Lactating Holstein Friesian Cows Research Articles

Latitude and seasons influence the prevalence of Theileria orientalis and affect the hematology of non-grazed dairy cows in Korea.

This pilot study aimed to investigate the effects of regional and seasonal variations on the prevalence of Theileria orientalis and the hematological profile of non-grazed dairy cows in Korea. A total of 365 clinically healthy lactating Holstein Friesian cows from 26 dairy farms in 7 provinces that were categorized into northern, central, and southern regions were sampled during the warm period from July to August and the cold period from October to December. The detection of T. orientalis major piroplasm surface protein gene and the hematology non-grazed dairy cows were analyzed using peripheral blood samples. The T. orientalis prevalence was 20.0% (73/365). The prevalence in the southern region was 35.9%, which was significantly higher than that in the central (21.6%) and northern (12.9%) regions (P < 0.05). The prevalence during warm period was higher (43.0%) than that during the cold season (13.5%). The infected cows showed significantly lower erythrocyte counts in the southern region (5.8 ± 0.6 M/µl) and during the warm period (5.8 ± 0.7 M/µl) compared with those in the central and northern regions and during the cold season, which affected the extended RBC parameters, including hematocrit and hemoglobin concentrations. Our findings revealed the prevalence of T. orientalis in Korea, highlighting its high occurrence during warm periods and in certain geographical regions. Climatic factors could contribute to the health and productivity of cattle, as evidenced by the prevalence of T. orientalis and its negative impact on animals.

Dairy Cows Offered Fresh Chicory Instead of Ensiled Pasture during an Acute Heat Challenge Produced More Milk and Had Lower Body Temperatures.

The frequency, duration, and intensity of heat waves in Australia are increasing. To reduce the impact of heat waves on milk production, novel management strategies are required. Altering the forage type and amount offered affect the heat load on dairy cows and offer potential strategies to ameliorate the effects of hot weather. Thirty-two multiparous, lactating Holstein-Friesian cows were assigned one of four dietary treatments: chicory high amount, chicory low amount, pasture silage high amount, or pasture silage low amount. These cows were exposed to a heat wave in controlled-environment chambers. Cows that were offered fresh chicory had similar feed intake to cows that were offered pasture silage (15.3 kg DM/d). However, cows that were offered chicory produced greater energy-corrected milk (21.9 vs. 17.2 kg/d) and had a lower maximum body temperature (39.4 vs. 39.6 °C) than cows that were offered pasture silage overall. Cows that were offered the high amount of forage had greater feed intake (16.5 vs. 14.1 kg DM/d) and energy corrected milk yield (20.0 vs. 17.9 kg/d) than cows that were offered the low amount, as intended, but with no difference in maximum body temperature (39.5 °C). We conclude that feeding chicory instead of pasture silage to dairy cows shows promise as a dietary strategy to ameliorate the effect of heat exposure, and there was no advantage in restricting feed amount.

Biorefined press cake silage as feed source for dairy cows: effect on milk production and composition, rumen fermentation, nitrogen and phosphorus excretion and in vitro methane production

The objective of this study is to investigate the effect of replacing grass silage with biorefined grass silage (press cake silage) on dry matter intake (DMI), milk production and composition, rumen fermentation parameters, nitrogen and phosphorus excretion of early lactation Holstein Friesian dairy cows. An in vitro experiment using the rumen simulation technique (RUSITEC) also investigated the in vitro dry matter disappearance and methane (CH₄) production of these feedstuffs. In this study, press cake silage was made from perennial ryegrass (Lolium perenne) using a novel biorefining process. Thirty early-lactation cows (Bos taurus strain Holstein Friesian) were used in a randomized complete block design experiment (n = 15) and offered two dietary treatments for a 56 d period: Grass silage (GS): 14 kg dry matter (DM) grass silage + 7.2 kg DM of concentrate + 0.44 kg DM of soyabean meal; Press cake (PC): 5 kg DM grass silage + 9 kg DM press cake silage + 7.2 kg DM concentrate + 0.44 kg DM soyabean meal. The dietary treatments were also incubated in vitro for a period of 18 days using the RUSITEC. In the in vivo study, DMI was lower for PC compared to GS. No difference was observed between the treatments for milk yield and milk quality; however, milk fat yield was lower and milk solids yield tended to be lower in PC compared to GS. Cows offered PC had higher N use efficiency (NUE, milk N/N intake), lower total N excretion and lower N excretion in feces and urine compared to cows offered GS. Total and fecal P excretion was lower in cows fed PC compared to cows fed GS. Ruminal NH₃-N concentration was lower when PC was offered. In vitro rumen fermentation parameters such as pH, volatile fatty acids and CH₄ output were not affected by treatment. In vitro dry matter disappearance and NH₃-N concentration were lower for PC compared to GS. This study suggests that press cake silage can partially replace grass silage in the diet of dairy cows with beneficial effects on the environment and without compromising animal productivity.

