Hasil untuk "Dairying"

J. Capper, R. Cady, D. Bauman

A common perception is that pasture-based, low-input dairy systems characteristic of the 1940s were more conducive to environmental stewardship than modern milk production systems. The objective of this study was to compare the environmental impact of modern (2007) US dairy production with historical production practices as exemplified by the US dairy system in 1944. A deterministic model based on the metabolism and nutrient requirements of the dairy herd was used to estimate resource inputs and waste outputs per billion kg of milk. Both the modern and historical production systems were modeled using characteristic management practices, herd population dynamics, and production data from US dairy farms. Modern dairy practices require considerably fewer resources than dairying in 1944 with 21% of animals, 23% of feedstuffs, 35% of the water, and only 10% of the land required to produce the same 1 billion kg of milk. Waste outputs were similarly reduced, with modern dairy systems producing 24% of the manure, 43% of CH(4), and 56% of N(2)O per billion kg of milk compared with equivalent milk from historical dairying. The carbon footprint per billion kilograms of milk produced in 2007 was 37% of equivalent milk production in 1944. To fulfill the increasing requirements of the US population for dairy products, it is essential to adopt management practices and technologies that improve productive efficiency, allowing milk production to be increased while reducing resource use and mitigating environmental impact.

C. Eastwood, L. Klerkx, M. Ayre et al.

Smart farming (also referred to as digital farming, digital agriculture and precision agriculture) has largely been driven by productivity and efficiency aims, but there is an increasing awareness of potential socio-ethical challenges. The responsible research and innovation (RRI) approach aims to address such challenges but has had limited application in smart farming contexts. Using smart dairying research and development (R&D) in New Zealand (NZ) as a case study, we examine the extent to which principles of RRI have been applied in NZ smart dairying development and assess the broader lessons for RRI application in smart farming. We draw on insights from: a review of research on dairy technology use in NZ; interviews with smart dairying stakeholders; and the application of an analytical framework based on RRI dimensions. We conclude that smart dairying R&D and innovation activities have focused on technology development and on-farm use without considering socio-ethical implications and have excluded certain actors such as citizens and consumers. This indicates that readiness to enact RRI in this context is not yet optimal, and future RRI efforts require leadership by government or dairy sector organisations to fully embed RRI principles in the guidelines for large R&D project design (what has also been referred to as ‘RRI maturity’). More broadly, enacting RRI in smart farming requires initial identification of RRI readiness in a given sector or country and devising a roadmap and coherent project portfolio to support capacity building for enacting RRI. Additionally, methods (such as RRI indicators) for operationalising RRI must be adapted to the context of the national or sectoral innovation system in which smart farming is being developed.

M. Ghelichkhan, L.H.P. Silva, K.J. Soder et al.

ABSTRACT: Canola meal (CM) contains glucosinolates, which are metabolites known to inhibit the transfer of I from feed to milk. Therefore, we aimed to compare the effects of diets containing soybean meal (SBM) or CM, each supplemented with ethylenediamine dihydroiodide (EDDI) and the I-rich brown seaweed Ascophyllum nodosum (ASCO), on I metabolism, production performance, and nutrient utilization in dairy cows. Sixteen multiparous Jersey cows averaging (mean ± SD) 138 ± 58 DIM and 456 ± 62.1 kg of BW at the beginning of the study were used in a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Each experimental period lasted 21 d, with 14 d for diet adaptation and 7 d for data and sample collection. Diets were formulated to yield similar concentrations of CP and I. Cows were fed (DM basis) the following experimental diets as TMR: (1) 10% SBM plus 110 mg/d of EDDI (SB+I), (2) 10% SBM plus 113 g/d of the brown seaweed ASCO (SB+SWD), (3) 12.5% CM plus 110 mg/d of EDDI (CAN+I), and (4) 12.5% CM plus 113 g/d of the brown seaweed ASCO (CAN+SWD). The I sources EDDI and ASCO meal were mixed with ground corn, placed inside rubber tubs, and offered to cows immediately before the delivery of the TMR. We observed a protein source by I source interaction for milk I concentration, which was similar between diets containing EDDI (SB+I and CAN+I), but it decreased by 27.8% when feeding CAN+SWD versus SB+SWD. We also detected a protein source by I source interaction for the serum concentration of free thyroxin, with cows fed CAN+I showing a tendency to have greater free thyroxin levels than those fed SB+I. Iodine intake, milk I yield, serum I concentration, and urinary excretion of I were lower in cows fed CAN+SWD and CAN+SWD than SB+I and CAN+I. In addition, milk I yield, milk I transfer efficiency (milk I yield/I intake), and the serum concentrations of thyroid-stimulating hormone and total triiodothyronine were lower in diets containing CM than SBM. Contrarily, the serum concentration of I and the urinary excretion of I increased in cows receiving CAN+I and CAN+SWD versus SB+I and SB+SWD. Whereas DMI and total glucosinolate intake were greater with feeding CAN+I and CAN+SWD versus SB+I and SB+SWD, milk yield, milk N efficiency, and the apparent total-tract digestibility of nutrients were lower in cows fed diets containing CM than SBM. The CM used in our study was likely overheated based on the high concentrations of neutral detergent insoluble CP (23.6%) and acid detergent insoluble CP (17.5%), possibly explaining the reduction in milk yield and nutrient utilization in cows fed CAN+I and CAN+SWD compared with SB+I and SB+SWD. In brief, our results revealed that feeding CM reduced milk I concentration, milk I yield, and milk I transfer efficiency, particularly when supplemented with ASCO meal.

