Mean Milk Yield Research Articles

Association of Cow Drying off Practices with Milk Yield and Udder Health Outcomes in Peri-Urban Smallholder Dairy Herds

In peri-urban smallholder dairy herds, farmers face challenges in drying off cows due to a lack of evidence-based recommendations. This study examined the associations between cow drying-off practices, mean milk yield at drying off and during early successive lactation, and the odds of mastitis and udder leakage cases in herds around Nakuru city, Kenya. A cross-sectional survey of 232 cows across 172 herds was conducted. Mean milk yield was determined using a general linear model, while the odds ratios for mastitis and udder leakage were estimated using a binary logistic regression model, with drying-off practice, cow breed, and dairy management intensification as explanatory variables. All the three explanatory variables were significantly associated (p<0.05) with mean milk yield at drying off, early successive lactation, and the occurrence of mastitis and udder leakages. Cessation of milking (57.3%) was more common than abrupt cessation (42.7%). Mean milk yield was 2.6 liters/day at drying off and 13.4 liters/day during early successive lactation. Teat sealants were applied to cows producing more than 5 liters/day, while gradual reduction in milking, complete cessation of milking, or dry-cow therapy was used for cows producing less than 3 liters/day. During early successive lactation, cows dried off using teat sealant, salt application, stopping concentrate feeding, or gradual reduction in milking produced more milk (14 liters/day) than those dried off by abrupt cessation or dry-cow therapy (10-12 liters/day).Relative to abrupt cessation, the odds of mastitis and udder leakage were lower (p<0.05) with dry-cow therapy (odds ratio 0.12; 0.12), gradual cessation of milking (odds ratio 0.22; 0.29), or stopping concentrate feeding (odds ratio 0.14; 0.26). The study found that gradual reduction in milking (47%) and abrupt cessation of milking (22%) were the most common drying-off practices. These methods are effective for cows producing less than 3 liters/day at the start of drying off and do not result in milk loss during early successive lactation. However, abrupt cessation of milking is more likely to result in poor udder health outcomes. Though teat sealant was rarely used (3.9%), it proved effective for cows producing more than 5 liters/day, maintaining milk production and udder health during early successive lactation. These findings provide crucial insights for farmers on selecting appropriate drying-off practices to optimize milk yield and udder health.

Efficacy of Supplementary Feeding of Bypass Fat and Area Specific Mineral Mixture on the Production and Reproductive Performance in Milch Buffaloes

Background: Bypass fat, also called rumen-protected fat, boosts dairy animals¢energy for better milk production and health. Mineral deficiency is a leading cause of poor growth, weakened immunity, lower milk yield and reproductive issues in dairy animals. Considering the aforementioned details, an on farm trial was undertaken at farmer’s field to assess the effectiveness of bypass fat and mineral mixture on overall performance of milch buffalo. Methods: Twenty lactating Murrah buffaloes reared under farmer's field were selected and distributed equally in two groups of ten buffaloes in each group, i.e. T1 (control) and T2 (supplementation bypass fat @ 100 g and minerals mixture @ 50 g/day/ buffalo beside the farmer practices). Result: The outcome of study revealed that the additional of bypass fat and a mineral mixture had no effect on the weights of the buffaloes undergoing the experiment. Supplementation of bypass fat and mineral mixture did not influence the DM intake (in terms of kg/d and DMI %) in lactating buffalo. The mean milk yield during supplementation period was determined 10.19 ±0.36 and 12.13±0.43 l/day in group T1 and T2, respectively; which was 19.04 per cent higher in group T2 than the control. The average length of the postpartum estrus cycle (62.20±5.86 days) and service period (82.49±7.46 days) was significantly (P less than 0.05) reduced in supplemented group than control (86.40±11.57 days and 131.00±12.33 days, respectively) at farmer¢s field. AI per conception was also observed to be significantly (P less than 0.05) higher in non-supplemented group than the supplemented group. AI per conceptions in supplemented group and control group was recorded 1.39±0.33 and 2.71±0.44, respectively. It could be inferred from the observations that the feeding of bypass fat and area-specific mineral mixture in the diet significantly (P less than 0.05) improved the yield of milk and its composition as well as postpartum reproductive performance in milch buffalo at farmer’s field.