Sprinkler flow rate affects physiological, behavioural and production responses of Holstein cows during heat stress

Holstein Friesian cows are known for their high milk yield. They are popular in the commercial dairy sector of Pakistan. Heat stress is a major challenge for these animals owing to the longer summer season with high ambient temperatures (35 - 40 °C) and relative humidity (30 - 50%) in the area (Butt et al., 2020). Mitigating the effects of heat stress requires substantial investments in energy and water. Spraying dairy cows with water in the holding pen or at the feed bunk is common practice as it lowers body temperature and respiration rate (Kendall et al., 2007; Chen et al., 2013; 2016), and improves feed intake and milk yield (Keister et al., 2002). Owing to the recent decrease in global groundwater, studies have focused on strategies to reduce the use of water to cool dairy cows (Chen et al., 2016). Sprinkler flow rates of 1.3 and 4.9 L/min had similar effects on physiological responses of cows to heat load but produced a 73% difference in water use (Chen et al., 2016). Similarly, Tresoldi et al. (2019) concluded that a sprinkler flow rate of 4.9 L/min had poor efficiency compared with 3.3 L/min, as the additional water did not result in increased biologically relevant cooling. These studies were conducted in Mediterranean climates with an average temperature humidity index in the range of 76 to 78. A recent study with Nili Ravi buffaloes revealed a sprinkler flow rate 1.25 L/min was more efficient than one of 2.0 L/min during subtropical summers (Bah et al., 2021). Because water is projected to be scarce in Pakistan by 2030 (Mustafa et al., 2013), holistic strategies for water conservation in the dairy sector are important nationally. The objective of this study was to evaluate the effects of various sprinkler flow rates on the performance of lactating Holstein Friesian cows in a typical corporate dairy farm setting during the subtropical summer. Performance of these cows was assumed to be similar, irrespective of the sprinkler flow rates.

Effect of a Blend of Essential Oils, Bioflavonoids and Tannins on In Vitro Methane Production and In Vivo Production Efficiency in Dairy Cows.

Simple SummaryThe dairy system is facing many environmentally related issues, such as green-house gas emissions (GHG), as well as an increased demand for milk by the growing world population. Dairy cow farming must evolve towards more efficient and sustainable ways of production. Strategies to reduce ruminal methane emissions must be considered, due both to methane’s direct involvement in global warming and its negative relationship with productivity. Besides being the most important GHG arising from dairy cows, methane is also correlated with a loss of energy and a reduction in production efficiency that further worsen the environmental impact. The use of natural extracts, such as essential oils, bioflavonoids, and tannins may be useful to reduce methane production and to modulate the ruminal microbiota toward more efficient fermentation, increased feed efficiency and improved overall productivity.Two trials were performed to evaluate the efficacy of a blend of essential oils, bioflavonoids and tannins on methane (CH4) emissions (in vitro) and on the production efficiency of dairy cows (in vivo). The in vitro trial tested the production of total gas and CH4 at 16, 20 and 24 h of incubation, and volatile fatty acids (VFA) at 16 and 24 h, through biochemical methane potential (BMP) assays. In the in vivo trial, milk yield, dry matter intake (DMI), feed conversion rate (FCR), milk quality and apparent total tract digestibility (aTTD) were evaluated in 140 lactating Holstein Friesian cows. Animals were allocated into two groups: (i) Control, standard diet; (ii) Treatment, standard diet plus 10 g/head/d of a powder with a 10% concentration of a blend of essential oils, bioflavonoids and tannins. Statistical analysis was performed using the mixed procedure of SAS either for single or repeated measures. For all the parameters a p-value ≤ 0.05 was considered statistically significant. The blend significantly reduced the in vitro total gas and CH4 emissions at 16, 20 and 24 h of incubation (p < 0.001). In addition, acetic acid was reduced (p < 0.001), while propionic acid concentration was increased (p < 0.001) at 16 h and 24 h. In the in vivo trial, the Treatment group showed significantly raised milk yield, DMI, FCR (p < 0.001), and of the aTTD of cellulose and starch (p ≤ 0.002), while the milk quality traits were not affected. Overall, the results from the study indicated that the blend of essential oils, bioflavonoids, and tannins significantly reduced in vitro total gas and CH4 production and improved the production efficiency of lactating dairy cows in vivo.