Xi Lu, Bingyan Zhang, Man Zhao et al.

ABSTRACT: This study established a systematic framework to isolate and functionally characterize lactic acid bacteria from camel milk collected in Western China, targeting strains exhibiting robust antioxidant properties. Among 199 isolates, Leuconostoc mesenteroides C8 exhibited high oxidative stress tolerance and superior antioxidant activity. Its incorporation into yogurt fermentation significantly improved product stability and antioxidant retention during 21-d storage, even under light and thermal stress. This dual-level validation—from functional screening to food system application—highlights C8's functional potential and positions camel milk–derived probiotics as valuable resources for developing antioxidant-enriched, value-added fermented dairy products.

C. Ferrari, C. Evangelista, L. Basiricò et al.

ABSTRACT: This study investigated the pattern of 6 behavioral parameters in Holstein dairy cows under heat stress (HS) conditions using a generalized additive mixed model (GAMM) statistical approach, while also evaluating the effectiveness of a commercial electrolyte, osmolyte, and antioxidant blend in mitigating HS-induced adverse effects. The trial was conducted during a severe Italian summer on 84 multiparous dairy cows in the Central Italy, divided into 4 balanced groups (2 treated and 2 control) of 21 cows each. All animals received the same diet, and the treatment groups were supplemented with 3,150 g/d of the additive. Behavioral parameters, namely low activity (LA), medium activity (MA), high activity (HA), rumination time (RUM), eating time (ET), and heavy breathing (OH), were monitored using neck collar sensors. Generalized additive mixed models were used to analyze trajectory changes of these parameters over time and climatic conditions. Results indicated significant variations in only one activity parameter, with treated cows showing increased MA with rising temperature-humidity index (THI). Eating time declined with increasing HS, particularly in the treated group, suggesting potential HS relief. Rumination time decreased with increasing HS levels but increased also with milk yield and lactation stage. As expected, heavy breathing significantly increased with THI, especially beyond THI 80, and was influenced by milk yield and lactation stage but not by the treatment. The use of GAMM enhanced visualization and understanding of severe climatic conditions' effects on behavioral parameters.

