Early Stages Of Lactation Research Articles

Indicators of lipid metabolism and their relationship with the thyroid status during the dry and post-calving periods in cows with different fertility

In black-and-white cows with reduced fertility, during the dry and early post-calving periods, changes in the functioning of the thyroid system are observed, which differ from those in individuals with high fertility. Such changes may lead to a lack of energy sources during the critical transition period.Purpose: To study the dynamics of changes in the lipid content before and after calving and its association with the content of thyroid hormones in the blood of black-and-white cows with various fertility.Materials and methods. Black-and-white cows of lactation 2-4 were used in the study. The animals were bled 6, 4 and 2 weeks before calving and 1, 3, 7 and 13 weeks after calving. In blood serum samples, the content of lipids was determined using a biochemical analyzer, as well as thyroid hormones and progesterone using ELISA. Cows were inseminated after treatment according to the Ovsynch protocol, and pregnancy was assessed on Day 33 based on ultrasound examination and progesterone levels in the blood.Results. The cows were divided into two groups: I – pregnant individuals (n=17) and II – individuals that remained infertile (n=12). The milk productivity of animals and their BCS before and after calving were similar in the compared groups. Thirteen weeks after calving, the cholesterol content in the blood of cows of group II was 1.2 times lower (p<0.05) compared to this content in animals of group I. At the same time, 6 weeks before calving, the concentration of phospholipids in the blood of individuals of group II was 1.3 times higher than that of individuals of group I (p<0.05). In addition, 3 weeks after calving, the level of triglycerides in cows of group I was 1.2 times higher (p<0.05) than that in animals of group II. During the postpartum period, the blood levels of cholesterol and triglycerides in animals of group I positively correlated with the content of total thyroxine, whereas such a correlation was not detected in group II.Conclusions. Thus, the metabolic state of cows with higher fertility was characterized by an increased supply of lipid energy sources during the post-calving period compared to animals with low fertility. At the same time, the reduced content of triglycerides at the early stage of lactation in the blood of cows that remained infertile points to their increased accumulation by the liver. A positive relationship between the concentration of total thyroxine in the blood and the concentration of triglycerides and cholesterol, revealed during the post-calving period in cows with high fertility, suggests the participation of the thyroid hormone in maintaining the reproductive function of these animals by modulating lipid metabolism.

Identification and characterization of long non-coding RNAs in mammary gland tissues of Chinese Holstein cows.

LncRNAs (Long non-coding RNA) is an RNA molecule with a length of more than 200bp. LncRNAs can directly act on mRNA, thus affecting the expression of downstream target genes and proteins, and widely participate in many important physiological and pathological regulation processes of the body. In this study, RNA-Seq was performed to detect lncRNAs from mammary gland tissues of three Chinese Holstein cows, including three cows at 7 d before calving and the same three cows at 30 d postpartum (early lactation stage). A total of 1,905 novel lncRNAs were detected, 57.3% of the predicted lncRNAs are ≥ 500bp and 612 lncRNAs are intronic lncRNAs. The exon number of lncRNAs ranged from 2 to 10. A total of 96 lncRNAs were significantly differentially expressed between two stages, of which 47 were upregulated and 49 were downregulated. Pathway analysis found that target genes were mainly concentrated on the ECM-receptor interaction, Jak-STAT signaling pathway, PI3K-Akt signaling pathway, and TGF-beta signaling pathway. This study revealed the expression profile and characteristics of lncRNAs in the mammary gland tissues of Holstein cows at non-lactation and early lactation periods, and provided a basis for studying the functions of lncRNAs in Holstein cows during different lactation periods.

A Preliminary Study on the Effect of Different Feeding Regimes on the Milk Chemical Composition of the Maltese Goat Breed During the Early Stage of Lactation

The Maltese goat is a breed of goats which is sparsely found in a few countries and also progressively being eradicated due to the Maltese goat being bred with other goat breeds, thus reducing the breed population. This research sets to understand how the effect of different feeding regimes affects the physiochemical characteristics of the Maltese goats’ milk. The researcher collected 112 milk samples from 112 Maltese goats, kept on 17 farms. The milk samples were categorised into four different feeding regimes. After collection, milk was stored and tested in the lab utilising an ultrasonic milkanalyser and a pH meter. Values for the content of fat, protein, salts, lactose, solid-not-fats, freezing point, density, and pH were recorded and tabulated. The results show that feeding regime three, consisting of high levels of protein (11% to 13%) and low levels of rich-quality fibre (12% to 20%), yield milk rich in protein (4.23%), fat (3.86%), lactose (4.09%), and salts (0.66%). The results also conclude that feeding regime one, consisting of low protein (7% to 10%) and low content of rich-quality fibre (12% to 20%), yields the highest milk fat content (4.23%), but the lowest levels of protein (3.82%), salts (0.59%), and lactose (3.62%). Consequently, feeding regime three results as being the ideal feed to obtain a high content of the indicated physio-chemical characteristics.

