The aim of this research communication was to identify chromosome regions and genes that could be related to milk yield (MY), milk fat (%F) and protein percentage (%P) in Brazilian buffalo cows using information from genotyped and non-genotyped animals. We used the 90 K Axiom® Buffalo Genotyping array. A repeatability model was used. An iterative process was performed to calculate the weights of markers as a function of the squared effects of Single Nucleotide Polymorphism (SNP) and allele frequencies. The 10 SNPs with the largest effects for MY, %F and %P were studied and they explained 7·48, 9·94 and 6·56% of the genetic variance, respectively. These regions harbor genes with biological functions that could be related to the traits analyzed. The identification of such regions and genes will contribute to a better understanding of their influence on milk production and milk quality traits of buffaloes.

The research reported in this Research Communication aimed to describe the influence of Toll-like receptor 4 gene polymorphisms on milk production traits in Chinese Holstein cows. Toll-like receptor 4 (TLR4) is an important member of the toll-like receptor gene family that is widely found in various organisms. Since TLR4 can identify molecular patterns from various pathogenic microorganisms and induce natural and acquired immunity, it plays an important role in disease resistance in dairy cows. Two single nucleotide polymorphisms (SNPs) of TLR4 (c.−226 G > C and c.2021 C > T) that were previously found to be associated with health traits were genotyped using Sequenom MassARRAY (Sequenom Inc., San Diego, CA) for Chinese Holstein cows (n = 866). The associations between SNPs or their haplotypes and milk production traits and somatic cell count were analyzed by the generalized linear model procedure of Statistics Analysis System software (SAS). The c.−226 G > C and c.2021 C > T showed low linkage disequilibrium (r2 = 0·192). There was no association between these two SNPs and SCC, but significant effects were found for SNP c.−226 G > C on test-day milk yield, fat content, protein content, and total solid and milk urea nitrogen (P < 0·05), and SNP c.2021 C > T and the SNP haplotypes on test-day milk yield, fat content, protein content, lactose content and total solids (P < 0·05). The software MatInspector revealed that c.−226 G > C was located within several potential transcription factor binding sites, including transcription factor AP-2. The polymorphisms c.−226 G > C and c.2021 C > T had significant effects on the milk production for Chinese Holstein, and these SNP could be used for molecular marker-assisted selection of milk production.

This Research Communication describes the polymorphisms in the coding region of DGAT1 gene in Riverine buffalo, Swamp buffalo and crossbred buffalo, and associations between polymorphisms and milk production performance in Riverine buffalo. Two polymorphisms of DGAT1were identified, located in exon 13 and exon 17, respectively. The distribution of the genotypes of the two SNP loci in different buffalo population varied, especially the polymorphism located in exon 13 which was not found in the Swamp buffalo. Moreover, SNP located in exon 17 was a nonsynonymous switch resulting in the animo acid sequence changed from an arginine (Arg) to a histidine (His) at position 484. Both SNPs were in Hardy–Weinberg equilibrium, and the polymorphism of g.8330T>C in the exon 13 was significantly associated with peak milk yield, total milk yield and protein percentage. The C variant was associated with an increase in milk yield and peak yield but less in protein percentage compared with the T variant. The polymorphisms of g.9046T>C in exon 17 were significantly associated with fat percentage, in that the buffaloes with TT genotype had a significantly higher fat percentage than those with CC genotype. These findings reveal the difference in the genetic evolution of the DGAT1 between Riverine buffalo and Swamp buffalo, and provide evidence that the DGAT1 gene has potential effects for Riverine buffalo milk production traits, which can be used as a candidate gene for marker-assisted selection in buffalo breeding.

The majority of the work today regarding the effects of extended milking intervals has focused on dairy cattle and only to a limited extent on dairy goats and sheep. The aim of this study was to investigate the effect of different non-milking intervals on milk yield and composition, mammary physiology and welfare indices in dairy ewes. Thirty-six multiparous ewes in late lactation were allocated to one of four groups of nine and subjected to 24, 48 or 72 h of non-milking or normal milking interval (12 h) (group A, B, C and D, respectively). Data showed that there were no significant differences in milk yield among the experimental groups during the third day after re-milking. Furthermore, no significant differences in milk lactose, protein and fat concentration among the experimental groups were observed after 7, 14 and 21 d of re-milking, respectively. Non-milking for 72 h resulted in a temporary increase of sodium concentration, Na + /K + ratio and enzymatic activities of plasmin (PL), plasminogen (PG) and plasminogen activator (PA) in milk. However, these parameters had similar values among the experimental groups on day 5 after re-milking. The concentration of lactose in blood was also significantly increased as a result of the 72 h non-milking interval and returned to its initial levels the second day after re-milking. These data, taken together, suggest that early involution events that occurred as an effect of non-milking were fully reversible within a short period of time. Finally, no significant signs of welfare impairment were observed in ewes due to extended milking intervals. In conclusion, non-milking up to 72 h had no negative effects on milk yield and composition, mammary physiology and welfare parameters in dairy ewes.