T. Touil, F. Huot, S. Claveau et al.

ABSTRACT: Low reticuloruminal pH (rpH) for a prolonged period could lead to SARA. This disease negatively affects cow health and is associated with monetary losses for the dairy industry. The aim of this study was to predict rpH and SARA separately using different machine learning (ML) models applied to Fourier-transform infrared spectroscopy (FTIR) spectra obtained from routine DHI milk analysis of individual cows. A total of 107 primiparous and multiparous Holstein cows were selected from 12 commercial farms in Québec, Canada, and their rpH was continuously monitored for 150 d using wireless boluses. In parallel, 2,634 individual milk samples were collected in the morning and afternoon and analyzed to obtain FTIR spectra. After the cleaning process, 1,744 samples remained, evenly divided into 872 morning (a.m.) and 872 afternoon (p.m.) samples. The FTIR and rpH data were combined to create 3 equally balanced datasets for ML model development: one for a.m. samples, one for p.m. samples, and one composed of both a.m. and p.m. samples, with 872 samples in each dataset. Various spectra preprocessing methods were evaluated, including using the first derivative of the spectra and filtering with 3 different sets of spectra. Additionally, different ML algorithms, including partial least squares, random forest, and gradient boosting, were used to predict rpH and SARA. A total of 36 different models were developed and evaluated for both rpH and SARA prediction. All ML models were assessed using 3 different cross-validation (C-V) methods: nested 10-fold, nested leave-one-farm-out (LOFO), and nested leave-cows-out (LCO) C-V. For rpH prediction, the best performance was achieved using nested 10-fold C-V with median R2 values of 0.26, 0.26, and 0.22 for the a.m., p.m., and a.m./p.m. datasets, respectively. However, these performances were likely overoptimistic as none of the models evaluated using nested LOFO or nested LCO C-V obtained R2 higher than 0.12. Unlike rpH, SARA prediction accuracies evaluated using nested LOFO (a.m.: 59%, p.m.: 69%, a.m./p.m.: 64%), and nested LCO (a.m.: 67%, p.m.: 66%, a.m./p.m.: 64%) were closer to the nested 10-fold C-V. These results indicated that rpH was likely not predictable from FTIR, but SARA can be predicted separately and directly from FTIR with 69% accuracy from routine DHI milk samples of individual cows.

G. Ferreira, C.L. Teets, H. Galyon et al.

ABSTRACT: We hypothesized that, relative to harvesting small-grain grasses at the soft dough stage (SFT) of maturity, harvesting small-grain grasses at the boot stage (BT) of maturity would result in less expensive dairy rations when commodity prices are high but not when commodity prices are low. Small plots of small-grain grasses were planted during the fall of 2020 and 2021 in Blacksburg, Blackstone, and Orange, Virginia. In each year and location, 2 varieties of barley, 2 varieties of rye, and 4 varieties of triticale were planted in plots replicated 6 times, yielding 288 plots. Within each year and location, we harvested half of the plots at BT and the other half at SFT. For each of the 6 small-grain grasses, we formulated 8 rations according to 8 different scenarios using the least-cost optimizer. The scenarios included high and low commodity prices, high and low dietary forage (60% and 40% forage, respectively), and the inclusion of small-grain grasses harvested at BT or SFT. Harvesting at SFT yielded 107% to 205% more DM than harvesting at BT. Relative to BT, small-grain grasses harvested at SFT had greater concentrations of OM, NDF, ADF, ADL, and starch but lower concentrations of CP. Relative to BT, small-grain grasses harvested at SFT also had a greater concentration of undegraded NDF (NDF basis). Species had minimal influence on the nutritional quality of small-grain grasses for silage. Under a low-price scenario, the ration formulation system ignored all 6 small-grain grass silages and included corn silage as the only forage source when we did not limit its inclusion. Under a high-price scenario, the ration formulation system included all 6 small-grain grass silages when formulating low-forage diets with unlimited corn silage. However, a preference between BT and SFT stages did not exist, with the optimizer not consistently selecting a specific maturity stage. After evaluating the yields, the chemical composition, and the effects on ration formulation in this study, future studies should aim to evaluate the influence of maturity at harvest of small-grain grasses on cow performance and environmental impacts.

K.J. Alward, A.J. Duncan, A.D. Ealy et al.

ABSTRACT: Multiparous Holstein cows exposed to short-day photoperiod (SDPP) of 8 h of light per day during their dry period produced up to 3.2 kg more milk per day compared with cows exposed to long-day photoperiod (LDPP) of 16 h of light per day; it is unknown if a similar response would be observed for Jersey cow milk production. The objective of this study was to determine the effect of photoperiod during the dry period on subsequent colostrum and milk production in Holstein and Jersey cattle. Holstein and Jersey cows (n = 33) were dried off 60 d before their due date and randomly assigned to SDPP (Holstein, n = 9; Jersey, n = 8) or LDPP (Holstein, n = 8; Jersey, n = 8) until calving. Cows were weighed at the time of enrollment (d 0) and were housed in an enclosed barn at 20°C and exposed to 250 to 450 lx during periods of light and <10 lx during periods of darkness. At calving, colostrum volume was weighed and tested for relative protein concentration with a Brix refractometer and a sample was collected for component analysis (fat, protein, lactose, SNF) via infrared spectroscopy, as well as IgA, IgG, IgG1, IgM, lactoferrin, and SCS analysis. After calving, cows were returned to the freestall barn and exposed to ambient photoperiod and temperature. Milk production data were collected for 15 wk postcalving. Data were analyzed using PROC MIXED in SAS (SAS 9.4; SAS Institute Inc., Cary, NC) with treatment, breed, and d 0 weight as fixed effects. PROC MIXED with repeated measures was used to evaluate the relationship of day length and breed with mature milk volume, fat, and protein production. Random effects included replicate, lactation number, genetic inbreeding percentage, previous lactation mature equivalent 305-d protein production, and calf sex. For colostrum, Brix score, colostral protein, fat, IgA, and IgM were increased in Jersey cows compared with Holstein cows. Total colostrum weight, SNF, lactose, lactoferrin, IgG, IgG1, and SCS did not differ by breed or treatment. Postcalving, ECM production was increased in Holstein cows compared with Jersey cows but unaffected by photoperiod treatment. Conversely, milk protein percentage was increased for Jersey cows relative to Holstein cows but was unaffected by photoperiod treatment. Milk fat increased in LDPP Holstein cows compared with SDPP Jersey cows during the first week of lactation, which is likely due to the transition from colostrum to mature milk production. Overall, photoperiod did not affect colostrum production, but differences by breed were detected. Photoperiod during the dry period did not affect mature milk production or protein, but milk fat percentage was affected by photoperiod × breed. Therefore, altered lighting during the dry period does not unfavorably affect colostrum or milk production in Jersey or Holstein cows.