Gram-scale chemical synthesis of galactosyllactoses and their impact on infant gut microbiota in vitro.

Galactooligosaccharides (GOS) are widely used as a supplement in infant nutrition to mimic the beneficial effects found in prebiotic human milk oligosaccharides (HMOs). However, the complexity of the GOS mixture makes it challenging to ascertain which of the GOS components contribute most to their health benefits. Galactosyllactoses (GLs) are lactose-based trisaccharides containing a β-galactopyranosyl residue at the 3'-position (3'galactosyllactose, 3'-GL), 4'-position (4'-galactosyllactose, 4'-GL), or the 6'-position (6'-galactosyllactose, 6'-GL). These GLs are of particular interest as they are present in both GOS mixtures and human milk at early stages of lactation. However, research on the potential health benefits of these individual GLs has been limited. Gram quantities are needed to assess their health benefits but these GLs are not readily available at this scale. In this study, we report the gram-scale chemical synthesis of 3'-GL, 4'-GL, and 6'-GL. All three galactosyllactoses were obtained on a gram scale in good purity from cheap and commercially available lactose. Furthermore, in vitro incubation of GLs with infant faecal microbiota demonstrates that the GLs were able to increase the abundance of Bifidobacterium and stimulate short chain fatty acid production.

Supplementation of Multistrain Probiotics Improves Milk Production, Blood Metabolites, Digestibility, and Rectal Microbiota during the Prepartum and Early Lactation Stages in Crossbred Cows

The current study aimed to study the effects of administration with a multistrain probiotic formulation (MPF) initiated from the prepartum stage on lactation performance, digestibility, rectal microbiota, and blood metabolites of postpartum dairy cows. A total of 30 multiparous crossbred (Holstein Friesian × Balady) dairy cows were randomized into three groups: control (no MPF supplementation), MPF1 (0.5 g MPF/cow/d), and MPF2 (1 g MPF/cow/d). The administration of MPF started 28 days before calving and continued for 84 days after. The results revealed that cows in the MPFI and MPF2 groups had higher milk production, 3.5% FCM, and ECM than those in the control group. The MPF‐supplemented cows had significantly greater milk energy output, DMI, and yields of solids‐not‐fat, lactose, total solids, ash, fat, and protein. The MPF supplementation significantly enhanced feed conversion and significantly interacted with milk solids‐not‐fat, lactose, total solids, and protein. Hematological indicators did not significantly alter between the MPF and control groups. However, cows receiving MPF supplements had higher levels of Hct. Serum biochemical measurements showed lower serum concentrations of LDL, total cholesterol, and VLDL in MPF‐fed cows than in the control group. The digestibility of organic and dry matter tended to be higher in MPF‐supplemented cows. The populations of lactobacillus, bacillus, and total bacterial count increased due to MPF administration, while the count of Clostridium, Salmonella, E. coli, and coliforms decreased in MPF‐fed cows. In summary, administering MPF during late gestation and early lactation period improved milk production, fecal microbial composition, and overall health of dairy cows.

Essential Trace and Toxic Element Content in Lacaune Sheep Milk during Lactation.

