ABSTRACT: Studies with sheep and cattle have identified the macroalga Asparagopsis taxiformis (AT) as a potent methane-mitigating feed additive but have also raised concerns related to bromoform's (a halogenated compound responsible for the antimethanogenic effect of AT) stability over prolonged storage. Previously, our laboratory conducted a study in which the effect of AT on enteric CH4 diminished over time. This effect had not been previously reported and warranted further investigation. The study was conducted with 18 Holstein cows in a replicated 3 × 3 Latin square design with 28-d periods. Treatments were control (basal diet), basal diet + 0.50% AT, and basal diet + 0.75% AT (feed DM basis). Methane emission was measured using the GreenFeed system. At the beginning of the experiment, bromoform concentration in AT was 4.41 mg/g DM. Daily CH4 emission decreased up to 30% with increasing AT dose. Inclusion of AT also decreased DMI by up to 22%, resulting in no effect on CH4 yield (g CH4/kg DMI). Milk true protein and lactose concentrations decreased up to 4% and 2% by AT, respectively. Asparagopsis taxiformis decreased milk fat yield up to 13%. Milk true protein and lactose yields were decreased up to 15% and 14% by AT, respectively, resulting in a decrease in ECM of up to 14%. Methane intensity (g CH4/kg of ECM) decreased by AT up to 18%. Additionally, there was a decrease in BW in cows fed AT, compared with the control. In conclusion, AT stored over 20 mo and included at up to 0.75% (feed DM basis) in the diet of dairy cows decreased daily CH4 emission but did not affect CH4 yield and decreased DMI and milk yield in mid-lactation dairy cows. These data confirm previous observations of inconsistent effects of AT on CH4 emission metrics and negative effects of AT on feed intake and productivity.
T.O. Cunha, P.L.J. Monteiro, Jr., W.S. Frizzarini
et al.
ABSTRACT: The purpose of this study was to use a secondary analysis to investigate the use of feeding high and low-energy diets to alter BCS at dry-off, and to assess the subsequent changes in BCS on feed intake, calcemia, and assessment of immune function, including inflammation, during the periparturient period. Multiparous Holstein lactating dairy cows at 150 d of gestation were blocked by expected calving date and randomly assigned to receive one of 2 dietary treatments during late lactation until dry-off, aiming to maintain or decrease BCS. To this end, a low-energy diet (LE; 1.54 ± 0.01 Mcal/kg DM; n = 27) was formulated not to exceed energy requirements, and a high-energy diet (HE; 1.8 ± 0.01 Mcal/kg DM; n = 28) was formulated to exceed energy requirements based on the NEL of cows during late lactation. The HE cows that gained ≥0.5 BCS and LE cows that lost, maintained, or gained ≤0.25 BCS were included in this study for analysis. Cows that did not respond to dietary treatment were not included in the analysis, resulting in a cohort of 40 cows: 20 cows in the HE group that responded, and 20 cows in the LE group that responded to dietary treatments. After dry-off, all cows were fed the same diets for the duration of the study. In the last week of gestation, the BCS of the HE and LE cows averaged 3.85 and 3.26 ± 0.1, respectively. During the last 10 d prepartum, HE cows consumed, on average, 1.6 kg DM per day less than LE cows. Plasma concentrations of IL-6 and haptoglobin did not differ between groups 7 d before parturition (725 ± 147 pg/mL and 0.57 ± 0.04 ng/mL, respectively). Serum leptin concentrations also did not differ between groups 7 d before parturition. No differences were detected in ionized calcium, total magnesium (Mg), and total phosphorus (P) between groups from −1 to 3 DIM. Nonesterified fatty acid concentrations tended to be elevated in HE cows from −7 to 7 DIM. Neutrophil phagocytic capacity, oxidative burst, and the expression of the cellular adhesion selectin CD62L were also similar between groups. The expression of the cellular adhesion integrin CD18 on neutrophils was increased in the LE group at 2 DIM but was not different at 0 and 7 DIM. Overall, our findings from this secondary analysis of cows that altered BCS in response to dietary treatment indicate that feeding a HE diet during late lactation affected feed intake without significantly altering immune function or calcemia during the periparturient period.