D. Zamudio, R.A. De Castro, A.P. Jimenez-Lagos et al.

ABSTRACT: We evaluated the effects of insufficient (WET) or extended (CUR) wilting on the concentration of phytoestrogens, nutritional value, microbial populations, in vitro ruminal methane emissions, and in situ degradability of red clover silage (DM: 294 and 453 g/kg) and hay (DM: 651 and 891 g/kg, respectively) across storage stages. Measurements were taken at the start of storage (STRT), after 14 d (early stage of storage), and once storage processes had stabilized for hay and silage (50 and 78 d, respectively; late stage). Only late samples of hay and silage were tested for the in situ procedure. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (wilting extents) × 2 (conservation methods) × 3 (storage stages) factorial. Results showed that storage DM losses were greater for WET versus CUR hay, but no differences were observed within silage. The CUR hay and silage preserved better sugars during storage relative to WET. Due to microbial spoilage, the NH3-N of WET hay was greater than CUR hay after 14 d of storage, but the opposite was observed after 50 d. The NDF of WET hay increased across storage stages, whereas it remained stable for CUR hay. In contrast, the NDF levels of both WET and CUR silage decreased during the ensiling period. The WET hay favored the growth of molds during storage, whereas CUR hay reduced their counts after 50 d of storage. For silage, mold counts were lower in WET compared with CUR after 14 d of storage, but no differences were observed after 78 d. When the ensiling period is limited to 14 d, the aerobic exposure DM losses and heating were greater for CUR silage compared with WET. However, when the ensiling period was extended to 78 d, no differences were observed between WET and CUR silage in terms of aerobic exposure DM losses and heating degree days. The CUR hay preserved ruminal in vitro DM fermentation kinetics compared with WET, whereas the ruminal DM fermentation kinetics of silage were not affected by the wilting extent. For both conservation methods, WET reduced methane yield only at the end of storage. The in situ rumen degradability kinetics showed that ensiling decreased the potentially degradable DM and CP fractions compared with haymaking. Haymaking reduced the ruminal degradation rate of DM but not of CP, compared with ensiling. Wilting was more critical for silage than hay in decreasing the concentration of formononetin and biochanin A. Across storage stages, hay had lower formononetin and biochanin A than silage. Overall, wilting red clover further helps conserve the nutritional quality of hay and silage while reducing phytoestrogen levels.

Gülfem Ünal, Elif Özer, Vildan Akdeniz et al.

The influence of different strawberry varieties on the microbiological, antioxidant and sensory properties of probiotic yoghurt, containing Bifidobacterium animalis subsp. lactis Bb12, were monitored for 21 days. For this purpose, strawberry pulp (15 %) containing strawberry and sugar in a 1:1 ratio was used in the yoghurt formulation. Higher total phenolic content and ferric reducing antioxidant power (FRAP) were detected in Albion and Camarosa varieties than Rubygem whereas Albion variety had the highest total anthocyanin content (p<0.05). Colour parameters (L*, a*, b*) of probiotic yoghurts differed significantly with the incorporation of strawberry pulp. The viable counts of yoghurt starter bacteria in the experimental yoghurts remained above 7.64 log cfu/g throughout the storage period. Addition of probiotic yoghurt with strawberry pulp enhanced the viability of S. thermophilus and L. bulgaricus depending on the variety of strawberry. A similar effect on B. lactis viability was observed in fruit probiotic yoghurt samples except the 1st day of storage. The counts of B. lactis were above 8.5 log cfu/g throughout the storage period. The highest total phenolic content, antioxidant activity (FRAP) and total anthocyanin content were found in Albion variety added probiotic yoghurt during the storage period. Sensory characteristics of probiotic yoghurt were not generally influenced by the addition of strawberry while sample enriched with Camarosa variety showed the lowest overall acceptability scores on 14th day.

