Late Lactation Period Research Articles

Spatial distribution of bats (Chiroptera) in valleys at northern latitudes in Europe

This study explores the spatial distribution of bats around lakes in valleys around 62° N in western Norway. Stationary ultrasound detectors were used to record ultrasound at various distances from the shores of lakes during the bats late pregnancy and lactation period. In this landscape, northern bat was the most commonly recorded species, followed by Myotis bats (pooled) and the soprano pipistrelle. None of the other European bat genera were present. There was a clear non-linear distribution pattern, with a steep increase in bat activity close to the shores. This is similar to what is found in fiords and thus could be a general pattern in landscapes with complex topography. Both climate and topography are factors likely to contribute to this pattern.

Seasonal variations of Saanen goat milk composition and the impact of climatic conditions.

The aim of this research was to investigate the effect of climatic conditions and their impact on seasonal variations of physico-chemical characteristics of Saanen goat milk produced over a period of 4years. Lactation period (early, mid and late) and year were considered as factors that influence physico-chemical composition of milk. Pearson's coefficient of correlation was calculated between the physico-chemical characteristics of milk (fat, proteins, lactose, non-fat dry matter, density, freezing point, pH, titrable acidity) and climatic condition parameters (air temperature, temperature humidity index-THI, solar radiation duration, relative humidity). Results showed that all physico-chemical characteristics of Saanen goat milk varied significantly throughout the lactation period and years. The decrease of fat, protein, non-fat dry matter and lactose content in goat milk during the mid-lactation period was more pronounced than was previously reported in the literature. The highest values for these characteristics were recorded in the late lactation period. Observed variations were explained by negative correlation between THI and the physico-chemical characteristics of Saanen goat milk. This indicated that Saanen goats were very prone to heat stress, which implied the decrease of physico-chemical characteristics during hot summers.

Alteration of adolescent aversive nicotine response and anxiety-like behavior in nicotine-exposed rats during late lactation period

Early nicotine exposure is an important cause of further habitual tobacco smoking. Although nicotine has not only rewarding but also aversive properties, the effects of early nicotine exposure on the distinct properties of nicotine are not well known. To reveal the effects of early adolescent nicotine exposure on further persistent tobacco smoking, we demonstrated developmental changes in nicotine-related appetitive and aversive behaviors of rats exposed to nicotine during the late lactation period. Sprague–Dawley rats were injected with saline or nicotine (2, 6 and 12mg/kg). We performed a two bottle free-choice test using escalating doses of nicotine (25, 50 and 100μg/ml), saccharin and quinine and the open field test in both adolescent and adult rats. The rats’ aversive response to nicotine was increased according to the increase in nicotine concentration. Adolescent rats showed higher nicotine preference and consumption behaviors than did adult rats at an aversive dose of nicotine. Nicotine-exposed rats increased adolescent nicotine consumption when the nicotine concentration was 12mg/kg. We observed significant increases in anxious behaviors in adolescent nicotine-injected rats compared to saline-injected rats, but there were no alterations in adult rats. In both adolescent and adult rats, saccharin and quinine intake were not significantly different between groups. Taken together, it suggests that repeated nicotine exposure in late lactation period affect changes in aversive nicotine responses and anxious behaviors during adolescence but there is no difference in adults.

Abstract 4240: Determination of normative patterns of gene expression levels and breast cancer risk biomarkers in human breast milk

Abstract Parity and breastfeeding influence a woman’s risk of developing breast cancer. Understanding the underlying molecular changes in the breast will facilitate identification of additional factors during pregnancy and postpartum that modify breast cancer risk. Most prior studies in humans on this topic, however, have been cross-sectional studies comparing breast tissue samples from nulliparous versus post-pregnant women, and are limited in their ability to characterize longitudinal changes and within-person variations. Breast milk contains cells of the mature gland, and may have a potential as a noninvasive source for studying molecular characteristics of the pregnancy-associated changes in the breast and their impact on breast cancer risk. The objectives of this study were to (1) determine normative patterns of gene expression levels in longitudinally collected breast milk samples and (2) correlate gene expression data in relation to self-reported measures of psychosocial stress during pregnancy and postpartum period. Our preliminary results showed that the post-pregnancy gene expression levels in breast milk samples can be measured reproducibly over a short period of time. Whole-genome transcriptome analysis revealed that expression levels of the post-pregnancy genes are different in early (less than 3 month postpartum) and late lactation period (more than 6 month postpartum). Moreover cytokine expression profiling correlated expression of inflammatory cytokines with early versus late postpartum period. The unique contribution of this study is to capture longitudinal gene expression data from breast milk samples collected over the course of lactation, hence providing a valuable basis for future studies to identify differential dynamics associated with breast cancer susceptibility. Note: This abstract was not presented at the meeting. Citation Format: Maria Ouzounova, Georgina Lewis, Raziye Piranlioglu, Tiana Curry-McCoy, Wonsuk Yoo, Nita Maihle, Sangmi Kim, Hasan Korkaya. Determination of normative patterns of gene expression levels and breast cancer risk biomarkers in human breast milk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4240. doi:10.1158/1538-7445.AM2017-4240

