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Heublein C.,Institute for Livestock science | Heublein C.,University of Bonn | Sudekum K.-H.,University of Bonn | Gill F.L.,University of Leeds | And 2 more authors.
Journal of Dairy Science | Year: 2017

The objective of this study was to test whether diet selection of dairy cows under grazing conditions could be estimated using plant wax markers. Furthermore, differences between 2 cow strains and the effect of concentrate supplementation on plant species selection were investigated. The experiment was a study with a crossover design performed on an organic farm with 12 Swiss Holstein cows and 12 New Zealand Holstein cows. Both experimental periods consisted of a 21-d adaptation and a 7-d measurement period. All cows grazed full time in a rotational stocking system and received either no concentrate or 6 kg/d of a commercial cereal-grain mix. Representative herbage samples of each grazed paddock were taken and botanical composition of subsamples was manually determined. The average proportions of the plant species were 27.8% Lolium perenne, 6.1% Dactylis glomerata, 10.4% Trifolium repens, and 9.0% Taraxacum officinale. Other grass species were merged as “other grass” (38.2%) and other forb species as “other forbs” (8.5%). n-Alkanes, long-chain fatty acids, and long-chain alcohols (LCOH) were analyzed in the samples of plant species, concentrate, and feces from each cow. A linear discriminant analysis indicated that diet components were differentiated best with LCOH (96%) and worst with the combination of all marker groups together (12%). For each marker, the fecal marker recovery (FR) relative to dosed ytterbium was determined in 2 ways. Estimation of diet composition was performed with the software “EatWhat,” and results were compared with botanical composition with the Aitchison distance. The results indicate that the diet composition of grazing dairy cows can be estimated using plant wax markers. Additionally, the calculation of FR led to mostly reliable results, yet this approach needs further validation. The most accurate estimation was achieved with the marker combination of n-alkanes and LCOH with a correction for FR. Less accurate estimations were achieved with long-chain fatty acids alone or in combination with n-alkanes. No difference relating to diet selection between the 2 cow strains was recorded, but supplemented cows apparently ingested higher proportions of T. repens than nonsupplemented cows. Awareness that supplementation influences selection behavior of grazing dairy cows may lead to adaptations in botanical composition of the pasture according to the demand of the animals. © 2017 American Dairy Science Association


PubMed | Institute for Livestock science, French National Institute for Agricultural Research and University of Reading
Type: Evaluation Studies | Journal: Journal of agricultural and food chemistry | Year: 2015

Little information exists on the effects of ensiling on condensed tannins or proanthocyanidins. The acetone-butanol-HCl assay is suitable for measuring proanthocyanidin contents in a wide range of samples, silages included, but provides limited information on proanthocyanidin composition, which is of interest for deciphering the relationships between tannins and their bioactivities in terms of animal nutrition or health. Degradation with benzyl mercaptan (thiolysis) provides information on proanthocyanidin composition, but proanthocyanidins in several sainfoin silages have proved resistant to thiolysis. We now report that a pretreatment step with sodium hydroxide prior to thiolysis was needed to enable their analysis. This alkaline treatment increased their extractability from ensiled sainfoin and facilitated especially the release of larger proanthocyanidins. Ensiling reduced assayable proanthocyanidins by 29%, but the composition of the remaining proanthocyanidins in silage resembled that of the fresh plants.


Helmreich S.,Institute for Livestock science | Hauser R.,Institute for Livestock science | Jungbluth T.,University of Hohenheim | Wechsler B.,Institute for Livestock science | Gygax L.,Institute for Livestock science
Livestock Science | Year: 2014

