5) extruder processing (EXT). The diets were fed to five growing pigs allotted to treatments in a 5×5 Latin square design. The HT (average of four HT diets) increased CAID of starch (P=0.001), but did not affect that of DM, CP or P. The CAID for total indispensible AA was improved by HT processing (P=0.041), as were the CAID for Arg (P=0.018), Ile (P=0.044), Lys (P=0.006) and Thr (P=0.013), when compared to the control. For Lys, CAID was greater (P=0.006) for pigs fed the HT diets compared to the control and for the average of EXP and EXT compared to the average of SC-Low and SC-High. For dispensable AA, CAID were not affected by the treatments. In conclusion, HT increased ileal digestibility of starch, total IAA, Arg, Ile, Lys and Thr compared to a control diet fed as mash in growing pigs, with expander conditioning and extruder processing of particular merit for Lys. [Copyright &y& Elsevier]

Abstract: The aim of the present study was to investigate effects of feed conditioning prior to pelleting and extrusion processing on average daily gain (ADG), average daily feed intake (ADFI), gain to feed (G:F) and coefficient of total tract apparent digestibility (CTTAD) in nursery pigs and broiler chickens. The mash, based on wheat, fishmeal and soybean meal, was subjected to 4 heat treatments (hydro-thermal processing) giving Diet 1: unconditioned mash as control (mash); Diet 2: low-temperature steam conditioning before pelleting (STP47); Diet 3: high-temperature steam conditioning before pelleting (STP90); Diet 4: expander conditioning before pelleting (EXP); and Diet 5: extruder processing (EXT). Nursery pigs (average body weight of 5.6kg) were used in a 36-d experiment. The results showed that hydro-thermal processing improved G:F in nursery pigs (P=0.006) compared to the mash. The G:F was also improved for pigs fed the EXT diet compared to the EXP diet (P=0.030). The CTTAD of dry matter was greater in pigs fed the hydro-thermal processed diets compared to the mash (P=0.018), and in pigs fed the STP47 compared to the STP90 (P=0.001). The CTTAD of organic matter was improved for pigs fed STP47 and STP90 diets compared to the EXP and EXT diets (P=0.010), and for the STP47 compared to the STP90 diets (P=0.001). The CTTAD of protein (P=0.004) and energy (P=0.001) was greatest in pigs fed the STP47 compared to the STP90. Starch digestibility was improved in pigs fed the EXT compared to the EXP diet (P=0.041). Broiler chickens (1-d old, average body weight of 41g) were used in a 21-d experiment. The ADFI and ADG were greater (P<0.05) for broiler chickens fed the STP47 and the STP90 diets compared to those fed the EXP and the EXT diets. The EXP diet improved ADG (P=0.015) and ADFI (P=0.003) compared to the EXT diet. Starch digestibility was greater in broiler chickens fed the hydro-thermal processed diets compared to the mash (P=0.023). In conclusion, hydro-thermal processing, in particular extruder processing, improved G:F for nursery pigs due to improved digestibility. For broiler chickens, all hydro-thermal processing increased starch digestibility, but due to reduced feed intake of the expanded and in particular the extruded diets, only steam conditioning before pelleting improved growth rate and feed utilisation. [Copyright &y& Elsevier]

Abstract: Two diets for finishing pigs were used to determine the effect of adding water into the mixer on processing characteristics and pellet quality. Diet 1 was based on barley, oats and soybean meal (barley-based diet) and Diet 2 was based on maize and soybean meal (maize-based diet). Both diets were produced without and with use of an expander. Adding up to 120gwater/kg into the mixer prior to steam conditioning and pelleting (steam conditioning) of the barley-based diet, improved pelleting efficiency, pellet durability index (PDI) and modified PDI (with five hexagonal nuts added into the tumbling box), by 15, 10 and 10%, respectively. When water was added into the mixer prior to expanding the barley-based diet, PDI increased from 93 to 95% and modified PDI from 91 to 94%. The maize-based diet was processed with motor load held constant to maximize feed mill output, and production rate held constant to minimize energy use. At a constant motor load and a constant production rate, adding up to 30gwater/kg into the maize-based diet prior to steam conditioning increased pelleting efficiency by 22 and 9%, PDI was improved from 84 to 89% and from 79 to 87%, respectively. Expander conditioning of the maize-based diet increased PDI from 92% at none to 94% at 30g/kgwater addition. Correspondingly, modified PDI was increased from 89 to 93% at none and 30gwater/kg into the mixer prior to expander conditioning. The overall conclusion from the experiment was that adding water into the mixer before steam conditioning improved pelleting efficiency and pellet quality in barley- and maize-based diet for finishing pigs. [Copyright &y& Elsevier]

Abstract: A study was conducted to assess the interactions between grinding, pelleting and broiler performance. A hard wheat was ground by the use of hammer mill fitted with a 3 or 6.1mm sieve, or to the same geometric mean diameter by the use of a roller mill. Dry sieving revealed that the amount of particles smaller than 0.5mm in size and larger than 1.6mm in size was less with the roller mill than with the hammer mill. When diets containing 573.5g ground wheat/kg were pelleted, wet sieving revealed that the proportion of fine particles smaller than 0.2mm in size increased substantially. In addition, the pelleting process tended to even out differences in particle distribution between diets. No major differences in power consumption during pelleting were seen for the different diets. A somewhat poorer pellet quality in terms of breaking strength and resistance to abrasion was observed for diets made from coarsely ground wheat than for diets made from finely ground wheat. Extent of gelatinisation, measured by viscosity analysis and differential scanning calorimetry, varied between 1 and 19% and was inversely related to coarseness of the wheat in the diets. When diets were fed to broiler chickens either as mash or after pelleting, extent of grinding had no conclusive effect on performance. Pelleting increased performance, and increased apparent metabolisable energy (AME) of the diets from 11.6 to 11.8MJ/kg. The increase in AME was however, not reflected in a higher starch digestibility. The results indicate that pelleting will even out differences in particle distribution, and that coarse grinding of wheat has no negative effect on broiler performance. [Copyright &y& Elsevier]