Hasil untuk "Dairying"

B. Fessenden, D.J. Weigel, D. Liang et al.

ABSTRACT: Reproductive performance affects the profitability of a dairy herd. The ability to understand the reproductive capabilities of individual cows and the use of targeted reproductive management could optimize reproductive performance of dairy herds. To address this need, the early reproductive success prediction was developed using a light gradient-boosting machine algorithm, which included herd-level reproduction data, weather data, genomic-enhanced predicted transmitting ability, individual cow information, milk production, health events, and previous lactation performance data. The objective of this retrospective study was to evaluate the ability of the early reproductive success algorithm to predict pregnancy probability by 110 DIM at 43 DIM, which was before the end of the voluntary waiting period for enrolled herds. The study included 9,969 Holstein and 9,464 Jersey multiparous cows that calved in 2022 from 7 US commercial herds. Cows were ranked by their predicted probability within their own herds and then assigned to deciles based upon this ranking. Cows' reproductive and herd exit data were collected for 18 mo following calving from on-farm management software. Data were analyzed using a generalized linear mixed model. The worst 10% and best 10% early reproductive success prediction deciles were different for pregnancy at first insemination (25.3% vs. 44.2%), proportion pregnant at 110 DIM (35.6% vs. 64.8%), and proportion of cows that gave birth to a live calf to initiate the following lactation (49.1% vs. 77.8%), with percentage improvements in performance of 75%, 82%, and 58%, respectively. The predicted worst 10% and best 10% deciles were different for abortion incidence (20.9% vs. 6.8%) and whether cows were sold within enrollment lactation (43.8% vs. 17.2%), with percentage improvements in performance of 67% and 61% for these 2 metrics. These results demonstrated the ability of the early reproductive success algorithm to predict differences in pregnancy per insemination for all services, abortion incidence, proportion of cows sold in enrollment lactation, and proportion of cows producing a live calf. Further research is needed to determine whether the early reproductive success prediction has potential to be used to help dairy producers develop targeted reproductive management strategies.

N.I. Carvalho, I.C.R. Oliveira, A.F. Toledo et al.

ABSTRACT: Water quality plays a crucial role in calf health and performance, mainly when it is used to dilute milk replacers, which can affect the incidence of diarrhea. This study assessed the effects of municipal tap water (TW) compared with purified water (PW) on calf performance and health. Thirty Holstein calves were randomly assigned to 2 treatment groups in a randomized block design. Calves received 6 L/d of milk replacer (14% solids) diluted with the respective water treatment until gradual weaning (49–53 d). A pelleted starter was offered from birth, and chopped hay was provided ad libitum from 49 to 70 d. Dry matter intake, water intake, and health scores were recorded daily. Average daily gain was measured weekly, whereas body measurements and blood samples were collected biweekly. The PW tended to improve feed efficiency and increased ADG in the third week of life, but the final BW did not differ between treatments. Calves that received PW consumed more hay and tended to have greater water intake. Moreover, PW reduced day with diarrhea and the number of antibiotic treatments. Blood metabolites varied primarily with age, except for higher albumin concentrations in TW calves at wk 10. In summary, the PW tended to enhance performance during preweaning, particularly after diarrhea episodes. These findings highlight the importance of water quality during early life, but further studies are needed to determine the effect on dairy calf health.

Chunxiao Dong, Peipei Ma, Yongjie Tang et al.

ABSTRACT: Chinese Simmental cattle serve as an important dual-purpose breed in sustainable livestock systems. Despite their economic value, the genetic architecture underlying milk-production traits in this breed under temperate conditions remains poorly characterized. In this study, we estimated genetic parameters and identified associated genomic loci for 9 milk-production traits in a Chinese Simmental population. Our dataset consisted of 17,556 test-day records from 1,788 cows (parities 1 to 3), including whole-genome sequencing data for 781 individuals. Using a random regression test-day model with Legendre polynomials, we estimated variance components, heritabilities, breeding values (EBVs), and genetic correlations between different DIM. Heritability estimates ranged from 0.09 (fat-to-protein ratio) to 0.52 (protein percentage), with intermediate values for fat percentage (0.28), lactose percentage (0.35), and total milk solids (0.35). Within-lactation genetic correlations varied by trait, ranging from −0.88 to 0.99, with the strongest correlations between adjacent DIM, which weakened as intervals widened. Genome-wide association analysis (using the mixed linear model in SLEMM version 0.90.1) and Bayesian fine-mapping analysis identified significant SNPs near known candidate genes (BOP1, MROH1, NEGR1). These analyses also revealed putative novel associations with CACNB4, MTHFD2L, and SGMS1. Overall, the results enhance our understanding of the genetic regulation of milk production and provide practical targets for genomic selection to improve dairy performance in dual-purpose breeding programs.