Impact of age at first calving on fertility and production performance in Murrah buffalo.

The present study analyses the effect of age at first calving (AFC) on future fertility and productivity in Murrah buffaloes. The data of 314 buffalo heifers of animal farm section, ICAR-CIRB, Hisar were collected over a period of 9 years from 2010 to 2018. The buffalo heifers were categorized into six groups according to the AFC named as 30-35, 36-41, 42-47, 48-53, 54-59 and 60-65 months. The influence of AFC on standard lactation milk (SLMY), peak yield (PY), days in milk (DIM), calving to first service, service per conception, calving to conception interval (CCI) and calving interval till fifth lactation were studied. The study revealed poor productive traits in buffalo heifers calved at younger age (30-35 months) during first parity. The productive value positively corresponded with increase in AFC. During successive lactations, higher mean milk yield (SLMY and PY) was found in groups with 36-41, 42-47 and 48-53 months. The mean number of services per conception was lower in buffalo heifers with 36-41 and 42-47 months following first calving till fifth lactation. Similarly, the said groups had lower mean calving to first service, CCI and CI up to fifth lactation. The survival rate was higher in heifers with AFC 36-41, 42-47, 48-53 and 54-59 months than with AFC 30-35 and 60-65 months. The buffalo heifers with 36-41 and 42-47 months of AFC had higher survival rate and better productive and reproductive traits till fifth parity in the current study. The study concluded that a minimum ideal AFC of 36-41 months yielded the highest productive gain.

Reducing dietary protein and supplementation with starch or rumen-protected methionine and its effect on performance and nitrogen efficiency in dairy cows fed a red clover and grass silage–based diet

The increasing cost of milk production, in association with tighter manure N application regulations and challenges associated with ammonia emissions in many countries, has increased interest in feeding lower crude protein (CP) diets based on legume silages. Most studies have focused on alfalfa silage, and little information is available on low-CP diets based on red clover silage. Our objectives were to examine the effects of dietary CP content and supplementing a low-CP diet with dietary starch or rumen-protected Met (RPMet) on the performance, metabolism, and nitrogen use efficiency (NUE; milk N output/N intake) in dairy cows fed a red clover and grass silage-based diet. A total of 56 Holstein-Friesian dairy cows were blocked and randomly allocated to 1 of 4 diets over a 14-wk feeding period. Diets were based on red clover and grass silages at a ratio of 50:50 on a dry matter (DM) basis and were fed as a total mixed ration, with a 53:47 ratio of forage to concentrate (DM basis). The diets were formulated to supply a similar metabolizable protein (MP) content, and had a CP concentration of either 175 g/kg DM (control [CON]) or 150 g/kg DM (low-protein [LP]), or LP supplemented with either additional barley as a source of starch (LPSt; +64 g/kg DM) or RPMet (LPM; +0.3 g/100 g MP). At the end of the 14-wk feeding period, 20 cows (5 per treatment) continued to be fed the same diets for a further 6 d, and total urine output and fecal samples were collected. We observed that dietary treatment did not affect DM intake, with a mean of 21.5 kg/d; however, we also observed an interaction between diet and week with intake being highest in cows fed LPSt in wk 4 and CON in wk 9 and 14. Mean milk yield, 4% fat-corrected milk, and energy-corrected milk were not altered by treatment. Similarly, we found no effect of dietary treatment on milk fat, protein, or lactose content. In contrast, milk and plasma urea concentrations were highest in cows fed CON. The concentration of blood plasma β-hydroxybutyrate was highest in cows receiving LPM and lowest in LPSt. Apparent NUE was 28.6% in cows fed CON and was higher in cows fed any of the low-protein diets (LP, LPSt, or LPM), with a mean value of 34.2%. The sum of milk fatty acids with a chain length below C16:0 was also highest in cows fed CON. We observed that dietary treatment did not affect the apparent whole-tract nutrient digestibility of organic matter, N, neutral detergent fiber, and acid detergent fiber, with mean values of 0.785, 0.659, 0.660, and 0.651 kg/kg respectively, but urinary N excretion was approximately 60 g/d lower in cows fed the low-CP diets compared with CON. We conclude that reducing the CP content of red clover and grass silage-based diets from 175 to 150 g/kg DM while maintaining MP supply did not affect performance, but reduced the urinary N excretion and improved NUE, and that supplementing additional starch or RPMet had little further effect.