High temperature is a major stress that negatively affects welfare, health, and productivity of dairy animals. Heat-stressed animals are more prone to disease, suggesting that their immunity is hindered. Although productive and physiologic responses of dairy animals to heat stress are well known, there is still limited information on the response at the transcriptome level. Our objective was to evaluate the changes in performance and blood transcriptomics of dairy goats under heat stress. Eight multiparous Murciano-Granadina dairy goats in mid-lactation were assigned to 1 of 2 climatic treatments for 35 d. Treatments and temperature-humidity index (THI) were: (1) thermal neutral (TN: n = 4; 15–20 °C, 40–45%, THI = 59–65), and (2) heat stress (HS: n = 4; 12 h at 37 °C–40%, THI = 86; 12 h at 30 °C–40%, THI = 77). Rectal temperature, respiratory rate, feed intake and milk yield were recorded daily. Additionally, milk composition was evaluated weekly. Blood samples were collected at d 35 and RNA was extracted for microarray analyses (Affymetrix GeneChip Bovine Genome Array). Differences in rectal temperature and respiratory rate between HS and TN goats were maximal during the first 3 d of the experiment, reduced thereafter, but remained significant throughout the 35-d experimental period. Heat stress reduced feed intake, milk yield, milk protein and milk fat contents by 29, 8, 12, and 13%, respectively. Microarray analysis of blood revealed that 55 genes were up-regulated, whereas 88 were down-regulated by HS. Bioinformatics analysis using the Dynamic Impact Approach revealed that 31 biological pathways were impacted by HS. Pathways associated with leukocyte transendothelial migration, cell adhesion, hematopoietic cell lineage, calcium signaling, and PPAR signaling were negatively impacted by HS, whereas nucleotide metabolism was activated. In conclusion, heat stress not only negatively affected milk production in dairy goats, but also resulted in alterations in the functionality of immune cells, which would make the immune system of heat-stressed goats less capable of fending-off diseases.

The aim of the present study was to evaluate the potential for diagnosis of fatty liver by means of ultrasonographic measurement of liver and perivisceral adipose tissue as an alternative to blood indicators of lipomobilization and liver biopsy in periparturient high-yielding dairy cows. Thirty cows were enrolled and divided into two groups. The evaluation of body condition score (BCS), non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHB), liver and perivisceral adipose tissue ultrasonographic measurement and histological liver lipid content (GdL) was performed at 15 ± 5 d prepartum (T0), 10 ± 2 d postpartum (T1), 30 ± 2 d postpartum (T2) and 50 ± 2 d postpartum (T3). Mesenteric fat thickness (the thickness of the perivascular adipose tissue) measured on ultrasound was shown to be an independent determinant of fatty liver. The cut-off of the ultrasonographic evaluation of the liver may be useful as a first and practical approach in identifying fatty liver. In conclusion, a non-invasive and reliable diagnostic method for predicting the risk of fatty liver in high yielding dairy cows has been demonstrated.

Sterol regulatory element binding protein 1 (SREBP1) has a central regulatory effect on milk fat synthesis. Lipopolysaccharides (LPS) can induce mastitis and cause milk fat depression in cows. SREBP1 is also known to be associated with inflammatory regulation. Thus, in the current study, we hypothesized that LPS-induced milk fat depression in dairy cow mammary epithelial cells (DCMECs) operates via decreased SREBP1 expression and activity. To examine the hypothesis, DCMECs were isolated and purified from dairy cow mammary tissue and treated with LPS (10 µg/ml). LPS treatment of DCMECs suppressed lipid-metabolism-related transcription factor SREBP1 mRNA expression, nuclear translocation and protein expression, leading to reduced triglyceride content. The transcription levels of acetyl-CoA carboxylase-1 and fatty acid synthetase were significantly down-regulated in DCMECs after LPS treatment, suggesting that acetyl-CoA carboxylase-1 and fatty acid synthetase involved in de novo milk fat synthesis was regulated by SREBP1. In summary, these results suggest that LPS induces milk fat depression in dairy cow mammary epithelial cells via decreased expression of SREBP1 in a time-dependent manner.