The aim of this study was to investigate the concentrations of essential trace and toxic elements in the milk of Lacaune sheep during lactation in intensive rearing systems. This research was conducted with 30 Lacaune sheep that were monitored in the early (60 days of lactation), medium (120 days of lactation), and late (180 days of lactation) stages of lactation. The sheep were fed a pelleted feed mixture (1 kg/day), a cereal mixture (600 g/day), and alfalfa hay (ad libitum). The essential (Fe, Zn, Cu, Co, Mn, Mo, Se, Cr, and Ni) and toxic element (heavy metals: Cd, Pb, As, and Hg) concentrations in the feed and milk were determined using an inductively coupled plasma mass spectrometer. Significant variations in the main essential trace and toxic elements, except for the Mo, Se, Ni, As, and Hg concentrations, were found in the milk of Lacaune sheep during lactation. As lactation progressed, in the late stage of lactation, significantly higher concentrations of Co, Mn, Mo, Cr, and Pb were found, while Zn and Cu in the milk of Lacaune sheep decreased significantly (4.15 and 0.21 mg/kg) compared to their concentrations in the early stage of lactation (5.66 and 0.43 mg/kg). Significantly lower concentrations of Fe and higher concentrations of Cd were found in the medium stage (0.23 mg/kg and 1.08 µg/kg) of lactation compared to both the early and late stages of lactation. An analysis of the correlation coefficients between the essential trace and toxic elements in Lacaune sheep milk during lactation determined a significantly positive correlation between Fe:Cr, Fe:Mn, Fe:Co, Fe:Se, Zn:Ni, Zn:Se, Cr:Mn, Cr:Co, Cr:Se, Cr:Mo, Mn:Co, Mn:Pb, Co:Ni, Co:Se, Ni:Se, Se:Mo, Se:Pb, and Cd:Pb. A significantly negative correlation was also found between Cu:Mn, Zn:Mo, Cg:Hg, and Hg:Pb. Based on the obtained results, it is recommended that the influence of the stage of lactation, as well as the breed of sheep, should be included when designing experiments. In general, sheep milk is rich in essential trace elements, but it also contains a very low content of toxic elements, which provides justification for increasing the breeding of Lacaune sheep and indicates the convenience of consuming their milk without risking the consumer's health.

Comparison of Total Antioxidant Capacity of Milk of Crossbred Holstein Friesian and Vechur Cattle during Different Lactation

Background: Milk is a rich source of vitamins, minerals, fats and high quality proteins. Milk proteins such as casein, lactoferrin and amino acids in milk like tyrosine, cysteine, tryptophan, lysine, etc. have antioxidant properties. The objective of this study was to compare the antioxidant level of milk of crossbred Holstein Friesian (CBHF) and Vechur cattle during different stages of lactation. Methods: Total antioxidant capacity (TAC) was estimated by using ferric reducing antioxidant assay. Milk samples from six animals each of CBHF and Vechur cattle were collected separately at early lactation, mid lactation and late lactation period. Results: Milk samples from CBHF and Vechur cattle during the early stages of lactation had significantly higher total antioxidant capacity than milk samples from later stages of lactation. This could be because of the high fat content in the early phases. The total antioxidant content of Vechur milk was higher than that of CBHF milk throughout lactation. The milk of the Vechur cow contains higher beta casein A2 than A1. No significant difference in the TAC values noticed between milk of mid and late lactation in both CBHF and Vechur cattle. The high antioxidant capacity of milk from Vechur cattle suggests that it has a great therapeutic potential. Different animal milk and milk products with antioxidant defense systems can be considered to have health-beneficial effects against free radical damage.

The effect of heat stress on performance, fertility, and adipokines involved in regulating systemic immune response during lipolysis of early lactating dairy cows

The aim of this study was to assess the potential effect of heat stress on dairy cow productivity, fertility, and biochemical blood indices during the early lactation stage in a temperate climate. Additionally, the study aimed to determine the role of leptin and adiponectin in regulating the immune response accompanying lipolysis after calving in dairy cows. The study included 100 clinically healthy Polish Holstein-Friesian dairy cows selected based on parity and 305 d of milk yield from 5 commercial farms with similar herd management and housing systems. Prospective cohort data were recorded from calving day until 150 d in milk, and microclimate loggers installed inside the barns were used to record temperature and relative humidity data to calculate daily temperature-humidity index (THI) on the calving day, through +7, +14, and +21 d during early lactation. Additionally, monthly productive performance parameters such as milk yield, chemical composition, fatty acids composition, and fertility indices were analyzed. Results showed that the THI from calving day through +7, +14, and +21 d during early lactation was negatively associated with fertility parameters such as delayed first estrus postpartum and an elongated calving interval, respectively, by 29, 27, 25, and 16 d. Furthermore, an increase in THI value during early lactation was associated with an elongated artificially inseminated service period, days open, and intercalving period. Increasing THI from calving day (0 d) through +7, +14, and up to +21 d during early lactation was also linked to decreased milk yield by 3.20, 4.10, 5.60, and 5.60 kg, respectively. The study also found that heat stress during early lactation was associated with a lower body condition score in dairy cows and higher concentrations of leptin, nonesterified fatty acids, and β-hydroxybutyrate, accompanied by a drastic reduction in adipose tissue-secreted adiponectin levels after calving. Additionally, heat stress-induced lipolysis in adipose tissue caused an inflammatory response that increased biochemical blood indices associated with immune responses such as cytokines, acute phase proteins, and heat shock protein. These findings suggest that exposing dairy cows to heat stress during early lactation can negatively affect their productive performance, fertility, and biochemical blood indices in subsequent lactations. Thus, farm management changes should be implemented during early lactation to mitigate the negative consequences of heat stress occurrence.