Effects of breed, feeding system, and lactation stage on milk fat characteristics and spontaneous lipolysis in dairy cows

Spontaneous lipolysis (SL) is an enzymatic reaction that leads to a release of fatty acids that can modify technological and sensory properties of milk and milk products. However, few studies have been done to assess the effect of feeding systems (FS) and breed on SL. Most of them were conducted in the 1980s and are not fully representative of cattle today. No previous study investigated the effect of cow breed at the whole-lactation scale. Thus, a trial was carried out to study the effects of 2 FS (high- and low-input FS) with 2 breeds [Holstein (HO) and Normande (NO)] during 1 entire lactation. Sixty-three cows were followed throughout 1 lactation. Cows were divided into 4 groups according to their breed and their FS. The high FS (HFS) consisted of a high-energy diet (in winter, corn silage with 30% concentrate; otherwise, pasture with 4 kg/d of concentrate) and the low FS (LFS) consisted of a low-energy diet (in winter, conserved grass with no concentrate; otherwise, pasture with no concentrate). The cows calved between January and March. Individual milk samples were collected every month from both morning and evening milkings for fat, protein, milk fat globule size, major fatty acids and proteins profiles, and SL determinations. Data were analyzed using the mixed procedure of SAS. The SL was higher in evening milks compared with morning milks. In early lactation, in evening milks, SL was higher in LFS than in HFS. No difference was shown according to the FS in mid and late lactation. Pasture was associated with low SL rate in mid lactation. The NO cows were less susceptible to SL during the entire lactation than HO cows. Finally, early and late lactation periods were identified as being more susceptible to SL, but this depended on breed and FS. During early lactation, HO cows and LFS were associated with higher levels of SL, particularly in evening milks, and, during late lactation, HO cows were associated with higher levels of SL. No intertreatment or intercow correlations (coefficient of determination <0.16) were found between SL, milk fat and protein contents, milk production, milk fat globule size, proportion of fatty acids and proteins, body condition, and weight during the entire lactation. Effects of breed, FS, and lactation stage were clearly identified and quantified. Causal mechanisms might involve energy balance and circadian secretion of milk fat globule components.

The effect of the zinc concentration in breast milk on neonatal weight gain

The change in breast milk zinc (Zn) concentration in a feeding period during lactation may affect neonatal weight gain. The aim of this study was to determine how to change the Zn concentrations in breast milk during a feeding period in early and late lactation periods and identify the relationship between the differences in the Zn levels in breast milk during lactation and neonatal weight gain. Breast milk was collected in the early and late lactation periods with samples being obtained before (foremilk) and after (hindmilk) a feeding period. Then, we determined the Zn concentrations in the breast milk and measured the weight of the infants before and after the same feeding period. The study was composed of 37 newborns and their mothers. During the feeding period, the Zn concentrations in both the transitional and mature milk decreased significantly. During the lactation period, the Zn levels were markedly lower in only the hindmilk. The body weights of the infants both before and after feeding in the early lactation period were negatively correlated with the delta Zn concentration in the same period, but the delta body weights in the early lactation period were positively correlated with the Zn levels in the hindmilk in the same period. In addition, body weights before feeding in the late lactation period were also positively correlated with Zn levels in hindmilk in the early lactation period. This study suggests that the Zn concentrations in both the transitional and mature milk decreased, which suggests that changes in the Zn content of breast milk during lactation might play a role in the weight gain of healthy neonates.

Changes in milk composition of domestic Balkan donkeys’ breed during lactation periods

Changes in the milk composition during early, middle and late stage of lactation period were monitored in 10 individual autochthonous donkeys of the Domestic Balkan breed. Animals were grazing ad libitum during early and middle lactation, while supplements (meadow hay, corn and corn stalks) were added during the late lactation period. The aim of this study was to evaluate the main compounds of donkeys? milk during different periods of lactation. Based on the obtained results it was noticed that nutritional effects on milk composition were the greatest in the early and middle lactation. Chemical analysis indicated that donkeys? milk was quite poor in dry matter (8.82-9.68%), fat (0.54-0.67%) and protein (1.44-1.79%), and conversely was high in lactose content (6.06-7.12%). Concentration of vitamin C varied significantly (P&lt;0.05) during the lactation period and was very high (12.84-26.89 ?g/mL) in comparison to milk from other animal species. Likewise, the content of lysozyme (1.95-3.29 g/L) and lactoferrin (1.56-3.14 g/L) during the early and middle lactation period showed an increase. Donkeys' milk did not show any significant differences in MUFA, n6-PUFA and UFA contents, while n3-PUFA, n6/n3 and UFA/SFA ratio showed a significant variability (P&lt;0.05) during the lactation period.