Adequate lying times and feed consumption are essential for the welfare and performance of dairy cows. The time budget of cows housed in barns with an automatic milking system (AMS) might be constrained in several ways. Cows with a high milking frequency might also have to visit the AMS at night, possibly interfering with their night-time lying behavior. Moreover, competition for access to the AMS might cause some cows to spend more time waiting in front of the milking unit, resulting in a lower milking frequency. In the present study, the individual total duration of stay and time spent per visit in the feeding, lying and waiting area, as well as lying behavior, was therefore investigated in the daytime and throughout the night in relation to milking frequency. A total of 138 focal cows (day of lactation: 1-200) housed on 4 Swiss working farms with an AMS were automatically tracked for 48. h. Individual lying times were recorded over 7 days with data loggers. The daily milking frequency was calculated from the AMS records and included as a continuous explanatory variable in linear mixed-effects models. Time spent in the waiting area at night increased with increasing milking frequency. In addition, cows with a relatively high milking frequency had shorter daytime lying bouts, and spent less time in the lying area per visit during the daytime as well as at night. The same individuals also visited the feeding area for shorter times during the day, and on average remained longer per visit in the waiting area at night. The daily time budget of cows with a relatively low milking frequency was not adversely affected. Cows with a relatively high milking frequency may face some trade-offs in their time-budget allocation, since the increased time spent by them in the waiting area at night as well as their shorter lying bouts might affect their welfare, health and performance. Nevertheless, the overall daily time budget for lying and feeding, and hence the welfare of cows with both a relatively high or low milking frequency, suffered no obvious adverse effects. © 2014 Elsevier B.V.


Abbeddou S.,ETH Zurich | Rischkowsky B.,International Center for Agricultural Research in the Dry Areas | Hilali M.E.-D.,International Center for Agricultural Research in the Dry Areas | Haylani M.,International Center for Agricultural Research in the Dry Areas | And 2 more authors.
Tropical Animal Health and Production | Year: 2014

Two experiments were carried out in Syria with the purpose of investigating to which extent the effects of including 30 % olive cake (replacing parts of forage and concentrate) or tomato pomace (replacing concentrate) in the diet, described under controlled on-station conditions, can be recovered on farm. A total of 180 lactating Awassi ewes (three farms per experiment, 15 ewes per treatment) were fed either control diets or test feed diets over a period of 7 weeks. Milk yield was measured bi-weekly and milk composition was analysed for gross physicochemical composition and fatty acid (FA) profile. Both feeds reduced milk yield (−10 %) and milk protein content, whereas milk fat content was increased by tomato pomace. Both feeds resulted in similar changes in milk FA profile, namely less saturated and polyunsaturated FA and more monounsaturated FA including 18:1 trans FA. Tomato pomace and olive cake also resulted in increased n-6:n-3 FA ratios, while the proportion of the conjugated linoleic acids was not affected by either treatment. In conclusion, the response of the ewes on farm was clear and similar in nature for most of milk-related traits as that found on station, but lower in magnitude. © 2014, Springer Science+Business Media Dordrecht.


Ruiz-Ascacibar I.,Institute for Livestock science | Ruiz-Ascacibar I.,ETH Zurich | Stoll P.,Institute for Livestock science | Kreuzer M.,ETH Zurich | And 3 more authors.
Animal | Year: 2016

Breeding leaner pigs during the last decades may have changed pig’s empty body (EB) composition, a key trait for elaborating feeding recommendations. This research aimed to provide new experimental data on changes in the chemical composition of the EB of pigs from 20 to 140 kg BW. In addition, the impact of a reduction in the dietary CP associated with lower lysine, methionine+cystine, threonine and tryptophan levels was determined. In total, 48 males, castrates and females weighing 20 kg BW were allocated either to a control grower–finisher diet formulated according to current Swiss feeding recommendations, or a low CP grower–finisher diet (80% of control). Feed intake was monitored and pigs were weighed weekly. The chemical composition of EB (blood, hairs and hoofs, offals, bile, carcass) was determined at 20, 40, 60, 80, 100, 120 and 140 kg BW on four pigs per gender and diet (eight pigs per gender at 20 kg). The five fractions were weighed and samples were analysed for dry matter, protein, fat and energy. Nutrient deposition rates and N efficiency were calculated by using the 20 kg BW category as reference. Analysis revealed an accurate feed optimisation for the aforementioned essential amino acids (EAA), whereas digestible isoleucine content in the low CP diet was at 70% of the control diet. Despite similar feed intake, daily gain and feed efficiency were impaired (P<0.01) from 20 to 100 kg BW in the low CP compared with the control pigs. In the same growth period, castrates had the greatest feed intake but, together with females, displayed the lowest (P<0.01) feed efficiency. Protein deposition was reduced (P<0.01) by up to 31% with low CP diet and was lower (P<0.01) in castrates and females than males at 100 kg BW. The greatest fat deposition rates were found with low CP diet and castrates. N efficiency improved (P<0.05) by 10% with the low CP diet from 100 to 140 kg. The males displayed the greatest (P<0.05) N efficiency. These findings suggest that the CP content of finisher II diets could be reduced to 102, 102 and 104 g/kg for females, castrates and males, respectively, without a negative impact on protein deposition or growth. It remains unclear whether the negative effects found in the BW range from 20 to 100 kg on the EB deposition were due to the 20% reduction of the dietary CP and the five limiting EAA or to other EAA via an unbalanced EAA profile. © The Animal Consortium 2016 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.


