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ABSTRACT: The effect of the horn status of cows on their milk composition and quality is a controversial research topic. In this study, 128 milk samples from 64 horned and 64 disbudded Brown Swiss and Original Braunvieh cows were collected from alpine farms where both horned and disbudded cows were grazing on mountain pastures. The samples were analyzed for their detailed composition and protein digestion in a simulated in vitro digestion (INFOGEST). To exclude probable influences on digestion, the β-CN genotype with its variants A1 and A2 was also included in the study. The effects of horn status and β-CN genotype were investigated in linear mixed models, which included additional influencing random factors such as Original Braunvieh blood proportion, stage of lactation, and farm. Horn status did not have any effect on milk composition or digestion. In contrast, milk from A1A1 cows showed a different protein digestion than milk of A1A2 and A2A2 cows in the gastric phase, including smaller amounts of β-casomorphin(BCM)21-associated peptides and larger amounts of BCM11-associated peptides. Abundances of BCM7 did not differ between β-CN genotypes. At the end of the intestinal phase, the digested milk of A1A1 and A2A2 β-CN genotypes did not differ.

The dynamics of cattle body chemical composition during growth and fattening periods determine animal performance and beef carcass quality. The aim of this study was to estimate the empty body (EB) and carcass chemical composition of growing beef-on-dairy crossbred bulls (Brown Swiss breed as dam with Angus, Limousin or Simmental as sire) using three-dimensional (3D) imaging. The 3D images of the cattle’s external body shape were recorded in vivo on 48 bulls along growth trajectory (75–520 kg BW and 34–306 kg hot carcass weight [HCW]; set 1) and on 70 bulls at target market slaughter weight, including 18 animals from set 1 (average 517 ± 10 kg BW and 289 ± 10 kg HCW; set 2). The linear, circumference, curve, surface and volume measurements on the 3D body shape were determined. Those predictive variables were used in partial least square regressions, together with the effect of the sire breed whenever significant (P

ABSTRACT: In the present experiment, 10 horned and 10 disbudded mid-lactating Brown Swiss cows were included in a crossover feeding trial with a hay or hay and concentrate diet. The effects of dietary neutral detergent fiber (NDF) content and horn status on thermoregulatory responses under thermoneutral and short-term heat stress conditions were studied, as both are considered to ease the cow's thermoregulation under an environmental heat load. Cows received either ad libitum hay and alfalfa pellets (85:15, C−, NDF content: 41.0%) or restricted amounts of hay and concentrate (70:30, C+, NDF content: 34.5%). The level of restriction applied with the C+ diet was determined from pre-experimental ad libitum intakes, ensuring that both diets provided the same intake of net energy for lactation (NEL). For data collection, cows were housed in respiration chambers for 5 d. The climatic conditions were 10°C and 60% relative humidity (RH), considered thermoneutral (TN) conditions (temperature-humidity index (THI): 52) for d 1 and 2, and 25°C and 70% RH, considered heat stress (HS) conditions (THI: 74), for d 4 and 5. On d 3, the temperature and RH were increased gradually. Compared with TN, HS conditions increased the water intake, skin temperature, respiration and heart rates, and endogenous heat production. They did not affect body temperature, feed intake, or milk production. Lowering dietary fiber content via concentrate supplementation lowered methane and increased carbon dioxide production. It did not mitigate physiological responses to HS. Although the responses of horned and disbudded cows were generally similar, the slower respiration rates of horned cows under HS conditions indicate a possible, albeit minor, role of the horn in thermoregulation. In conclusion, future investigations on nutritional strategies must be conducted to mitigate mild heat stress.

ABSTRACT: This study investigated the effects of acacia (extract of Acacia mearnsii) and sainfoin (Onobrychis viciifolia) as condensed tannin (CT)-rich sources on ruminal and manure methane (CH4) emissions in comparison with non-CT silages characterized by different contents of the cell wall and water-soluble carbohydrates. In a 3 × 6 incomplete Latin square design, 30 Holstein cows (63 ± 23 d in milk; mean ± SD; 33.8 ± 7.6 kg of milk per day, body weight 642 ± 81 kg) were provided with ad libitum access to 1 of 6 total mixed rations comprising 790 g of silage and 210 g of concentrate per kilogram of dry matter (DM). The silages were either rich in sainfoin [neutral detergent fiber (NDF): 349 g/kg of DM], perennial ryegrass (NDF: 420 g/kg of DM), or red clover (NDF: 357 g/kg of DM). Each silage was supplemented with 20 g/kg (of total diet DM) of acacia or straw meal. Feed intake and milk yield were recorded daily. Milk composition and ruminal fluid characteristics and microbiota were analyzed. The individual ruminal CH4 production was determined using the GreenFeed system, and CH4 emissions from the manure of cows fed the same diets were measured in a parallel experiment over 30 d at 25°C using a dynamic flux chamber. The CT sources did not reduce CH4 yield or emission intensity. Acacia reduced milk production (from 26.3 to 23.2 kg/d) and DM intake (from 19.7 to 16.7 kg/d) when supplemented with ryegrass, and both CT sources reduced the milk protein content and yield. Acacia supplementation and ryegrass silage reduced the ruminal acetate:propionate ratio. Furthermore, during acacia treatment, the abundance of Methanobrevibacter archaea tended to be lower and that of Thermoplasmata was higher. Acacia reduced the CH4 emissions from manure for the ryegrass group by 17% but not for the sainfoin and clover groups. Feeding sainfoin silage resulted in the lowest manure-derived CH4 emissions (−47% compared with ryegrass). In conclusion, acacia reduced ruminal CH4 production by 10%, but not emission intensity, and the mitigation effect of sainfoin depended on the silage to which it was compared. Because mitigation was partially associated with animal productivity losses, careful evaluation is required before the implementation of tanniferous feeds in farm practice.

Exposure to direct solar radiation, high ambient temperature, lack of wind movement, coupled with own metabolic heat production, makes grazing dairy cows vulnerable to heat stress. In pastures, it would be beneficial to monitor heat stress by observable changes in behaviour. We hypothesised that grazing dairy cows exhibit behavioural changes due to increasing heat load in temperate climate. Over two consecutive summers, 38 full-time grazing Holstein dairy cows were investigated in 12 experimental periods of up to 3 consecutive days where the cows were repeatedly exposed to various levels of moderate heat load determined by the comprehensive climate index (CCI). The CCI defines the ambient climate conditions, combining air temperature, relative humidity, solar radiation and wind speed. Vaginal temperature (VT) was automatically measured as an indicator of heat stress. In addition, as a less invasive method, we investigated if reticular temperature (RET) can be indicative of heat stress on pastures. Walking activity, lying-, feeding, and ruminating durations were recorded continuously with sensors. Respiration rate (RR), proximity to and competition at the water trough, social licking, self-licking, inter-individual distance, and fly intensity were directly observed. Data were analysed in the morning (0900–1100 h) and during the hottest time of day when cows were on pasture (1230–1430 h). The VT and RET showed similar patterns in relation to the CCI, suggesting that RET can be suitable for continuous monitoring of heat stress on pastures. In the morning, the cow’s VT and RET did not relevantly react to the CCI. During the period 1230–1430 h, the cow’s mean VT (mean vaginal temperature (VTMEAN); range: 37.7–40.3 °C) and mean RET (mean reticular temperature; range: 37.0–41.1 °C) were positively related to the mean CCI (mean comprehensive climate index) in this period (mean ± SD: 25.9 ± 5.71 °C). For cows with greater VTMEAN, an increased mean RR and decreased durations of walking, lying, feeding, and ruminating were found. These cows were also more likely to be in proximity to the water trough and to have small inter-individual distances. Changes in these traits seem to reflect behavioural adaptations to heat stress in a temperate climate and could be used to detect the heat stress in individual dairy cows on pastures.