The effects of dietary addition of acetic acid on milk yield and composition in Awassi ewes at an early stage of lactation

This study was conducted to evaluate the effect of dietary supplementation of acetic acid at different levels on milk yield and composition. A total of eighteen Awassi ewes in the early stage of lactation were used in this study, with average body weight (37.631.84) and ages (3–4 years). Animals were allocated to three treatments; the first treatment was control fed with a basal diet without additives (T1). Acetic acid (98%) was added to the concentrate feed daily before feeding by 5 mL/ewe daily in T2 and 10 mL/ewe in T3 after dilution 1:10 with tab water. Results indicate an insignificant increase in ewes' body weight in T2 and T3, which were 40.41 and 41.11 kg compared to T1 at 37.93 kg. Actual milk yield was not affected while fat corrected milk Increased in T3 was 390 g/day compared to T2 with 323 g/day. Milk fat percentage increased (p ≤ 0.05) in T3 at 6.26% as compared to T1 and T2 at 5.65% and 5.43%, respectively, while fat yield was higher (p ≤ 0.05) in T3 at 23.85 g/day than in T2 17.58 g/day. This was reflected in increased milk energy (p ≤ 0.05) in the T3 at 953 kcal/kg compared to T2 at 858 kcal/kg. From the results, it can be concluded that acetic acid can be used as an additive to the ewes diet, and effect positively in ewes’ weight and milk fat.

Dietary protein levels modulate the gut microbiome composition through fecal samples derived from lactating ewes.

In ruminants, the digestion and utilization of dietary proteins are closely linked to the bacterial populations that are present in the gastrointestinal tract. In the present study, 16S rDNA sequencing, together with a metagenomic strategy was used to characterize the fecal bacteria of ewes in the early lactation stage after feeding with three levels of dietary proteins 8.58%, 10.34%, and 13.93%, in three different groups (H_1), (H_m) and (H_h), respectively. A total of 376,278,516 clean data-points were obtained by metagenomic sequencing. Firmicutes and Bacteroidetes were the dominant phyla, regardless of the dietary protein levels. In the H_h group, the phyla Proteobacteria, Caldiserica, and Candidatus_Cryosericota were less abundant than those in the H_I group. In contrast, Lentisphaerae, Chlamydiae, and Planctomycetes were significantly more abundant in the H_h group. Some genera, such as Prevotella, Roseburia, and Firmicutes_unclassified, were less abundant in the H_h group than those in the H_I group. In contrast, Ruminococcus, Ruminococcaceae_noname, Anaerotruncus, Thermotalae, Lentisphaerae_noname, and Paraprevotella were enriched in the H_h group. The acquired microbial genes were mainly clustered into biological processes; molecular functions; cytosol; cellular components; cytoplasm; structural constituents of ribosomes; plasma membranes; translation; and catalytic activities. 205987 genes were significantly enriched in the H_h group. In contrast, 108129 genes were more abundant in the H_I group. Our findings reveal that dynamic changes in fecal bacteria and their genes are strongly influenced by the levels of dietary proteins. We discovered that differentially expressed genes mainly regulate metabolic activity and KEGG demonstrated the primary involvement of these genes in the metabolism of carbohydrates, amino acids, nucleotides, and vitamins. Additionally, genes responsible for metabolism were more abundant in the H_h group. Investigating fecal bacterial characteristics may help researchers develop a dietary formula for lactating ewes to optimize the growth and health of ewes and lambs.

Comparison of goat and cow milk-derived extracellular vesicle miRNomes

miRNAs present in milk are mainly found in extracellular vesicles (EVs), which are nanosized membrane vesicles released by most of the cell types to ensure intercellular communication. The majority of the studies performed so far on these vesicles have been conducted on human and cow’s milk and focused on their miRNA content. The objectives of this study were to profile the miRNA content of purified EVs from five healthy goats and to compare their miRNome to those obtained from five healthy cows, at an early stage of lactation. EV populations were morphologically characterized using Transmission Electron Microscopy and Nanoparticle Tracking Analysis. The presence of EV protein markers checked by Western blotting and the absence of contamination of preparations by milk proteins. The size distribution and concentration of bovine and goat milk-derived EVs were similar. RNA-sequencing were performed, and all sequences were mapped to the cow genome identifying a total of 295 miRNAs. This study reports for the first-time a goat miRNome from milk EVs and its validation using cow miRNomes.

