COMPARATIVE CHARACTERISTICS OF COW AND GOAT MILK COMPONENT BY MIR-SPECTROSCOPY

На основе анализа компонентного состава молока проведено изучение белковой и жировой фракций, метаболитов веществ и соматических клеток для голштинизированных черно-пестрых коров и карачаевских коз в сравнительном аспекте. Молоко коров предназначалось для переработки, а молоко коз использовалось для выкармливания козлят. В этой связи представляет интерес использование экспресс-метода инфракрасной (ИК) спектроскопии для исследования точности прогностической модели анализа молока от разных видов животных, в частности, для определения в образцах содержания жирных кислот (ЖК). Скрининг молока по 25 показателям выполняли с помощью анализатора CombiFOSS 7 DSCC. Установлено, что в молоке коз было достоверно больше жира и белка, насыщенных ЖК (69,59% против 65,67% в коровьем) и более значимых для питания человека полиненасыщенных ЖК (4,05% против 3,66% у коров). Коэффициент детерминации показал высокую значимость совокупных факторов, включенных в GLM-уравнение, для массовой доли лактозы (23,9%), короткоцепочечных ЖК (28,1%), ацетона (24,3%), бетагидроксибутирата (37,9%), точки замерзания молока (46,0%) и мочевины (85,1%). Корреляции между компонентами имели биологическую направленность, характерную для процессов синтеза молока в организме жвачных животных. Проведенный комплексный анализ показал перспективность ИК-спектров для использования как в менеджменте стада коров и коз, так и в накоплении информации для изучения генетической детерминации процессов образования молока у сельскохозяйственных животных. The protein and fat fractions, metabolites and somatic cells count for Holsteinized Black-and-White cows and Karachai goats were studied by in a comparative aspect. The cows’ milk was intended for processing, and milk of goats was used to feed the goatlet. In this regard, to use the express method of infrared (MIR) spectroscopy to study the accuracy of the predictive model for analyzing milk from different animal species, in particular, to determine the content of fatty acids (FA) was interesting. Milk screening for 25 parameters was performed using a CombiFOSS 7 DSCC analyzer. It was found that under the same paratypical conditions, there was significantly more fat and protein in goat milk, however, in terms of lactose content, milk pH values were higher in cows’ milk. Goat milk has a higher content of saturated FAs (69.59% opp. 65.67% in cow milk) and polyunsaturated FAs that are more significant for human nutrition (4.05% opp. 3.66% in cows). The determination coefficient showed the high significance of the aggregate factors included in the GLM equation for the lactose percentage (23.9%), short-chain FA (28.1%), acetone (24.3%), betahydroxybutyrate (37.9%), milk freezing point (46.0%) and urea (85.1%). The correlations between components had a biological orientation that characterized for the milk synthesis processes into the body of ruminants. The analysis showed that MIR spectra are promising for use in the management of a herd of cows and goats, and in the information accumulation for studying the genetic determination of milk processes synthesis in animals.

Core circadian clock transcription factor BMAL1 regulates mammary epithelial cell growth, differentiation, and milk component synthesis

The role the mammary epithelial circadian clock plays in gland development and lactation is unknown. We hypothesized that mammary epithelial clocks function to regulate mammogenesis and lactogenesis, and propose the core clock transcription factor BMAL1:CLOCK regulates genes that control mammary epithelial development and milk synthesis. Our objective was to identify transcriptional targets of BMAL1 in undifferentiated (UNDIFF) and lactogen differentiated (DIFF) mammary epithelial cells (HC11) using ChIP-seq. Ensembl gene IDs with the nearest transcriptional start site to ChIP-seq peaks were explored as potential targets, and represented 846 protein coding genes common to UNDIFF and DIFF cells and 2773 unique to DIFF samples. Genes with overlapping peaks between samples (1343) enriched cell-cell adhesion, membrane transporters and lipid metabolism categories. To functionally verify targets, an HC11 line with Bmal1 gene knocked out (BMAL1-KO) using CRISPR-CAS was created. BMAL1-KO cultures had lower cell densities over an eight-day growth curve, which was associated with increased (p<0.05) levels of reactive oxygen species and lower expression of superoxide dismutase 3 (Sod3). RT-qPCR analysis also found lower expression of the putative targets, prolactin receptor (Prlr), Ppara, and beta-casein (Csn2). Findings support our hypothesis and highlight potential importance of clock in mammary development and substrate transport.