Because of the relevant effects of plant-derived polyphenols (PPs) on monogastrics and ruminants’ nutrition, emissions and performance, an increasing number of in vivo and in vitro studies are being performed to better understand the mechanisms of action of polyphenols at both the ruminal and intestinal levels. The biological properties of these phenolic compounds strongly depend on their degradation, absorption and metabolism. The harmonised in vitro digestion method (INFOGEST) is one of the most reliable in vitro methods used to assess the bioaccessibility and or antioxidant activity of PP contained in different matrixes, as well as the interactions of PP and their degradation products with other feed ingredients. The effects of PP released from their matrix after in vitro digestion on different intestinal physiological parameters, such as epithelium integrity, can be further evaluated by the use of ex vivo models such as the Ussing chamber. This review aims to describe the combination of the INFOGEST method, coupled with the Ussing chamber as a valuable model for the digestion and subsequent effects and absorption of phenolic compounds in monogastrics and potentially in ruminants. The advances, challenges and limits of this approach are also discussed.

Even in temperate climate regions, an increase in ambient temperature and exposure to solar radiation can cause heat stress in lactating dairy cows. We hypothesised that grazing dairy cows exhibit short-term physiological changes due to increasing heat load under moderate climate conditions. Over two consecutive summers, 38 lactating Holstein dairy cows were studied in a full-time grazing system. Data were collected in 10 experimental periods of up to three consecutive days with a moderate comprehensive climate index (CCI). The individual animals’ vaginal temperature (VT), heart rate, and locomotor activity data were automatically monitored with sensors. Blood samples and proportional whole milk samples were collected at afternoon milking. The concentrations of beta-hydroxybutyrate, glucose, non-esterified fatty acids, urea nitrogen, plasma thyroxine and triiodothyronine were analysed in blood plasma, and fat, protein, lactose, urea nitrogen, cortisol, Na+, K+, and Cl− concentrations were analysed in milk. The daily distribution of VT recordings greater than 39 °C showed a circadian rhythm with a proportion of recordings of 2% and lower during the night and a percentage of 10% or higher in the afternoon. The cows’ maximal daily vaginal temperature (VTMAX) between 0830 and 1430 h was positively related to the mean daily CCI in the same time period (CCIMEAN; mean and SD 23.6 ± 5.4 °C). Cows with greater VTMAX had an increased mean heart rate, plasma glucose and milk cortisol concentrations and decreased concentrations of plasma thyroxine and triiodothyronine. The concentration of Na+ in milk was lower, and the concentration of K+ in milk tended to be higher in cows with increased VTMAX. For beta-hydroxybutyrate, non-esterified fatty acids and urea nitrogen concentrations in plasma and fat and lactose concentrations in milk no relationships were found in terms of increasing VT. For milk urea nitrogen and protein concentrations, the proportion of total variance explained by inter-individual or -period variance was high. In conclusion, changes observed in milk and blood likely reflected short-term physiological responses to moderate heat stress. In particular, milk cortisol and Na+ may be useful traits for timely monitoring of heat stress in individual cows because their inter-individual variances were relatively small and samples can be collected non-invasively.

Sainfoin is a protein-rich legume with an ideal amino acid profile and therefore could partly replace soybeans in the diets of growing pigs. However, sainfoin also contains a non-negligible amount of condensed tannins (CTs), which can act as antinutritional factors. Bioactive plant compounds, like hydrolysable tannins, have been suggested to be suitable in entire male (EM) production, as they impair the development of accessory sex glands and, by that, reduce boar taint compound levels without negatively impacting growth. It is unknown whether, similar to hydrolysable tannins, CTs from sainfoin reduce the incidence of boar taint without impacting growth performance, carcass traits, and meat quality. For the experiment, 48 Swiss Large White EM were assigned within litter to one of four grower (25–60 kg BW) and finisher (60–105 kg BW) diets supplemented with 0 (T0), 5 (T5), 10 (T10), and 15% (T15) sainfoin meal, respectively. The four diets were designed to be isocaloric and isoproteic. Increasing the dietary sainfoin level had no negative effect on growth performance or the carcass characteristics. Despite leading to a similar feed intake between the treatment groups, increasing the dietary sainfoin levels tended (P ≤ 0.08) to reduce the number of feeder visits but increased the time spent at the feeder as well as the feed intake per visit during the finisher period. By increasing sainfoin intake, the levels of C18:3n-3 and long-chain homologs linearly increased (P

The extensive protein degradation occurring during ensiling decreases the nutritive value of silages, but this might be counteracted by tannins. Therefore, silages from two legume species containing condensed tannins (CT) – sainfoin (SF) and birdsfoot trefoil (two cultivars: birdsfoot trefoil, cv. Bull (BTB) and birdsfoot trefoil, cv. Polom) – were compared for their in vitro ruminal fermentation characteristics. The effect of combining them with two CT-free legume silages (lucerne (LU) and red clover (RC)) was also determined. The supply of duodenally utilisable CP (uCP) in the forages was emphasised. The legumes were each harvested from three field sites. After 24 h of wilting on the field, the legumes were ensiled in laboratory silos for 86 days. Proximate constituents, silage fermentation characteristics, CT content and CP fractions were determined. Subsequently, silage samples and 1 : 1 mixtures of the CT-containing and CT-free silages were incubated for 24 h in batch cultures using ruminal fluid and buffer (1 : 2, v/v). Each treatment was replicated six times in six runs. The effects on pH, ammonia and volatile fatty acid concentrations, protozoal counts, and total gas and methane production were determined. uCP content was calculated by considering the CP in the silage and the ammonia in the incubation fluid from treatments and blanks. Statistical evaluation compared data from single plants alone and together with that from the mixtures. Among treatments, SF silage contained the least CP and the most CT. The non-protein nitrogen content was lower, favouring neutral detergent soluble and insoluble protein fractions, in the SF and RC silages. Absolute uCP content was lowest in SF and SF mixtures, although the ratio to total CP was the highest. In comparison with LU, the ammonia concentration of the incubation fluid was lower for SF, RC and BTB and for the mixture of SF with LU. The total gas and methane production was similar among the treatments, and the total volatile fatty acid production was decreased with the CT-containing legumes. Protozoal count was increased with the mixtures containing LU and either SF or BTB compared with single LU. In conclusion, compared with the other legumes, SF and RC have similar advantages as they show limited proteolysis during ensiling. In addition, SF supplies more uCP relative to total CP. The CT-containing legumes also differed in their effect on ruminal fermentation and ammonia formation, probably because of their different CT contents. Thus, SF and its mixtures appear promising for improving the protein utilisation of ruminants.

As ruminants are able to digest fibre efficiently and assuming that competition for feed v. food use would intensify in the future, cereals and other field crops should primarily be destined to cover the dietary needs of humans and monogastric animals such as poultry and pigs. Farming systems with a reduced or absent concentrate supplementation, as postulated by organic agriculture associations, require adapted dairy cows. The aim of this experiment was to examine the impact of concentrate supplementation on milk production, grazing and rumination behaviour, feed intake, physical activity and blood traits with two Holstein-Friesian cow strains and to conclude the consequences for sustainable and organic farming. The experiment was a cross-over study and took place on an organic farm in Switzerland. In all, 12 Swiss Holstein-Friesian (HCH) cows and 12 New Zealand Holstein-Friesian (HNZ) cows, which were paired according to lactation number, days in milk and age for primiparous cows, were used. All cows grazed full time and were supplemented either with 6 kg/day of a commercial, organic cereal-grain mix or received no supplement. After an adaptation period of 21 days, a measurement period of 7 days followed, where milk yield and composition, pasture dry matter intake estimated with the n-alkane double-indicator technique, physical activity based on pedometer measurements, grazing behaviour recorded by automatic jaw movement recorder and blood samples were investigated. Non-supplemented cows had a lower milk yield and supplemented HCH cows produced more milk than supplemented HNZ cows. Grazing time and physical activity were greater for non-supplemented cows. Supplementation had no effect on rumination behaviour, but HNZ cows spent longer ruminating compared with HCH cows. Pasture dry matter intake decreased with the concentrate supplementation. Results of blood analysis did not indicate a strong negative energy balance for either non-supplemented or supplemented cows. Minor differences between cow strains in this short-term study indicated that both cow strains are equally suited for an organic pasture-based production system with no concentrate supplementation. Many factors such as milk yield potential, animal welfare and health, efficiency, grazing behaviour and social aspects influence the decision to supplement grazing dairy cows with concentrates.