Mirco Vacca, Giuseppe Celano, Nadia Serale et al.

ABSTRACT: The microbiota of a cheese play a critical role in influencing its sensory and physicochemical properties. In this study, traditional Apulian Caciocavallo cheeses coming from 4 different dairies in the same area and produced following standardized procedures were examined, as well as the different bulk milks and natural whey starter (NWS) cultures used. Moreover, considering the cheese wheels as the blocks of Caciocavallo cheeses as whole, these were characterized at different layers (i.e., core, under-rind, and rind) of the block using a multi-omics approach. In addition to physical-chemical characterization, culturomics, quantitative PCR, metagenomics, and metabolomics analysis were carried out after salting and throughout the ripening time (2 mo) to investigate major shifts in the succession of the microbiota and flavor development. Culture-dependent and 16S rRNA metataxonomics results clearly clustered samples based on microbiota biodiversity related to the production dairy plant as a result of the use of different NWS or the intrinsic conditions of each production site. At the beginning of the ripening, cheeses were dominated by Lactobacillus, and in 2 dairies (Art and SdC), Streptococcus genera were associated with the NWS. The analysis allowed us to show that although the diversity of identified genera did not change significantly between the rind, under-rind, and core fractions of the same samples, there was an evolution in the relative abundance and absolute quantification, modifying and differentiating profiles during ripening. The real-time PCR, also known as quantitative or qPCR, mainly differentiated the temporal adaptation of those species originating from bulk milks and those provided by NWS. The primary starters detected in NWS and cheeses contributed to the high relative concentration of 1-butanol, 2-butanol, 2-heptanol, 2-butanone, acetoin, delta-dodecalactone, hexanoic acid ethyl ester, octanoic acid ethyl ester, and volatile free fatty acids during ripening, whereas cheeses displaying low abundances of Streptococcus and Lactococcus (dairy Del) had a lower total concentration of acetoin compared with Art and SdC. However, the subdominant strains and nonstarter lactic acid bacteria present in cheeses are responsible for the production of secondary metabolites belonging to the chemical classes of ketones, alcohols, and organic acids, reaffirming the importance and relevance of autochthonous strains of each dairy plant although only considering a delimited production area.

Giulio Giagnoni, Peter Lund, Marianne Johansen et al.

ABSTRACT: Dietary carbohydrate manipulation can be used to reduce enteric CH4 emission, but few studies have focused on the interaction of the different types of carbohydrates that can affect feed intake and ruminal fermentation. Understanding this interaction is necessary to make the most out of CH4 mitigation feeding strategies using different dietary carbohydrates. The aim of this study was to test the effect on enteric CH4 emission, feed intake, and milk production response when cows were fed either grass-clover silage (GCS) or corn silage (CS) as the sole forage source (55% of dry matter, DM), in combination with either barley (BAR) or dried beet pulp (DBP) as a concentrate (21.5% of DM). A total of 24 (half first-parity and half second-parity) cows were used in a crossover design with 2 periods of 21 d each, receiving 2 of 4 diets obtained from a 2 × 2 factorial arrangement of the experimental diet. Feed intake, CH4 emission metrics, and milk production were recorded at the end of the experimental periods. The diets had NDF concentrations between 258 and 340 g/kg of DM and starch concentrations between 340 and 7.45 g/kg of DM (CS-BAR and GCS-DBP, respectively). The effects of silage and concentrate on dry matter intake (DMI) were additive, with the highest feed intake in cows fed CS-BAR, followed by cows fed CS-DBP, GCS-BAR, and GCS-DBP (21.2, 19.9, 19.1, and 18.3 kg/d, respectively). Energy corrected milk (ECM) yield was not affected by silage source in first parity cows, but it was higher for cows fed CS than cows fed GCS in second parity. The effects of silage and concentrate on CH4 production (g/d), yield (g/kg of DMI), and intensity (g/kg of ECM) were not additive, as cows fed GCS had similar responses regardless of the concentrate used, but cows fed CS had lower CH4 production, yield, and intensity when fed BAR instead of DBP. The lower CH4 production, yield, and intensity in cows fed CS-BAR compared with other diets could be partially explained by the nonlinear relationship between ruminal VFA and carbohydrates (NDF and starch) concentration reported in the literature; however, we observed a linear relationship between the acetate/propionate ratio and CH4 yield, suggesting possible other effects. The effects of silage and concentrate on the ruminal VFA were additive in first parity cows, but not in second parity cows. The interaction between dietary carbohydrate type and parity might indicate an effect of feed intake or the energy balance of the cow. Feeding cows silage and concentrate both rich in starch can result in the lowest enteric CH4 emission.