Circulating metabolic hormones in different metabolic states of high producing Holstein dairy cows

Background: Information regarding the metabolic hormones in different metabolic states of high producing dairy cows can aid high producing herds to manage and resolve the metabolic and production problems. Furthermore, it can be considered as a tool to evaluate metabolic status of dairy cows. Herd managers can also evaluate the energy input-output relationships by assessing the metabolic profile to prevent and control negative energy balance, metabolic disorders and nutritional insufficiencies. OBJECTIVES: The present study was performed to clarify the metabolic hormone profile in each metabolic state of high producing Holstein dairy cows. The results of this research can reveal the normal metabolic state of these animals. METHODS: 25 multiparous Holstein dairy cows were divided to 5 equal groups containing early, mid and late lactations, far-off and close-up dry periods. Blood samples were collected from all cows and sera were analyzed for concentrations of triiodothyronine (T3), thyroxine (T4), free T3 (fT3), free T4 (fT4), cortisol and insulin like growth factor-1 (IGF-1). RESULTS: Serum T3 concentration in early lactation group was significantly higher than other ones (p<0.05). T4 levels in early and mid lactation dairy cows were lower than other studied groups, significantly. The cows in early lactation and close-up dry periods had the highest and the lowest serum fT3 concentrations, respectively (p<0.05). fT4 in far-off dry cows was significantly higher than others. The highest and the lowest circulating levels of cortisol were detected in mid and late lactation periods, respectively (p<0.05). The lowest concentrations of IGF1 were detected in early lactation period and its highest levels were seen in mid and late lactation and far-off dry cows (p<0.05). CONCLUSIONS: Metabolic hormones change in different metabolic states of high producing Holstein dairy cows. The presented metabolic hormone profile can be considered as criteria to monitor the metabolic status of dairy cows at different metabolic states.

1744 Effects of different sources and routes of administration of copper and vitamins A and D on piglets gut microbiota

Placental and colostral transfers of copper and vitamins A and D micronutrients from dams to neonates are limited in pig species (Matte et al., 2014, JAS 92-Suppl. 2:153). The aim of the study was to evaluate the influence of different perinatal micronutrient supplementation strategies on piglets’ gut microbiota. Within each litter from 5 sows, 10 newborn piglets were allocated to one of the following combinations of sources and routes of micronutrient administrations: oral vitamin D3, retinol-acetate and CuSO4 (T1); oral 25-OH-vitamin D3, β-carotene and Cu-yeast (T2); exposure to UVB light (20 min every second day), oral retinol-palmitate and Cu-gluconate (T3); intramuscular vitamin D3 and retinol-propionate and oral Cu-acetate (T4); oral saline (CTL). Oral or intramuscular provisions corresponded to 12 mg of copper and 70 and 12 MIU of vitamins A and D, respectively. This design was repeated with 5 other sows fed daily extra supplements of 25-OH-vitamin D3 (4 MIU), β-carotene (24 MIU) and Cu-yeast (45 mg) from 90 d of gestation to 21 d of lactation. At 21 d of age, feces were collected and piglets were weaned. At 23 d of age, 5 repetitions of a combination of sow and piglet factorial treatments were sacrificed and feces and content from mid-jejunum, ileum, mid-colon, and rectum were collected to characterize gut microbiota. Bacterial communities were analyzed by sequencing the V3-V4 regions of 16S rRNA genes on an Illumina MiSeq. Bioinformatic analyses were performed on our internal data analysis pipeline and statistics were performed in R. The analysis of bacterial community composition at the class level revealed that sow supplementation significantly increased the relative abundance of Bacilli in feces at d 21 (P = 0.04) but not at d 23. Gut microbiota diversity significantly differed (P = 0.03) according to supplemental treatments provided to piglets. However there was no piglet treatment effect on gut microbiota based on PCoA analyses. The Shannon diversity of jejunal and ileal microbiota was significantly (P ≺ 0.05) decreased when supplementation was given to sows. Sow supplementation also significantly increased Bacilli in both jejunum and ileum (P≺ 0.001, both). The study demonstrated that piglet gut microbiota can be modulated by daily extra supplementation of vitamins A and D and organic copper to sows during late pregnancy and lactation periods. Further studies are thus warranted to study mechanisms of action explaining the impact of such maternal micronutrient supplementation on bacterial colonization in piglets gut.