Grape seed tannin extract and polyunsaturated fatty acids affect in vitro ruminal fermentation and methane production.

Condensed tannins (CT), one of the most ubiquitous compounds in the plant kingdom, can modulate ruminal nutrient metabolism. Objectives were to study potential interactions of CT and polyunsaturated fatty acids (PUFA) on ruminal fermentation, biohydrogenation (BH), and methane production. Ruminal fluid obtained from lactating Holstein Friesian cows was used. All experiments were carried out as a completely randomized design with the same mixed diet: control (60:40 forage:concentrate) without supplement (CON), 2.5% soybean oil (SBO), and SBO + grape seed tannin extract (GSTE) at 0.2%, 0.4%, 0.6%, or 0.8% dietary DM (ST0.2, ST0.4, ST0.6, and ST0.8, respectively). Compared with CON (84.7mM), total VFA concentration was not affected by SBO, but decreased (P < 0.001) with ST0.8 vs. ST0.6 (75.3 vs. 78.3mM). Relative to CON, methane production was depressed (P < 0.001) by 17.7% and 28.0% in ST0.4 and ST0.8. The highest (P < 0.001) mean concentrations of c9,t11 CLA and C18:1 t11 were observed with ST0.4 compared with CON, but there was no difference between SBO and CT-containing diets. Disappearance of C18:2 c9,c12 was 49.1% vs. 50.3% in CON vs. SBO, whereas it ranged from 39.9% to 46.3% in CT-containing diets after 2h incubation (P < 0.001). Concentrations of c9,t11 CLA with supplemental SBO and ST0.8 nearly peaked (P < 0.001) at 2h incubation, but this fatty acid peaked (P > 0.05) at 6h incubation and remained higher (P < 0.001; 15.9-17.0 µg/mL) at 24h incubation with ST0.2, ST0.4, and ST0.6 compared with other diets (13.5-14.5 µg/mL). Compared with CON (50.6 µg/mL), concentration of C18:1 t11 with SBO and CT-containing diets reached a peak (P < 0.001; 241-265 µg/mL) at 12h incubation. Concentration of C18:0 was 171%-231% higher (P < 0.001) with SBO and CT relative to CON at 24h incubation. Overall, these results demonstrated that PUFA in SBO are more effective in modulating ruminal BH and CH4 production when combined with CT. However, high doses of added CT can reduce ruminal VFA concentration. Thus, a level of 0.4% GSTE added to diets containing 2.5% PUFA from plant origin might be suitable for optimizing ruminal fermentation and BH of C18:2 c9,c12 to fatty acid intermediates that could have beneficial effects to human health.

Mangosteen Peel Liquid-Protected Soybean Meal Can Shift Rumen Microbiome and Rumen Fermentation End-Products in Lactating Crossbred Holstein Friesian Cows.

Rumen bypass protein can enhance protein availability in the lower gut. This study investigated the use of liquid-containing phytonutrients in dairy cows as a dietary additives to reduce rumen protein degradation. Four crossbred lactating Holstein Friesian cows (75% Holstein Friesian with 25% Thai native breed) with an initial body weight (BW) of 410 ± 20 kg were randomly assigned to a 2 × 2 factorial arrangement [two crude protein (CP) levels with soybean meal (SBM) or mangosteen peel liquid-protected soybean meal (MPLP)-SBM] in a 4 × 4 Latin square design experiment. Dietary treatments were as follows: T1 = SBM in low crude protein concentrate (LPC) (SBM-LPC); T2 = MPLP-SBM in LPC (MPLP-SBM-LPC); T3 = SBM in high crude protein concentrate (HPC) (SBM-HPC); T4 = MPLP-SBM in HPC (MPLP-SBM-HPC). Apparent digestibilities of organic matter (OM) and neutral detergent fiber (aNDF) were increased (p < 0.05) by CP level in the HPC diet (19% CP), with higher OM and aNDF digestibilities. High crude protein concentrate increased (p < 0.05) the propionic acid in the rumen but reduced (p < 0.05) the acetic acid-to-propionic acid ratio and methane (CH4) production. Rumen microbial populations of the total bacteria, Fibrobacter succinogenes and Butyrivibrio fibrisolvens were increased (p < 0.05) by HPC. Real-time PCR revealed a 30.6% reduction of rumen methanogens by the MPLP-SBM in HPC. Furthermore, efficiency of microbial nitrogen synthesis (EMNS) was 15.8% increased (p < 0.05) by the MPLP-SBM in HPC when compared to SBM-LPC. Milk yield and milk composition protein content were enhanced (p < 0.05) by both the CP level in concentrate and by MPLP inclusion. In this experiment, a high level of CP and the MPLP-SBM enhanced the ruminal propionate, shifted rumen microbiome, and enhanced milk yield and compositions.