ABSTRACT: Single-step GBLUP (ssGBLUP) is becoming the most used method to predict breeding values in livestock, offering several advantages in terms of computational efficiency and simplifying the genetic evaluation process by integrating genomic, pedigree, and phenotypic information in a single step. Genomic information is now available for the Italian Mediterranean buffalo (IMB), and its inclusion in the genetic evaluation system could increase both evaluation accuracy and genetic progress of the breeding objectives. The aim of this study was to test the feasibility of ssGBLUP and to present the first results of the implementation of a genomic evaluation for IMB. Phenotypic information on production traits (milk yield adjusted to 270 d, fat and protein yield and content, and cheese yield) and morphology traits (feet and legs scores and udder teat scores) were used in this study. Production records included 792,200 lactations from 293,633 buffalo cows born from 1984 to 2021. Morphological traits were from 99,609 buffalo cows from 2004 to 2023. Regarding the genotypes, a total of 3,647 genotyped animals were used. Data were analyzed fitting 2 multitrait animal models, a 6-trait model for production data, and a 2-trait model for morphology data. Breeding values (BV) were estimated with BLUP and ssGBLUP models, both considering unknown parent groups. The methods were compared in terms of correlation between BV and genetic trends. Results were also validated with the linear regression (LR) method. Three different scenarios were used according to the cut-off year used to create the partial datasets, namely T2013, T2016, and T2018. The genomic and nongenomic BV were strongly correlated, and genetic trends for each trait were similar. The average increase in accuracy moving from BLUP to ssGBLUP across traits ranged from +3% to +12%. The LR method statistics confirmed the effectiveness of the ssGBLUP method. The average validation correlations across production traits and scenarios for BLUP and ssGBLUP by female and bull groups were 0.54 and 0.47, and 0.63 and 0.52, respectively. Accuracies were also higher with ssGBLUP (0.62/0.55) compared with BLUP (0.53/0.51). The best dispersion values (i.e., closer to 1) were observed for ssGBLUP (T2013, T2016). The ssGBLUP method provided better results across genotyped and nongenotyped animals, particularly in terms of a relative increase in accuracy associated with the inclusion of phenotypes. These results showed that implementing ssGBLUP in the breeding program can generate more accurate predictions for production and morphological traits in dairy IMB.
ABSTRACT: The objective of this study was to evaluate the possible role of the peroxisome proliferator-activated receptors (PPAR: PPAR-α, PPAR-β/δ, and PPAR-γ) in diet and CLA-induced milk fat depression (MFD) in dairy cows. We hypothesized that the expression of PPAR, which regulate lipid metabolism and bind to PUFA, could be modulated by biohydrogenation intermediates that induce MFD, thereby interfering with milk fat synthesis. First, tissue profiling revealed that PPAR-α and PPAR-β/δ had low expression in mammary tissue compared with the liver. A comparison of lactating and nonlactating tissue from the same cows showed that expression of all 3 PPAR isoforms did increase during lactation. Mammary expression of the PPAR family during MFD was then observed in 9 mid-lactation cows in a 3 × 3 Latin square design with MFD induced by a 3-d intravenous infusion of trans-10,cis-12 CLA or feeding a high-oil and low-forage diet. The expression of all 3 PPAR isoforms remained largely unaltered during CLA and diet-induced MFD, except for an increase in PPAR-α target genes CPT1A and ACADVL that are involved in β-oxidation. The interaction of PPAR-γ chemical agonist troglitazone and antagonist T0070907 and CLA was then investigated in bovine mammary epithelial cells. The activation and inhibition of PPAR-γ did not overcome trans-10,cis-12 CLA inhibition of lipogenesis despite the agonist stimulating PPAR-γ expression. Furthermore, PPAR-γ activation did not modify the expression of lipogenic genes. Overall, the results fail to support a functional role of the PPAR family in the inhibition of lipogenesis during MFD in dairy cows.