Relative Late Gestational Muscle and Adipose Thickness Reflect the Amount of Mobilization of These Tissues in Periparturient Dairy Cattle

Due to insufficient dry matter intake and heightened nutrient requirements in early lactation, periparturient dairy cows mobilize adipose and muscle tissues to bridge energy and amino acid gaps, respectively. Our objective was to evaluate the relationship between the relative muscle thickness of late pregnant cows and their early lactation performance. At 35 d before expected calving (BEC), longissimus dorsi muscle thickness (LDT) was measured in forty-one multiparous Holstein cows via ultrasound. Tissue mobilization was evaluated via ultrasound images of LDT and backfat thickness (BFT) at 21 and 7 d BEC as well as at 0, 10, 30, and 60 DIM. Plasma concentrations of 3-methylhistidine (3-MH), creatinine (CRE), non-esterified fatty acids (NEFA), and β-hydroxybutyrate (BHB) were evaluated weekly. Milk yield and milk component data were collected through 60 DIM. Cattle were assigned post hoc to high-muscle (HM; n = 20; LDT > 4.49 cm) or low-muscle (LM; n = 21; ≤4.37 cm) groups, with mean LDT at 35 d BEC greater in HM (5.05 ± 0.49) than in LM (3.52 ± 0.65) animals. Between 35 and 21 d BEC, LM cows gained LDT, whereas HM cows gained BFT. HM cows mobilized more muscle from 21 d BEC to 30 DIM, as reflected by a greater loss of LDT, greater 3-MH concentrations (532 vs. 438 ± 30 ng/mL), and a greater 3-MH:CRE ratio (0.164 vs. 0.131 ± 0.008) in the first three weeks postpartum. The LDT and BFT at 21 d BEC were related to the amount of respective tissue mobilized through 30 DIM (R2 = 0.37 and 0.88, respectively). Although calves born to HM cattle were larger (45.2 vs. 41.8 ± 0.7 kg), HM cows produced less milk (38.8 vs. 41.6 ± 0.8 kg/d) with a tendency towards higher fat content (4.33 vs. 4.05 ± 0.12%), likely related to the mobilization of more backfat from 0 to 60 DIM (1.78 vs. 0.68 ± 0.34 mm), compared to LM cattle. These findings suggest that a cow’s metabolic status, as measured by LDT and BFT prepartum, may influence the metabolic strategy the animal uses to meet energy and amino acid requirements in late gestation and early lactation.

Effects of SLC27A3 and β-Lactoglobulin Gene Polymorphisms on The Milk Composition in Hamdani Sheep

Background: SLC27A3 and β-Lactoglobulin gene are candidate genes that effects milk traits.Results: This study aimed to determine the effect of polymorphisms of the SLC27A3 gene on Hamdani sheep's milk components. The PCR-RFLP method was used to detect the SLC27A3 polymorphisms at exon 2, exon 3 and exon 4. The allele frequency of SNP1, SNP2 and SNP3 were 0.59(G), 0.41(T); 0.57(G), 0.43(C) and 0.58(A) and 0.42(C) respectively. β-lactoglobulin allele frequency was 0.56(A) and 0.44(B). The statistical analysis showed an association between SLC27A3 and β-lactoglobulin polymorphisms and milk composition. Conclusions: The SLC27A3 and β-lactoglobulin polymorphisms can be used as a genetic marker to select milk component traits in the sheep breeding programs.

Nutritional Regulation of Mammary Gland Development and Milk Synthesis in Animal Models and Dairy Species

In mammals, milk is essential for the growth, development, and health. Milk quantity and quality are dependent on mammary development, strongly influenced by nutrition. This review provides an overview of the data on nutritional regulations of mammary development and gene expression involved in milk component synthesis. Mammary development is described related to rodents, rabbits, and pigs, common models in mammary biology. Molecular mechanisms of the nutritional regulation of milk synthesis are reported in ruminants regarding the importance of ruminant milk in human health. The effects of dietary quantitative and qualitative alterations are described considering the dietary composition and in regard to the periods of nutritional susceptibly. During lactation, the effects of lipid supplementation and feed restriction or deprivation are discussed regarding gene expression involved in milk biosynthesis, in ruminants. Moreover, nutrigenomic studies underline the role of the mammary structure and the potential influence of microRNAs. Knowledge from three lactating and three dairy livestock species contribute to understanding the variety of phenotypes reported in this review and highlight (1) the importance of critical physiological stages, such as puberty gestation and early lactation and (2) the relative importance of the various nutrients besides the total energetic value and their interaction.

Epigenetics: New Insights into Mammary Gland Biology

The mammary gland undergoes important anatomical and physiological changes from embryogenesis through puberty, pregnancy, lactation and involution. These steps are under the control of a complex network of molecular factors, in which epigenetic mechanisms play a role that is increasingly well described. Recently, studies investigating epigenetic modifications and their impacts on gene expression in the mammary gland have been performed at different physiological stages and in different mammary cell types. This has led to the establishment of a role for epigenetic marks in milk component biosynthesis. This review aims to summarize the available knowledge regarding the involvement of the four main molecular mechanisms in epigenetics: DNA methylation, histone modifications, polycomb protein activity and non-coding RNA functions.