C. Saro, C. Martin, G. Cantalapiedra-Hijar et al.

ABSTRACT: The aim of this study was to test the effect of 3-nitrooxypropanol (3-NOP) on methane emissions, animal performance, milk composition, and rumen fermentation in early-lactation dairy cows fed a forage-rich diet. A second objective was to assess the 13C isotopic signature of milk as a potential proxy for methane-emission status. Twenty-seven cows with similar BW and age in early lactation (7–11 DIM) and fed a 75% forage-based diet were selected and distributed to 2 balanced groups in a randomized block design. The treatment group (n = 13) received 3-NOP (60 mg/kg DM basis) in a TMR for 105 d and the control group (n = 14) received a placebo. The 3-NOP additive was included in a supplement formulated with propylene glycol and adsorbed on silicon dioxide. The control group received the same supplement without the additive. Individual daily methane emissions were quantified using the GreenFeed system throughout the study. Intake and milk production were recorded daily, and milk composition (fat, protein, lactose, urea) twice a week. Natural 13C abundance (δ13C) in milk and feed samples was determined using isotope-ratio MS coupled with elemental analysis for each cow at wk 3, 7, 11, and 15. Methane emissions, methane yield, and methane intensity were lower in the treatment group throughout the 105 d (on average −31% g/d, −24% g/kg DMI, and −30% g/kg ECM). By monitoring methane emissions throughout the day, we found that the main effect occurred after feeding, preventing the postprandial peak in methane emissions. Intake was reduced by ∼7% with 3-NOP, whereas milk production was similar between groups (34.7 kg ECM/d). Consequently, feed conversion efficiency in animals tended to increase with 3-NOP (1.39 vs. 1.48 kg milk/kg DMI on average). Milk composition did not vary between groups. Although no differences were found in dietary δ13C across the treatments, milk from the treatment group had lower δ13C than the control group throughout the experimental period. The results of this work with medium-producing dairy cows confirm the efficacy of the additive on diets relatively high in NDF, which broadens its applicability to less intensive production systems. The results for milk δ13C, suggesting its potential as a qualitative proxy for methane emissions, merit further investigation, as it could be used in breeding and in monitoring, reporting, and validation systems.

Yi Li, Xiaoyu Yue, Xinxin Ren et al.

ABSTRACT: Mare milk (MM) and fermented mare milk (FM) are specialized animal milks with high nutritional value, containing a variety of functionally active substances that are capable of resisting inflammatory responses and oxidative stress. However, little relevant research on the maintenance of intestinal homeostasis has been performed. This study aimed to investigate the effects of MM and FM on the prevention of dextran sulfate sodium salt (DSS)-induced ulcerative colitis in a mouse model and to preliminarily elucidate the underlying mechanisms. The results showed that MM and FM had different degrees of protective effects against the damage caused by DSS and alleviated ulcerative colitis by inhibiting weight loss, reducing colon length shortening, and restoring intestinal structure. Additionally, MM and FM maintained intestinal tight junction protein levels to repair barrier function, downregulated inflammatory cytokines (e.g., IL-1β, TNF-α, IL-6, and iNOS) and bolstered the body's antioxidant defense system. Moreover, MM and FM regulated dysregulation of the intestinal microenvironment by improving the diversity of the gut microbiota and reshaping its structure, including increasing the proportion of Firmicutes and Bacteroidetes and the relative abundance of beneficial bacterial genera (e.g., Akkermansia). In summary, MM and FMM can serve as dietary resources for preventing ulcerative colitis and maintaining intestinal homeostasis.

D.F. Pipino, N. López-Villalobos, R.E. Hickson et al.

ABSTRACT: An economic analysis was performed using a bioeconomic simulation model based on production, reproduction, and longevity indicators to compare the profitability (net income per cow) of Swedish Red-and-White × Holstein (S×H) cows and pure Holstein (HOL) cows in commercial dairy farms of the center-south of Córdoba province, Argentina. The reproductive events analyzed in the model were pregnancy, calving, and abortion. The longevity events were culling, sale, and death. The lactation curve for each cow was modeled with a lactation function. Estimations were made for the first, second, and third and later lactations. Income sources were from milk, culled cows, and calves. Costs were from feeding, reproductive program, and replacement heifers. The reproductive cost of a HOL cow per year was greater than that of a S×H crossbred cow (US$6.30). The replacement costs were also higher in pure HOL cows than in S×H cows (US$67.80). The revenues from the sale of calves (US$12.10) and milk production minus the feed cost (US$8.20) were greater for S×H cows than HOL cows. Hence, the S×H cows generated a greater total profit (US$94.40) per cow per year than HOL cows. The present results show that in the studied production systems, S×H crossbred cows are more profitable than HOL cows.

Taiyu Shen, Shijie Xia, Muhammad Usman et al.