Metabolic Changes Associated with Different Levels of Energy Deficits in Mediterranean Buffaloes during the Early Lactation Stage: Type and Role of the Main Lipid Fractions Involved.

Cell function and energy redistribution are influenced by lipid classes (phospholipids (PLs), free fatty acids (FFAs), triglycerides (TGs), and cholesterol esters (CEs)). The aim of this study was to investigate metabolic alterations that are related to changes in lipid classes according to different levels of energy deficits in early lactating Mediterranean buffaloes (MBs). Sixty-three MBs were enrolled at the beginning of lactation using an observational study with a cross-sectional experimental design. Serum β-hydroxybutyrate (BHB) levels were used to group the animals into a healthy group (Group H; n = 38; BHB < 0.70 mmol/L) and hyperketonemia risk group (Group K; n = 25; BHB ≥ 0.70 mmol/L). Statistical analysis was performed using a linear model that included the effect of the group and body condition score to assess differences in fatty acid (FA) concentrations. A total of 40 plasma FAs were assessed in each lipid class. Among the FAs, eight PLs, seven FFAs, four TGs, and four CEs increased according to BHB levels, while three FFAs, three TGs, and one CE decreased. The changes among lipid class profiles suggested the influence of inflammatory response, liver metabolism, and the state of body lipid reserves. In addition, the possible similarities of buffaloes at risk of hyperketonemia with ketotic cows suggest the necessity of further investigations in these ruminants.

Association between white line disease and sole ulcers with certain milk components in Simmental cows

Lameness is one of the high influence production illnesses in intensive dairy production farming, it reduces milk yield and can also negatively affect the quality of milk. Many factors can affect the production of milk components. In addition race, nutrition, milk yield, various metabolic disorders, and lameness can have an effect on the synthesis of milk components. White line disease and sole ulcers are widespread hoof diseases of cows in tied-holding systems. Albeit the main cause of lameness, associations between claw disorders of cows and variation of milk components haven’t been widely studied in Simmental cows. The objective of our study was to investigate the effect of white line disease and sole ulcers on the production of milk components of Simmental dairy cows kept in the small households in Mačva locality, Serbia. Cows were selected with a history of lameness. A total of 3 groups of cows: affected by white line disease (n=12), sole ulcers (n=12), and healthy cows (n=12) in the early stage of lactation were selected for analysis of milk components. Milk components (milk protein, fat, and non-fat dry matter) were analyzed using Lactoscan S. Significance of differences in milk component characteristics between white line disease, sole ulcers, and healthy groups were tested using a Kruskal-Wallis multiple comparisons test. The contents of milk fat of cows affected by white line disease and cows affected by sole ulcers were significantly lower than those of non-lame cows: 3.80%, 3.69%, and 4.18%, respectively (both p&lt;0.05). However, differences in the contents of milk protein and the contents of non-fat dry matter cows affected by white line disease, sole ulcers, and in health cows were not significantly different (p&gt;0.05). Our results indicate that hoof diseases of cows namely whitee line disease and sole ulcers, significantly reduce the milk fat production in lame Simmental cows.

Interaction between the Concentration of β-Hydroxybutyric Acid and the Content of Long-Chain Fatty Acids in the Early Stage of Lactation––Comparing Multiparous and Primiparous Cows

The aim of the experiment was to study the relationship between the age of cows, blood BHBA content, and CLA isomer (C18:2 cis9,trans11, CLA9; C18:2 trans10,cis12, CLA10) content during the first three weeks post-partum. For the experiment, 105 cows were selected from the entire herd and assigned to one of four groups: healthy primiparous (PH), healthy multiparous (MH) or ketotic primiparous (PK), ketotic multiparous (MK) based on their symptoms, and blood serum BHBA concentrations at 5 ± 2 days post-partum. Milk and blood samples were taken from the animals for a period of three weeks at weekly intervals on the same day. High levels of ketone bodies inhibit the activity of acetyl-CoA, thus decreasing the transport of acetyl-CoA, which may result in a decrease in CLA9 and CLA10 synthesis. Studies have shown that the age of the cows was an additional factor in determining the formation of CLA isomer levels during the early stage of lactation. The CLA9 content in the milk of PH cows in the first week of lactation was 32.75% higher than that of PK milk, while in MH milk, it was 67.7% higher than that of MK milk. The CLA10 content in the milk PH, when compared to the healthy groups, was 319% lower for primiparous cows. In summary, different reference limits in CLA9 and CLA10 content should be considered in the diagnosis of ketosis, taking into account, among other things, parity.