There is no serious dispute that farmer profitability and national milk production are underpinned by grazed pasture. DairyNZ data shows that the amount of homegrown pasture and crop consumed is the best predictor of profit per hectare (Macdonald and Roche 2023). National feed consumption data shows that approximately 75% of dairy cattle diets are from directly grazed forages (DairyNZ Economic Survey). The importance of high genetic merit cows and management skill in turning the inherent competitive advantage of grazed pasture into profit and production are also well documented (e.g. Macdonald and Roche 2023).
Zelmar Rodriguez, Victor E. Cabrera, Henk Hogeveen
et al.
ABSTRACT: Treatment of subclinical mastitis (SCM) during lactation is rarely recommended due to concerns related to both antimicrobial usage and the costs associated with milk discard. Nisin is a naturally produced antimicrobial peptide with a gram-positive spectrum that, when given to dairy cows, does not require milk discard. We evaluated the economic impact of the treatment of SCM during early lactation using a nisin-based intramammary treatment under different scenarios that included various treatment costs, milk prices, and cure rates. We stochastically simulated the dynamics of SCM detected during the first week of lactation. The net economic impact was expressed in US dollars per case. The probabilities of an event and their related costs were estimated using a model that was based on pathogen-specific assumptions selected from peer-reviewed articles. Nisin cure rates were based on results of pivotal studies included in the US Food and Drug Administration (FDA) approval submission. Based on our model, the average cost of a case of intramammary infection (i.e., only true-positive cases) in early lactation was $170 (90% = $148–$187), whereas the cost of a clinical mastitis case was $521 (90% range = $435–$581). Both estimates varied with etiology, parity, and stage of lactation. When comparing the net cost of SCM cases (i.e., CMT-positive tests) detected during the first week of lactation, nisin treatment generated an average positive economic impact of $19 per CMT-positive case. The use of nisin to treat SCM was beneficial 93% of the time. Based on the sensitivity analysis, treatment would result in an economically beneficial outcome for 95% and 73% of multiparous and primiparous cows, respectively. At the herd level, use of intramammary nisin to treat SCM in cows in early lactation was economically beneficial in most tested scenarios. However, the economic impact was highly influenced by factors such as rate of bacteriological cure, cost of treatment, and parity of the affected animal. These factors should be considered when deciding to use nisin as a treatment for SCM.
ABSTRACT: During the perinatal period, dairy cows undergo negative energy balance, resulting in elevated circulating levels of nonesterified fatty acids (NEFA). Although increased blood NEFA concentrations are a physiological adaptation of early lactation, excessive NEFA in dairy cows is a major cause of fatty liver. Aberrant lipid metabolism leads to hepatic lipid accumulation and subsequently the development of fatty liver. Both inositol-requiring enzyme 1α (IRE1α) and c-Jun N-terminal kinase (JNK) have been validated for their association with hepatic lipid accumulation, including their regulatory functions in calf hepatocyte insulin resistance, oxidative stress, and apoptosis. Meanwhile, both IRE1α and JNK are involved in lipid metabolism in nonruminants. Therefore, the aim of this study was to investigate how IRE1α and JNK regulate lipid metabolism in bovine hepatocytes. An experiment was conducted on randomly selected 10 healthy cows (hepatic triglyceride [TG] content <1%) and 10 cows with fatty liver (hepatic TG content >5%). Liver tissue and blood samples were collected from experimental cows. Serum concentrations of NEFA and β-hydroxybutyrate (BHB) were greater, whereas serum concentrations of glucose and milk production were lower in cows with fatty