Does knowledge of blood calcium concentration at 2 days postpartum affect decisions of calcium supplementation?

Delaying oral Ca supplementation might benefit cows with low blood Ca concentrations at 4 d in milk (DIM), a time when reduced blood total Ca (tCa) is associated with negative health and production outcomes. To implement a targeted approach to manage subclinical hypocalcemia (SCH) at the herd level, it is important to identify which cows benefit from supplemental Ca. Therefore, our objective was to determine if SCH diagnosis at 2 DIM could inform decisions of oral Ca supplementation at 2 and 3 DIM based on milk yield and 4 DIM blood Ca concentration. Data were analyzed from a previously conducted randomized controlled trial on multiparous cows (n = 518) from 4 farms in New York State. Cows were randomly assigned to 1 of 2 treatment groups at calving: (1) control (CON; no Ca supplementation, n = 259) or (2) bolus (BOL; 43 g of oral Ca administered at 2 and 3 DIM postcalving, n = 259). For each parity group (2, 3, 4+), we used generalized linear mixed models to identify serum tCa concentrations at 2 DIM that maximized the difference in milk yield to diagnose SCH. Cows were classified as normocalcemic (NC; parity 2 tCa >1.9 mmol/L, parity 3 tCa >1.87 mmol/L, n = 327; parity ≥4 had no defining threshold) or SCH (parity 2 tCa ≤1.9 mmol/L, parity 3 tCa ≤1.87 mmol/L, n = 58; parity ≥4 had no defining threshold). Parity 2 and 3 cows were further classified into 1 of 4 SCH-treatment groups (SCHTRT) based on 2 DIM SCH status and random treatment allocation: (1) NC-CON, n = 165, (2) SCH-CON, n = 28, (3) NC-BOL, n = 162, or (4) SCH-BOL, n = 30. Generalized linear mixed models were used to analyze the difference in milk yield for the first 10 wk of lactation and tCa at 4 DIM between SCHTRT groups with separate analyses performed for parities 2 and 3. Mean milk yield differed between SCHTRT groups for both parities. For parity 2, SCH-CON and SCH-BOL cows produced more milk than NC-CON and NC-BOL cows with SCH-CON producing 50.9 (95% confidence interval [CI] = 48.4, 53.4) kg/d, SCH-BOL 51.7 (49.1, 54.2) kg/d, NC-CON 47.5 (46.3, 48.7) kg/d, and NC-BOL 47.2 (45.8, 48.5) kg/d of milk. Milk yield was also different between SCHTRT groups for parity 3 with SCH-BOL cows producing more milk than NC-CON and NC-BOL cows. In parity 3, SCH-BOL cows produced 56.3 (95% CI = 53.1, 59.3) kg/d, SCH-CON 51.7 (48.6, 54.7) kg/d, NC-BOL 50.6 (49.0, 52.2) kg/d, and NC-CON 48.7 (46.9, 50.5) kg/d of milk. For both parities, SCH-CON and SCH-BOL cows had lower tCa at 2 DIM than NC-CON and NC-BOL cows. At 4 DIM, tCa concentrations were similar for all SCHTRT groups respective to parity. Our results suggest that although delayed Ca bolus administration does not improve blood Ca concentration when compared with controls, it does support increased milk production in parity 3 cows regardless of Ca status at 2 DIM. Thus, knowledge of blood Ca at 2 DIM should not affect decisions of Ca supplementation in this parity of cows.