ABSTRACT: Ketosis is a common metabolic disorder in high-yielding cows and is characterized by high concentrations of BHB and free fatty acids (FFA). High concentrations of FFA induce endoplasmic reticulum (ER) stress in multiple organs including mammary tissue, and result in reduced milk production and lower milk quality. In nonruminants, loss of nuclear factor erythroid 2-related factor 1 (NFE2L1) results in ER stress. The physiological functions and molecular mechanisms controlled by NFE2L1 in bovine mammary tissue are poorly understood. Thus, the present study aimed to elucidate the role of the NFE2L1 on proteasomal homeostasis and ER stress in mammary tissue from early lactation (DIM 6–14) healthy cows (CON, blood concentration of BHB <1.2 mM, n = 10) and cows with clinical ketosis (CK blood concentration of BHB >3 mM, n = 10). Compared with CON, serum concentration of glucose was lower due to CK, while serum concentrations of BHB and FFA were greater. Protein and mRNA abundance of NFE2L1 along with abundance of proteasomal subunits (PSMD1, PSMD14, PSMA1, PSMB1, and PSMB5 genes and PSMB4 and PSMB6 proteins) were lower in cows with CK, indicating that expression of NFE2L1 and proteasomal homeostasis was impaired by ketosis. In vitro, primary bovine mammary epithelial cells were exposed to various concentrations of FFA (0, 0.3, 0.6, or 1.2 mM). Compared with the 0 mM FFA, the ratio of phosphorylated (p)-protein kinase R-like ER kinase (PERK)/PERK along with the expression of inositol-requiring enzyme 1 (IRE1) α, activating transcription factor 6 (ATF6), glucose regulated protein 78 (GRP78), and C/EBP homologous protein (CHOP) was higher with 1.2 mM FFA. A similar response was observed for ER stress-associated genes (CHOP, GRP78, and XBP1) indicating that high concentrations of FFA-induced ER stress. In line with in vivo results, 1.2 mM FFA downregulated the protein and mRNA abundance of NFE2L1, the abundance of PSMB6 protein, and proteasome subunit (PSM) genes (PSMC1, PSMC3, and PSMD1), and increased the accumulation of ubiquitin. This suggested a marked negative effect of high FFA on NFE2L1 and proteasomal homeostasis. Silencing of NFE2L1 triggered upregulation of ER stress-associated genes as well as protein abundance of GRP78 and CHOP. Further, compared with CON-siRNA, the abundance of PSM genes was downregulated in the NFE2L1-siRNA group. In contrast, abundance of markers of ER stress and PSM genes and proteins indicated that overexpression of NFE2L1 relieved the FFA-induced ER stress and improved 26S proteasome homeostasis. Our data suggested that the mammary gland experiences ER stress during ketosis partly due to disruption of proteasomal homeostasis from the excess FFA. As such, NFE2L1 could represent a target for potential therapeutic applications in the field to alleviate the accumulation of malformed proteins that may impair the long-term lactogenic capacity of the udder.

Xiaojun Wang, Linlin Wang, Xinyao Wei et al.

ABSTRACT: Yogurt, as a globally prevalent fermented dairy product, is renowned for its substantial nutritional value and a myriad of health benefits, particularly pertaining to the digestive system. This narrative review elucidates the latest advancements in yogurt development from 2019 to 2024, addressing aspects of microbiological safety, quality, functionality, sensory evaluation, and consumer perceptions across diverse protein sources. The intrinsic quality of yogurt is notably influenced by its primary ingredient, milk, traditionally derived from animals such as cows, goats, and sheep. In recent years, plant-based yogurt (PBY) have emerged as a popular alternative to traditional dairy yogurts, that are made from plant sources and offer similar textures and flavors, catering to those seeking nondairy options. This discussion encompasses the advantages and limitations of various sources and explores methodologies to enhance yogurt quality using these diverse sources. Ensuring the microbiological safety of yogurt is thus paramount to its quality, as it involves both preventing the presence of harmful pathogens and managing spoilage to maintain freshness. This article encapsulates the potential hazards and corresponding antibacterial strategies that safeguard yogurt consumption. These strategies include the use of natural preservatives, advancements in packaging technologies, and the implementation of stringent hygiene practices throughout the production process. Moreover, the quality of yogurt is dependent not only on the source but also on the fermentation process and additional ingredients used. By addressing both the prevention of pathogen contamination and the control of spoilage organisms, this article explores comprehensive approaches but also examines the use of high-quality starter cultures, the role of prebiotics in enhancing probiotic efficacy, and genetic advancements, as well as improvements in the overall nutritional profile and shelf life of yogurt. Techniques to improve texture, flavor, and nutrient content are also discussed, providing a comprehensive overview of current quality enhancement methods. This analysis delves into the intricate mechanisms underpinning probiotic development, including the roles of prebiotics, supplementary starter cultures, and genetic factors that facilitate probiotic proliferation. These benefits include improved digestive health, enhanced immune function, and potential reductions in the risk of certain chronic diseases. Beyond quality and functionality, the sensory evaluation of yogurt remains crucial for consumer acceptance. In recent years, the incorporation of diverse additional ingredients into yogurt has been observed, aimed at augmenting its sensory attributes. This examination reveals these ingredients and their respective functions, such as natural flavorings, sweeteners, and texturizing agents, with the ultimate goal of enhancing overall consumer satisfaction. Consumer preferences exert a profound influence on yogurt production, rendering the understanding of customer opinions essential for devising competitive industry strategies. This article consolidates consumer feedback and preferences, striving to elevate yogurt quality and promote dietary diversity. The analysis includes trends such as the growing demand for organic and nondairy yogurts, the importance of sustainable practices, and the impact of marketing and packaging on consumer choices. This comprehensive overview serves as a valuable reference for the dairy industry and researchers dedicated to the advancement of yogurt development.