liver. The western blot results revealed that dairy cows with fatty liver had higher phosphorylation levels of JNK, c-Jun, and IRE1α in the liver tissue. Three in vitro experiments were conducted using primary calf hepatocytes isolated from 5 healthy calves (body weight: 30–40 kg; 1 d old). First, hepatocytes were treated with NEFA (1.2 mM) for 0.5, 1, 2, 3, 5, 7, 9, or 12 h, which showed that the phosphorylated levels of JNK, c-Jun, and IRE1α increased in both linear and quadratic effects. In the second experiment, hepatocytes were treated with high concentrations of NEFA (1.2 mM) for 12 h with or without SP600125, a canonical inhibitor of JNK. Western blot results showed that SP600125 treatment could decrease the expression of lipogenesis-associated proteins (PPARγ and SREBP-1c) and increase the expression of fatty acid oxidation (FAO)-associated proteins (CPT1A and PPARα) in NEFA-treated hepatocytes. The perturbed expression of lipogenesis-associated genes (FASN, ACACA, and CD36) and FAO-associated gene ACOX1 were also recovered by JNK inhibition, indicating that JNK reduced excessive NEFA-induced lipogenesis and FAO dysregulation in calf hepatocytes. Third, short hairpin RNA targeting IRE1α (sh-IRE1α) was transfected into calf hepatocytes to silence IRE1α, and KIRA6 was used to inhibit the kinase activity of IRE1α. The blockage of IRE1α could at least partially suppressed NEFA-induced JNK activation. Moreover, the blockage of IRE1α downregulated the expression of lipogenesis genes and upregulated the expression of FAO genes in NEFA-treated hepatocytes. In conclusion, these findings indicate that targeting the IRE1α-JNK axis can reduce NEFA-induced lipid accumulation in bovine hepatocytes by modulating lipogenesis and FAO. This may offer a prospective therapeutic target for fatty liver in dairy cows.
ABSTRACT: Several studies have described variations in lactose content (LC) in dairy cows during udder quarter health disorder or negative energy balance (NEB). However, their joint effects on LC have never been described. This was the aim of a longitudinal observational study performed on 5 Quebec dairy farms using automatic milking systems. Quarter milk samples were collected every 14 d from 5 to 300 DIM. Quarter health status was described by combining SCC level (SCC− or SCC+: < or ≥100,000 cells/mL, respectively) and infectious status (Patho− or Patho+: absence or presence of pathogens on a milk culture, respectively). Cows with NEB in early lactation (DIM <70) were identified using milk BHB content: <0.15 mM = BHB−; 0.15 to 0.19 mM = BHB+; >0.19 mM = BHB++. A total of 14,505 quarter cisternal milk samples were collected from 380 lactating cows. The quarter LC was analyzed using a mixed linear regression model with the following fixed effects: quarter health status, parity, time interval between last milking and sampling, quarter milk yield (in kg/d), DIM, and herd. A random quarter intercept with a repeated measures correlation structure and a cow random intercept were also specified. The LC of SCC+ quarters was lower (−0.17 ± 0.013 percentage points) compared with LC of SCC- quarters for both primiparous and multiparous cows. Of the 162 bacterial species identified, only 8 species had a prevalence greater than 4.0%, and just 5 of them were associated with a reduction in LC: Staphylococcus aureus, Staphylococcus chromogenes, Streptococcus dysgalactiae, Staphylococcus epidermidis, and Staphylococcus simulans. Cows identified as BHB+ and BHB++ in early lactation had a lower LC (−0.05 ± 0.019 and −0.13 ± 0.020 percentage points, respectively) compared with BHB− cows. For BHB++ cows, in both parity groups the decrease in LC (−0.20 ± 0.025 percentage points) was higher in SCC+ quarters compared with SCC− quarters. Moreover, the additive effect of the quarter health status and NEB on milk LC was greater with larger increases in BHB. Our findings highlight the necessity to jointly take into consideration both quarter health status and milk BHB concentration when using LC as a biomarker for NEB.
