ABSTRACT: The rising demand for nondairy and nonanimal protein sources has increased plant-based beverages (PBB) consumption. However, research on their functional properties, metabolic profile, and discrimination potential is limited. This study evaluated the potential of proton nuclear magnetic resonance (1H NMR) spectroscopy as an authentication method to discriminate milk (cow and goat) and PBB macro-groups, including soy-based, fruit-based (almond and coconut), and cereal-based (rice and oat) beverages, based on their metabolic profile. A total of 22 PBB (soy-, almond-, coconut-, rice-, and oat-based beverages), 4 cow milk, and 4 goat milk cartons were analyzed with 1H NMR spectroscopy to obtain their metabolic profile. Relevant metabolites to discriminate PBB macro-groups and cow and goat milk were identified through the Mann-Whitney U test and partial least squares-discriminant analysis. Results revealed that uridine diphosphate glucose and adenosine were key metabolites for the identification of goat and cow milk. At the same time, choline and guanosine emerged as important markers for different PBB macro-group detection. In addition, lactose played a significant role in differentiating milk from PBB. In conclusion, these findings represent an initial step toward applying 1H NMR spectroscopy for authentication and nutritional analysis of PBB, opening the door for further research into their authenticity and metabolic profiling.
Mahmoud H. Emam, Abdelmonem Abdallah, Elise Shepley
et al.
Hyperketonemia (HYK) is a common disorder in high-producing dairy cows, resulting in significant economic losses. Defined by elevated beta-hydroxybutyrate (BHB; ≥1.2 mmol/L) without clinical signs, HYK is often considered a gateway disease, predisposing cows to other metabolic and infectious problems. Our objective was to investigate the association between previous lactation risk factors and both BHB concentration and HYK status during the first week postpartum in the subsequent lactation. A retrospective study was conducted using previously collected blood samples from 2336 Holstein multiparous dairy cows from 7 dairy herds, where BHB concentration was measured during the first week postpartum. Data from the previous lactation were extracted from electronic farm records. Log-transformed BHB concentrations and HYK status were each modeled using separate linear mixed models. Both models included the same set of risk factors—lactation, previous lactation total times bred, dry length period, previous lactation days in milk, previous lactation days open, previous lactation days carried calf, previous lactation peak milk production, previous lactation total milk production, previous lactation total milk fat, and previous lactation total milk protein—to investigate their association with these outcomes. Potential confounding variables were offered to the models, and stepwise backward elimination was used to determine which covariates to retain. Significant associations were detected between BHB concentration and dry period length (DDRY), lactation number (LACT), previous lactation total milk protein (TOTP), and previous lactation days open (PDOPN). Inclusive, significant associations were detected between HYK status and previous lactation total milk production (PTOTM), DDRY, LACT, TOTP, and PDOPN. Our results suggest that a dry period longer than 60 days, days open exceeding 130 days, being in their third or greater lactation, and each additional 1000 kg of milk produced in the previous lactation are associated with an increased risk of having high BHB and HYK in the first week postpartum in the subsequent lactation.