An experiment was conducted to compare the effect of the same amount of 18:2 offered either as 18:2n-6 or as a mixture of unprotected 18:2c9t11 and 18:2t10c12 on feed intake, milk components as well as plasma and milk fatty acid profile. Fifteen cows were blocked by milk yield and milk fat percentage and within block assigned randomly to 1 of 3 treatments (n = 5). Each cow passed a 12-d adjustment period (AP) on a basal diet. After the AP cows received 1 of 3 supplements during an 18-d experimental period (EP). The supplements contained either 1.0 kg ground sunflower seeds (S), 0.5 kg conjugated linoleic acid (CLA)-oil (C) or 0.75 kg of a mixture of ground sunflower seeds and CLA-oil (2:1; SC). All 3 supplements contained the same amount of 18:2 either as CLA (∑18:2c9t11+18:2t10c12, 1:1) or as 18:2c9c12. During the last 2 d of AP and the last 4 d of EP feed intake and milk yield were recorded daily and milk samples were collected at each milking. Blood samples were collected from the jugular vein on d 11 of AP and d 15 and 18 of EP. The 18:2 intake increased in all treatments from AP to EP. Regardless of the amount of supplemented CLA, the milk fat percentage decreased by 2.35 and 2.10%-units in treatment C and SC, respectively, whereas in the treatment S the decrease was with 0.99%-unit less pronounced. Thus, C and SC cows excreted daily a lower amount of milk fat than S cows. The concentration of trans 18:1 in the plasma and the milk increased from AP to EP and increased with increasing dietary CLA supply. While the concentration of 18:2c9t11 and 18:2t10c12 in the plasma and that of 18:2t10c12 in the milk paralleled dietary supply, the level of 18:2c9t11 in the milk was similar in C and CS but still lower in S. Although the dietary concentration of CLA was highest in treatment C, the partial replacement of CLA by sunflower seeds had a similar inhibitory effect on milk fat synthesis. Comparable 18:2c9t11 levels in the milk in both CLA treatments implies that this isomer is subjected to greater biohydrogenation with increasing supply than 18:2t10c12. The fact that unprotected 18:2t10c12 escaped biohydrogenation in sufficient amounts to affect milk fat synthesis reveals opportunities to develop feeding strategies where reduced milk fat production is desirable or required by the metabolic state of the cow.

To investigate dietary influences on the volatilome, the volatile subcategory of the metabolome, we performed a comparative untargeted volatilome analysis of exhaled breath, ruminal fluid, serum, urine, and milk from lactating Holstein cows fed different diets. Thirty-two cows (79.4 ± 31.3 d in milk [DIM], 30.6 ± 4.83 kg milk/d) were assigned to 4 diets. The experiment lasted 16 weeks. Throughout the experiment, half of the animals were fed a hay-based diet (HAY; n = 16), and the other half were fed a silage-based diet (SIL; n = 16). In experimental wk 5 to 12, half of the animals in each group received the control concentrate (CON), and the other half was fed with the CON supplemented with a blend of essential oils (EXP). We hypothesized that the basal diet and the essential oils influence the VOC profiles of the cows through potential changes in ruminal fermentation, digestion, and metabolism (hypothesis 1). Furthermore, we hypothesized that the potential effects of essential oils would have a delayed onset and a carryover effect (hypothesis 2). Every 4 experimental weeks, i.e., in W4, W8, W12 and W16, samples of exhaled breath, ruminal fluid, serum, urine, milk, and feed were collected for dynamic headspace extraction and gas chromatographic analysis of volatile organic compounds (VOC) in their gaseous phase. Milk yield, milk composition, body weight, and feed intake were recorded regularly. Linear mixed models and multivariate and univariate data analyses were performed. The total DMI and basal diet intake was similar between HAY and SIL cows. However, SIL cows consumed less of the concentrate, neutral detergent fiber, and water-soluble carbohydrates (WSC) and more starch than HAY cows. The SIL cows had a higher milk production than the HAY cows. No effect was found regarding the concentrate type on feed intake or milk production. Irrespective of diet, 2,957 VOC were detected in the gaseous phase of serum; 2,771 in exhaled breath; 1,016 in urine; 1,001 in milk; and 921 in ruminal fluid. Across the experimental wk 4, 8, 12 and 16, the basal diet altered the VOC profiles of ruminal fluid, urine, and exhaled breath but not those of serum and milk. The concentrate type affected only the VOC profiles of the exhaled breath. Most diet-influenced VOC in the affected biological matrices were identified as dietary components. The experimental week influenced the VOC profiles of all matrices, especially those of exhaled breath. The VOC profile of exhaled breath strongly correlated with that of urine, followed by that of ruminal fluid, milk, and serum. This study provides the first description of diet- and time-specific VOC profiles from the biological matrices of dairy cows. The identified discriminatory VOC seem suitable as markers to discriminate between HAY and SIL cows. Exhaled breath may be a promising, sensitive, and less invasive tool to follow diet- and time-related metabolic changes., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The effect of the horn status of cows on their milk composition and quality is a controversial research topic. In this study, 128 milk samples from 64 horned and 64 disbudded Brown Swiss and Original Braunvieh cows were collected from alpine farms where both horned and disbudded cows were grazing on mountain pastures. The samples were analyzed for their detailed composition and protein digestion in a simulated in vitro digestion (INFOGEST). To exclude probable influences on digestion, the β-CN genotype with its variants A1 and A2 was also included in the study. The effects of horn status and β-CN genotype were investigated in linear mixed models, which included additional influencing random factors such as Original Braunvieh blood proportion, stage of lactation, and farm. Horn status did not have any effect on milk composition or digestion. In contrast, milk from A1A1 cows showed a different protein digestion than milk of A1A2 and A2A2 cows in the gastric phase, including smaller amounts of β-casomorphin(BCM)21-associated peptides and larger amounts of BCM11-associated peptides. Abundances of BCM7 did not differ between β-CN genotypes. At the end of the intestinal phase, the digested milk of A1A1 and A2A2 β-CN genotypes did not differ., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Understanding the transfer of polychlorinated dibenzo- p -dioxins and dibenzofurans (PCDD/Fs) in farm animals is essential for ensuring food safety, but such information for suckler ewes ( Ovis aries ) has been lacking. This work quantifies the accumulation, tissue distribution, and depuration kinetics of PCDD/Fs in these animals. Six suckler ewes (EXP group) were exposed to PCDD/Fs through contaminated hay (2.3-12.7 ng toxic-equivalent kg -1 dry matter) and then allowed to depurate by switching to noncontaminated hay from 29 days of lactation. Four control ewes were fed continuously with noncontaminated hay. At different time points covering depuration, weaning and slaughter, PCDD/F analysis of milk (three time points), blood and sternal adipose tissue (five time points), Longissimus thoracis muscle, liver, and empty body homogenate at slaughter (188 days of depuration) was performed. A relevant PCDD/F bioaccumulation was observed from oral intake in milk and adipose tissue (biotransfer factors of 1.24 and 1.06 day kg -1 lipids for the sum toxic-equivalent, respectively) in the EXP ewes, especially for penta- and hexa-chlorinated congeners. The EXP ewes' adipose tissue started at 10-fold the EU maximum level (ML) and showed depuration below the ML after 130 days. Specific PCDD/F accumulation in the ewe liver was observed, especially for dibenzofurans. These toxicokinetic data can inform recommendations to ensure the chemical safety of sheep food products.