İhsan Bakirci, Murat Emre Terzioğlu, İbrahim Akkaya
Stirred-type fruit yoghurts with two different fruit purees (kiwifruit and banana) were produced and were investigated the physicochemical, volatile compounds, 2,2-diphenylpicrylhydrazyl (DPPH) free radical scavenging activity, cupric ion reducing capability (CUPRAC), total phenolic compounds (TPC), angiotensin-converting enzyme (ACE) inhibitory activity, 5-hydroxymethylfurfural (HMF) content, reducing sugar content and microstructure. The addition of fruit puree affected (p<0.01) total solids, fat, protein, ash, L*, a*, b*, volatile compounds, DPPH, CUPRAC, TPC, ACE inhibitory activity, HMF content, reducing sugar content and overall acceptability whereas it had an insignificant effect on the pH, titratable acidity, apparent viscosity, syneresis (p>0.05). Storage period significantly (p<0.01) affected the titratable acidity, DPPH, CUPRAC, TPC, ACE inhibitory activity, HMF content, reducing sugar content and overall acceptability, as well as the pH, apparent viscosity and a* (p<0.05). Although the addition of banana and kiwi relatively suppressed the characteristic flavour of the experimental yoghurt samples, it improved the DPPH, CUPRAC and TPC. On the other hand, the addition of banana-kiwi was found to increase the content of HMF, the toxic compound. Yoghurt can be recommended as an important source of bioactive compounds with ACE inhibitory activity. According to the microstructure analysis results, a more homogeneous structure was observed in the control group samples compared to the fruit-added yoghurt samples and it was determined that the serum pore diameters were smaller.
Saheed A. Ahmed, Ibrahim Kayode Banjoko, Olanrewaju Majeed Shuaib
et al.
Five Matured Noiler chickens 3 months old weighing 3kg±120g were used for the experiment. The birds have fasted for 16 hours without food but with a supply of fresh cool water. The birds were slaughtered and dressed conventionally. The breast meat was excised within one-hour post-mortem and used for the preparation of Asun using charcoal and oven smoking. The breast meats were cut into fillets of average weight without bone; the fillets were spiced, rubbed with vegetable oil, and smoked using charcoal and oven to an internal temperature of 720C for 20 minutes with regular turning. The result shows a significant difference (p<0.05) in the nutritional and chemical composition of raw and smoke Noiler meat. The charcoal and oven-smoked Asun were not different, but both differ from the raw. The organoleptic properties show no significant difference (p>0.05) in color, aroma, and texture while flavor, juiciness, and overall acceptability differ. There was a significantly different (p>0.05) in WHC, cooking loss, and cooking yield. Preparation of Asun using charcoal and oven smoking contributed to the nutritional component except for the moisture content. The cholesterol, SFA, MUFA, PUFA, and amines were also increased. The value obtained shows that charcoal and oven-smoked Noiler meat Asun is safe for consumption and has no negative effect, also impacts positively on both the physical and organoleptic properties of the prepared product and therefore, recommended for the preparation of Asun using Noiler meat.
Giselle K.P. Guron, Phoebe X. Qi, Michael J. McAnulty
et al.
ABSTRACT: Consumers' growing interest in fermented dairy foods necessitates research on a wide array of lactic acid bacterial strains to be explored and used. This study aimed to investigate the differences in the proteolytic capacity of Lactobacillus helveticus strains B1929 and ATCC 15009 on the fermentation of commercial ultra-pasteurized (UHT) skim milk and reconstituted nonfat dried milk powder (at a comparable protein concentration, 4%). The antihypertensive properties of the fermented milk, measured by angiotensin-I-converting enzyme inhibitory (ACE-I) activity, were compared. The B1929 strain lowered the pH of the milk to 4.13 ± 0.09 at 37°C after 24 h, whereas ATCC 15009 needed 48 h to drop the pH to 4.70 ± 0.18 at 37°C. Two soluble protein fractions, one (CFS1) obtained after fermentation (acidic conditions) and the other (CFS2) after the neutralization (pH 6.70) of the pellet from CFS1 separation, were analyzed for d-/l-lactic acid production, protein concentration, the degree of protein hydrolysis, and ACE-I activity. The CFS1 fractions, dominated by whey proteins, demonstrated a greater degree of protein hydrolysis (7.9%) than CFS2. On the other hand, CFS2, mainly casein proteins, showed a higher level of ACE-I activity (33.8%) than CFS1. Significant differences were also found in the d- and l-lactic acid produced by the UHT milk between the 2 strains. These results attest that milk casein proteins possessed more detectable ACE-I activity than whey fractions, even without a measurable degree of hydrolysis. Findings from this study suggest that careful consideration must be given when selecting the bacterial strain and milk substrate for fermentation.