Molecular identification, antimicrobial resistance and virulence gene profiling of Staphylococcus spp. associated with bovine sub-clinical mastitis in Bangladesh

This study was conducted to investigate the diversity and antimicrobial resistance profiling of Staphylococcus species causing sub-clinical mastitis (SCM) in dairy herds in Bangladesh as well as putative risk factors associated with the infections. Individual quarter milk samples were collected from a total of 284 lactating cows from 30 dairy farms were screened by means of California mastitis test; 178 (62.7%) of them had at least of quarter affected by SCM. After conventional microbiological isolation procedures, PCR tests were used for Staphylococcus species identification and detection of antimicrobial resistance and virulence genes. S. chromogenes (65.7%) was the most predominant species followed by, S. epidermidis (20.2%), S. haemolyticus (19.1%), S. aureus (15.7%), and S. sciuri (5.6%). High levels of antimicrobial resistance to ampicillin and amoxicillin/clavulanic acid were observed in S. aureus (82.1% and 75%) and S. sciuri (80% and 70%), while resistance to cefepime was markedly higher in S. chromogenes (95.7%), S. haemolyticus (94.1%), and S. epidermidis (97.2%). Multidrug resistance isolates were identified in all five species. The mecA gene was detected in S. aureus (32.1%) and S. chromogenes (5.98%). In addition, 20% S. sciuri and 17.7% S. haemolyticus carried the cytotoxin (pvl) gene, while 14.3% S. aureus harbored the toxic shock syndrome toxin (tst) gene. Multivariable logistic regression analysis identified “Old aged” (OR [CI]: 3.5 [1–12.4]); “Early stage of lactation” (OR [CI]: 3.4 [1.2–9.7]) and, “Firm udder condition” (OR [CI]: 4.2 [1.2–14.6]) as risk factors associated with SCM caused by S. aureus, S. chromogenes, and S. haemolyticus, respectively. Moreover, “Use of antimicrobials” (OR [CI]: 10.4 [3.4–32.1] and “History of previous clinical mastitis” (OR [CI]: 4.9 [1.2–19.7] for the carriage of methicillin-resistant Staphylococcus spp.

STUDIES ON THE MILK YIELD AND COMPOSITION OF LACTATING RED SOKOTO DOES FED GINGER (Zingiber officinale) AS FEED ADDITIVE

A study was conducted to evaluate the effect of inclusion levels of ginger on milk yield and composition of Red Sokoto does. A total of twenty-eight (28) Red Sokoto does (RSD) weighing on the average 16.29 kg were used. The animals were randomly assigned to four diets, containing 0, 250, 500 and 750g/100kg diet levels of ginger respectively in a completely randomized design. Each of the animals were fed concentrate at 1.5% of body weight. Milk yield and composition were recorded. Udder and teats of each doe were washed with cotton wool soaked in disinfectant (Methylated spirit) and then they were hand-milked into sterilized containers and measured using calibrated cylinder. Milk samples were analyzed for total solids, fat and protein using infrared spectrophotometry. Ash content was determined after heating in a muffle furnace for 3 hours and the solids not fat content was calculated by difference. Results obtained showed that higher total milk yield of 360 liters was recorded in RSD fed diet containing 250 g ginger. All milk composition parameters (total solid, ash, fat, solid not fat and crude protein), were significantly affected (P&lt;0.05) by ginger inclusion. Fat and crude protein contents were significantly affected (P&lt;0.05) by lactation stages with their higher values (P&lt;0.05) recorded in mid lactation stage (4.35% and 3.61%) respectively. Ash content recorded significantly higher value (P&lt;0.05) in early lactation stage (1.05%). Ginger inclusion levels in the diets of RSD improved milk yield and milk composition.

Milk metabolomics analyses of lactating dairy cows with divergent residual feed intake reveals physiological underpinnings and novel biomarkers.