O. González-Recio, A. Fernández, J.A. Jiménez Montero
ABSTRACT: Epizootic hemorrhagic disease (EHD) is a noncontagious viral infection that can cause important economic losses on dairy farms. This study aimed to identify epidemiological and genetic factors influencing the susceptibility and severity of EHD in Holstein dairy cattle during the 2023 outbreak in Spain. Data from 2,852 animals in 7 affected farms from 5 Spanish provinces were used. Symptoms were categorized in 5 categories: no symptoms, mild symptoms, severe symptoms and recovery, severe symptoms with aftereffects (sequelae), and severe symptoms followed by death. All animals were genotyped using the Illumina EuroG MD SNP array, and imputation to whole-genome sequencing was carried out using the 1,000 bull genomes dataset as a reference. Risk factors for EHD were explored using linear mixed effects models, as well as the loss of milk yield and culling risk probability due to severe EHD. In all, ∼66% of animals showed EHD virus antibodies, although only 25% of the sample in this study showed severe symptoms, and the death rate was 2% to 3%. Results indicated that age was the main risk factor for severe EHD, with older cows showing greater susceptibility. Production losses were significant in cows with moderate to severe symptoms, especially if the outbreak occurred mid lactation (up to −9 kg/d). Cows exhibiting severe symptoms demonstrated a markedly increased likelihood of being culled, with an odds ratio of 10.86 (95% CI: 6.08–19.41) for cows with severe symptoms. The genetic component of EHD was evaluated using REML procedures, and a GWAS was conducted to investigate genomic regions associated with the disease. An h2 of 0.08 was estimated, with some genes (AOC1, BST1, CD38, DPP6, DPYS, HOGA1, KMT2C, PIK2A, PIK3, and PI4K2A) associated with the disease showing involvement in immunity processes and the development of the pulmonary tree. This study underscores the genetic and epidemiological factors influencing EHD severity in dairy cattle, providing insights for managing future outbreaks and mitigating economic losses in affected regions.
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.
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.
Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, mainly through the process of replacing or including beneficial bacteria in the gastrointestinal tract. Fermented dairy foods such as yogurt, fermented milk and cheese are the major vehicle in delivering probiotics, and probiotic delivery have been traditionally associated with these fermented dairy foods. Additionally, many other non-dairy probiotic products and non-food form such as capsules, pills and tablets are also available and some of these non-food forms are highly popular among the consumers. Certain non-dairy probiotic foods, especially beverages that are non-fermented products, can also play an important role in probiotic delivery. There is an increasing demand for non-dairy probiotic foods (both fermented and non-fermented) including fruit and vegetable juices, soy and certain cereal products due to vegetarianism, lactose intolerance and dairy allergies, as well as interest in low cholesterol foods. In this context, this review mainly focus on the different types of probiotic food products including beverages with special reference to their viability followed by a brief account on the applicability of using fermented and non-fermented beverage products in probiotic delivery.
ABSTRACT: Udder health has a crucial role in sustainable milk production, and various reports have pointed out that changes in udder condition seem to affect milk mineral content. The somatic cell count (SCC) is the most recognized indicator for the determination of udder health status. Recently, a new parameter, the differential somatic cell count (DSCC), has been proposed for a more detailed evaluation of intramammary infection patterns. Specifically, the DSCC is the combined proportions of polymorphonuclear neutrophils and lymphocytes (PMN-LYM) on the total SCC, with macrophages (MAC) representing the remainder proportion. In this study, we evaluated the association between DSCC in combination with SCC on a detailed milk mineral profile in 1,013 Holstein-Friesian cows reared in 5 herds. An inductively coupled plasma–optical emission spectrometry was used to quantify 32 milk mineral elements. Two different linear mixed models were fitted to explore the associations between the milk mineral elements and first, the DSCC combined with SCC, and second, DSCC expressed as the PMN-LYM and MAC counts, obtained by multiplying the proportion of PMN-LYM and MAC by SCC. We observed a significant positive association between SCC and milk Na, S, and Fe levels. Differential somatic cell count showed an opposite behavior to the one displayed by SCC, with a negative association with Na and positive association with K milk concentrations. When considering DSCC as count, Na and K showed contrasting behavior when associated with PMN-LYM or MAC counts, with decreasing of Na content and increasing K when associated with increasing PMN-LYM counts, and increasing Na and decreasing K when associated with increasing MAC count. These findings confirmed that an increase in SCC is associated with altered milk Na and K amounts. Moreover, MAC count seemed to mirror SCC patterns, with the worsening of inflammation. Differently, PMN-LYM count exhibited patterns of associations with milk Na and K contents attributable more to LYM than PMN, given the nonpathological condition of the majority of the investigated population. An interesting association was observed for milk S content, which increased with increasing of inflammatory conditions (i.e., increased SCC and MAC count) probably attributable to its relationship with milk proteins, especially whey proteins. Moreover, milk Fe content showed positive associations with the PMN-LYM population, highlighting its role in immune regulation during inflammation. Further studies including individuals with clinical condition are needed to achieve a comprehensive view of milk mineral behavior during udder health impairment.