Effect of protein dietary protein levels on milk component, udder parameters, blood and physiological indices of West African dwarf goat

This study was conducted to evaluate the effect of protein supplementation at 12%, 14% and 16.41% crude protein (CP) levels on the milk yield of West African dwarf dams. A total of twelve lactating dams, which were intensively managed and hand-milked on weekly basis were used for the study. Feed intakes, weight gain, feed conversion ratio (FCR) and protein efficiency ratios (PER) were monitored. Milk and blood samples were taken. The udder morphometry and milk composition were determined. Result showed that the dry matter and crude protein values ranged between 89.7 and 90.1% and 11.51 and 14.88% respectively. Dams on 12% protein supplemented feed recorded the highest daily dry matter intake (DMI) of (203.63 g/day) while, 16% protein supplemented feed had the least DMI (195.54 g/day). The value of crude fiber ranged between 9.98 and 13.31% while the value of ash ranged between 6.23 and 9.99%. Also, the values of ether extract ranged between 2.88 and 6.65%. Dams on 16% protein diet gained significantly (p<0.05) more weight (106.19g/day) and had the least feed conversion ratio (1.88). Milk component and nutrient digestibility did not vary among diets except for ether extract that was least in dams on 16% CP level. Dams on 14% and 16% protein diet supported the highest calcium concentration. Udder parameters and blood indices were not significantly (p>0.05) influenced by dietary protein levels. The rectal, espiratory and pulse rate were within the normal range. Pulse rate was more normal in dams on 12% and 16% dietary protein level. It can therefore be concluded that 16% crude protein level could be used for lactating West African dwarf dams to improve milk production and health condition of lactating dams.

Milk yield, composition and their correlated relationships in some selected indigenous breeds of cattle in late wet season of Adamawa state, Nigeria

There is need for characterization of performances of cattle breeds in relation to milk yield and composition particularly in Adamawa State where seasonal fluctuations in climatic elements can affect livestock resilience. This study was carried out to evaluate the breed variation in milk yield and composition of some selected breeds of Nigerian indigenous cattle in Adamawa State in the late wet season (August-October). The milk of 20 cows each from four breeds (Bunaji, Rahaji, Adamawa Gudali and Bokoloji) was sampled for milk yield and composition analysis three times within the season. Milk was analysed for its composition. Breed significantly (p<0.05) influenced the milk component evaluated. Bunaji was superior in milk yield (1.92), fat yield (5.73) and total solid non-fat (4.59). Rahaji was superior in phosphorus (410), sodium (61.01) and iron (3.16) while Bokoloji was superior in protein (4.98) and calcium (721). For the correlated relationships between the milk components evaluated in different breeds, there was a significant (p<0.05-0.01; r = -0.89 to 1.00) correlation between milk components except (p>0.05; r = -0.21 to 0.24) within various breeds. Zero relationship existed between milk yield and Fe in Adamawa Gudali (p>0.05; r =0.00) while a perfect relation exists between milk yield and protein yield (p>0.01; r = 1.00) in Rahaji, Adamawa Gudali and Bokoloji and between protein yield and fat yield (p>0.01; r = 1.00) in Bunaji and Bokoloji.For the pooled correlated responses, there was significant (p<0.05-0.01; r = -0.95 to 0.99) relationships between most milk components. It was therefore concluded that Bunaji had the highest milk yield, Bokoloji was best in milk protein and fat contents while Rahaji was best in mineral contents. Also, correlated relationship between milk components should be maximized in formulating a selection programme for improvement of milk in Nigerian indigenous cattle.

Human milk triggers coagulation via tissue factor–exposing extracellular vesicles

Almost a century ago, it was discovered that human milk activates the coagulation system, but the milk component that triggers coagulation had until now been unidentified. In the present study, we identify this component and demonstrate that extracellular vesicles (EVs) present in normal human milk expose coagulant tissue factor (TF). This coagulant activity withstands digestive conditions, mimicking those of breastfed infants, but is sensitive to pasteurization of pooled donor milk, which is routinely used in neonatal intensive care units. In contrast to human milk, bovine milk, the basis of most infant formulas, lacks coagulant activity. Currently, the physiological function of TF-exposing vesicles in human milk is unknown, but we speculate that these vesicles may be protective for infants. Another explanation could be nipple skin damage, which occurs in most breastfeeding women. Milk-derived TF-exposing EVs may seal the wound and thereby reduce bleeding and breast inflammation.