PubMed | University of Leeds, University of Bonn and Institute for Livestock science
Type: | Journal: Journal of dairy science | Year: 2016

The objective of this study was to test whether diet selection of dairy cows under grazing conditions could be estimated using plant wax markers. Furthermore, differences between 2 cow strains and the effect of concentrate supplementation on plant species selection were investigated. The experiment was a study with a crossover design performed on an organic farm with 12 Swiss Holstein cows and 12 New Zealand Holstein cows. Both experimental periods consisted of a 21-d adaptation and a 7-d measurement period. All cows grazed full time in a rotational stocking system and received either no concentrate or 6 kg/d of a commercial cereal-grain mix. Representative herbage samples of each grazed paddock were taken and botanical composition of subsamples was manually determined. The average proportions of the plant species were 27.8% Lolium perenne, 6.1% Dactylis glomerata, 10.4% Trifolium repens, and 9.0% Taraxacum officinale. Other grass species were merged as other grass (38.2%) and other forb species as other forbs (8.5%). n-Alkanes, long-chain fatty acids, and long-chain alcohols (LCOH) were analyzed in the samples of plant species, concentrate, and feces from each cow. A linear discriminant analysis indicated that diet components were differentiated best with LCOH (96%) and worst with the combination of all marker groups together (12%). For each marker, the fecal marker recovery (FR) relative to dosed ytterbium was determined in 2 ways. Estimation of diet composition was performed with the software EatWhat, and results were compared with botanical composition with the Aitchison distance. The results indicate that the diet composition of grazing dairy cows can be estimated using plant wax markers. Additionally, the calculation of FR led to mostly reliable results, yet this approach needs further validation. The most accurate estimation was achieved with the marker combination of n-alkanes and LCOH with a correction for FR. Less accurate estimations were achieved with long-chain fatty acids alone or in combination with n-alkanes. No difference relating to diet selection between the 2 cow strains was recorded, but supplemented cows apparently ingested higher proportions of T. repens than nonsupplemented cows. Awareness that supplementation influences selection behavior of grazing dairy cows may lead to adaptations in botanical composition of the pasture according to the demand of the animals.


Vogeli S.,Institute for Livestock Science | Vogeli S.,University of Zürich | Wechsler B.,Institute for Livestock Science | Gygax L.,Institute for Livestock Science
Animal Welfare | Year: 2014

Given the increased interest in animal emotional reactions for assessing welfare, indicators for such reactions are sought. Ear postures and movements have been found to be promising indicators of emotional states in sheep and other animals. The manual recording of ear postures, however, is very time consuming and possibly prone to a degree of inaccuracy due to the subtle and fast nature of ear movements that have to be identified. Therefore, a number of previous studies have analysed the frequency of certain ear postures relative to all ear posture changes rather than measuring the relative duration spent with different ear postures. Here, we present an automated, continuous tracking system that keeps track of small and lightweight marker balls attached to the head and ears of sheep. We measured ear postures and movements when the animals were confronted with three physical stimuli thought to differ in valence (from negative to intermediate to positive). We then compared new ear-posture definitions reflecting the real time spent with certain ear postures during stimulation with previous definitions used for video-based analyses that assessed ear-posture changes in relation to the total number of observed ear postures. In the analysis, we correlated new and previous measures both between and within experimental stimuli using residuals from mixed-effects models. We found that the new and previous definitions of ear postures and movements correlated highly. Given these high correlations and the discussed theoretical and practical advantages of the automated tracking, the new recording system can be recommended highly for assessing reactions in animals that may indicate emotional states. © 2014 Universities Federation for Animal Welfare.