Incomplete milking before drying off does not impair the udder health of cows infected with minor pathogens.

When implementing the transition from regular milk production to the dry period, drying off is mostly conducted simply by abrupt cessation of milking. Efforts to reduce milk synthesis before cessation of milking aim to reduce stress in cows as well as to lower the risk of mastitis. A previous study demonstrated that incomplete milking during the last ten days of lactation gradually reduced the milk yield of healthy, high-yielding cows. However, a reduction period of ten days might be too long for cows with lower yields. Therefore, a follow-up study was conducted on an organic dairy research farm with a lower average milk yield. We investigated whether automated incomplete milking can reduce milk synthesis within one week without impairing the health status of udder quarters infected with minor pathogens. Before drying off, 15 German-Holstein cows with 58 lactating quarters, 21 of which were infected with minor pathogens (coagulase-negative Staphylococci (CNS) and Corynebacterium bovis), were milked twice daily using the software module AutoDry (GEA Farm Technologies) with the 5%-step-down-per-day-program. The level of udder emptying was gradually reduced over 8-10 milkings beginning at a mean milk yield of 17.2 ± 4.4 kg d-1. During the last three milkings before drying off, milking clusters were automatically removed when a milk flow rate of 0.3 kg min-1 was reached. Quarter fore-milk samples were collected at two time points (14 d before and at the date of the last milking, ie drying off) and were analysed for mastitis pathogens and somatic cell count. The gradual reduced emptying of the udder induced a clear decline in milk yield by 0.8 ± 0.3 kg d-1. Within the reduction period, the somatic cell count of quarter foremilk did not change regardless of the infection status. Furthermore, no cow suffered from clinical mastitis. Thus, a reduction in milk synthesis could be achieved within less than one week before drying off without any impairment in udder health of cows, even when infected with minor mastitis pathogens.

Recording of culling reasons in Danish dairy cows

Culling in dairy cows has major impacts on production economy and animal welfare, and has been described and evaluated in many studies. Information about why a cow is culled (culling reason) may be useful for many different purposes. Still, the present study is the first to evaluate explanatory factors for recording of culling reasons. Danish dairy farmers are required to report the culling mode (slaughter, unassisted death, or euthanasia) to the Danish Cattle Database. Further, the reporting of one or two culling reasons – from a list of options – is possible but not mandatory. Data from 281,682 cows culled in Danish dairy herds in 2020 and 2021 were analyzed. The mean age at culling was 1,845 days, 83.3 % of the culled cows were slaughtered, 10.2 % died unassisted and 6.5 % were euthanized. In 66.8 % of the culled cows, the farmer had reported at least one culling reason. The most frequent culling reasons for slaughtered cows were milk production (29 % of all culling reasons reported), followed by reproduction (25 %), and udder health (16 %). For unassisted dead cows, metabolic/digestive disorders were most frequently reported (25 %), followed by unknown reasons (18 %), and udder health (15 %). For euthanized cows, accidents were most frequent (29 %), followed by locomotor disorders (18 %), and metabolic/digestive disorders (17 %). Culling mode, as well as culling reasons, differed by parity and breed. Results from a logistic regression model showed that the odds of at least one culling reason being reported was significantly higher in Jersey cows compared to other breeds. Compared to Holstein cows, the odds of a reason being reported was 2.5 times higher in Jersey cows. The odds increased with increasing parity of the cow. In herds with a high mean milk yield and a low somatic cell count, the odds of reporting a culling reason was higher than in herds with lower milk yield and higher somatic cell counts, and the odds of reporting a culling reason increased with an increasing number of disease treatments recorded per cow per year.