Sole ulcers negatively affect cow welfare and production economy. Previous cases of sole ulcers increase the risk of new or recurrent cases, and prevention of sole ulcers during the first lactation may therefore have a long-term effect, also in later lactations. Until now, risk factors for sole ulcers in the first lactation, associated with the period before heifers calve for the first time, have not been investigated. This study evaluated early-life cow-level risk factors for sole ulcers at the first hoof trimming in the first lactation. Early-life risk factors were defined as risk factors associated with the period before a cow calves for the first time. A dataset including information about all hoof trimming recordings during the years 2020 to 2022, and information about individual cows, was retrieved from the Danish Cattle Database. The dataset included only primiparous cows, and only cows that were hoof trimmed at least once during the first lactation. Overall, 1.95% of 466,113 cows included in the study had sole ulcers at the first hoof trimming in the first lactation. Results from a logistic regression model demonstrated a statistically significant interaction between breed and age at first calving (grouped based on quartiles within breed). Overall, across breeds, odds ratios of sole ulcers at the first hoof trimming in the first lactation were generally approximately 0.5 in the first quartile of age at first calving, approximately 0.6 in the second quartile, and approximately 0.75 in the third quartile, compared with the fourth quartile within the same breed. Odds of sole ulcers were generally higher in Jersey and Danish Red Dairy cows, compared with Holstein. In conclusion, the odds of sole ulcers in the first lactation increased with increasing age at first calving, and was approximately twice as high in cows calving among the oldest 25% within a breed, compared with cows calving among the youngest 25%. Focus on early-life risk factors for sole ulcers may have a major influence on the occurrence of sole ulcers throughout the life of cows.
ABSTRACT: We investigated the prevalence and spatial distribution of selected pathogens associated with infectious diseases of dairy cattle in Ontario, Canada. The cross-sectional study surveyed bulk tank milk for antibodies against bovine leukemia virus (BLV), Mycobacterium avium ssp. paratuberculosis (MAP), and Salmonella Dublin, and for the presence of mastitis pathogens (Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma bovis). Between October 2021 and June 2022, bulk tank milk samples were obtained from every commercial dairy farm in Ontario (n = 3,286). Samples underwent ELISA testing for the presence of BLV, MAP, and S. Dublin antibodies, and quantitative PCR testing for the detection of specific antigens of pathogens associated with mastitis. Bayesian models were used to estimate prevalence, and spatial analysis was carried out to identify regional clusters of high pathogen prevalence. Prevalence varied for different pathogens, and BLV was widespread across dairy farms in Ontario, with an estimated prevalence of 88.3%. The prevalence of MAP, Staph. aureus and S. Dublin in Ontario dairy herds was 39.8%, 31.5%, and 5.1%, respectively. The vast majority of dairy herds in Ontario were free of intramammary infections caused by Strep. agalactiae and M. bovis. Clusters of increased positive test rates were detected for S. Dublin, MAP, and Staph. aureus, indicating potential geographic risk factors for pathogen transmission. For S. Dublin, an area of increased test positivity rates was detected in southwestern Ontario, close to the Canada-United States border where most of the dairy herds in Ontario are located. Conversely, a localized cluster of positive test outcomes involving 14 subdivisions located in the southeastern region of Ontario was detected for Staph. aureus. Findings from our survey highlight the importance of the testing of aggregated samples and conducting spatial analysis as part of disease surveillance programs, and for implementing risk-based trading approaches among dairy producers.
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.
Rika Zahera, Mega Indah Pratiwi, Ainissya Fitri
et al.