The relationship between milk oestradiol concentrations and oestrus activity in lactating Holstein–Friesian cows

Context Detecting oestrus to facilitate the optimal timing of artificial insemination is key to optimal reproductive performance in dairy cows. Aims The aims of the present study were to investigate the relationship between activity and milk oestradiol concentrations during oestrus. Methods Accelerometers (IceQubes, IceRobotics Ltd, UK) were used to monitor the activity (the number of steps per day) of 37 lactating Holstein–Friesian cows during the peri-oestrus period. Daily milk samples were analysed for oestradiol and progesterone concentrations. Key results An increase in activity sufficient to generate an oestrus alert (behavioural oestrus) from an activity sensor (GEA Rescounter II) was detected in 29 of 37 (78%) cows. Milk oestradiol increased from 2.0 ± 0.5 pg/mL 4 days before oestrus to 8.3 ± 1.1 pg/mL on the day of behavioural oestrus, then fell to 2.6 ± 0.6 pg/mL by 3 days afterwards. Similarly, activity also increased and peaked on the day of oestrus. However, in 8 of 37 (22%) cows, although milk oestradiol concentrations increased following the fall in progesterone, there was no significant increase in activity (silent oestrus). Milk oestradiol concentrations were positively correlated (r = 0.37; P = 0.03) with activity on the day of oestrus. Cows that subsequently became pregnant took a similar number of steps (2806 ± 282.3 vs 2850 ± 372.5 steps for PD+ vs PD− cows respectively) but had higher oestradiol concentrations (11.2 ± 2.06 vs 5.1 ± 0.51 pg/mL for PD+ vs PD− cows respectively) on the day of oestrus than did cows that did not become pregnant. Conclusions Increases in oestradiol concentrations above a threshold of approximately 10 pg/mL are associated with an increased activity, and higher oestral oestradiol concentrations are associated with a higher rate of pregnancy following insemination. Implications This study has demonstrated the significance of oestradiol concentration to the fertility of dairy cows. Thus, strategies to enhance oestradiol secretion may enhance fertility. Further, milk oestradiol measures may be developed as an aid to oestrus detection in lactating dairy cows, although further studies are required to determine whether on-farm assessment of milk oestradiol concentration can be developed to add to the repertoire of biomarkers of oestrus in lactating cattle.

Are subjectively scored linear type traits suitable predictors of the genetic merit for feed intake in grazing Holstein-Friesian dairy cows?

Measuring dry matter intake (DMI) in grazing dairy cows using currently available techniques is invasive, time consuming, and expensive. An alternative to directly measuring DMI for use in genetic evaluations is to identify a set of readily available animal features that can be used in a multitrait genetic evaluation for DMI. The objectives of the present study were thus to estimate the genetic correlations between readily available body-related linear type traits and DMI in grazing lactating Holstein-Friesian cows, but importantly also estimate the partial genetic correlations between these linear traits and DMI, after adjusting for differences in genetic merit for body weight. Also of interest was whether the predictive ability derived from the estimated genetic correlations materialized upon validation. After edits, a total of 8,055 test-day records of DMI, body weight, and milk yield from 1,331 Holstein-Friesian cows were available, as were chest width, body depth, and stature from 47,141 first lactation Holstein-Friesian cows. In addition to considering the routinely recorded linear type traits individually, novel composite traits were defined as the product of the linear type traits as an approximation of rumen volume. All linear type traits were moderately heritable, with heritability estimates ranging from 0.27 (standard error = 0.14) to 0.49 (standard error = 0.15); furthermore, all linear type traits were genetically correlated (0.29 to 0.63, standard error 0.14 to 0.12) with DMI. The genetic correlations between the individual linear type traits and DMI, when adjusted for genetic differences in body weight, varied from -0.51 (stature) to 0.48 (chest width). These genetic correlations between DMI and linear type traits suggest linear type traits may be useful predictors of DMI, even when body weight information is available. Nonetheless, estimated genetic merit of DMI derived from a multitrait genetic evaluation of linear type traits did not correlate strongly with actual DMI in a set of validation animals; the benefit was even less if body weight data were also available.