Ye Tao, Qingcheng Wang, Min Xiao et al.

ABSTRACT: Breastfeeding by mothers with gestational diabetes mellitus (GDM) has been shown to reduce maternal insulin demands and diminish the risks of diabetes in infants, leading to improved long-term health outcomes. Milk fat globule membrane (MFGM) proteins play a crucial role in influencing the immunity and cognitive development of infants. Understanding the alterations in MFGM proteins in breast milk from mothers with GDM is essential for enhancing their self-efficacy and increase breastfeeding rates. The objective of this study is to investigate and compare MFGM proteins in milk from mothers with and without GDM based on tandem mass tag (TMT) labeling and liquid chromatography–tandem MS techniques. A total of 5,402 proteins were identified, including 4 upregulated proteins and 24 downregulated proteins. These significantly altered proteins were found to be associated with human diseases, cellular processes, and metabolism pathways. Additionally, the oxidative phosphorylation pathway emerged as the predominant pathway through Gene Set Enrichment Analysis involving all genes.

Kehan Sheng, Borbala Foris, Joseph Krahn et al.

ABSTRACT: Dominance hierarchies are known for mitigating conflicts and guiding priority of access to limited resources in gregarious animals. The dominance hierarchy of dairy cows is typically investigated using agonistic interactions, often monitored at the feed bunk right after fresh feed delivery when competition is high, resulting in frequent interactions. Yet, the outcome of agonistic interactions during times of high competition may be more influenced by cows' high valuation of fresh feed than their intrinsic attributes, such that the dominance hierarchy constructed using agonistic interactions under high versus low competition times might differ. We tested how the structure of the dominance hierarchy changes in relation to different levels of competition in a dynamic group of 48 lactating dairy cows over 10 mo, with 6 cows exchanged every 16 d, for a total of 159 cows. Using a validated algorithm, we continuously detected the actor and reactor of replacement behaviors in 30 feed bins as cows competed for feed. We also calculated the percentage of occupied feed bins to characterize competition at the moment of each replacement. These data were combined to create hierarchies using Elo ratings, separately for 25 occupancy levels ranging from 13% to 100%. For each 1% rise in feeder occupancy, hierarchy steepness fell by 2.41 × 10−3 ± 9.71 × 10−5 (SE), and the percentage of dyads where both cows replaced each other rose by 0.13% ± 0.01%. At the highest feeder occupancy level in comparison to the lowest one, we observed 7.57% more dyads in which the dominant individual (those that won more interactions at the lowest feeder occupancy) started to lose proportionally more. The magnitude of decrease in the winning rate of the dominant individual in those dyads also got amplified by 1.06 × 10−3% ± 1.37 × 10−4% (SE) for each 1% increase in feeder occupancy. These findings illustrate how inferred hierarchies vary with competition, with high competition flattening the hierarchy due to increased success of subordinate animals. We suggest that during heightened competition, increased valuation of resources can affect competitive success more than the individual's intrinsic dominance attributes. We recommend against calculating dominance hierarchies based on agonistic interactions during periods of high competition alone, and more generally urge researchers to differentiate agonistic interactions based on context when constructing dominance hierarchies.

Wenhua Zhang, Majida Al-Wraikata, Linqiang Li et al.