A. Ule, K. Erjavec, M. Klopčič

ABSTRACT: The aim of the study was to determine the role played by farmers' sociodemographic factors in the characteristics of dairy farmers' breeding goals and how they are clustered in Slovenia. Understanding how farmers formulate their breeding objectives is crucial because their perspectives may diverge from those of the stakeholders engaged in selection and breeding. Involving farmers in the process of setting breeding goals can improve the use of selection tools and confidence in the selection process. For a more complete picture of how farmers view breeding work, their expectations, and the changes they would prefer to see in the future in terms of new traits and a total merit index, a mixed methods approach was used. Initially, 3 focus groups with 30 participants were conducted on the following main topics: farmers' needs and attitudes regarding genomic selection, the main barriers and advantages to adopting genomic selection, the design of a total merit index, and preferences for breeding goals. To generalize the results to the whole population, an additional online questionnaire was sent to dairy farmers affiliated with Slovenian breeding associations, with 212 farmers responding. Based on how the farmers distributed weights across the trait categories in the total merit index, a cluster analysis identifies 3 distinct groups of farmers. Milk production proved to be an important common factor for all farmers, especially production-focused ones. Functionality-focused farmers expressed the strongest preference for fertility (22%), longevity (18%), and animal health (18%), whereas resilience-focused farmers concentrated on fertility (13%), health (13%), longevity (11%), and workability (11%). Yet, the results also showed that dairy farmers hold quite similar preferences for breeding goal traits, with animal health and welfare, reproductive traits, dominating across the sample and environmental and meat traits being the least important. The quantitative analysis of the preference for new environmental traits showed that farmers express less importance to them due to pressure and negative public opinion about the environmental impact of dairy farming. The focus group participants, although acknowledging that adaptation to climate change and heat stress will be essential, were even more negative about traits related to greenhouse gas emissions, which can be attributed to negative public opinion and constraints on agricultural activity.

S.Y. Li, M.M. Tong, L. Li et al.

ABSTRACT: This study is aimed at investigating the effects of dietary supplementation with Artemisia ordosica crude polysaccharides (AOCP) on lactation performance, antioxidant status, and immune status of lactating donkeys and analyzing rectal microbiomes and serum metabolomes. Fourteen lactating Dezhou donkeys with similar age (6.16 ± 0.67 yr of BW ± SD), weight (250.06 ± 25.18 kg), DIM (39.11 ± 7.42 d), and average parity of 3 were randomly allocated into 2 treatments: a control group (CON, basal diet) and an AOCP group (AOCP, basal diet with 1.0 g/kg DM AOCP). Ten weeks were allotted for the experiment, 2 wk for adaptation, and 8 wk for collecting data and samples. The results showed that supplementation of donkey diets with AOCP increased lactation performance, including DMI, milking yield, estimated milk yield, solids-corrected milk, ECM, milk fat yield, milk protein yield, milk lactose yield, milk TS yield, and milk SNF yield. The digestibility of DM, CP, ADF, and NDF was increased in the AOCP group compared with the CON group. The AOCP group increased the concentrations of IgA, IgG, and IgM, the activities of the superoxide dismutase, catalase, and total antioxidant capacity in the serum. Artemisia ordosica crude polysaccharides decreased the concentrations of tumor necrosis factor-α, nitric oxide, reactive oxygen species, and malondialdehyde in the serum. Compared with the CON group, AOCP increased propionate, butyrate, isovalerate, and total VFA concentrations in rectal feces (P < 0.05). The addition of AOCP to increased diversity (Shannon index) and altered structure of the rectal microflora. As a result of AOCP supplementation, there has been a significant improvement in the colonization of beneficial bacteria, including Lactobacillus, Unclassified_f_Prevotellacea, Ruminococcus, and Fibrobacter genera. In contrast, a decrease in the colonization of the Clostridium_sensu_stricto_1 bacterial genus and other pathogenic bacteria was observed. Meanwhile, metabolomics analysis found that AOCP supplementation upregulated metabolites l-tyrosine content while downregulating 9(S)-HODE, choline, sucrose, lysophosphatidylcholine (LysoPC) (18:0), LysoPC (18:1(9Z)), and LysoPC (20:2(11Z,14Z)) concentrations. These altered metabolites were involved in the PPAR signaling pathway, prolactin signaling pathway, glycerophospholipid metabolism, carbohydrate digestion and absorption, and tyrosine metabolism pathways, which were mainly related to antioxidant capacity, immune responses, and protein metabolism in the lactating donkeys. As a consequence of feeding AOCP diets, beneficial bacteria were abundant, and antioxidant and protein metabolism-related pathways were enriched, which may enhance lactation performance in donkeys. Therefore, supplementing AOCP diets is a desirable dietary strategy to improve donkey health and lactation performance.