The Association of Calcium Profiles at Calving with Health and Performance of Holstein Cows and Their Calves

The aim of this study was to assess the association of hypocalcemia at calving with health and performance of Holstein cows and their calves. Data were collected January 1st 2017 to December 31st 2020. A total of 431 lactating Holstein Friesian cows (118 primiparous and 313 multiparous) from a research of hypocalcemia was 2 groups (hypo and non-hypo). The overall prevalence of hypocalcemia was 3.4% for first-lactation cows and 18% for multiparous cows. Lactating dairy cows with hypocalcemia had greater proportion of cows with Retained Fetal Membranes (RFM) metritis and culling within 60 days in milk (DIM), compared with non-hypocalcemia respectively. For the first 2 official milk tests milk yield and components (% fat, % protein on SCC) did not differ between hypo and non-hypo cows. The days in milk at first service, mastitis, dystocia and pregnancy at first service were not different between hypo and non-hypo groups. The proportion of stillbirth, survival at 60 days of age in calves did not differ between calves born from hypo or non-hypo cows. Calves born from Hypo cows had greater incidence of diarrhea (38.3%) than calves born (22.3%) from non-hypo cows. The results of this study show that hypocalcemia in calving has significant health implications for both dams and their calves.&#x0D;

118. Dietary starch concentration influences milk protein via the phenylalanine and tyrosine metabolism in early lactation Holstein Friesian dairy cows

118. Dietary starch concentration influences milk protein via the phenylalanine and tyrosine metabolism in early lactation Holstein Friesian dairy cows

3-Nitrooxypropanol decreases methane emissions and increases hydrogen emissions of early lactation dairy cows, with associated changes in nutrient digestibility and energy metabolism

The aim of this study was to determine the methane (CH4) mitigation potential of 3-nitrooxypropanol and the persistency of its effect when fed to dairy cows in early lactation. Sixteen Holstein-Friesian cows (all multiparous; 11 cows in their second parity and 5 cows in their third parity) were blocked in pairs, based on actual calving date, parity, and previous lactation milk yield, and randomly allocated to 1 of 2 dietary treatments: a diet including 51 mg of 3-nitrooxypropanol/kg of dry matter (3-NOP) and a diet including a placebo at the same concentration (CON). Cows were fed a 35% grass silage, 25% corn silage, and 40% concentrate (on dry matter basis) diet from 3 d after calving up to 115 d in milk (DIM). Every 4 weeks, the cows were housed in climate respiration chambers for 5 d to measure lactation performance, feed and nutrient intake, apparent total-tract digestibility of nutrients, energy and N metabolism, and gaseous exchange (4 chamber visits per cow in total, representing 27, 55, 83, and 111 DIM). Feeding 3-NOP did not affect dry matter intake (DMI), milk yield, milk component yield, or feed efficiency. These variables were affected by stage of lactation, following the expected pattern of advanced lactation. Feeding 3-NOP did not affect CH4 production (g/d) at 27 and 83 DIM, but decreased CH4 production at 55 and 111 DIM by an average of 18.5%. This response in CH4 production is most likely due to the differences observed in feed intake across the different stages of lactation because CH4 yield (g/kg of DMI) was lower (on average 16%) at each stage of lactation upon feeding 3-NOP. On average, feeding 3-NOP increased H2 production and intensity 12-fold; with the control diet, H2 yield did not differ between the different stages of lactation, whereas with the 3-NOP treatment H2 yield decreased from 0.429 g/kg of DMI at 27 DIM to 0.387 g/kg of DMI at 111 DIM. The apparent total-tract digestibility of dry matter, organic matter, neutral detergent fiber, and gross energy was greater for the 3-NOP treatment. In comparison to the control treatment, 3-NOP did not affect energy and N balance, except for a greater metabolizable energy intake to gross energy intake ratio (65.4 and 63.7%, respectively) and a greater body weight gain (average 0.90 and 0.01% body weight change, respectively). In conclusion, feeding 3-NOP is an effective strategy to decrease CH4 emissions (while increasing H2 emission) in early lactation Holstein-Friesian cows with positive effects on apparent total-tract digestibility of nutrients.