Causal relationships between clinical mastitis events, milk yields and lactation persistency in US Holsteins

Complex relationships exist between udder susceptibility to mastitis and milk production traits. Identifying causal association between these traits could help to disentangle these complex relationships. The main objective of the study was to use producer-recorded health data to examine the causal relationship between mastitis events, milk yield and lactation persistency. A total of 48,058 first lactation cows, daughters of 2213 Holstein bulls and raised across 207 herds were analyzed using structural equation models. Traits included in the dataset were mastitis events and average test day milk yields recorded in three different periods: period 1 (5–60 DIM), period 2 (61–120 DIM) and period 3 (121–180 DIM). In addition, lactation persistency was also included. A subset including 28,867 daughters of 1809 Holstein sires having both first and second lactation across 201 herds was further investigated. In these datasets, mastitis events were defined on a lactation basis as binary trait; either a cow was assigned a score of 1 (had a mastitis event in that lactation) or a score of 0 (healthy) for that particular lactation, regardless of the time of occurrence. Total milk yield from first and second lactation were also included in the analyses. We estimated negative structural coefficient (−0.032) between clinical mastitis and test day milk production in early lactation period suggesting that mastitis results in a direct decline in milk production in early lactation. We nonetheless elicited little impact of mastitis on test day milk production of mid and late lactation periods, and on milk yield lactation persistency. Likewise the positive estimate of the structural coefficient (0.123) from mastitis event in first lactation to second lactation suggests an increased risk of mastitis in second lactation if a case of mastitis occurs in the primiparous cow. Heritability estimates obtained from the structural equation models were low for mastitis (ranged 0.04 to 0.07), and negative genetic correlations were found between mastitis events and milk yield. The study illustrates how mastitis events and production are causally linked. Through the use of structural equation models we elicited the causal effect among mastitis and production traits that evolve over the course of cow life.

Dietary administration of probiotics to sows and/or their neonates improves the reproductive performance, incidence of post-weaning diarrhea and histopathological parameters in the intestine of weaned piglets.

Probiotics have gained considerable attention with respect to their beneficial effects on livestock performance and health. The most significant effects of probiotics on the gut microbiota and the host animals take place when they are included in diets during particularly stressful periods such as weaning and/or at the beginning of the lactation period. The probiotics Bacillus mesentericus strain TO-A at 1 × 108 colony forming units (CFU)/g, Clostridium butyricum strain TO-A at 1 × 108 CFU/g and Enterococcus faecalis strain T-110 at 1 × 109 CFU/g were used. Litter weight at delivery and ratio of return to estrous improved significantly (17% and 24% improvement, respectively) by probiotic administration to sows (0.2% (w/w)). Furthermore, the feed intake of the probiotics-administered sows was greater than that of the control sows during the late lactation period. Post-weaning diarrheal incidence and growth performance was improved by probiotics administration to neonates (0.02% (w/w)), while the combined use of probiotics in sows and their neonates induced the enlargement of villous height and prevented muscle layer thinning in the small intestine of weaning piglets. The administration of probiotics of three species of live bacteria improved the porcine reproductive performance around stressful periods of sows (farrowing) and piglets (weaning). [Corrections added on 26 April 2016, after first online publication: 'Enterococcus faecalis strain T-100' has been corrected to 'Enterococcus faecalis strain T-110' in the above paragraph and in the 'Probiotics' section under the Materials and Methods heading.].

Screening for diets that reduce urinary nitrogen excretion and methane emissions while maintaining or increasing production by dairy cows

Farmers face complex decisions at the time to feed animals, trying to achieve production goals while contemplating social and environmental constraints. Our purpose was to facilitate such decision making for pastoral dairy farmers, aiming to reduce urinary N (UN) and methane emissions (CH4), while maintaining or increasing milk production (MP). There is a number of feeds the farmers can choose from and combine. We used 50 feeds (forages and grains) combined systematically in different proportions producing 11,526 binary diets. Diets were screened, using an a posteriori approach and a Pareto front (PF) analysis of model (Molly) outputs. The objective was to identify combinations with the best possible compromise (i.e. frontier) between UN, CH4, and MP. Using high MP and low UN as objective functions, PF included 10, 14, 12 and 50 diets, for non-lactating, early-, mid- and late-lactation periods, with cereals and beets featuring strongly. Using the same objective functions, but including ryegrass as dietary base PF included 2, 4, 8 and 4 diets for those periods. Therefore, from a wide range of diets, farmers could choose from few feeds combined into binary diets to reduce UN while maintaining or increasing MP. If the intention is maintaining pasture-based systems, there are fewer suitable options. Reducing UN will simply require dilution of N supplied by pasture by supplementing low N conserved forages. The results also evidence the risk of pollution swapping, reaching the frontier means arriving at a point where trade-off decisions need to be made. Any further reduction in UN implies an increment in CH4, or reduction in CH4 emissions increases UN. There is no perfect diet to optimize all objectives simultaneously; but if the current diet is not in the frontier some options can offset pollution swapping. The choice is with the farmers and conditioned by their context.