PubMed | University of Zürich and Institute for Livestock science
Type: Journal Article | Journal: Schweizer Archiv fur Tierheilkunde | Year: 2016

The oral group treatment is still a common procedure in swine production. This project studied the effect of the application of 3 different formulations of antimicrobial premixes (1. chlortetracycline, 2. chlortetracycline + sulfadimidine + tylosin, 3. sulfadimidine + sulfathiazole + trimethoprim) via the liquid feeding system on the occurrence of tetracycline-resistant Enterobacteriaceae (Ent-Tetr) in the liquid feed. 156 and 112 feed samples were collected between April and December 2015 in 13 case and 14 control farms, respectively. The 27 farms were randomly selected pig fattening farms located in different parts of Switzerland. The number of feed samples that contained Ent-Tetr as well as the number of Enterobacteriaceae resistant to tetracycline per sample was significantly higher in the case group than in the control group. The use of any of the 3 antimicrobial combinations turned out to be the main risk factor for the occurrence of Ent-Tetr in the liquid feed. Our results suggest that liquid feed containing antimicrobials is a reservoir of antimicrobial resistant bacteria in swine production.


Rerat M.,Institute for Livestock science | Schlegel P.,Institute for Livestock science
Journal of Animal Physiology and Animal Nutrition | Year: 2014

Dry cow diets based on grassland forage from intensive production contain high amounts of K and could be responsible for a reduced ability to maintain Ca homoeostasis. The aim of this study was to determine whether a moderate anionic salt supplementation to a forage-based pre-calving diet with varying native K content affects the mineral and acid-base status in transition cows. Twenty-four dry and pregnant Holstein cows, without antecedent episodes of clinical hypocalcemia, were assigned to two diets during the last 4 weeks before estimated calving date. Twelve cows were fed a hay-based diet low in K (18 g K/kg DM), and 12, a hay-based diet high in K (35 g K/kg DM). Within each diet, six cows received anionic salts during the last 2 weeks before the estimated calving day. After calving, all cows received the high K diet ad libitum. Blood samples were taken daily from day 11 pre-partum to day 5 post-partum. Urine samples were taken on days 7 and 2 pre-partum and on day 2 post-partum. The anionic salt did not alter feed intake during the pre-partum period. Serum Ca was not influenced by the dietary treatments. Feeding pre-partum diets with low K concentrations induced a reduced metabolic alkalotic charge, as indicated by reduced pre-partum urinary base-acid quotient. Transition cows fed the low K diet including anionic salts induced a mild metabolic acidosis before calving, as indicated by higher urinary Ca, lower urinary pH and net acid-base excretion. Although serum Ca during the post-partum period was not affected by dietary treatment, feeding a low K diet moderately supplemented with anionic salts to reach a dietary cation-anion difference close to zero permitted to obtain a metabolic response in periparturient cows without altering the dry matter intake. © 2013 Blackwell Verlag GmbH.


Schlegel P.,Institute for Livestock science | Ampuero Kragten S.,Institute for Livestock science | Gutzwiller A.,Institute for Livestock science
Animal Feed Science and Technology | Year: 2014

The aim of this study was to validate an enzymatic in vitro method that estimates the apparent total tract digestibility (ATTD) of phosphorus (P) in feed ingredients from plant origin used in pig nutrition. Sixteen individually housed castrated male pigs (19.5±2.9kg) were fed a semisynthetic diet, either alone (control) or containing: wheat, barley, maize, potato protein concentrate, soybean expeller or rapeseed expeller for periods of 14 days. The ATTD of P was determined indirectly using celite as a marker. The in vitro released P was determined after three consecutive steps: preliminary soaking in acid medium, pepsin digestion in strong acid medium and pancreatin digestion in neutral medium. The in vivo ATTD of P were 0.21, 0.37, 0.48, 0.41, 0.33 and 0.39 in the respective feed ingredients as listed above. The in vivo ATTD of P and the in vitro released P were linearly correlated (in vitro released P=-0.118 (P>0.10)+1.171 (P<0.01)×in vivo ATTD of P, R2=0.91). Thus, the in vitro method was successful in predicting in vivo ATTD of P in the plant feed ingredients tested here. The in vitro method can be proposed as an inexpensive tool to rapidly estimate ATTD of P in plant feed ingredients. © 2014 Elsevier B.V.

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