Heat Stress Impacts on Lactating Cows Grazing Australian Summer Pastures on an Automatic Robotic Dairy.

Simple SummaryHeat stress (HS) is a major challenge for sustainable livestock production, which compromises animal welfare and performance during the hot summer months, leading to multibillion-dollar losses to the global livestock industries. In this study, we investigated the effect of summer heat events on lactating Holstein Friesian cows at the Robotic milking farm of the University of Melbourne in Victoria, Australia. We followed the cows during the entire summer period (December 2018–February 2019) and measured the effect of high temperature and humidity on physiological variables such as respiratory rate, panting scores and body temperature. All these parameters were significantly affected by high-temperature-humidity conditions with a significant drop in milk production. Most cows stopped grazing, sought shade, panted and spent more time at the watering points. These indicate that lactating dairy cows grazing summer pastures experience severe HS, compromising their welfare and leading to some changes in behaviour such as suspension of grazing and jumping into water troughs. However, the quantum of production losses, though significant, can be reduced by the provision of shade and water for the cows to cool down, as was observed in this study where the production losses were lower than previously reported in heat stress studies.The objective of this study was to measure the impacts of summer heat events on physiological parameters (body temperature, respiratory rate and panting scores), grazing behaviour and production parameters of lactating Holstein Friesian cows managed on an Automated Robotic Dairy during Australian summer. The severity of heat stress was measured using Temperature-Humidity Index (THI) and impacts of different THIs—low (≤72), moderate (73–82) and high (≥83)—on physiological responses and production performance were measured. There was a highly significant (p ≤ 0.01) effect of THI on respiratory rate (66.7, 84.7 and 109.1/min), panting scores (1.4, 1.9 and 2.3) and average body temperature of cows (38.4, 39.4 and 41.5 °C), which increased as THI increased from low to moderate to high over the summer. Average milk production parameters were also significantly (p ≤ 0.01) affected by THI, such that daily milk production dropped by 14% from low to high THI, milk temperature and fat% increased by 3%, whilst protein% increased by 2%. The lactation stage of cow had no significant effect on physiological parameters but affected (p ≤ 0.05) average daily milk yield and milk solids. Highly significant (p ≤ 0.01) positive correlations were obtained between THI and milk temperature, fat% and protein% whilst the reverse was observed between THI and milk yield, feed intake and rumination time. Under moderate and high THI, most cows sought shade, spent more time around watering points and showed signs of distress (excessive salivation and open mouth panting). In view of the expected future increase in the frequency and severity of heat events, additional strategies including selection and breeding for thermotolerance and dietary interventions to improve resilience of cows need to be pursued.

EFFECT OF ANAEROBIC PROBIOTIC AND/OR BIOLOGICAL ANTITOXIN SUPPLEMENTATIONS ON PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF LACTATING COWS

Forty-eight lactating Holstein Friesian cows were utilized to assess impact of supplementing probiotic ZAD (mixture of live bacterial cells and enzymes) compared with T5X (antitoxins product) on some productive, reproductive and antitoxins activity parameters. we have divided the animals to three experimental categories (16 each). The first category, control treatment, was fed basal diet without any supplements. The second category, ZAD treatment, was fed basal diet supplemented with ZAD probiotic (1.1 L/ton). The third category, T5X treatment, was fed basal diet supplemented with T5X antitoxins product (1.1 Kg/ton). Milk yield was recorded. we have collected and analyzed milk samples, blood samples and feed samples in order to constitutes. Time-interval between calving and fertilizing artificial insemination and pregnancy rate were recorded. The gained outcomes demonstrated that milk yield was significantly raised by ZAD treatment than other treatment. Milk components yield were significantly raised by ZAD probiotic and T5X treatments than control. Blood serum total protein, albumin, globulin, glucose, urea and total lipids were not significantly influenced by treatments. Total aflatoxins in concentrate mixture and aflatoxin M1 in milk were significantly diminished by ZAD and T5X than control. Number of days between calving and fertilized artificial insemination were diminished by treatments than control. Pregnancy rate was significantly raised by ZAD probiotic than T5X and control treatments, respectively. The overall conclusion of this study illustrated that Probiotic ZAD, potentially, has antitoxins activity leading to reinforcing the productive and reproductive performance of lactating cows.