ABSTRACT: There is growing interest in the origin, preparation, and application of bioactive peptides. This study investigated the effect of 6 enzymes on the structural, physicochemical properties, antioxidant activities, and antidiabetic potential of defatted fresh goat milk. Structural and functional changes resulting from enzymatic hydrolysis were assessed using gel electrophoresis, laser particle size analysis, multi-spectroscopy, and evaluations of foaming and emulsification properties. Antioxidant capacity was determined through free radical scavenging, Fe2+ chelation, and reducing ability experiments. Additionally, the inhibitory effects of the hydrolysates on α-glucosidase and α-amylase were measured to evaluate antidiabetic activity. Results showed that enzymatic hydrolysis disrupted the spatial structure of goat milk protein and reduced its molecular weight. Papain hydrolysate exhibited the highest degree of hydrolysis (32.87% ± 0.11%) and smallest particle size (294.75 ± 3.33 nm), followed by alcalase hydrolysate (29.12% ± 0.09%, 302.03 ± 7.28 nm). Alcalase hydrolysate showed the best foaming properties, and papain hydrolysate demonstrated the strongest 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging activity, Fe2+ chelation, and antidiabetic potential. These findings provide a solid theoretical basis for utilizing defatted goat milk as functional ingredients or excipients in the food, medical, and cosmetic industries.

Helen Schneider, Dierck Segelke, Jens Tetens et al.

ABSTRACT: Claw diseases and mastitis represent the most important disease traits in dairy cattle with increasing incidences and a frequently mentioned connection to milk yield. Yet, many studies aimed to detect the genetic background of both trait complexes via fine-mapping of quantitative trait loci. However, little is known about genomic regions that simultaneously affect milk production and disease traits. For this purpose, several tools to detect local genetic correlations have been developed. In this study, we attempted a detailed analysis of milk production and disease traits as well as their interrelationship using a sample of 34,497 50K genotyped German Holstein cows with milk production and claw and udder disease traits records. We performed a pedigree-based quantitative genetic analysis to estimate heritabilities and genetic correlations. Additionally, we generated GWAS summary statistics, paying special attention to genomic inflation, and used these data to identify shared genomic regions, which affect various trait combinations. The heritability on the liability scale of the disease traits was low, between 0.02 for laminitis and 0.19 for interdigital hyperplasia. The heritabilities for milk production traits were higher (between 0.27 for milk energy yield and 0.48 for fat-protein ratio). Global genetic correlations indicate the shared genetic effect between milk production and disease traits on a whole genome level. Most of these estimates were not significantly different from zero, only mastitis showed a positive one to milk (0.18) and milk energy yield (0.13), as well as a negative one to fat-protein ratio (−0.07). The genomic analysis revealed significant SNPs for milk production traits that were enriched on Bos taurus autosome 5, 6, and 14. For digital dermatitis, we found significant hits, predominantly on Bos taurus autosome 5, 10, 22, and 23, whereas we did not find significantly trait-associated SNPs for the other disease traits. Our results confirm the known genetic background of disease and milk production traits. We further detected 13 regions that harbor strong concordant effects on a trait combination of milk production and disease traits. This detailed investigation of genetic correlations reveals additional knowledge about the localization of regions with shared genetic effects on these trait complexes, which in turn enables a better understanding of the underlying biological pathways and putatively the utilization for a more precise design of breeding schemes.

Mengxiao Yang, Aiqian Ye, Zhi Yang et al.

Y. Steyn, T. Lawlor, Y. Masuda et al.

ABSTRACT: Maintaining genetic variation in a population is important for long-term genetic gain. The existence of subpopulations within a breed helps maintain genetic variation and diversity. The 20,990 genotyped animals, representing the breeding animals in the year 2014, were identified as the sires of animals born after 2010 with at least 25 progenies, and females measured for type traits within the last 2 yr of data. K-means clustering with 5 clusters (C1, C2, C3, C4, and C5) was applied to the genomic relationship matrix based on 58,990 SNP markers to stratify the selected candidates into subpopulations. The general higher inbreeding resulting from within-cluster mating than across-cluster mating suggests the successful stratification into genetically different groups. The largest cluster (C4) contained animals that were less related to each animal within and across clusters. The average fixation index was 0.03, indicating that the populations were differentiated, and allele differences across the subpopulations were not due to drift alone. Starting with the selected candidates within each cluster, a family unit was identified by tracing back through the pedigree, identifying the genotyped ancestors, and assigning them to a pseudogeneration. Each of the 5 families (F1, F2, F3, F4, and F5) was traced back for 10 generations, allowing for changes in frequency of individual SNPs over time to be observed, which we call allele frequencies change. Alternative procedures were used to identify SNPs changing in a parallel or nonparallel way across families. For example, markers that have changed the most in the whole population, markers that have changed differently across families, and genes previously identified as those that have changed in allele frequency. The genomic trajectory taken by each family involves selective sweeps, polygenic changes, hitchhiking, and epistasis. The replicate frequency spectrum was used to measure the similarity of change across families and showed that populations have changed differently. The proportion of markers that reversed direction in allele frequency change varied from 0.00 to 0.02 if the rate of change was greater than 0.02 per generation, or from 0.14 to 0.24 if the rate of change was greater than 0.005 per generation within each family. Cluster-specific SNP effects for stature were estimated using only females and applied to obtain indirect genomic predictions for males. Reranking occurs depending on SNP effects used. Additive genetic correlations between clusters show possible differences in populations. Further research is required to determine how this knowledge can be applied to maintain diversity and optimize selection decisions in the future.