A. Jezequel, L. Delaby, Z.C. McKay et al.

ABSTRACT: The objective of this study was to evaluate the effect of sward diversification combined with a reduction of chemical nitrogen (N) fertilizer on the performance of spring-calving grazing dairy cows within a farm systems experiment. Three farmlets were created: a monoculture of perennial ryegrass (Lolium perenne L.; PRG) fertilized with 250 kg N/ha (PRG-250N), a PRG–white clover (Trifolium repens L; WC) sward fertilized with 125 kg N/ha (PRGWC-125N), and a multispecies sward (MSS) comprising grasses, legumes, and herbs, also fertilized with 125 kg N/ha (MSS-125N). Each farmlet had its own herd of dairy cows on a total area of 18.7 ha divided into 20 paddocks. Each herd comprised pure Holstein-Friesian (HF) and HF–Jersey crossbred (JFX) animals, and cows were randomly assigned through the 3 treatments. For 3 years (2021 to 2023), the performances of both swards (grass yield, botanical composition, nutritive value) and grazing animals (milk production and composition, BW, and BCS) were recorded. We found no significant differences in pasture production or sward nutritive value between sward systems, and grazing season length was also similar (264 d). On average over the 3 years, PRGWC-125N contained 150 g/kg DM of legumes, and MSS-125N contained 160 g/kg DM legumes, 130 g/kg DM plantain, and 40 g/kg DM chicory. Both individual cow milk and fat plus protein (milk solids) yield were lower for PRG-250N (5,018 and 452 kg, respectively), intermediate for PRGWC-125N (5,139 and 463 kg, respectively), and highest for MSS-125N (5,297 and 476 kg, respectively) whereas milk and milk solids production per hectare from grazing were similar during the study period (11,523 and 1,016 kg/ha, respectively). Breed also had a significant effect, with the JFX having lower milk yield but higher fat and protein concentration compared with HF. This resulted in higher milk solids production per kilogram of BW for the JFX compared with HF (0.96 and 0.87 kg milk solids/kg BW, respectively). The results of this study highlight the possibility for more diverse pastures to reduce chemical N fertilizer input requirements and maintain pasture productivity while increasing animal performance within pasture-based spring-calving systems.

M.A. Abeyta, M. Al-Qaisi, E.A. Horst et al.

ABSTRACT: Heat-stress-induced inflammation may be ameliorated by antioxidant supplementation due to the purported effects of increased production of reactive oxygen species or oxidative stress on the gastrointestinal tract barrier. Thus, study objectives were to evaluate whether antioxidant supplementation [AGRADO Plus 2.0 (AP); EW Nutrition] affects metabolism and inflammatory biomarkers in heat-stressed lactating dairy cows. Thirty-two mid-lactation multiparous Holstein cows were assigned to 1 of 4 dietary-environmental treatments: (1) thermoneutral (TN) conditions and fed a control diet (TN-CON; n = 8), (2) TN and fed a diet with AP (10 g antioxidant; n = 8), (3) heat stress (HS) and fed a control diet (HS-CON; n = 8), or (4) HS and fed a diet with AP (HS-AP; n = 8). The trial consisted of a 23-d prefeeding phase and 2 experimental periods (P). Respective dietary treatments were top-dressed starting on d 1 of the prefeeding period and continued daily throughout the duration of the experiment. During P1 (4 d), baseline data were collected. During P2 (7 d), HS was artificially induced using an electric heat blanket (Thermotex Therapy Systems Ltd.). During P2, the effects of treatment, day, and treatment-by-day interaction were assessed using PROC MIXED of SAS (SAS Institute Inc.). Heat stress (treatments 3 and 4) increased rectal, vaginal, and skin temperatures (1.2°C, 1.1°C, and 2.0°C, respectively) and respiration rate (33 breaths per minute) relative to TN cows. As expected, HS decreased dry matter intake, milk yield, and energy-corrected milk yield (32%, 28%, and 28% from d 4 to 7, respectively) relative to TN. There were no effects of AP on body temperature indices or production. Milk fat, protein, and lactose concentrations remained unaltered by HS or AP; however, milk urea nitrogen was increased during HS regardless of AP supplementation (26% relative to TN). Circulating glucose remained unchanged by HS, AP, or time. Additionally, HS decreased circulating glucagon (29% from d 3 to 7 relative to TN), but there was no additional effect of AP. There was a tendency for nonesterified fatty acid concentrations to be increased in HS-AP cows throughout P2 (60% relative to TN-CON), whereas it remained similar in all other treatments. Blood urea nitrogen increased for both HS treatments from d 1 to 3 before steadily decreasing from d 5 to 7, with the overall increase being most pronounced in HS-CON cows (27% relative to TN-CON). Further, supplementing AP decreased blood urea nitrogen in HS-AP on d 3 relative to HS-CON (15%). Circulating serum amyloid A tended to be and lipopolysaccharide binding protein was increased by HS, but neither acute-phase protein was affected by AP. Overall, AP supplementation appeared to marginally alter metabolism but did not meaningfully alter inflammation during HS.