Fatty acid profile of milk for determining reproductive status in lactating Holstein Friesian cows

Large percentages of dairy cows do not express behavioural signs of oestrus. Faecal and urine fatty acid concentrations increase during oestrus. The objective of the present study was to determine the milk FA profile of dairy cows during the oestrous and dioestrous periods and the relationship with behavioural signs on the day of oestrus. The activity of 32 Holstein Friesian cows was measured continuously using GEA Rescounter ll pedometers (GEA Farm Technologies, Düsseldorf, Germany) and IceQubes (IceRobotics Ltd., Edinburgh, UK). Milk samples were collected on the day of oestrus and on day 14 of the subsequent oestrous cycle and analysed for FA concentration using gas chromatography (GC) and milk composition was also determined. All cows were artificially inseminated within 12 h of the onset of oestrus. On the day of oestrus, the concentration of acetic acid (P < 0.001), valeric acid (P = 0.016), caproic acid (P < 0.001) and myristoleic (P = 0.035) were greater in milk compared to day 14. On day 14 milk arachidonic acid concentration, however, was greater (P = 0.004) compared to the day of oestrus. Also, on day 14 arachidonic acid concentration was greater (P = 0.002) in non-pregnant compared to pregnant cows. In conclusion, the results of this study indicate there are changes in the concentrations of some milk FA during oestrus and dioestrus in lactating dairy cows.

An Essential Oil Blend Decreases Methane Emissions and Increases Milk Yield in Dairy Cows

This study was conducted to investigate the effect of a commercial essential oil (EO) additive on milk production and methane (CH4) emissions from dairy cows. Early lactation Holstein-Friesian dairy cows were fed grass, whole crop wheat and corn silage total mixed ration. Cows were allocated to one of two experimental treatments: Control (no additive, CON) or 1 g/head/day of EO. Cows were housed in a free stall barn, split into two pens for the duration of the experiment. Two gas data loggers units used to measure CH4 emissions were provided per pen for the duration of the 22 week-long study. Milk yield was determined daily, and milk components were analyzed every two weeks. CH4 was recorded continuously, and daily values were tabulated. Body weight and body condition score were determined at the start and bi-weekly. Results were analyzed as a randomized complete block trial. In total, 149 cows participated in the study (76 CON, 73 EO). Milk yields were greater (P 0.05) by treatment. Yields of fat, protein, lactose, and solids were higher for EO fed cows (P < 0.05). CH4 output was reduced with the EO compared to the CON treatment (411 g/day vs 438 g/day; 13.8 g/L of milk vs 17.2 g/L of milk, P < 0.05) over the duration of the trial. There were no effects of treatment on reproductive performance or the occurrence of mastitis. Feeding EO to dairy cows reduced CH4 emissions whilst also increasing performance.

Immunological effects of altering the concentrate inclusion level in a grass silage-based diet for early lactation Holstein Friesian cows

Concentrate inclusion levels in dairy cow diets are often adjusted so that the milk yield responses remain economic. While changes in concentrate level on performance is well known, their impact on other biological parameters, including immune function, is less well understood. The objective of this study was to evaluate the effect of concentrate inclusion level in a grass silage-based mixed ration on immune function. Following calving 63 (45 multiparous and 18 primiparous) Holstein Friesian dairy cows were allocated to one of three isonitrogenous diets for the first 70 days of lactation. Diets comprised of a mixture of concentrates and grass silage, with concentrates comprising either a low (30%, LC), medium (50%, MC) or high (70%, HC) proportion of the diet on a dry matter (DM) basis. Daily DM intakes, milk yields and BW were recorded, along with weekly body condition score, milk composition and vaginal mucus scores. Blood biochemistry was measured using a chemistry analyzer, neutrophil phagocytic and oxidative burst assessed using commercial kits and flow cytometry, and interferon-γ production evaluated by ELISA after whole blood stimulation. Over the study period cows on HC had a higher total DM intake, milk yield, fat yield, protein yield, fat+protein yield, protein content, mean BW and mean daily energy balance, and a lower BW loss than cows on MC, whose respective values were higher than cows on LC. Cows on HC and MC had a lower serum non-esterified fatty acid concentration than cows on LC (0.37, 0.37 and 0.50 mmol/l, respectively, P=0.005, SED=0.032), while cows on HC had a lower serum β-hydroxybutyrate concentration than cows on MC and LC (0.42, 0.55 and 0.55 mmol/l, respectively, P=0.002, SED=0.03). Concentrate inclusion level had no effect on vaginal mucus scores. At week 3 postpartum, cows on HC tended to have a higher percentage of oxidative burst positive neutrophils than cows on LC (43.2% and 35.3%, respectively, P=0.078, SED=3.11), although at all other times concentrate inclusion level in the total mixed ration had no effect on neutrophil phagocytic or oxidative burst characteristics, or on interferon-γ production by pokeweed mitogen stimulated whole blood culture. This study demonstrates that for high yielding Holstein Friesian cows managed on a grass silage-based diet, concentrate inclusion levels in early lactation affects performance but has no effect on neutrophil or lymphocyte immune parameters.