This study's objective was to compare two options of pasture supplementation: corn silage (CS) alone or corn silage mixed with protein concentrate. The experiment was conducted with 18 lactating Holstein cows in mid-lactation in a crossover design that included three treatments and three data collection periods. All cows had access to pasture for 17 h/day with an average herbage allowance of 16 kg dry matter (DM)/cow/day and were offered in-barn corn silage, corn silage mixed with protein concentrate, or no supplementation. Cows were equipped with pH sensors residing in the reticulum and, during the 7-day data collection periods, with a jaw movement recorder. Nonsupplemented cows produced 21.3 kg energy-corrected milk (ECM) and ate 13.3 kg DM herbage at pasture. Cows supplemented with corn silage and corn silage plus protein produced 2.5 and 4.5 kg/day more ECM, respectively, consumed 3.4 and 3.3 kg/day more DM in total, respectively, ate for a shorter period of time, and ruminated longer than their nonsupplemented peers. Supplemented cows were almost able to cover their energy requirements and mobilised less body mass in contrast to the nonsupplemented cows. Cows offered corn silage plus protein showed increased ECM production, increased milk urea content and lower nitrogen use efficiency (NUE) compared to cows supplemented with corn silage only. Nonsupplemented dairy cows had the highest milk urea content and performed worst in terms of NUE. The best feed conversion efficiency resulted from the nonsupplemented dairy cows and those supplemented with corn silage plus protein. In nonsupplemented cows, the high feed conversion efficiency seemed to be due to the increased mobilisation of body mass. As a result of the starch-rich supplementations, the ruminal acetic:propionic acid ratio became smaller, and the proportions of n-butyric acid increased. The mean reticular pH values did not substantially vary across the three feeding treatments. For the choice of a supplementation option, herbage allowance and cost of supplement will have to be considered, but aspects of feed-food competition as well as animal welfare should not be ignored., (© 2024 The Authors. Journal of Animal Physiology and Animal Nutrition published by Wiley‐VCH GmbH.)

The dynamics of cattle body chemical composition during growth and fattening periods determine animal performance and beef carcass quality. The aim of this study was to estimate the empty body (EB) and carcass chemical composition of growing beef-on-dairy crossbred bulls (Brown Swiss breed as dam with Angus, Limousin or Simmental as sire) using three-dimensional (3D) imaging. The 3D images of the cattle's external body shape were recorded in vivo on 48 bulls along growth trajectory (75-520 kg BW and 34-306 kg hot carcass weight [HCW]; set 1) and on 70 bulls at target market slaughter weight, including 18 animals from set 1 (average 517 ± 10 kg BW and 289 ± 10 kg HCW; set 2). The linear, circumference, curve, surface and volume measurements on the 3D body shape were determined. Those predictive variables were used in partial least square regressions, together with the effect of the sire breed whenever significant (P < 0.05), with leave-one-out cross-validation to estimate water, lipid, protein, mineral and energy mass or proportions in the EB and carcass. Mass and proportions were determined directly from postmortem grinding and chemical analyses (set 1) or indirectly using the 11 th rib dissection method (set 2). In set 1, bulls' BW and HCW were estimated via 3D imaging, with root mean square error of prediction (RMSEP) of 12 kg and 6 kg, respectively. The EB and carcass chemical component proportions were estimated with RMSEP from 0.2% for EB minerals (observed mean 3.7 ± 0.2%) to 1.8% for EB lipid (11.6 ± 4.2%), close to the RMSEP found for the carcass. In set 2, the RMSEP for estimation via 3D imaging was 9 kg for BW and 6 kg for HCW. The EB energy and protein proportions were estimated, with RMSEP of 0.5 MJ/kg fresh matter (10.1 ± 0.8 MJ/DM) and 0.2% (18.7 ± 0.7%), respectively. Overall, the estimations of chemical component proportions from 3D imaging were slightly less precise for both sets than the mass estimations. The morphological traits from the 3D images appeared to be precise estimators of BW, HCW as well as EB and carcass chemical component masses and proportions., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

We explored appropriate technical setups for the detection of volatile organic compounds (VOCs) from exhaled cow breath by comparing six different polymer-based solid-phase extraction (SPE) cartridges currently on the market for gas chromatography/mass spectrometry (GC-MS) screening. Exhaled breath was sampled at a single timepoint from five lactating dairy cows using six different SPE cartridges (Bond Elut ENV (ENV); Chromabond HRX (HRX); Chromabond HRP (HRP); Chromabond HLB (HLB); Chromabond HR-XCW (XCW) and Chromabond HR-XAW (XAW)). The trapped VOCs were analyzed by dynamic headspace vacuum in-tube extraction GC-MS (DHS-V-ITEX-GC-MS). Depending on the SPE cartridge, we detected 1174-1312 VOCs per cartridge. Most VOCs were alkenes, alkanes, esters, ketones, alcohols, aldehydes, amines, nitriles, ethers, amides, carboxylic acids, alkynes, azoles, terpenes, pyridines, or sulfur-containing compounds. The six SPE cartridges differed in their specificity for the chemical compounds, with the XAW cartridge showing the best specificity for ketones. The greatest differences between the tested SPE cartridges appeared in the detection of specific VOCs. In total, 176 different VOCs were detected with a match factor >80%. The greatest number of specific VOCs was captured by XAW (149), followed by ENV (118), HLB (117), HRP (115), HRX (114), and XCW (114). We conclude that the tested SPE cartridges are suitable for VOC sampling from exhaled cow breath, but the SPE cartridge choice enormously affects the detected chemical groups and the number of detected VOCs. Therefore, an appropriate SPE adsorbent cartridge should be selected according to our proposed inclusion criteria. For targeted metabolomics approaches, the SPE cartridge choice depends on the VOCs or chemical compound groups of interest based on our provided VOC list. For untargeted approaches without information on the animals' metabolic condition, we suggest using multi-sorbent SPE cartridges or multiple cartridges per animal., (Creative Commons Attribution license.)

Exposure to direct solar radiation, high ambient temperature, lack of wind movement, coupled with own metabolic heat production, makes grazing dairy cows vulnerable to heat stress. In pastures, it would be beneficial to monitor heat stress by observable changes in behaviour. We hypothesised that grazing dairy cows exhibit behavioural changes due to increasing heat load in temperate climate. Over two consecutive summers, 38 full-time grazing Holstein dairy cows were investigated in 12 experimental periods of up to 3 consecutive days where the cows were repeatedly exposed to various levels of moderate heat load determined by the comprehensive climate index (CCI). The CCI defines the ambient climate conditions, combining air temperature, relative humidity, solar radiation and wind speed. Vaginal temperature (VT) was automatically measured as an indicator of heat stress. In addition, as a less invasive method, we investigated if reticular temperature (RET) can be indicative of heat stress on pastures. Walking activity, lying-, feeding, and ruminating durations were recorded continuously with sensors. Respiration rate (RR), proximity to and competition at the water trough, social licking, self-licking, inter-individual distance, and fly intensity were directly observed. Data were analysed in the morning (0900-1100 h) and during the hottest time of day when cows were on pasture (1230-1430 h). The VT and RET showed similar patterns in relation to the CCI, suggesting that RET can be suitable for continuous monitoring of heat stress on pastures. In the morning, the cow's VT and RET did not relevantly react to the CCI. During the period 1230-1430 h, the cow's mean VT (mean vaginal temperature (VT MEAN ); range: 37.7-40.3 °C) and mean RET (mean reticular temperature; range: 37.0-41.1 °C) were positively related to the mean CCI (mean comprehensive climate index) in this period (mean ± SD: 25.9 ± 5.71 °C). For cows with greater VT MEAN , an increased mean RR and decreased durations of walking, lying, feeding, and ruminating were found. These cows were also more likely to be in proximity to the water trough and to have small inter-individual distances. Changes in these traits seem to reflect behavioural adaptations to heat stress in a temperate climate and could be used to detect the heat stress in individual dairy cows on pastures., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