This study aimed to compare calcium oxide (CaO) and calcium chloride (CaCl<sub>2</sub>) as calcium sources for coconut fatty acid distillate (CFAD) calcium soap (Ca-soap) production and to evaluate the supplementation ratios of unprotected and protected CFAD in dairy rations to optimize rumen function. This research included two steps: (1) assessing the protection strength of Ca-soap made with CaO and CaCl<sub>2</sub> at mole ratios of Ca to CFAD of 1, 1.5, 2, and 2.5; (2) evaluating CFAD supplementation in an in vitro dairy ration study using a 5 × 4 randomized factorial block design. Factor A compared unprotected and protected CFAD ratios of A1 = 100:0, A2 = 75:25, A3 = 50:50, A4 = 25:75, and A5 = 0:100, and factor B compared supplementation levels of B1 = 0%, B2 = 1%, B3 = 2%, and B4 = 3%. CaCl<sub>2</sub> at a 2.5-mole ratio to CFAD produced the lowest acid value and the carboxylic acid (C=O) chemical bond. Complete protection (0:100) exhibited the highest densities of <i>Bacteroides</i> and nutrient digestibility (<i>p</i> < 0.05) without significantly affecting rumen fermentability (<i>p</i> > 0.05). Higher CFAD levels significantly reduced methanogens and protozoa (<i>p</i> < 0.05) without significantly affecting estimated methane production. In conclusion, CaCl<sub>2</sub> at a 2.5-mole ratio to CFAD provided the best protection, and its complete protection in CFAD supplementation optimized rumen function.
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.
This review aims to emphasize the occurrence and abundant presence of mannans in nature, their classification, structural differences and significance in food and feed industry. With rising demand from the consumers' end for novel natural foods, usage of galactomannan and glucomannan has also increased alternatively. Non toxicity of mannans permits their usage in the pharmaceutical, biomedical, cosmetics, and textile industries. In the food industry, mannans have various applications such as edible films/coating, gel formation, stiffeners, viscosity modifiers, stabilizers, texture improvers, water absorbants, as prebiotics in dairy products and bakery, seasonings, diet foods, coffee whiteners etc. Applications and functions of these commonly used commercially available mannans have therefore, been highlighted. Mannans improve the texture and appeal of food products and provide numerous health benefits like controlling obesity and body weight control, prebiotic benefits, constipation alleviaton, prevent occurrence of diarrhea, check inflammation due to gut related diseases, management of diverticular disease management, balance intestinal microbiota, immune system modulator, reduced risk of colorectal cancer etc. Mannan degrading enzymes are the key enzymes involved in degradation and are useful in various industrial processes such as fruit juice clarification, viscosity reduction of coffee extracts etc. besides facilitating the process steps and improving process quality.
ABSTRACT: Energy intake and partitioning are determined by many interacting factors and their prediction is the Achilles' heel of ration formulation. Inadequate energy intake can limit milk yield and reproductive performance, whereas excessive energy intake will increase body condition, increasing the risk of health and reproductive issues in the subsequent lactation. Ration composition interacts with the physiological state of cows, making it difficult to predict DMI and the partitioning of energy accurately. However, understanding the factors controlling these allows us to devise grouping strategies and manipulate rations to optimize energy intake through lactation. Eating is controlled by the integration of signals in brain feeding centers. Ration composition affects DMI of cows via signals from ruminal distention and the hepatic oxidation of fuels. Dairy cow rations must contain a minimal concentration of relatively low-energy roughages for proper rumen function, but signals from ruminal distension can limit DMI when the drive to eat is high. Signals from the hepatic oxidation of fuels likely dominate the control of DMI in the peripartum period when cows are in a lipolytic state and later in lactation when signals from distension diminish. Therefore, the effects of the ration on DMI vary with the physiological state of the animal. Furthermore, they interact with environmental stressors such as social (e.g., overcrowding) and thermal stress. The objective of this article is to discuss the effects of ration composition on energy intake and partitioning in lactating cows and how they can be manipulated to optimize productive performance.
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.