Lactoferrin and Immunoglobulin G Concentration in Bovine Milk from Cows with Subclinical Mastitis during the Late Lactation Period

Background: Lactoferrin and immunoglobulin G in milk have an important role in udder resistance to infection in the involution period. Both proteins express antimicrobial activity- lactoferrin by the binding and sequestration of iron ion; and immunoglobulin G by complement activation, bacterial opsonization and agglutination. Many factors affect lactoferrin and immunoglobulin G concentrations in bovine milk, such as the stage of lactation, milk production, and intramammary infections. The aim of this study was to determine concentrations of lactoferrin and immunoglobulin G in milk from healthy cows and subclinical mastitic cows during the late lactation period, and to evaluate the relationship between them.Materials, Methods &amp; Results: A total of 150 quarter milk samples from 41 cows (Holstein-Friesian breed) in late lactation period were reviewed in this study. Milk samples were collected during morning milking, using aseptic techniques in sterile test tubes. From each sample, 0.1 mL of milk was plated on Columbia blood agar base with 5% defibrinated ovine blood, MacConkey agar and Sabouraud dextrose agar and incubated for 24 h - 48 h (bacteria) and 5 days (yeasts, mould) at 37oC. Milk samples for detection lactoferrin and immunoglobulin G concentration were skimmed at 1,400 g for 45 min and stored at -20°C until analysis. Lactoferrin concentration in bovine milk was determined using the Bovine Lactoferrin ELISA Quantitation Set. Milk samples were diluted at a ratio of 1:10,000. Plates were read at 450 nm absorbence values. Immunoglobulin G concentration was determined by the immunodiffusion method using radial immunodiffusion (RID) plates. Milk samples were diluted in a ratio of 1:30. Reading of results was done after incubation for 48 h by measuring the diameter of the precipitation ring. The highest mean lactoferrin concentration was observed in udder quarters infected with contagious pathogens (Streptococcus agalactiae and Staphylococcus aureus), while the highest mean immunoglobulin G concentration was detected in milk samples where minor mastitis pathogens (coagulase-negative staphylococci and Corynebacterium spp.) were isolated. Milk samples where Staphylococcus aureus was isolated had the lowest immunoglobulin G concentration, and the lowest lactoferrin concentration was observed in samples infected with enviromental pathogens (Streptococcus dysgalactiae).Discussion: This study showed that lactoferrin and immunoglobulin G concentrations are higher in milk samples from subclinical mastitic cows than in milk from normal lactating cows. Lactoferrin concentrations in milk samples from udder quarters infected with major mastitis pathogens were significantly higher than in milk infected with minor mastitis pathogens. The lowest concentration of immunoglobulin G was detected in milk samples where Staphylococcus aureus was isolated, while the highest immunoglobulin G concentration was observed in milk samples from quarters infected with minor mastitis pathogens. Lactoferrin and immunoglobulin G concentrations were significantly and positively correlated in all milk samples. This means that cows with high lactoferrin concentrations have high immunoglobulin G concentrations. In quarter milk samples infected with Staphylococcus aureus, lactoferrin and immunoglobulin G concentrations were negatively correlated. The cause of these findings could be the suppression of local immune response of mammary gland.