In the present experiment, 10 horned and 10 disbudded mid-lactating Brown Swiss cows were included in a crossover feeding trial with a hay or hay and concentrate diet. The effects of dietary neutral detergent fiber (NDF) content and horn status on thermoregulatory responses under thermoneutral and short-term heat stress conditions were studied, as both are considered to ease the cow's thermoregulation under an environmental heat load. Cows received either ad libitum hay and alfalfa pellets (85:15, C-, NDF content: 41.0%) or restricted amounts of hay and concentrate (70:30, C+, NDF content: 34.5%). The level of restriction applied with the C+ diet was determined from pre-experimental ad libitum intakes, ensuring that both diets provided the same intake of net energy for lactation (NE L ). For data collection, cows were housed in respiration chambers for 5 d. The climatic conditions were 10°C and 60% relative humidity (RH), considered thermoneutral (TN) conditions (temperature-humidity index (THI): 52) for d 1 and 2, and 25°C and 70% RH, considered heat stress (HS) conditions (THI: 74), for d 4 and 5. On d 3, the temperature and RH were increased gradually. Compared with TN, HS conditions increased the water intake, skin temperature, respiration and heart rates, and endogenous heat production. They did not affect body temperature, feed intake, or milk production. Lowering dietary fiber content via concentrate supplementation lowered methane and increased carbon dioxide production. It did not mitigate physiological responses to HS. Although the responses of horned and disbudded cows were generally similar, the slower respiration rates of horned cows under HS conditions indicate a possible, albeit minor, role of the horn in thermoregulation. In conclusion, future investigations on nutritional strategies must be conducted to mitigate mild heat stress., (© 2023, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

This study investigated the effects of acacia (extract of Acacia mearnsii) and sainfoin (Onobrychis viciifolia) as condensed tannin (CT)-rich sources on ruminal and manure methane (CH 4 ) emissions in comparison with non-CT silages characterized by different contents of the cell wall and water-soluble carbohydrates. In a 3 × 6 incomplete Latin square design, 30 Holstein cows (63 ± 23 d in milk; mean ± SD; 33.8 ± 7.6 kg of milk per day, body weight 642 ± 81 kg) were provided with ad libitum access to 1 of 6 total mixed rations comprising 790 g of silage and 210 g of concentrate per kilogram of dry matter (DM). The silages were either rich in sainfoin [neutral detergent fiber (NDF): 349 g/kg of DM], perennial ryegrass (NDF: 420 g/kg of DM), or red clover (NDF: 357 g/kg of DM). Each silage was supplemented with 20 g/kg (of total diet DM) of acacia or straw meal. Feed intake and milk yield were recorded daily. Milk composition and ruminal fluid characteristics and microbiota were analyzed. The individual ruminal CH 4 production was determined using the GreenFeed system, and CH 4 emissions from the manure of cows fed the same diets were measured in a parallel experiment over 30 d at 25°C using a dynamic flux chamber. The CT sources did not reduce CH 4 yield or emission intensity. Acacia reduced milk production (from 26.3 to 23.2 kg/d) and DM intake (from 19.7 to 16.7 kg/d) when supplemented with ryegrass, and both CT sources reduced the milk protein content and yield. Acacia supplementation and ryegrass silage reduced the ruminal acetate:propionate ratio. Furthermore, during acacia treatment, the abundance of Methanobrevibacter archaea tended to be lower and that of Thermoplasmata was higher. Acacia reduced the CH 4 emissions from manure for the ryegrass group by 17% but not for the sainfoin and clover groups. Feeding sainfoin silage resulted in the lowest manure-derived CH 4 emissions (-47% compared with ryegrass). In conclusion, acacia reduced ruminal CH 4 production by 10%, but not emission intensity, and the mitigation effect of sainfoin depended on the silage to which it was compared. Because mitigation was partially associated with animal productivity losses, careful evaluation is required before the implementation of tanniferous feeds in farm practice., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Monitoring the feeding and ruminating behaviour of ruminants can be used to assess their health and welfare. The MSR-jaw movement recording system (JAM-R) can automatically record the jaw movements of ruminants. The associated software Viewer2 was developed to classify these recordings in adult cattle and calculate the duration and number of mastications of feeding and ruminating. The purpose of this study was to evaluate the performance of Viewer2 in classifying the behaviour of sheep and goats and assessing their feeding and ruminating. The feeding and ruminating behaviour of ten sheep and ten goats on pasture (observed live) and of five sheep and five goats in the barn (observed by video) were compared with Viewer2 behaviour classifications. To assess the technical and welfare issues of the JAM-R, its application was tested in a feeding experiment with 24 h monitoring of the feeding behaviours of 24 sheep and 24 goats. Viewer2 worked equally well on both species. The mean (95% confidence interval) performance of Viewer2 was at a good level for feeding (accuracy: 0.8-1.0; sensitivity: 0.9-1.0; specificity: 0.6-0.9; precision: 0.7-0.9) and ruminating (accuracy: 0.8-0.9; sensitivity: 0.6-0.8; specificity: 0.8-1.0; precision: 0.9-1.0) compared with human observations, with minor differences between the conditions on pasture and in the barn. The performance improved when recording frequency was increased from 10 Hz to 20 Hz. Applying the JAM-R in a feeding experiment, 71% of the recordings executed were defined as technically error-free and produced plausible values for feeding behaviours. In conclusion, according to the values of accuracy, sensitivity, specificity and precision, the presented JAM-R system with Viewer2 is a reliable and applicable technology for automatic recording of feeding and ruminating behaviour of sheep and goats on pasture and in the barn., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Berthel et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Because of the relevant effects of plant-derived polyphenols (PPs) on monogastrics and ruminants' nutrition, emissions and performance, an increasing number of in vivo and in vitro studies are being performed to better understand the mechanisms of action of polyphenols at both the ruminal and intestinal levels. The biological properties of these phenolic compounds strongly depend on their degradation, absorption and metabolism. The harmonised in vitro digestion method (INFOGEST) is one of the most reliable in vitro methods used to assess the bioaccessibility and or antioxidant activity of PP contained in different matrixes, as well as the interactions of PP and their degradation products with other feed ingredients. The effects of PP released from their matrix after in vitro digestion on different intestinal physiological parameters, such as epithelium integrity, can be further evaluated by the use of ex vivo models such as the Ussing chamber. This review aims to describe the combination of the INFOGEST method, coupled with the Ussing chamber as a valuable model for the digestion and subsequent effects and absorption of phenolic compounds in monogastrics and potentially in ruminants. The advances, challenges and limits of this approach are also discussed., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Even in temperate climate regions, an increase in ambient temperature and exposure to solar radiation can cause heat stress in lactating dairy cows. We hypothesised that grazing dairy cows exhibit short-term physiological changes due to increasing heat load under moderate climate conditions. Over two consecutive summers, 38 lactating Holstein dairy cows were studied in a full-time grazing system. Data were collected in 10 experimental periods of up to three consecutive days with a moderate comprehensive climate index (CCI). The individual animals' vaginal temperature (VT), heart rate, and locomotor activity data were automatically monitored with sensors. Blood samples and proportional whole milk samples were collected at afternoon milking. The concentrations of beta-hydroxybutyrate, glucose, non-esterified fatty acids, urea nitrogen, plasma thyroxine and triiodothyronine were analysed in blood plasma, and fat, protein, lactose, urea nitrogen, cortisol, Na + , K + , and Cl - concentrations were analysed in milk. The daily distribution of VT recordings greater than 39 °C showed a circadian rhythm with a proportion of recordings of 2% and lower during the night and a percentage of 10% or higher in the afternoon. The cows' maximal daily vaginal temperature (VT MAX ) between 0830 and 1430 h was positively related to the mean daily CCI in the same time period (CCI MEAN ; mean and SD 23.6 ± 5.4 °C). Cows with greater VT MAX had an increased mean heart rate, plasma glucose and milk cortisol concentrations and decreased concentrations of plasma thyroxine and triiodothyronine. The concentration of Na + in milk was lower, and the concentration of K + in milk tended to be higher in cows with increased VT MAX . For beta-hydroxybutyrate, non-esterified fatty acids and urea nitrogen concentrations in plasma and fat and lactose concentrations in milk no relationships were found in terms of increasing VT. For milk urea nitrogen and protein concentrations, the proportion of total variance explained by inter-individual or -period variance was high. In conclusion, changes observed in milk and blood likely reflected short-term physiological responses to moderate heat stress. In particular, milk cortisol and Na + may be useful traits for timely monitoring of heat stress in individual cows because their inter-individual variances were relatively small and samples can be collected non-invasively., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