Hafedh Ben Zaabza, Curtis P. Van Tassell, Jeremie Vandenplas
et al.
ABSTRACT: The calculation of exact reliabilities involving the inversion of mixed model equations poses a heavy computational challenge when the system of equations is large. This has prompted the development of different approximation methods. We give an overview of the various methods and computational approaches in calculating reliability from the era before the animal model to the era of single-step genomic models. The different methods are discussed in terms of modeling, development, and applicability in large dairy cattle populations. The paper also describes the problems faced in reliability computation. Many details dispersed throughout the literature are presented in this paper. It is clear that a universal solution applicable to every model and input data may not be possible, but we point out several efficient and accurate algorithms developed recently for a variety of very large genomic evaluations.
ABSTRACT: Yogurt and its related products are popular worldwide. During transportation and storage, Lactobacillus delbrueckii ssp. bulgaricus in yogurt continues to metabolize to form lactic acid, the postacidification phenomenon of yogurt. Postacidification of yogurt is a widespread phenomenon in the dairy industry. Many scholars have done research on controlling the postacidification process, but few report on the molecular mechanisms involved. In this study, we used a molecular-assisted approach to screen food additives that can inhibit postacidification and analyzed its effects on yogurt quality as well as its regulatory mechanism from multi-omics perspectives in combination. The copper ion was found to upregulate the expression of the LDB_RS05285 gene, and the copper transporter-related genes were regulated by copper. Based on the metabolic-level analysis, copper was found to promote lactose hydrolysis, accumulate a large amount of glucose and galactose, inhibit the conversion of glucose to lactic acid, and reduce the production of lactic acid. The significantly greater abundance of l-isoleucine and l-phenylalanine increased the abundance of 3-methylbutyraldehyde (∼1.2 times) and benzaldehyde (∼7.9 times) to different degrees, which contributed to the formation of the overall flavor of yogurt. Copper not only stabilizes the acidity of yogurt, but also it improves the flavor of yogurt. Through this established method involving quantitative and correlation analyses at the transcriptional and metabolic levels, this study provides guidance for the research and development of food additives that inhibit postacidification of yogurt and provide a reference for studying the changes of metabolites during storage of yogurt.
Bulei Sheng, Søren D. Nielsen, Maria Glantz
et al.
ABSTRACT: Milk with different κ-casein (CN) phenotypes has previously been found to influence its gastric digestion rate. Therefore, the aim of the present study is to disentangle contributions of genetic variation and its related sialylation on the in vitro digestion process of κ-CN. Accordingly, κ-CN was purified from milk representing homozygous cows with κ-CN phenotypes AA, BB, or EE and used as substrate molecules in model studies using the INFOGEST 2.0 in vitro static digestion model. Furthermore, the effect of removal of the terminal sialic acids present on the O-linked oligosaccharides of the purified κ-CN A, B, and E protein variants were studied by desialylation enzymatic assays. The κ-CN proteins were purified by reducing anion exchange chromatography with purities of variants A, B, and E of 93.0, 97.1, and 90.0%, respectively. Protein degradations of native and desialylated κ-CN isolates in gastric and intestinal phases were investigated by sodium dodecyl sulfate-PAGE, degree of hydrolysis (DH), and liquid chromatography electrospray ionization mass spectrometry. It was shown that after purification, the κ-CN molecules reassembled into multimer states, which then constituted the basis for the digestion studies. As assessed by DH, purified variants A and E were found to exhibit faster in vitro digestion rates in both gastric and intestinal phases compared with variant B. Desialylation increased both gastric and intestinal digestion rates for all variants, as measured by DH. In the gastric phase, desialylation promoted digestion of variant B at a rate comparable with native variants A and E, whereas in the intestinal phase, desialylation of variant B promoted better digestion than native A or E. Taken together, the results confirm that low glycosylation degree of purified κ-CN promotes faster in vitro digestion rates, and that desialylation of the O-linked oligosaccharides further promotes digestion. This finding could be applied to produce dairy products with enhanced digestibility.