Effects of targeted clinical examination based on alerts from automated health monitoring systems on herd health and performance of lactating dairy cows

Our objectives were to compare the proportion of lactating dairy cows diagnosed with health disorders (HD) and herd performance when using a health monitoring program designed to rely primarily but not exclusively on alerts from automated health monitoring (AHM) systems or a health monitoring program based primarily on systematic clinical examinations, milk yield monitoring, and visual observation of cows. In a clinical trial, at ∼30 d before expected parturition, nulliparous and parous Holstein cows, stratified by parity and days in gestation, were randomly assigned to the high-intensity clinical monitoring (HIC-M; n = 625) or automated monitoring (AUT-M; n = 624) treatment. Cows were fitted with a neck-attached rumination and physical activity monitoring tag, and individual daily milk yield data were collected from parlor milk meters. For cows in HIC-M, clinical examination was conducted daily until 10 d in milk (DIM) and then in response to milk yield reduction alerts or visual observation of clinical signs of HD over the course of 21 DIM. For cows in AUT-M, clinical examination until 21 DIM was because of health index (HI) score alerts and reduced milk yield alerts. The HI score alerts used were generated based on the manufacturer's settings for the system for the last 2-h period before cows were selected for examination. Visual observation of clinical signs of HD was used for identifying cows potentially missed by automated alerts. Binomial and quantitative data were analyzed by logistic regression and ANOVA with repeated measures, respectively. The percentage of cows diagnosed with at least 1 HD during the experimental treatments risk period tended to be greater and the incidence rate ratio of HD diagnosed was greater in the HIC-M than in the AUT-M treatment. We found no difference between treatments for cows that exited the herd up to 60 or 150 DIM, but more cows tended to exit the herd from 61 to 150 DIM in the HIC-M than in the AUT-M treatment. No differences were detectable between treatments in daily or total milk yield to 21 DIM or in weekly mean milk yield and total milk yield to 150 DIM. More cows were inseminated in estrus for first service if in the HIC-M treatment and had no HD diagnosed than if in the HIC-M treatment but with HD diagnosed, or in the AUT-M treatment and had no HD diagnosed. Cows in the AUT-M treatment with HD diagnosed did not differ from other groups. No differences between treatments were observed in pregnancies per artificial insemination or pregnancy loss for first service. Despite a reduction in the risk of diagnosis of HD, no evidence indicated that a health monitoring program that relied on AHM system alerts to select cows for clinical examination reduced herd performance compared with a more intensive program that included systematic clinical examinations of all cows for the first 10 DIM, reduced milk yield alerts, and visual observation. However, to obtain the same herd performance as with the HIC-M treatment, the AUT-M treatment required use of visual observation. In conclusion, a health monitoring program designed to rely primarily on targeted clinical examination based on alerts from automated health monitoring systems might be a feasible alternative to programs that rely more on clinical examination, provided that visual observation is used to identify cows not detected by automated alerts.

Effect of urea-molasses-treated highland bamboo leaves supplementation on lactating crossbred dairy cows nutrient utilization, body weight, milk yield and its composition and economic performance under on-farm condition in Guagusa Shikudad district, Ethiopia.