Effect of Hoof Trimming on Milk Yield in Dairy Cows with Foot Disease

Backround: Milk is produced at the cost of other metabolic processes in the body and high milk yield has been associated with lameness and claw lesions. Lameness has also been associated with a decrease in milk yield. In the past, claw disorders and lameness in dairy cattle have been an increasing problem of the modern dairy industry. Hoof trimming is performed to prevent hoof lesions and improve gait by correction and maintenance of the hoof symmetry and shape. Lameness caused by hoof disorders can be treated by correct hoof trimming. The aim of this study was to test the hypothesis that one-time claw trimming affect the milk production in dairy cattle with hoof disorders on commercial dairy farms.Materials, Methods &amp; Results: Milk yield level was examined before and after claw trimming in dairy cattle. Eighteen Holstein dairy cows were examined on a commercial dairy farm. Calving number, calving time, lactation number, lactation stage, culling date and milk yield in liters were detected from farm recording system. All cows were visual signs of claw disorders or lameness. Their hooves had not been were trimmed for several years. Trimming technique included leveling the 2 claws, aiming for symmetric bulbs. The axial and abaxial walls were both intended to be parts of the bearing surface and the 2 claws were trimmed flat and balanced with each other. The caudal two-thirds of the axial sole of both claws were sloped toward the interdigital area. All of the cows checked for hoof diseases. The period of observation spanned 45 d, starting day of claw trimming. The observation period was the lactation when the claw trimming was performed. Milk yield was performed one day before and 10, 30, and 45 days after hoof trimming. Cows that were in the mid to late lactation period were selected for the study. The mean days in milk for the group was 221.8 (150-272 days) and the mean number of calvings was 2.8 times (range: 2-5 times) before trimming.Discussion: The shape of the lactation curve is influenced by herd factors such as management and nutrition and individual factors like genetics, parity, and disease. Discrepancies in the literature with regard to the effect of lameness and claw lesions on milk yield are partly the result of these complex influences. Daily milk production of cows in the current study averaged 21 L/d, so milk weight represented approximately 3% of a cow’s body weight per milking. In this study cows were 2 to 5th lactation. Most hoof diseases are accrued around the time of calving. Hoof diseases is becomed visible on the bearing surface of the sole after 2 to 3 months such as white-line disease, sole ulcer, and hemorrhages. We assessed milk yield as the one time claw trimming performed, so any possible healing effect of claw trimming could have led to an underestimation of any negative effects of bad claw health on milk production. Cows with painful claw lesions eat less, are more reluctant to move, and might consequently produce less milk than cows without claw lesions. The significant associations between most claw disorders and increased yield in this study do not prove direct relationships. At claw trimming, the average lactation stage in first parity was 148 DIM; 25% of the cows were before 74 DIM and 25% were later than 226 DIM. After the claw trimming between days 10-30 and 10-45 were determined differences in milk yield (P &lt; 0.05; P &lt; 0.01). In conclusion, this study showed that one time hoof trimming during the lactation period changed the milk yield of the dairy cows with hoof diseases.

Impact of Supplementing Propylene Glycol and Calcium Propionate to Primiparous Buffalo Cows During the Late Gestation and Early Lactation Period on Reproductive Performance and Metabolic Parameters

Eighteen primiparous Egyptian buffalo cows (Bubalus bubalis) at late pregnancy (last 8 weeks of gestation) with an average live body weight of 500±25 kg and aged 35±5 months were used to assess the effect of supplementation propylene glycol (PG) and calcium propionate (CP) as a source of energy on some productive traits of Primiparous dams and some metabolic parameters related to fertility. Animals were divided into three similar groups (6/each) based on live body weight (LBW), body condition scores (BCS), expected calving date. The experimental animal in the 1st group control (C), were drenched 3 liters of saline solution (Nacl 0.9%) without any other supplementation, while in the 2nd group (PG) were drenched 300 ml of propylene glycol dissolved in 3 liters of a saline solution and in the 3rd group (CP), animals supplemented with 335g of calcium propionate dissolved in 3 liters of a saline solution. All treatments were administered through esophagus via esophagus feeder tube twice/weekly throughout the experimental period. Animals were fed individually allowances of concentrate feed mixture (CFM), berseem hay and rice straw which were adjusted according to the physiological and productive stage according to N.R.C (1988). Live body weight of Primiparous buffaloes and their calves at birth, Drop of fetal membranes (hour), First estrus post-partum (day), the interval from calving to first estrus were recorded. Number of service per conception, days open, calving interval and frequency distribution (%) were also calculated. Blood samples were collected from all buffalo cows for measuring non-esterified fatty acids (NEFA), blood urea nitrogen (BUN), glucose and Insulin concentration. Supplementation of (PG) and (CP) treatment revealed significant differences on live body weights, reproductive parameters as first estrus post partum, days open and number of service per conception and blood metabolites as NEFA, BUN and glucose concentration. In brief supplementation of (PG) and (CP) treatment during transition period to primiparous buffalo cows had a great impact on reproductive performance and some metabolic parameters related to fertility.

PERFORMANCE AND SOME RUMEN AND BLOOD PARAMETERS OF BALADI COWS FED RATIONS SUPPLEMENTED WITH PRODUCTIVE CHAMOMILE FLOWERS DURING LATE PREGNANCY AND LACTATING PERIODS.