ABSTRACT: The objective of this study was to determine the effects of milk fat depression induced by supplementing conjugated linoleic acid (CLA; trans-10,cis-12 and cis-9,trans-11 CLA) or feeding a higher starch and oil-containing diet (HSO) on metabolic changes in dairy cows after calving. The main hypothesis was that the 2 strategies to decrease milk fat yield could have different effects on performance, energy balance (EB), and inflammatory status in early lactation. Thirty-three Nordic Red dairy cows were used in a randomized block design from 1 to 112 d of lactation and fed one of the following treatments: control (CON), CLA-supplemented diet, or HSO diet. Dry matter intake and milk yield were measured daily whereas milk composition was measured weekly throughout the experiment. Nutrient digestibility, EB, and plasma hormones and metabolites were measured at 3, 7, 11, and 15 wk of lactation in respiration chambers. The HSO diet led to lower intakes of dry matter, neutral detergent fiber, and gross energy compared with CON and CLA diets. The CLA diet and especially the HSO diet resulted in lower energy-corrected milk yield during the first 7 wk of lactation than those fed CON. The EB was numerically higher for HSO and CLA diets compared with CON at wk 3 and 7. Plasma glucose concentration was higher by the CLA diet at wk 3 and by the HSO diet from wk 3 to 15 compared with CON. Plasma nonesterified fatty acids were higher at wk 3 in the CON group (indicating more lipid mobilization) but decreased thereafter to similar levels with the other groups. The HSO-fed cows had higher plasma ceruloplasmin, paraoxonase, and total bilirubin concentrations in the entire experiment and showed the highest levels of reactive oxygen metabolites. These results suggest an increased inflammatory and oxidative stress state in the HSO cows and probably different regulation of the innate immune system. This study provides evidence that milk fat depression induced by feeding HSO (as well as CLA) decreased milk fat secretion and improved EB compared with CON in early lactation. The increase in plasma glucose and paraoxonase levels with the HSO diet may imply a better ability of the liver to cope with the metabolic demand after parturition. However, the negative effect of HSO on feed intake, and the indication of increased inflammatory and oxidative stress warrant further studies before the HSO feeding strategy could be supported as an alternative to improve EB in early lactation.
Yu-Hang Jiang, Jian-Ping Ying, Wei-Gang Xin
et al.
ABSTRACT: Phenyllactic acid (PLA) has been demonstrated to possess antibacterial activity and capacity to prolong food shelf life. However, studies on the performance of PLA in inhibiting Staphylococcus aureus and its effectiveness when applied to dairy products are largely lacking. Here, antibacterial activity (planktonic and biofilm states) of PLA against S. aureus CICC10145 (S. aureus_45) were investigated. The results showed that PLA inhibited growth of S. aureus_45 and formation of S. aureus_45 biofilm. Next, the antibacterial action target of PLA was uncovered from both physiological and phenotypic perspectives. The results showed that PLA decreased cell metabolic activity and cell viability, damaged cell membrane integrity, triggered leakage of intracellular contents (DNA, proteins, and ATP), and caused oxidative stress damage and morphological deformation of S. aureus_45. In practical application, the antibacterial activity of PLA against S. aureus_45 cells was further confirmed in skim milk and cheese as dairy food models, and the antibacterial effects can be adequately maintained during storage for 21 d, at least at 4°C. These findings suggested that PLA could be a potential candidate for controlling S. aureus outgrowth in dairy foods.