M. Khatun, P.C. Thomson, S.C. García et al.

ABSTRACT: In response to intramammary infection (IMI), blood-derived leukocytes are transferred into milk, which can be measured as an increase of somatic cell count (SCC). Additionally, pathogen-dependent IgG increases in milk following infection. The IgG transfer into milk is associated with the opening of the blood-milk barrier, which is much more pronounced during gram-negative than gram-positive IMI. Thus, milk IgG concentration may help to predict the pathogen type causing IMI. Likewise, lactate dehydrogenase (LDH) and serum albumin (SA) cross the blood-milk barrier with IgG if its integrity is reduced. Because exact IgG analysis is complicated and difficult to automate, LDH activity and SA concentration aid as markers to predict the IgG transfer into milk in automatic milking systems (AMS). This study was conducted to test the hypothesis that LDH and SA in milk correlate with the IgG transfer, and in combination with SCC these factors allow the differentiation between gram-positive and gram-negative IMI or even more precisely the infection-causing pathogen. Further, the expression of these parameters in foremilk before (BME) and after (AME) milk ejection was tested. In the AMS, quarter milk samples (n = 686) from 48 Holstein-Friesian cows were collected manually BME and AME, followed by an aseptic sample for bacteriological culture. Mixed models were used to (1) predict the concentration of IgG transmitted from blood into milk based on LDH and SA; (2) use principal component analysis to evaluate joint patterns of SCC (cells/mL), IgG (mg/mL), LDH (U/L), and SA (mg/mL) and use the principal component scores to compare gram-positive, gram-negative, and control IMI types and BME versus AME samples; and (3) predict gram-positive and gram-negative IMI by inclusion of combined SCC-LDH and SCC-SA as predictors in the model. Overall, the SA and LDH had similar ability to predict IgG transmission from blood into milk. Comparing the areas under the curve (AUC) of the receiver operator characteristic curves, the SCC-LDH versus SCC-SA had lower gram-positive (AUC = 0.984 vs. 0.986) but similar gram-negative (AUC = 0.995 vs. 0.998) IMI prediction ability. The SCC, IgG, LDH, and SA were greater in gram-negative than in gram-positive IMI (BME and AME) in early lactation. All measured factors had higher values in milk samples taken BME than AME. In conclusion, LDH and SA could be used as replacement markers to indicate the presence of IgG transfer from blood into milk; in combination with SCC, both SA and LDH are suitable for differentiating IMI type, and BME is better for mastitis detection in AMS.

Darko Stojanovski, Ivana Živaljević, Vesna Dimitrijević et al.

The application of biomolecular techniques to archaeological materials from the Balkans is providing valuable new information on the prehistory of the region. This is especially relevant for the study of the neolithisation process in SE Europe, which gradually affected the rest of the continent. Here, to answer questions regarding diet and subsistence practices in early farming societies in the central Balkans, we combine organic residue analyses of archaeological pottery, taxonomic and isotopic study of domestic animal remains and biomolecular analyses of human dental calculus. The results from the analyses of the lipid residues from pottery suggest that milk was processed in ceramic vessels. Dairy products were shown to be part of the subsistence strategies of the earliest Neolithic communities in the region but were of varying importance in different areas of the Balkan. Conversely, milk proteins were not detected within the dental calculus. The molecular and isotopic identification of meat, dairy, plants and beeswax in the pottery lipids also provided insights into the diversity of diet in these early Neolithic communities, mainly based on terrestrial resources. We also present the first compound-specific radiocarbon dates for the region, obtained directly from absorbed organic residues extracted from pottery, identified as dairy lipids.