The aim of the present study was to estimate the chemical composition (water, lipid, protein, mineral, and energy contents) of carcasses measured postmortem using dual-energy X-ray absorptiometry (DXA) scans of cold half-carcass or 11th rib cut. One hundred and twenty beef-on-dairy (dam: Swiss Brown, sire: Angus, Limousin, or Simmental) bulls (n = 66), heifers (n = 42), and steers (n = 12) were included in the study. The reference carcass composition measured after grinding, homogenization, and chemical analyses was estimated from DXA variables using simple or multiple linear regressions with model training on 70% (n = 84) and validation on 30% (n = 36) of the observations. In the validation step, the estimates of water and protein masses from the half-carcass (R2 = 0.998 and 0.997; root mean square error of prediction [RMSEP], 1.0 and 0.5 kg, respectively) and 11th rib DXA scans (R2 = 0.997 and 0.996; RMSEP, 1.5 and 0.5 kg, respectively) were precise. Lipid mass was estimated precisely from the half-carcass DXA scan (R2 = 0.990; RMSEP = 1.0 kg) with a slightly lower precision from the 11th rib DXA scan (R2 = 0.968; RMSEP = 1.7 kg). Mineral mass was estimated from half-carcass (R² = 0.975 and RMSEP = 0.3 kg) and 11th rib DXA scans (R2 = 0.947 and RMSEP = 0.4 kg). For the energy content, the R2 values ranged from 0.989 (11th rib DXA scan) to 0.996 (half-carcass DXA scan), and the RMSEP ranged from 36 (half-carcass) to 55 MJ (11th rib). The proportions of water, lipids, and energy in the carcasses were also precisely estimated (R2 ≥ 0.882) using either the half-carcass (RMSEP ≤ 1.0%) or 11th rib-cut DXA scans (RMSEP ≤ 1.3%). Precision was lower for the protein and mineral proportions (R2 ≤ 0.794, RMSEP ≤ 0.5%). The cattle category (sex and breed of sire) effect was observed only in some estimative models for proportions from the 11th rib cut. In conclusion, DXA imaging of either a cold half-carcass or 11th rib cut is a precise method for estimating the chemical composition of carcasses from beef-on-dairy cattle., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Mixed rations provide ruminants with a balanced diet by aiming to prevent selective feeding. However, this is a natural behavior of sheep and goats based on their dietary needs and the nutritional properties of feedstuffs. Therefore, the present study investigates non-lactating dairy sheep's and goats' acceptance of a mixed ration when it is offered as choice next to its single components. Because all offered feeds were of comparable nutritional value, the animals were expected to not show a particular preference. Twelve pairs of sheep and goats each, were offered three different feeds simultaneously for 5 replicate days. Two feeds consisted of a single component, hay (H) or grass-silage (G) of similar nutritional value. The third feed was a mixed ration (M) including both single-feed components in a 50:50 dry matter (DM) ratio. Feeds were offered ad libitum twice daily. The animals' intake of each feed was recorded at six time points per day by weighing the leftovers. Feed preference was expressed as the natural logarithm of the ratio of the intake of the single component to the intake of M and analyzed using linear mixed-effects models. Additionally, the animals' first choices after gaining access to the feeds were recorded at each weighing event and analyzed using an item response tree generalized mixed-effects model. The sheep's average daily DM intake was 59 (±11)% G, 26 (±10)% H, and 15 (±10)% M (mean ± standard deviation). Goats consumed an average of 56 (±13)% G, 37 (±12)% H, and 7 (±6)% M daily. Both species preferred the single components to M in all observation periods. The proportions of the three feeds consumed differed throughout the day and between species. For both species, the estimated probability that an animal chooses a single component over M first was over 94% at all time points. These results show that, contrary to our expectations, non-lactating dairy sheep and goats prefer single components over a mixed ration of the same components and similar nutritional value. This might be caused by the animals seeking to diversify their feed throughout the day independent of apparent nutritional values and/or because sensory properties of the single components, indicating palatability, are relevantly reduced by mixing., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Berthel, Simmler, Dohme-Meier and Keil.)

The aim of present study was to compare in vivo and post mortem methods for estimating the empty body (EB) and carcass chemical compositions of Simmental lactating and growing cattle. Indirect methods were calibrated against the direct post mortem reference determination of chemical compositions of EB and carcass, determined after grinding and analyzing the water, lipid, protein, mineral masses, and energy content. The indirect methods applied to 12 lactating cows and 10 of their offspring were ultrasound (US), half-carcass and 11th rib dual-energy X-ray absorptiometry (DXA) scans, subcutaneous and perirenal adipose cell size (ACS), and dissection of the 11th rib. Additionally, three-dimensional (3D) images were captured for 8 cows. Multiple linear regressions with leave-one-out-cross-validations were tested between predictive variables derived from the methods tested, and the EB and carcass chemical compositions. Partial least square regressions were used to estimate body composition with morphological traits measured on 3D images. Body weight (BW) alone estimated the EB and carcass composition masses with a root mean squared error of prediction (RMSEP) for the EB from 1 kg for minerals to 12.4 kg for lipids, and for carcass from 0.9 kg for minerals to 7.8 kg for water. Subcutaneous adipose tissue thickness measured by US was the most accurate in vivo predictor when associated with BW to estimate chemical composition, with the EB lipid mass RMSEP = 11 kg and R 2 = 0.75; carcass water mass RMSEP = 6 kg and R 2 = 0.98; and carcass energy content RMSEP = 236 MJ and R 2 = 0.91. Post mortem, carcass lipid mass was best estimated by half-carcass DXA scan (RMSEP = 2 kg, R 2 = 0.98), 11th rib DXA scan (RMSEP = 3 kg, R 2 = 0.96), 11th rib dissection (RMSEP = 4 kg, R 2 = 0.92), and perirenal ACS (RMSEP = 6 kg, R 2 = 0.79) in this respective order. The results obtained by 11th rib DXA scan were accurate and close to the half-carcass DXA scan with a reduction in scan time. Morphological traits from 3D images delivered promising estimations of the cow EB and carcass chemical component masses with an error less than 13 kg for the EB lipid mass and than 740 MJ for the EB energy. Future research is required to test the 3D imaging method on a larger number of animals to confirm and quantify its interest in estimating body composition in living animals., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Low plasma total cholesterol (TC) concentrations are characteristic during the negative energy balance in early lactating dairy cows. The objective was to investigate short-term effects of different TC concentrations during an aggravated energy deficiency through a 1-week concentrate withdrawal on adaptations of metabolism and milk production. Multiparous Holstein cows (n = 15) were investigated during 3 week beginning at 24 ± 7 DIM (mean ± SD). Cows were kept on pasture and received additional concentrate in experimental week 1 and 3, while in week 2, concentrate was withdrawn. Blood was sampled once and milk twice daily. Based on their average TC concentration during week 1 (prior to concentrate withdrawal), cows were retrospectively assigned into a high (H-Chol; n = 8, TC ≥ 3.36 mmol/L) and a low TC groups (L-Chol; n = 7, TC < 3.36 mmol/L). Concentrations of phospholipids and lipoproteins were higher in H-Chol compared to L-Chol throughout the study (p < 0.05). During concentrate withdrawal, milk yield, glucose and insulin concentrations decreased similarly in both groups, while milk fat, milk acetone and plasma BHB were higher in H-Chol compared to L-Chol (p < 0.05). Compared to initial values, plasma NEFA, TAG and VLDL increased in both groups within 2 days after concentrate withdrawal (p < 0.05). Concentrations of NEFA during week 2 were greater in L-Chol compared to H-Chol (p < 0.05). Despite reintroduction of concentrate, milk yield in H-Chol remained lower for two more days compared to week 1 (p < .05), whereas milk yield recovered immediately in L-Chol. Activity of aspartate aminotransferase was higher in H-Chol compared to L-Chol in week 2 (p < 0.05). Greater plasma TC concentrations were associated with a reduced increase of NEFA. Further research is warranted if TC concentrations are related to adipose tissue mobilization and fatty acid turnover., (© 2021 Wiley-VCH GmbH.)