Mengru Chen, Wan Xie, Shendong Zhou et al.

ABSTRACT: Long-term feeding of a high-concentrate diet can induce subacute ruminal acidosis (SARA) in ruminants, which further leads to systemic inflammatory response. However, few studies have examined the effects of feeding a high-concentrate diet on the hindgut of ruminants. The purpose of this study was to investigate the effects of a high-concentrate diet on the composition of gut microbiota in colonic contents, inflammatory response, and barrier damage in the colon tissue of ruminants. A total of 12 healthy multiparous lactating Hu sheep were randomly allotted into the following 2 groups: a high-concentrate (HC) group (concentrate:forage = 7:3) and a low-concentrate (LC) group (concentrate:forage = 3:7). All sheep were fitted with ruminal fistulas. The formal feeding experiment lasted for 8 wk. After the feeding experiment, rumen fluid, portal vein blood, hepatic vein blood, colonic contents, and colon tissue samples were collected. The results showed that feeding the HC diet induced SARA in Hu sheep and significantly reduced pH in the colonic contents. The abundances of Firmicutes, Verrucomicrobiota, and Actinobacteriota decreased significantly, whereas those of Bacteroidota, Spirochaetota, and Fibrobacterota significantly increased in colonic contents. At the genus level, the relative abundances of 29 genera were significantly altered depending on the different type of diets. Analysis of the 10 bacterial genera with high relative abundance revealed that feeding the HC diet significantly reduced the abundance of UCG-005, Christensenellaceae R-7 group, UCG-010-norank, Monoglobus, [Eubacterium] coprostanoligenes group_norank, and Alistipes, whereas the abundances of Rikenellaceae RC9 gut group, Treponema, Bacteroides, and Prevotella increased. Compared with the LC group, feeding the HC diet significantly increased the concentration of LPS in rumen fluid, portal vein blood, hepatic vein blood, and colonic contents, and significantly upregulated the mRNA expression levels of proinflammatory cytokines in colon tissue, including TNF-α, IL-1β, IL-6, and IL-8, indicating the occurrence of inflammatory response in the colon tissue. In addition, the structure of colonic epithelial cells was loose, the intercellular space became larger, epithelial cells were exfoliated, and the mRNA and protein abundances of ZO-1, occludin, claudin-1, claudin-3, and claudin-4 were significantly decreased in the HC group, which was consistent with the results of immunohistochemistry. Furthermore, feeding the HC diet increased the ratios of DNA methylation and chromatin compaction in the promoter regions of occludin and claudin-1, which in turn inhibited their transcriptional expression. Therefore, the present study demonstrated that feeding an HC diet induced SARA in Hu sheep, altered the composition and structure of the microbial community in the colonic contents, induced an inflammatory response, and disrupted the intestinal mucosal barrier in the colonic tissue.

Rebecca N. Klopp, Juan F. Hernandez Franco, Harm Hogenesch et al.