The opportunity to select for feed efficient cows has been limited by inability to cost-effectively record individual feed efficiency on an appropriate scale. This study investigated the differences in milk metabolite profiles between high- and low residual feed intake (RFI) categories and identified biomarkers of residual feed intake and models that can be used to predict residual feed intake in lactating Holsteins. Milk metabolomics analyses were undertaken at early, mid and late lactation stages and residual feed intake was calculated in 72 lactating dairy cows. Cows were ranked and grouped into high residual feed intake (RFI >0.5 SD above the mean, n = 20) and low residual feed intake (RFI <0.5 SD below the mean, n = 20). Milk metabolite profiles were compared between high residual feed intake (least efficient) and low residual feed intake (most efficient) groups. Results indicated that early lactation was predominantly characterized by significantly elevated levels of medium chain acyl carnitines and glycerophospholipids in high residual feed intake cows. Citrate cycle and glycerophospholipid metabolism were the associated pathways enriched with the significantly different metabolites in early lactation. At mid lactation short and medium chain acyl carnitines, glycerophospholipids and amino acids were the main metabolite groups differing according to residual feed intake category. Late lactation was mainly characterized by increased levels of amino acids in high residual feed intake cows. Amino acid metabolism and biosynthesis pathways were enriched for metabolites that differed between residual feed intake groups at the mid and late lactation stages. Receiver operating characteristic curve analysis identified candidate biomarkers: decanoylcarnitine (area under the curve: AUC = 0.81), dodecenoylcarnitine (AUC = 0.81) and phenylalanine (AUC = 0.85) at early, mid and late stages of lactation, respectively. Furthermore, panels of metabolites predicted residual feed intake with validation coefficient of determination (R 2) of 0.65, 0.37 and 0.60 at early, mid and late lactation stages, respectively. The study sheds light on lactation stage specific metabolic differences between high-residual feed intake and low-residual feed intake lactating dairy cows. Candidate biomarkers that distinguished divergent residual feed intake groups and panels of metabolites that predict individual residual feed intake phenotypes were identified. This result supports the potential of milk metabolites to select for more efficient cows given that traditional residual feed intake phenotyping is costly and difficult to conduct in commercial farms.

Prevalence, distribution, and risk factors of bovine tuberculosis in dairy cattle in central China.

Bovine tuberculosis (bTB) is one of the priority epidemic diseases in dairy cattle in China. Continuous surveillance and evaluation of the control programs will help on improving the efficiency of bTB control policy. We designed this study to investigate both animal and herd level prevalence of bTB, as well as to determine the associated factors in dairy farms in Henan and Hubei provinces. A cross-sectional study was conducted from May 2019 to September 2020 in central China (Henan and Hubei provinces). We sampled 40 herds in Henan and six herds in Hubei via stratified systematic sampling and administrated a questionnaire consisting of 35 factors. A total of 4900 whole blood samples were collected from 46 farms, including 545 calves <six months old and 4355 cows ≥six months old. This study demonstrated a high animal-(18.65%, 95% CI: 17.6-19.8) and herd-level (93.48%, 95%CI: 82.1-98.6) prevalence of bTB in dairy farms in central China. The Least Absolute Shrinkage and Selection Operator (LASSO) and negative binomial regression models showed that herd positivity was associated with the practice of introducing new animals (RR = 1.7, 95%CI: 1.0-3.0, p=0.042), and changing the disinfectant water in the wheel bath at the farm entrance every three days or less (RR = 0.4, 95%CI: 0.2-0.8, p=0.005) which reduced the odds of herd positivity. In addition, the result illustrated that testing cows with a higher age group (≥ 60 months old) (OR=1.57, 95%CI: 1.14-2.17, p=0.006) and within the early stage of lactation (DIM=60-120 days, OR=1.85, 95%CI: 1.19-2.88, p=0.006) and the later stage of lactation (DIM≥301 days, OR=2.14, 95%CI: 1.30-3.52, p=0.003) could maximize the odds of detecting seropositive animals. Our results have plenty of benefit to improve bTB surveillance strategies in China and elsewhere in the world. The LASSO and the negative binomial regression models were recommended when dealing with high herd-level prevalence and high dimensional data in questionnaire-based risk studies.