Until now there are only few data on the effects of thermal treatments on the nutritional and hygienic characteristics of donkey milk. This Research Communication aims to provide information on the effects of pasteurization (at +65 °C for 30 min) and prolonged storage at refrigeration and freezing temperatures (21 d at + 3 °C ± 2 °C and up to 90 d at −20 °C ± 5 °C) on some nutritional and hygienic characteristics of Amiata donkey milk. The milk was monitored by chemical and microbiological analysis. Pasteurization ensured compliance with EC Regulation No 1441/2007, as Enterobacteriaceae were never found in the milk, or during storage at refrigeration and freezing temperatures. Colony count at 30 °C in pasteurized milk never went beyond 1 log CFU/ml. The heat treatment and the storage did not result in any variations in the main constituents of the milk. Only a decrease in lactose and few variations in some fatty acids at 90 d of freezing were observed. In conclusion, pasteurization was able to achieve and maintain a high hygienic-sanitary quality over time; storage at refrigeration or freezing temperatures did not alter the nutritional quality of fat and the gross composition of the product. These findings are useful to improve knowledge on the milk shelf life in order to guarantee safety and nutritional quality for infants who need small quantities of daily milk.

This Research Communication describes the relationship between casein, free fatty acids (FFAs) and the storage period of ultra-high temperature-treated (UHT) whole milk observed for a period of 120 d of labelled shelf-life. Moreover, we aim to estimate the daily rate of casein degradation in UHT whole milk, and the total length of time estimated for its full degradation. With this aim, ten sets of samples were evaluated from batches of UHT milk manufactured by a dairy processing plant in Parana State, Brazil on 10 different days. Each set was comprised of one liter of raw milk and 12 units of 1 litre cartons of UHT milk, and represented one batch of production. Total mesophilic (TMC), psychrotrophic (TPC), and somatic cell counts (SCC) of raw milk were assessed. UHT milk was assessed for fat (%), sialic acid (mg/l), casein (%), and FFA contents. TMC ranged from 3·5 × 106 to 3·1 × 107 CFU/ml; TPC, from 106 UFC/ml and higher; and SCC, from 18 × 104 SC/ml to 4·83 × 105 CS/ml. Casein (r = −0·991; R2 = 0·9822) and FFA (r = 0·962; R2 = 0·9245) contents, and storage time of UHT milk were correlated (P < 0·05). The rate of casein hydrolysis was estimated as 0·021 g/100 g UHT whole milk/day. A complete breakdown of casein was estimated to occur by the 560th day post-manufacture. Although age gelation was not observed in our study, the report herein corroborates the understanding that the microbiological quality and SCC of raw milk are important components involving the integrity of casein and lipids of UHT milk during shelf-life.

Optimization of dairy fermentation processes often requires multiplexed pH measurements over several hours. The method developed here measures up to 90 samples simultaneously, where traditional electrode-based methods require a lot more time for handing the same number of samples. Moreover, the new method employs commonly used materials and can be used with a wider range of fluorescence readers than commercial 96-well plates with optical pH sensors. For this application, a milk-like transparent medium is developed that shows acidification properties with dairy starters that are similar to milk. Combination of this milk-like medium and 3 fluorescent indicators allow precise measurements of pH in a range of 4·0–7·0. The new method showed much higher throughput compared to the benchmark electrode systems while being as accurate, as shown by successful application for a comparison of various dairy starter cultures and for optimizing the inoculation rate.

Lactoperoxidase (LPO) is an antimicrobial protein present in milk that plays an important role in natural defence mechanisms during neonatal and adult life. The antimicrobial activity of LPO has been commercially adapted for increasing the shelf life of dairy products. Immobilization of LPO on silver nanoparticles (AgNPs) is a promising way to enhance the antimicrobial activity of LPO. In the current study, LPO was immobilized on AgNPs to form LPO/AgNP conjugate. The immobilized LPO/AgNP conjugate was characterized by various biophysical techniques. The enhanced antibacterial activity of the conjugate was tested against E. coli in culture at 2 h intervals for 10 h. The results showed successful synthesis of spherical AgNPs. LPO was immobilized on AgNPs with agglomerate sizes averaging approximately 50 nm. The immobilized conjugate exhibited stronger antibacterial activity against E. coli in comparison to free LPO. This study may help in increasing the efficiency of lactoperoxidase system and will assist in identifying novel avenues to enhance the stability and antimicrobial function of LPO system in dairy and other industries.

Goaty flavor and poor consistency may impact consumer acceptance of fermented goat milk. The undesirable characteristics can mainly be attributed to the presence of short-medium chain free fatty acid (SM-FFA) especially C6-C10 fatty acids and low αs1-casein content in goat milk. This study aimed to investigate the effects of polymerized whey protein (PWP) on goaty flavor as well as the texture properties of fermented goat milk in comparison with β-cyclodextrin (β-CD). Samples were evaluated on sensory properties, SM-FFA contents, texture, and apparent viscosity. Compared with control, the fatty acids contents (C6, C8, C10) decreased significantly in fermented goat milk with 0·5% β-CD (22, 71, 54%, respectively) and with 0·7% PWP (45, 58, 71%, respectively). There was a synergistic effect of 0·3% β-CD and 0·6% PWP in decreasing the contents of SM-FFA (C6, C8, C10) sharply by 89, 90, 79%. Under the same percentage of addition, yogurts made with β-CD showed a higher (P < 0·05) apparent viscosity than those with PWP. However, the addition of PWP could increase the texture parameters of fermented goat milk (P < 0·05). Combination of PWP and β-CD presented a more desirable texture and consistency in fermented goat milk. Results indicated that polymerized whey protein can be used to reduce the goaty flavor and improve the texture of fermented goat milk.