Sainfoin is a protein-rich legume with an ideal amino acid profile and therefore could partly replace soybeans in the diets of growing pigs. However, sainfoin also contains a non-negligible amount of condensed tannins (CTs), which can act as antinutritional factors. Bioactive plant compounds, like hydrolysable tannins, have been suggested to be suitable in entire male (EM) production, as they impair the development of accessory sex glands and, by that, reduce boar taint compound levels without negatively impacting growth. It is unknown whether, similar to hydrolysable tannins, CTs from sainfoin reduce the incidence of boar taint without impacting growth performance, carcass traits, and meat quality. For the experiment, 48 Swiss Large White EM were assigned within litter to one of four grower (25-60 kg BW) and finisher (60-105 kg BW) diets supplemented with 0 (T0), 5 (T5), 10 (T10), and 15% (T15) sainfoin meal, respectively. The four diets were designed to be isocaloric and isoproteic. Increasing the dietary sainfoin level had no negative effect on growth performance or the carcass characteristics. Despite leading to a similar feed intake between the treatment groups, increasing the dietary sainfoin levels tended (P ≤ 0.08) to reduce the number of feeder visits but increased the time spent at the feeder as well as the feed intake per visit during the finisher period. By increasing sainfoin intake, the levels of C18:3n-3 and long-chain homologs linearly increased (P < 0.01) in the backfat and intramuscular fat (IMF), whereas in the backfat, but not the IMF, the 18:2n-6 levels decreased (P < 0.01). The latter triggered a greater (P < 0.01) desaturation rate (C18:1n-9/C18:0) of the saturated fatty acids, resulting in a greater (P < 0.01) proportion of monounsaturated fatty acid. Apart from a linear decrease (P = 0.02) in the androstenone levels in the longissimus thoracis (LT), increasing the sainfoin intake had no effect on the level of boar taint in the LT and backfat. As determined by the elevated correlation coefficient, skatole and indole levels, but not androstenone levels, in the adipose tissue seem to be reliable proxies for their respective levels in LT and, therefore, in pork. In conclusion, sainfoin is a suitable homegrown protein source for grower finisher pigs and can be included at up to 15% in the diet to replace 7% of soybean in a diet without producing any noteworthy effects on growth, whereas the impact of CTs on boar taint was limited., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Two experimental periods were employed to investigate the fate of ingested CT from BT and their effects on the intake, digestibility, and N balance in lambs fed diets differing in CP levels. In period 1, 24 lambs were fed a basal diet either treated with polyethylene glycol (PEG+) to deactivate CT or without polyethylene glycol (PEG-). In period 2, the same lambs were used in a 2 × 2 factorial design and fed either the basal diet (BP) or a high protein diet (HP), again treated with or without PEG. In both experimental periods, feeding lambs diets without PEG caused a reduction in the dry matter (DM) intake and an increase in the DM digestibility. Urinary and total N excretion decreased in lambs fed diets without PEG, but only in absolute terms and not in relation to the N intake. The total N intake, total N excretion, and body N retention were higher with a higher dietary CP level. Related to the CT intake, less soluble and protein-bound CT were excreted by lambs fed diets without PEG, and more protein-bound and fiber-bound CT were excreted by lambs fed BP diets. Regardless of the PEG treatment and CP level, not all CT that are ingested are also excreted. The effect of PEG treatment on the N excretion pathway was independent of the CP level.

Proanthocyanidins are plant specialized metabolites which are beneficial to animal nutrition and health. This study determined how proanthocyanidin profiles of sainfoin ( Onobrychis viciifolia ) and birdsfoot trefoil ( Lotus corniculatus ) change during the forage conservation process and along the digestive tract of lamb. We determined soluble, protein- and fiber-bound proanthocyanidins by spectrophotometric methods and soluble proanthocyanidin profiles by UPLC-MS/MS. During the conservation process, the total proanthocyanidin contents reduced in both forages and the relative proportion of insoluble proanthocyanidins increased, especially in sainfoin. The soluble proanthocyanidins, their mean degree of polymerization and the relative prodelphinidin share declined in both feed species. In the abomasum of lambs fed sainfoin silage, most of the proanthocyanidins were in insoluble form bound to proteins and fibers, but in the small and large intestines, the proportion of soluble proanthocyanidins increased again. For lambs fed birdsfoot trefoil, the trend was not so clear as proanthocyanidins were already mainly soluble in the abomasum. Nevertheless, a large part of soluble proanthocyanidins was recovered in the digestive tract but could not be detected by the UPLC-MS/MS method used. This study suggests that proanthocyanidins have probably been metabolized in the digestive tract by the resident microbiota.

Introduction: Milk production in Switzerland is mainly based on herbage feeding with little input of concentrates. The present study investigated the effects of a solely herbage-based diet with (C) and without concentrate (nC) supplementation on luteal activity, milk production and metabolic status in 23 multiparous Holstein dairy cows with early or delayed resumption of ovarian cyclicity post partum (pp). Cows were retrospectively assigned either to a group with early (until d 25 pp, EOV) or delayed resumption of ovarian activity (> d 30 pp, DOV), resulting in four subgroups depending on concentrate feeding: DOV-C, DOV-nC, EOV-C, EOV-nC. Milk progesterone (P4) concentration was measured every 3 d, and different metabolites were analyzed in weekly blood samples. Resumption of ovarian activity was detected between d 19 and 25 pp in EOV, and between d 30 and 60 pp in DOV. In DOV-C, resumption of cyclicity tended to start earlier (38.3 ± 1.7 d pp) compared to DOV-nC (45.2 ± 6.3 d pp; P = 0.10). Independent of grouping, the ovarian activity occurred later in cows with greater plasma β-hydroxybutyrate (BHB) concentrations (P  1 ng/mL did not differ between groups (P > 0.05), but milk P4 peaks during the experiment were higher in EOV compared to DOV (P .