This research was conducted to evaluate effects of two levels of chamomile flowers to the rations of baladi cows on their milk production, feed conversion and feeding values as well as some rumen and blood parameters. A total of 18 cows with average live body weight of 401.00 kg and 2-7 parities, were used in this study. Animals were divided into three groups ( 6 in each group) and fed diets according to NRC (1988) recommendation that contained 0, 5 and 10 g chamomile / 100 kg BW / day. The animals were in the late pregnancy period and continued for 4 months after calving. In addition, 9 Zaraibi bucks were used to evaluate the feeding values of the tested rations, and some rumen liquor parameters . The results showed that the digestion coefficients of all nutrients and feeding values were improved with increasing the level of chamomile ( 0, 5 and 10 g / 100 kg BW / day) in the rations (G1, G2 and G3, respectively) and the differences were significantly in digestibility of DM, CF and CP as well as TDN and DCP %. The results of rumen parameters of Zaraibi bucks showed that pH value and ammonia-N were not significantly different among the groups. But, addition of chamomile had significantly increased total volatile fatty acids (TVFA's) concentrations at 4 hr post-feeding in rumen fluied of bucks. The highest values of protozoa count and microbial protein at 4 hr were recorded with G3 (0.840 and 0.685, respectively) and the lowest values were recorded with G1 ( 0.770 and 0.580, respectively). Concerning biochemical parameters, the results indicated that most tested constituents of blood were not significantly affected by the tested experimental rations during the late pregnancy and lactation periods. Serum globulin was increased while ALT enzyme were reduced as a result of adding chamomile especially with the high level (G3). Daily milk yield was increased by 5.81 and 9.42 % for G2 ( 9.10 kg) and G3 (9.41 kg) compared with the control ( 8.60 kg). However, milk composition was not significantly affected by both of the two levels of chamomile. But, yields of fat and protein as g/d were significantly increased ( p< 0.05) by the high chamomile level. The feed conversion based on DM was improved by about 6.0 and 8.5 % as a result of using chamomile in G2 and G3, respectively compared to G1. A similar trend was noticed when feed efficiency was based on TDN where the best was G3 ( 0.752 ) followed by G2 ( 0.767) and lowest the control group ( 0.794). Accordingly, it could be concluded that using chamomile in baladi cows rations had positive effects not only in improving milk yield, but also in improving feed utilization without any adverse effects on milk composition and blood metabolic parameters.

Dromedary milk exosomes as mammary transcriptome nano-vehicle: Their isolation, vesicular and phospholipidomic characterizations

Exosomes are extracellular nanovesicles that play a role in cellular trafficking and communication. Camel milk exosomes might carry the potential of recovery of several illnesses that coins the dromedary milk. This study shows for the first time their isolation and fine characterization. The differential ultracentrifugation was used for their isolation. Their recovery from dromedary milk during different lactation periods was evaluated. The vesicular characterization and stability testing of the recovered exosome were examined by transmission electron microscopy (TEM). The proteome footprinting was resolved by gel electrophoresis prior to their specific protein biomarker analysis. The immunoblotting of their specific protein biomarker TSG101 unexpectedly revealed a truncated 35KDa protein specific for dromedary milk exosome rather than the previously reported 43KDa mammalian one. The reversed-phase HPLC screening of their phospholipid makeup was compared with that of cattle milk exosomes at different lactation periods. Since dromedary milk exosomes reflect their mammary transcriptome outcome, further assessment of their content of αs1casein, αs2casein β-casein κ-casein mRNAs parallel with a constitutive glyceraldehyde dehydrogenase (GAPD) gene was performed using real-time PCR. The TEM scanning indicated that dromedary milk exosomes are freeze-stress unstable homogeneous with average size of 30nm. There was no significant difference in expression level of different casein genes in mid lactation period in dromedary milk exosomes over late lactation period. The phospholipidomic survey proved that phosphatidylcholine is the major candidate of the examined phospholipids in dromedary milk exosomes. The obtained data give novel interpretation about the content of camel milk exosomes with possible insight for use as potentially-safe nano carrier.

Ruminal Bacterial Community Composition in Dairy Cows Is Dynamic over the Course of Two Lactations and Correlates with Feed Efficiency.

Fourteen Holstein cows of similar ages were monitored through their first two lactation cycles, during which ruminal solids and liquids, milk samples, production data, and feed consumption data were collected for each cow during early (76 to 82 days in milk [DIM]), middle (151 to 157 DIM), and late (251 to 257 DIM) lactation periods. The bacterial community of each ruminal sample was determined by sequencing the region from V6 to V8 of the 16S rRNA gene using 454 pyrosequencing. Gross feed efficiency (GFE) for each cow was calculated by dividing her energy-corrected milk by dry matter intake (ECM/DMI) for each period of both lactation cycles. Four pairs of cows were identified that differed in milk production efficiency, as defined by residual feed intake (RFI), at the same level of ECM production. The most abundant phyla detected for all cows were Bacteroidetes (49.42%), Firmicutes (39.32%), Proteobacteria (5.67%), and Tenericutes (2.17%), and the most abundant genera included Prevotella (40.15%), Butyrivibrio (2.38%), Ruminococcus (2.35%), Coprococcus (2.29%), and Succiniclasticum (2.28%). The bacterial microbiota between the first and second lactation cycles were highly similar, but with a significant correlation between total community composition by ruminal phase and specific bacteria whose relative sequence abundances displayed significant positive or negative correlation with GFE or RFI. These data suggest that the ruminal bacterial community is dynamic in terms of membership and diversity and that specific members are associated with high and low milk production efficiency over two lactation cycles.