ABSTRACT: It is necessary for the dairy industry to reduce calf morbidity and mortality, and the reliance on antibiotics to treat sick calves, to address the growing concern regarding antibiotic resistant bacteria. The primary objective of this study was to evaluate the effect that feeding dairy calves medium-chain fatty acids (MCFA) has on growth performance and health, and the secondary objective was to evaluate the effect of MCFA on energy status around weaning and the adaptive immune response following a vaccine challenge. Thirty-three Holstein bull calves (5 ± 1.6 d of age) were randomly assigned to 1 of 2 treatments. Control (CON) calves were fed milk replacer with no C8:0 or C10:0 oil added and MCFA calves were fed milk replacer with 0.5% of a combination of C8:0 or C10:0 oil added. Body weight and average daily gain were measured weekly. Feed efficiency (gain/feed) and the change in body condition score, hip width, hip height, heart girth, and paunch girth were calculated for the duration of the study. Fecal scores were recorded daily and all medical treatments were documented for the duration of the trial. On d 42, 49, and 56 of the study, a serum sample was collected from each calf and used to measure nonesterified fatty acids, β-hydroxybutyric acid, insulin, and glucose concentrations to evaluate energy status around weaning. A subset of 11 calves per treatment were enrolled in a vaccine challenge. At 21 ± 1.9 d of age (mean ± standard deviation) calves were vaccinated intramuscularly with 1 mL of endotoxin-free ovalbumin (OVA) mixed with aluminum hydroxide adjuvant. At 42 d of age (±1.9 d), blood samples were collected and used to analyze OVA-specific IgG1 and IgG2, and calves were vaccinated a second time. At 56 d of age (±1.9 d), blood samples were collected to analyze IgG1 and IgG2 as well as IFN-γ and IL-4 secreted from peripheral blood mononuclear cells (PBMC) treated with OVA or phytohemagglutinin. Data were analyzed as a completely randomized design with repeated measures when applicable. A tendency for greater daily fecal score was observed for MCFA calves compared with CON. At d 42 of the study, nonesterified fatty acid concentrations were greater in CON calves compared with MCFA. At 42 and 56 d of age, anti-OVA IgG1 concentrations for CON and MCFA calves were greater than prevaccination samples. This study suggests that feeding MCFA to calves affects the energy status of calves around weaning and vaccinating dairy calves with ovalbumin combined with an aluminum hydroxide adjuvant is an effective way to evaluate the adaptive immune responses.

J.A. Johnson, K.S. Paddick, M. Gardner et al.

ABSTRACT: Provision of a palatable feed in automated milking systems (AMS) is considered an essential motivating factor to encourage voluntary visits to the milking stall. Although the quantity and composition of AMS concentrates have been previously investigated, the form of the concentrate has not been extensively evaluated. The objective of this study was to evaluate the effects of feeding pelleted (PB; 132.9 ± 56 DIM, 47.4 ± 9.51 kg/d milk yield) versus steam-flaked barley (SFB; 133.0 ± 63 DIM, 40.5 ± 8.23 kg/d milk yield) in an AMS on dry matter intake, AMS visits, milk and milk component yield, and partial mixed ration (PMR) feeding behavior. Twenty-nine Holstein cows of varying parities were enrolled in this study. Cows were housed in freestall housing with a feed-first guided-flow barn design; 7 cows were housed in a separate freestall pen to enable individual PMR intake and feeding behavior monitoring. This study was conducted as a 2-way crossover, with two 21-d periods in which each cow received the same basal PMR but was offered 2 kg/d (dry matter basis) of PB or SFB in the AMS. Cows receiving the SFB had fewer voluntary AMS visits (2.71 vs. 2.90 ± 0.051, no./d), tended to have a longer interval between milkings (541.7 vs. 505.8 ± 21.02 min), spent more time in the holding pen before entering the AMS (139.9 vs. 81.2 ± 11.68 min/d), and had lower total box time (19.7 vs. 21.4 ± 0.35 min/d) than cows fed PB. Despite changes in AMS attendance, there were no differences for average milk (44.0 kg/d), fat (1.62 kg/d), and protein (1.47 kg/d) yields or AMS concentrate intake (2.02 kg/d). These behavioral changes indicate that offering SFB as an alternative to PB may reduce motivation for cows to voluntarily enter the AMS.

J.O. Giordano, E.M. Sitko, C. Rial et al.

ABSTRACT: As the reproductive efficiency of dairy cattle continues to improve in response to better management and use of technology, novel reproductive management approaches will be required to improve herd performance, profitability, and sustainability. A potential approach currently being explored is targeted reproductive management. This approach consists of identifying cows with different reproductive and performance potential using multiple traditional and novel sources of biological, management, and performance data. Once subgroups of cows that share biological and performance features are identified, reproductive management strategies specifically designed to optimize cow performance, herd profitability, or alternative outcomes of interest are implemented on different subgroups of cows. Tailoring reproductive management to subgroups of cows is expected to generate greater gains in outcomes of interest than if the whole herd is under similar management. Major steps in the development and implementation of targeted reproductive management programs for dairy cattle include identification and validation of robust predictors of reproductive outcomes and cow performance, and the development and on-farm evaluation of reproductive management strategies for optimizing outcomes of interest for subgroups of cows. Predictors of cow performance currently explored for use in targeted management include genomic predictions; behavioral, physiological, and performance parameters monitored by sensor technologies; and individual cow and herd performance records. Once the most valuable predictive sources of variation are identified and their effects quantified, novel analytic methods (e.g., machine learning) for prediction will likely be required. These tools must identify groups of cows for targeted management in real time and with no human input. Despite some encouraging research evidence supporting the development of targeted reproductive management strategies, extensive work is required before widespread implementation by commercial farms.