Adrenocorticotropic hormone (ACTH) challenges are frequently performed in repetition when evaluating stress or welfare in animals. To our knowledge, the repeatability of ACTH challenges in cattle, although fundamental to further studies of this type, has not yet been the subject of research. Therefore, the objective of this study was to evaluate the repeatability of ACTH challenges in fattening bulls of different horn status. Eight-one bulls were subjected to 3 consecutive ACTH challenges. The first challenge (C1) was performed in calves aged 1.5 mo. Subsequently, animals were characterized as high or low cortisol responders and either disbudded or left with horns. They were then assigned to 1 of 3 rearing groups: a horned group (H+), a disbudded group (H-), and a mixed group (M; 50% horned and 50% disbudded), with each group containing an equal number of high and low responders. The second ACTH challenge (C2) was performed at the age of 11 mo. Time of day (TOD) of challenge was either fixed (ST = same TOD) or alternated (AT = alternate TOD) between C1 and C2. The third ACTH challenge (C3) was performed 7 d after and at the same TOD as C2. Saliva samples were taken 60 and 30 min before and 30, 60, 90, 120, and 150 min after each intravenous ACTH injection. The area under the curve (AUC) was calculated with respect to both ground (AUC G ) and to increase (AUC I ). The AUC I increased markedly between C1 and C2 (P < 0.05) in ST bulls, and no effects were observed for AUC G between C1 and C2 in ST or AT bulls, nor for any AUC between C2 and C3 (P > 0.1). The overall repeatability of AUC G and AUC I between C1 and C2, reflecting the repeatability between 2 different physiological states, was poor and moderate, respectively, for ST bulls (AUC G : r = 0.24, P > 0.1, intraclass correlation coefficient (ICC) = 0.21; AUC I : r = 0.48, P < 0.01, ICC = 0.41) and lacked in AT bulls (AUC G : r = 0.07, P > 0.1; ICC = 0.03; AUC I : r = 0.08, P > 0.1, ICC = 0.06). The repeatability of AUC G and AUC I between C2 and C3, reflecting the repeatability within the same physiological state, was moderate (AUC G : r = 0.59, P < 0.001; ICC = 0.53; AUC I : r = 0.58, P < 0.001, ICC = 0.52). Assignment to high and low responder groups based on peak cortisol concentration in C1 did not persist over time. H+ bulls showed higher AUC I in C2 and C3 (P < 0.1 and P < 0.05, respectively) than H- bulls. The M group differed from the H- group only in C3 (P < 0.05). Thus, the effect of horn status on ACTH challenges needs further investigation. In conclusion, our results report poor repeatability of the cortisol response to ACTH challenges for challenges performed in different physiological states and moderate repeatability for challenges performed within the same physiological state. Moreover, they point out the importance of standardization of TOD when performing repeated ACTH challenge., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Since heritability of CH 4 emissions in ruminants was demonstrated, various attempts to generate large individual animal CH 4 data sets have been initiated. Predicting individual CH 4 emissions based on equations using milk mid-infrared (MIR) spectra is currently considered promising as a low-cost proxy. However, the CH 4 emission predicted by MIR in individuals still has to be confirmed by measurements. In addition, it remains unclear how low CH 4 emitting cows differ in intake, digestion, and efficiency from high CH 4 emitters. In the current study, putatively low and putatively high CH 4 emitting Brown Swiss cows were selected from the entire Swiss herdbook population (176,611 cows), using an MIR-based prediction equation. Eventually, 15 low and 15 high CH 4 emitters from 29 different farms were chosen for a respiration chamber (RC) experiment in which all cows were fed the same forage-based diet. Several traits related to intake, digestion, and efficiency were quantified over 8 d, and CH 4 emission was measured in 4 open circuit RC. Daily CH 4 emissions were also estimated using data from 2 laser CH 4 detectors (LMD). The MIR-predicted CH 4 production (g/d) was quite constant in low and high emission categories, in individuals across sites (home farm, experimental station), and within equations (first available and refined versions). The variation of the MIR-predicted values was substantially lower using the refined equation. However, the predicted low and high emitting cows (n = 28) did not differ on average in daily CH 4 emissions measured either with RC or estimated using LMD, and no correlation was found between CH 4 predictions (MIR) and CH 4 emissions measured in RC. When individuals were recategorized based on CH 4 yield measured in RC, differences between categories of 10 low and 10 high CH 4 emitters were about 20%. Low CH 4 emitting cows had a higher feed intake, milk yield, and residual feed intake, but they differed only weakly in eating pattern and digesta mean retention times. Low CH 4 emitters were characterized by lower acetate and higher propionate proportions of total ruminal volatile fatty acids. We concluded that the current MIR-based CH 4 predictions are not accurate enough to be implemented in breeding programs for cows fed forage-based diets. In addition, low CH 4 emitting cows have to be characterized in more detail using mechanistic studies to clarify in more detail the properties that explain the functional differences found in comparison with other cows., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Currently, various attempts are being made to implement breeding schemes aimed at producing low methane (CH 4 ) emitting cows. We investigated the persistence of differences in CH 4 emission between groups of cows categorized as either low or high emitters over a 5-mo period. Two feeding regimens (pasture vs. indoors) were used. Early- to mid-lactation Holstein Friesian cows were categorized as low or high emitters (n = 10 each) retrospectively, using predictions from milk mid-infrared (MIR) spectra, before the start of the experiment. Data from MIR estimates and from measurements with the GreenFeed (GF; C-Lock Technology Inc., Rapid City, SD) system over the 5-mo experiment were combined into 7-, 14-, and 28-d periods. Feed intake, eating and ruminating behavior, and ruminal fluid traits were determined in two 7-d measurement periods in the grazing season. The CH 4 emission data were analyzed using a split-plot ANOVA, and the repeatability of each of the applied methods for determining CH 4 emission was calculated. Traits other than CH 4 emission were analyzed for differences between low and high emitters using a linear mixed model. The initial category-dependent differences in daily CH 4 production persisted over the subsequent 5 mo and across 2 feeding regimens with both methods. The repeatability analysis indicated that the biweekly milk control scheme, and even a monthly scheme as practiced on farms, might be sufficient for confirming category differences. However, the relationship between CH 4 data estimated by MIR and measured with GF for individual cows was weak (R 2 = 0.26). The categorization based on CH 4 production also generated differences in CH 4 emission per kilogram of milk; differentiation between cow categories was not persistent based on milk MIR spectra and GF. Compared with the high emitters, low emitters tended to show a lower acetate-to-propionate ratio in ruminal volatile fatty acids, whereas feed intake and ruminating time did not differ. Interestingly, the low emitters spent less time eating than the high emitters. In conclusion, the CH 4 estimation from analyzing the milk MIR spectra is an appropriate proxy to form and regularly control categories of cows with different CH 4 production levels. The categorization was also sufficient to secure similar and persistent differences in emission intensity when estimated by MIR spectra of the milk. Further studies are needed to determine whether MIR data from individual cows are sufficiently accurate for breeding., (The Authors. Published by FASS Inc. and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

The study used 81 young bulls, half of which were disbudded at 7 weeks of age. The effects of horn status during rearing and of acute physical and emotional stress just before slaughter on the physiological status at slaughter and subsequent meat quality were investigated. Bulls were reared in groups containing i) only bulls with horns, ii) only bulls without horns, or iii) mixed (half with, and half without horns). Bulls of each rearing condition were assigned to one of two slaughter conditions: with limited (LS) or with supplementary stress (SS). LS resulted in lower heart rates, stress hormone concentrations and carcass temperature, whereas SS resulted in faster post mortem pH decline and lower juiciness. Horned bulls from unmixed rearing groups had lower early pm temperature, shorter sarcomeres, and lower tenderness compared to disbudded bulls. Correlations and regression analysis revealed relationships between physiological indicators, mainly heart rate before slaughter, and meat quality, including water-holding capacity and indicators of proteolysis., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In Switzerland, fresh herbage is a favoured feed for dairy cows due to its high quality and availability and low production costs. However, transition and early lactation are periods characterized by an increased nutrient demand that may not be covered by herbage alone. To compare the effects of concentrate supplementation in early lactation on nutrient efficiency and ruminal fermentation, 24 multiparous Holstein cows were assigned to two performance groups according to their previous lactation milk yield: high- (8,959 ± 984 kg) and low- (6,204 ± 1,000 kg) potential cows. Within this group, cows were allocated to two treatment groups receiving either herbage ad libitum (n = 11) or herbage supplemented with concentrate (n = 13). The experiment started for each cow 2 weeks before the predicted calving date (LW-2) and lasted until lactation week (LW) 8. Milk yield and dry matter intake (DMI) were recorded daily. The reticular pH was measured continuously using a telemetric pH bolus. Milk components and ruminal fermentation traits were analysed in LW-2, LW2, LW4, LW6 and LW8. Supplemented cows (p < 0.001) and high-potential cows (p = 0.015) produced more milk than unsupplemented cows and low-potential cows, respectively. Milk acetone was affected by supplementation (p < 0.001) and milk potential (p = 0.002) and was especially high in unsupplemented, high-potential cows until LW6. Supplementation caused a decrease in herbage DMI (p < 0.001) but resulted in an increased total DMI (p < 0.001), whereas milk potential had no effect on DMI. Associated with an increasing DMI (p < 0.001), ruminal volatile fatty acid concentration (p = 0.024) increased and reticular pH (p < 0.001) decreased from LW2 until LW6. Apart from that, effects on ruminal fermentation and reticular pH were minor. In conclusion, even though apparent nutrient efficiency was high, high-potential cows without supplementation seem to struggle more with reduced nutrient availability than other cows; therefore, they appear to be more prone to metabolic stress and consequently to production diseases., (© 2018 Blackwell Verlag GmbH.)