ABSTRACT: Accurate and timely pregnancy diagnosis is an important component of effective herd management in dairy cattle. Predicting pregnancy from Fourier-transform mid-infrared (FT-MIR) spectroscopy data is of particular interest because the data are often already available from routine milk testing. The purpose of this study was to evaluate how well pregnancy status could be predicted in a large data set of 1,161,436 FT-MIR milk spectra records from 863,982 mixed-breed pasture-based New Zealand dairy cattle managed within seasonal calving systems. Three strategies were assessed for defining the nonpregnant cows when partitioning the records according to pregnancy status in the training population. Two of these used records for cows with a subsequent calving only, whereas the third also included records for cows without a subsequent calving. For each partitioning strategy, partial least squares discriminant analysis models were developed, whereby spectra from all the cows in 80% of herds were used to train the models, and predictions on cows in the remaining herds were used for validation. A separate data set was also used as a secondary validation, whereby pregnancy diagnosis had been assigned according to the presence of pregnancy-associated glycoproteins (PAG) in the milk samples. We examined different ways of accounting for stage of lactation in the prediction models, either by including it as an effect in the prediction model, or by pre-adjusting spectra before fitting the model. For a subset of strategies, we also assessed prediction accuracies from deep learning approaches, utilizing either the raw spectra or images of spectra. Across all strategies, prediction accuracies were highest for models using the unadjusted spectra as model predictors. Strategies for cows with a subsequent calving performed well in herd-independent validation with sensitivities above 0.79, specificities above 0.91 and area under the receiver operating characteristic curve (AUC) values over 0.91. However, for these strategies, the specificity to predict nonpregnant cows in the external PAG data set was poor (0.002–0.04). The best performing models were those that included records for cows without a subsequent calving, and used unadjusted spectra and days in milk as predictors, with consistent results observed across the training, herd-independent validation and PAG data sets. For the partial least squares discriminant analysis model, sensitivity was 0.71, specificity was 0.54 and AUC values were 0.68 in the PAG data set; and for an image-based deep learning model, the sensitivity was 0.74, specificity was 0.52 and the AUC value was 0.69. Our results demonstrate that in pasture-based seasonal calving herds, confounding between pregnancy status and spectral changes associated with stage of lactation can inflate prediction accuracies. When the effect of this confounding was reduced, prediction accuracies were not sufficiently high enough to use as a sole indicator of pregnancy status.
ABSTRACT: Goat milk whey protein concentrates were manufactured by microfiltration (MF) and ultrafiltration (UF). When MF retentate blended with cream, which could be used as a starting material in yogurt making. The objective of this study was to prepare goat milk whey protein concentrates by membrane separation technology and to investigate the effects of polymerized goat milk whey protein (PGWP) on the physicochemical properties and microstructure of recombined goat milk yogurt. A 3-stage MF study was conducted to separate whey protein from casein in skim milk with 0.1-µm ceramic membrane. The MF permeate was ultrafiltered using a 10 kDa cut-off membrane to 10-fold, followed by 3 step diafiltration. The ultrafiltration-diafiltration-treated whey was electrodialyzed to remove 85% of salt, and to obtain goat milk whey protein concentrates with 80.99% protein content (wt/wt, dry basis). Recombined goat milk yogurt was prepared by mixing cream and MF retentate, and PGWP was used as main thickening agent. Compared with the recombined goat milk yogurt without PGWP, the yogurt with 0.50% PGWP had desirable viscosity and low level of syneresis. There was no significant difference in chemical composition and pH between the recombined goat milk yogurt with PGWP and control (without PGWP). Viscosity of all the yogurt samples decreased during the study. There was a slight but not significant decrease in pH during storage. Bifidobacterium and Lactobacillus acidophilus in yogurt samples remained above 106 cfu/g during 8-wk storage. Scanning electron microscopy of the recombined goat milk yogurt with PGWP displayed a compact protein network. Results indicated that PGWP prepared directly from raw milk may be a novel protein-based thickening agent for authentic goat milk yogurt making.