Lactation stages modulate the hematological, serum biochemical, and endocrinological profiles and oxidative stress markers in crossbred cows under tropical humid island ecosystem of Andaman and Nicobar Islands

The present study was designed to assess the interrelationship between hematological, serum biochemical, and endocrinological profiles and oxidative stress markers and lactational stages in crossbred (CB) dairy cows of Andaman and Nicobar Islands (ANI). Healthy (n = 6) CB cows (50-62.50% exotic inheritance; Holstein Friesian × Andaman local) of 4th parity with age of 7-9years and body weight of 350-400kg were selected from Cattle Breeding Farm, ICAR-Central Island Agricultural Research Institute (ICAR-CIARI), Port Blair, ANI. These experimental cows were synchronized with Ovsynch protocol, and parturition was planned to happen in the month of May-June. Lactation was allowed for 305days. Hematological profiles, serum biochemical profiles, oxidative stress markers and endocrinological profiles were measured at a 15-day interval from day 07 to 305 of lactation (after 6days of colostrum). The lactation period was divided into first (day 07 to 90), second (day 91 to 180), and third (day 181 to 305) stage of lactation. Average daily milk yield (L) did not vary among the stages of lactations; however, first (8.56 ± 1.26) and second (9.79 ± 0.87) stages had higher milk yield compared to third (7.93 ± 0.79) stage of lactation. Hematological profiles did not vary among the stages of lactation; however, these values were within the range of bovine species at lactation. Serum glucose, triglyceride, total cholesterol, total protein, globulin, and blood urea nitrogen (BUN) increased (P < 0.05) and albumin and creatinine decreased (P < 0.05) gradually as lactation stages advanced. Activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) and concentration of calcium, phosphorous, and magnesium were nearly similar among the stages of lactation. Similarly, triiodothyronine (T3), and thyroxine (T4) increased and prolactin and cortisol decreased (P < 0.05) gradually as stages of lactation advanced. Total antioxidant capacity (TAC) increased and malondialdehyde (MDA) decreased (P < 0.05) as lactation stages advanced. The results of the present study indicated that the lactating CB cows suffered nutritional stress (deficiency of protein, carbohydrate, lipids, and minerals), physiological stress (higher cortisol), oxidative stress (higher MDA and deficiency of total antioxidant capacity), and hormonal imbalance (higher prolactin and cortisol and deficiency of thyroid hormones) during the early stages of lactation. Thus, the first and second stages are more stressful events compared to the third stage of lactation in the CB cows in ANI. Therefore, regular monitoring of blood components and accordingly suitable feeding strategies with balanced nutrients and minerals, supplementation of suitable antioxidants, and appropriate management practices need to be implemented to mitigate these stresses and to prevent metabolic disorders with maximum milk production during different stages of lactation in CB cows under humid tropical island ecosystem of Andaman and Nicobar Islands.

Dairy Cows Are Limited in Their Ability to Increase Glucose Availability for Immune Function during Disease.

Shortages of energy and glucose have been hypothesized to play a key role in the development of and responses to production diseases in dairy cows during early lactation. Given the importance of glucose for immune functions, we used a recently established method for the estimation of glucose balance (GB) to evaluate glucose availability during disease phases. A dataset comprising ration analyses as well as individual daily milk yields (MY), dry matter intake (DMI), body weights, and health records of 417 lactations (298 cows) was used to calculate individual daily GB and energy balance (EB). The magnitude and dynamics of MY, DMI, GB, and EB were evaluated in the weeks before, at, and after diagnoses of inflammatory diseases in different stages of early lactation from week in milk 1 to 15. Diagnoses were categorized as mastitis, claw and leg diseases, and other inflammatory diseases. Mixed linear models with a random intercept and slope term for each lactation were used to evaluate the effect of diagnosis on MY, DMI, GB, and EB while accounting for the background effects of week in milk, parity, season, and year. When unaffected by disease, in general, the GB of cows was close to zero in the first weeks of lactation and increased as lactation progressed. Weekly means of EB were negative throughout all lactation stages investigated. Disease decreased both the input of glucose precursors due to a reduced DMI as well as the output of glucose via milk due to a reduced MY. On average, the decrease in DMI was -1.5 (-1.9 to -1.1) kg and was proportionally higher than the decrease in MY, which averaged -1.0 (-1.4 to -0.6) kg. Mastitis reduced yield less than claw and leg disease or other diseases. On average, GB and EB were reduced by -3.8 (-5.6 to -2.1) mol C and -7.5 (-10.2 to -4.9) MJ in the week of diagnosis. This indicates the need to investigate strategies to increase the availability of glucogenic carbon for immune function during disease in dairy cows.