Nutritional Evaluation of Various Stages of Maturity of Oat Hay and its Effect on Milk Production and Composition in Lactating Holstein Friesian Cows

Nutritional Evaluation of Various Stages of Maturity of Oat Hay and its Effect on Milk Production and Composition in Lactating Holstein Friesian Cows

Effect of exogenous estradiol Benzoate on uterine blood flow in postpartum dairy cows

The objective of this study was to assess the uterine blood flow following estradiol benzoate administration in Holstein-Friesian dairy cows by trans-rectal color Doppler ultrasonography. Six healthy lactating Holstein–Friesian cows were examined daily for 10 days starting at 4 weeks postpartum. All the cows, which were clinically healthy based on vaginal mucus scoring and endometrial cytology, were examined by trans-rectal Doppler ultrasonography to measure pulsatility index (PI), resistance index (RI), time average maximum velocity (TAMAX), blood flow volume (BFV) and diameter in the uterine arteries ipsilateral and contralateral to the previously pregnant uterine horn. On the third day of the experiment, the six cows were administered 10 mg intramuscular injection of estradiol-17β (E2).Blood samples were collected at the time of daily examination for the assessment ofE2concentrations.The PI and RI values decreased while TAMAX, BFV and diameter of uterine arteries increased in response toE2 administration (P < 0.05).There was a high correlation between both the ipsilateral and contralateral uterine arteries for all variables that were studied(r = 0.860, P < 0.0001, r = 0.922, P < 0.0001, r = 0.651, P < 0.0001, r = 0.879, P < 0.0001, r = 0.861, P < 0.0001 for the PI, RI, TAMAX, BFV and uterine arteries diameter, respectively).In conclusion, the greater blood concentrations ofE2may be responsible for the greater TAMAX, BFV, increased diameters and decreased PI and RI of the uterine arteries during the puerperium in dairy cows.

Replacing wheat with canola meal and maize grain in the diet of lactating dairy cows: Feed intake, milk production and cow condition responses.

This research paper describes the effect of partially replacing wheat with maize grain and canola meal on milk production and body condition changes in early lactation Holstein-Friesian dairy cows consuming a grass silage-based diet over an 83-d period. Two groups of 39 cows were stratified for age, parity, historical milk yield and days in milk (DIM), and offered one of two treatment diets. The first treatment (CON) reflected a typical diet used by Western Australian dairy producers in summer and comprised (kg DM/cow per d); 8 kg of annual ryegrass silage, 6 kg of crushed wheat (provided once daily in a mixed ration), 3·6 kg of crushed lupins (provided in the milking parlour in two daily portions) and ad libitum lucerne haylage. The second treatment diet (COMP) was identical except the 6 kg of crushed wheat was replaced by 6 kg of a more complex concentrate mix (27% crushed wheat, 34% maize grain and 37% canola meal). Lucerne haylage was provided independently in the paddock to all cows, and no pasture was available throughout the experiment. The COMP group had a greater mean overall daily intake (22·5 vs 20·4 kg DM/cow) and a higher energy corrected milk (ECM) yield (29·2 vs 27·1 kg/cow; P = 0·047) than the CON cows. The difference in overall intake was caused by a higher daily intake of lucerne haylage in COMP cows (4·5 vs 2·3 kg DM/cow). The CON group had a higher concentration of milk fat (42·1 vs 39·3 g/kg; P = 0·029) than COMP cows. Milk protein yield was greater in COMP cows (P < 0·021); however, milk fat yield was unaffected by treatment. It is concluded that partially replacing wheat with canola meal and maize grain in a grass silage-based diet increases voluntary DMI of conserved forage and consequently yields of ECM and milk protein.