Blood Malondialdehyde, Reproductive, and Lactation Performances of Ewes Fed High PUFA Rations Supplemented with Different Antioxidant Sources

The aims of this study were to evaluate the effect of vitamin E (vit E) and black tea extract (BTE) as antioxidant sources in high poly-unsaturated fatty acid (PUFA) rations on blood malondialdehyde (MDA) concentrations and the performance of reproduction and lactation of Garut ewes. Twelve ewes on late pregnancy periods were divided into completely randomized design (CRD) with 3 treatments and 4 replicates. The treatments were control: basal diet without antioxidant, vit E: basal diet supplemented with vit E, and BTE: basal diet supplemented with BTE. The results showed that vit E and BTE supplementation did not affect blood MDA concentration of ewes on late pregnancy, lactation periods, and weaning periods. Antioxidant sources supplementation had no effect on ewe’s nutrient intake, pre-lambing live weight change (LWC), and post-lambing average daily gain (ADG). Vit E supplementation had decreased the milk production, but both of antioxidant sources give positive effect on the milk composition. Nevertheless, the supplementation of vit E and BTE increased the twin type of birth. The vit E supplementation resulted higher lambing rate than BTE, although it had the highest mortality rate of twin lamb. BTE also had better lamb weaning weight than vit E. BTE and vit E gave similar results in ewes productivity on lactation period. In conclusion, this study confirmed that BTE was more effective used as antioxidant source than vit E to prevent the oxidative reaction of PUFA. Vit E supplementation on high PUFA ration reduced ewes milk production but it had similar reproduction performance with BTE. Key words: antioxidant, black tea extract, ewes, lactation, reproduction, vitamin E

Expression Analysis of Solute Carrier (SLC2A) Genes in Milk Derived Mammary Epithelial Cells during Different Stages of Lactation in Sahiwal (Bos indicus) Cows

Solute carriers (SLC2A/ GLUT) are one of the major types of transporter superfamily that have been predominantly involved in active transport of glucose across the plasma membrane. Glucose uptake by mammary epithelial cells (MECs) is an important step in the milk synthesis during lactation, and hence directly influences the milk yield. Use of MEC isolated from milk has been speculated to be a good alternative to mammary gland tissues in order to understand the expression profile of important genes associated with lactation, in particular large dairy animals where obtaining biopsies is sometimes difficult. The present study was therefore undertaken in milk purified MECs to assess relative mRNA expression of major solute carriers/glucose transporters (SLC2A/GLUTs) viz., SLC2A1(GLUT1), SLC2A(GLUT4), SLC2A8(GLUT8), SLC2A12(GLUT12) and hexokinase (HK2) genes during; early(10-20 days), peak (30-50 days), mid (100-140 days) and late (215-245 days) lactation stages of Sahiwal cows. MECs were isolated from fresh milk, using Dyna Beads coated with anticytokeratin 18 antibodies. For normalization of qPCR expression data, 10 known housekeeping genes (HKGs) from different functional classes were evaluated. A panel of four best stable HKGs; eukaryotic translation elongation factor 1 alpha (EEF1A1), ribosomal protein L4(RPL4), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin-beta (ACTB) were identified through ge Norm, Norm Finder and Best Keeper analysis. Expression level of SLC2A1 was significantly (P<0.05) higher during peak/mid lactation period as compared to late lactation period. Similarly, SLC2A8 mRNA expression was relatively higher during mid-lactation stages than other stages of lactation. In contrast, SLC2A4 expression level was relatively higher during the late lactation stages. The SLC2A12 mRNA on the other hand was undetectable, indicating its expression to be either very low or absent in MEC of Sahiwal cows. Our expression data indicated SLC2A1, SLC2A4 and SLC2A8 to be the major solute carriers in Sahiwal MEC. Further, HK2 expression was significantly (P<0.05) higher during early and mid-lactation stages. The stage specific expression about of major SLC2A/GLUT and HK2 genes indicate their functional role in regulating glucose uptake in MECs of Sahiwal cows.