ABSTRACT: Milk preservative and freezing are used as strategies to prevent microbial growth and milk degradation, especially when immediate analytical processing is not feasible. The effects of the addition of preservative and freezing procedures have been investigated mainly in relation to milk gross chemical composition predicted through mid-infrared spectroscopy. This study aimed to determine whether different preservatives (i.e., no preservative, hydrogen peroxide, Bronopol, and Azidiol), freezing times (i.e., 0, 7, and 30 d), and temperatures of analysis (i.e., 5 and 21°C) influence the composition of milk protein fractions determined through reversed-phase HPLC. Bulk milk samples for the analysis of protein profile were collected from 5 commercial dairy farms. Data were analyzed with a linear mixed model, which included type of preservative, time of storage, temperature of analysis, and the interaction between type of preservative and time of storage as fixed effects, with the farm and the residual as random effects. Samples with no preservative had the greatest amount of all protein fractions, whereas Bronopol-preserved milk had the lowest amount. Increasing storage time under freezing conditions had a nonlinear detrimental effect on milk protein fractions. The temperature of analysis significantly contributed to the variation of κ-casein, β-casein, αS1-casein, β-lactoglobulin, and α-lactalbumin fractions. The z-scores were calculated to evaluate the similarity between detailed protein profile of fresh milk without preservative analyzed at 5°C and detailed protein profile of milk treated according to the tested conditions. Overall results suggested a good agreement between different analytical conditions. Still, short storage time under freezing conditions is recommended to avoid degradation of milk protein fractions and consequent analytical underestimation.
Farheen Badrealam Khan, Irfa Anwar, Elrashdy M. Redwan
et al.
ABSTRACT: Lactoferrin (LF) is a milk protein that may be an interesting candidate for the antidiabetic properties of milk due to its well-documented bioactivity and implication in diabetes. Here, we investigated the functional action of LF purified from camel and bovine milk (cLF, bLF) on insulin receptors (IR) and their pharmacology and signaling in hepatocarcinoma (HepG2) and human embryonic kidney (HEK293) cells. For this, we examined IR activation by bioluminescence resonance energy transfer (BRET) technology and the phosphorylation of its key downstream signaling kinases by western blot. The purified cLF and bLF induced phosphorylation of IR, AKT, and ERK1/2 in HepG2 and HEK293 cells. The BRET assays in HEK293 cells confirm the pharmacological action of cLF and bLF on IR, with a possible allosteric mode of action. This reveals for the first time the bioactivity of LF toward IR function, indicating it as a potential bioactive protein behind the antidiabetic properties of camel milk.
SADANANDA THEJESH, ABHIJIT DAS, MAKARABBI GURURAJ
et al.
The novel corona virus (COVID-19) which was first identified on November 17, 2019 in Wuhan city of China turned out to be a pandemic. As a preventive measure against the pandemic, the Government of India announced nationwide lockdown on 24 March, 2020 which continued till 31 May, 2020. This not only limited the movement of people across the country but also led to the implementation of the policies like quarantines, containment zones, social distancing, travel restrictions etc. These polices have affected every sector of the Indian economy including the dairy sector. Against this backdrop, the present study was undertaken to assess the economic impact of COVID-19 pandemic on dairy farmers. The study covered pre-lockdown, lockdown and post-lockdown phases up to December 2020. The data was collected from 200 dairy farmers across Bengaluru Rural and Chikkaballapura districts of Karnataka state. A large majority of the farmers from Bengaluru Rural (81%) and Chikkaballapura (87%) districts reported loss in their income from dairying during lockdown and post-lockdown periods. In both the districts the crossbred cattle were dominant (90%). In Bengaluru Rural district, the net return per litre of milk of crossbred was reduced to the extent of 33.06% during lockdown and by 48.64% during post-lockdown as compared to prelockdown period. In Chikkaballapura district, the net return per litre of milk of crossbred was reduced to the extent of 20.90% during lockdown and by 22.77% during post-lockdown as compared to pre-lockdown period. The loss in net return was attributed to reduction in procurement prices of milk, increased feed cost and decline in milk yield in that order respectively.