The objective of the study reported in this Research Communication was to investigate the effect of fermentation temperature (37 and 45 °C) and different ratios of Streptococcus thermophilus to Lactobacillus bulgaricus (3 : 1, 1 : 1 and 1 : 3) on Kermanshahi roghan and yoghurt fatty acid profiles (FAP) in order to obtain a product with optimized fatty acid profiles. Kermanshahi roghan is a yoghurt by-product in western Iran (Kermanshah). The results revealed that incubation temperature at 37 °C as compared to 45 °C had a better effect on fatty acid profiles of roghan and yoghurt. Furthermore, the results showed that fatty acid profile of roghan is better than yoghurt at two experimental temperatures. On the other hand, the roghan products made by equal ratio of S. thermophilus and L. bulgaricus (1 : 1) had the best quality of fatty acid profiles. Although a lower incubation temperature increases incubation time, our finding suggests that inoculation ratio 1 : 1 at 37 °C as compared to 45 °C can affect the quality of roghan and yoghurt fatty acid profiles.

This Research Paper addresses the hypothesis that the type of dulce de leche formula affects formation of 5-hydroxymethylfurfural (HMF) during production and storage. Milk and sweetened condensed milk are products in which the Maillard reaction (MR) defines important characteristics such as colour and taste. There are few studies on the effects of pH, time, concentration, and sugar type on the formation of HMF or other MR markers in DL. Four formulas (varying in the addition of sodium bicarbonate and the type of sugar) were analysed for moisture, lipid, protein, ash, carbohydrate, water activity (Aw), and soluble solids. We found low variability in physicochemical and compositional attributes, but an elevation of HMF indices throughout the manufacturing. We determined that the addition of glucose and the use of relatively high concentrations of sodium bicarbonate caused these HMF indicator increases. These results inform DL research and production by the dairy industries and the scientific community, and highlight the importance of control in manufacturing.

This Technical Research Communication describes a new method by which thermally treated Coxiella in milk products may be grown in a liquid growth medium and quantitated using an MPN-PCR assay. Coxiella is generally not used in studies on thermal and non-thermal processing of milk due to the need for specialized and highly laborious techniques such as animal assays and tissue culture for determining viability. Recently, a liquid growth medium (ACCM-2) and modified atmosphere were used to grow Coxiella from pure cultures, infected mouse tissues, and clinical samples, however, the ability to grow Coxiella from a food such as milk has not been shown. The potential ability to enrich Coxiella directly from contaminated milk presents a new avenue for conducting pasteurization research in which the viability of heat-treated or injured cultures could be more easily determined through direct enrichment of Coxiella in ACCM-2. ACCM-2 medium allowed enrichment of Coxiella from bovine whole milk and cream, whole goat, and whole camel milks but not whole water buffalo milk. Enrichment was possible from whole bovine milk containing as few as 6 Coxiella ge/ml of milk. The applicability of this ACCM-2 enrichment method was shown when using an MPN-PCR assay to quantitate the number of viable Coxiella remaining in whole bovine milk after 64 °C thermal treatment for up to 10 min.

Scientific studies demonstrate the importance of intestinal microbiota to human health and how probiotic microorganisms can positively affect health when administered regularly and in adequate amounts. Probiotic bacteria can be part of fermented products and their functional importance is associated mainly with their metabolism. They are thought to benefit individuals to maintain their health and also to strengthen resistance against various types of diseases. The acceptance of probiotic cultures and products by consumers increased when these bacteria were marketed as natural cultures that help in digestion and health. Considering this, the food industry has an increasing demand for new candidates as probiotic cultures, and the dairy industry has a particular interest for fermented milks and other dairy products, since these are the most common food vehicles for probiotic cultures. Therefore, the dairy industries are increasingly seeking to improve their products with these beneficial bacteria. However, the legal peculiarities and excess of control agencies in Brazil makes the registration of these products and the collection of data very complex. Prospective analysis suggests that probiotic foods have the potential to effect a considerable expansion of the dairy industry, allowing the dairy sector to grow and for these products to be increasingly sought by consumers globally. For this, not only actions on research and innovation are necessary, but also official clarifications on the claims for considerations of microbiological security and functionality of these products. This review aims to elucidate important probiotic research regarding the isolation and characterization of beneficial cultures in Brazil, and to demonstrate the relevance of the dairy chain as a potential source of novel cultures for the development of new probiotic products to expand the Brazilian dairy industry.