M. Rest

This article outlines an interdisciplinary research project emerging from biomolecular archaeology interested in the prehistoric spread of dairying in Mongolia, Europe, and the Near East. By comparing the microbes present in ancient and contemporary dairy products, the Heirloom Microbes project is in conversation with two of the most exciting fields of science to the general public: ancient DNA (aDNA)—which promises a new science of history through genomics—and microbiome research—which promises new treatments to some of the most mysterious ailments of industrialized populations. In this encounter the politics of life itself meets the politics of history itself, as I will show through a detailed ethnography of contemporary peasant dairying practices in Switzerland and a discussion of the microbial bioprospecting underway among hunter-gatherer groups like the Hadza of East Africa. Contrary to imaginations of revolutionary ruptures and “missing microbes” prevalent in ancient DNA and microbiome research, I argue for the continuous reproduction of human-microbe relations in millions of multispecies peasant fermentation collectives in most of the world. These microbial commons have to be protected from attempts of patenting and commodification through the collective efforts of scientists and small-scale producers.

J. Wells, Emma Pomeroy, J. Stock

The emergence of the capacity to digest milk in some populations represents a landmark in human evolution, linking genetic change with a component of niche construction, namely dairying. Alleles promoting continued activity of the enzyme lactase through the life-course (lactase persistence) evolved in several global regions within the last 7,000 years. In some European regions, these alleles underwent rapid selection and must have profoundly affected fertility or mortality. Elsewhere, alleles spread more locally. However, the functional benefits underlying the rapid spread of lactase persistence remain unclear. Here, we set out the hypothesis that lactase persistence promoted skeletal growth, thereby offering a generic rapid solution to childbirth complications arising from exposure to ecological change, or to new environments through migration. Since reduced maternal growth and greater neonatal size both increase the risk of obstructed labour, any ecological exposure impacting these traits may increase maternal mortality risk. Over many generations, maternal skeletal dimensions could adapt to new ecological conditions through genetic change. However, this adaptive strategy would fail if ecological change was rapid, including through migration into new niches. We propose that the combination of consuming milk and lactase persistence could have reduced maternal mortality by promoting growth of the pelvis after weaning, while high calcium intake would reduce risk of pelvic deformities. Our conceptual framework provides locally relevant hypotheses to explain selection for lactase persistence in different global regions. For any given diet and individual genotype, the combination of lactase persistence and milk consumption would divert more energy to skeletal growth, either increasing pelvic dimensions or buffering them from worsening ecological conditions. The emergence of lactase persistence among dairying populations could have helped early European farmers adapt rapidly to northern latitudes, East African pastoralists adapt to sudden climate shifts to drier environments, and Near Eastern populations counteract secular declines in height associated with early agriculture. In each case, we assume that lactase persistence accelerated the timescale over which maternal skeletal dimensions could change, thus promoting both maternal and offspring survival. Where lactase persistence did not emerge, birth weight was constrained at lower levels, and this contributes to contemporary variability in diabetes risk.

J. Drewry, S. Carrick, Nicole L. Mesman et al.

ABSTRACT In Canterbury, New Zealand, there has been a widespread conversion of dryland sheep grazing to more intensive irrigated dairying. We determined the effects of these land uses on soil physical properties, and water release characteristics, on adjacent sites: a centre-pivot sprinkler-irrigated dairy farm site, a dryland sheep site, and a non-grazed, non-irrigated control site. Despite the Pallic Soil being well drained, greater soil compaction occurred at the dairy site than at other sites, to at least 30 cm depth. The dairy site typically had significantly lower total porosity and macroporosity, and greater bulk density and volumetric water content, than the other sites. Available water capacity varied but was greater at the dairy site (0–30 cm) than at the sheep site and control site. Further research is required across more farms and soils to confirm these results in other conditions.

Nicolas Schoof, R. Luick, K. Jürgens et al.

Germany is the largest milk producer of the 28 EU Member States (statistically still including Great Britain) and dairying is the most important single sector in German agriculture. Dairies are of central importance in the value chain, but very little is known about their objectives and perspectives in relation to grassland management, feedstuffs deriving from grassland and towards resource conservation issues. This study gives an insight on the way German dairies think about and act in such topics by using a standardized survey method. The survey revealed little to no linkage between the size of dairies and their interest in conservation issues on grassland and very little consideration of extensive grasslands. Dairies are divided over questions of governance for a more sustainable milk market and on the nature of their relationships with farmers. There is evidence that the German dairy industry is willing to contribute to a more sustainable and more robust milk market, but the enterprises mostly regard other market actors as more important. According to this survey, consumers will tend to opt for more sustainable milk products in future and there are possibilities to raise the willingness to pay.