In Ethiopia, locally available feed resources are commendable in livestock production to make the sector sustainable and productive. This on-farm evaluation was conducted to evaluate the effect of urea-molasses-treated highland bamboo (Yushania alpina) leaves (UMTHBL) in lactating crossbred dairy cows' nutrient utilization, body performance, milk yield and quality and economic performance. On-farm feeding trial was conducted using 12 lactating cows with initial body weight (328.08±0.98kg), initial milk yield (3.14±0.78L) of uniform parity (2) and stage of lactation (early) using a Randomized Complete Block Design. Three dietary treatments, namely, 6h grazing (control)+concentrate (T1), control+UMTHBL ad lib (T2), control+untreated BL adlib (T3) with three replications were used. Analysis of variance was employed for the feeding trial data analysis. The UMTHBL increased more dry matter and nutrients intake than untreated. A significant difference (p<0.05) was recorded between UMTHBL feeding (T2) and T1 and T3 in terms of increased milk yield. The highest (6.26L) and the lowest (3.27L) mean milk yield per day were recorded for cows fed UMTHBL and the control group, respectively. Urea-molasses treatment improved the crude protein (CP) and reduced fibres content than untreated. Treatment effects were not-significant (p>0.05) for milk compositions. Similar to milk yield, dairy cows in T2 consumed more CP which is also reflected in higher body weight and economic benefit. It can be concluded that employing treatment technology for highland bamboo leaves could support the crossbred dairy cows' production in smallholder farmers.

Nutritional Parameters of Goat Milk and Its Consumption in Rural Communities

A survey was conducted using a pretested, semi-structured questionnaire in Mutoko district to determine the extent of goat milk consumption and reasons for the possible low-to-non-consumption of goat milk. A total of 120 respondents were randomly selected. Fresh goat milk samples were also collected from Mashona and Matabele goat breeds and analysed using a Milko-scan FT 6000 (FOSS, HillerOD, Denmark) to determine nutrient composition. Results from the study indicated that goat milk is lowly utilized – with only 14% of the surveyed households consuming goat milk. The respondents cited that goat milk was lowly utilised because goat milk consumption is traditionally uncommon in the area (57.70%) and has an undesirable strong smell (17.06%). Consuming goat milk was associated with reduced social status (10.66%). Respondents that had access to sufficient cow milk (13.96%) do not consume goat milk. Estimated mean milk yield per goat per milking, as reported in the study was 310.0±114.02 mL. High levels of education were associated with increased tendency to consume goat milk (χ2=246; df=40, p=0.000). Mashona goat milk had higher lactose (4.36%) and protein (4.77%) but lower fat content (3.45%) than Matabele goat milk. While goat milk is less popular in the study area, the milk from these indigenous goat genotypes is characterised by good nutritional value comparable to the accepted values of good quality milk. The quality of the milk, coupled with feeding and breed selection interventions to increase yield, has potential to be a rich nutrient source for small-holder communities threatened by malnutrition.

Effect of Particle Size of Silage of Flint Corn Grain on Dairy Cows Fed Tropical Pasture: Performance, Intake, Ruminal Fermentation, and Digestibility.

The particle size (PS) of reconstituted corn (REC) can affect the grinding rate and starch digestibility in dairy cows. We evaluated the effect of the PS of REC ensiled for 40 days on the pasture dry matter intake (DMI), lactation performance, total tract digestibility, and ruminal fermentation of grazing dairy cows. The treatments were coarse REC (CO, 1694 µm), fine REC (FI, 1364 µm), or finely ground (GC, 366 µm) flint corn (68% vitreousness) at 29.6 ± 1.4% of diet DM (mean ± SD). Eighteen dairy cows (mean milk yield 21.3 kg/d) were split into three groups by production level and were assigned within each group to a sequence of treatments in 3 × 3 Latin squares of 21-day periods. Cows were individually fed a constant amount of whole-plant corn silage 3 ×/d (2.7 kg DM/d) and corn treatments and soybean meal according to their group. There was no significant interaction between treatment and the production level. Cows fed FI had a lower DMI (16.7 vs. 18.1 kg/d) than those fed GC, and both did not differ from CO (17.7 kg/d). There was no treatment effect on milk yield (mean: 19.2 kg/d). Cows fed CO had the lowest total tract digestibility of starch (86.3 vs. 92.3% of intake) and the highest fecal starch concentration (7.0 vs. 4.0% of DM). The NDF digestibility was lower for GC-fed cows than CO- and FI-fed cows. Plasma glucose was higher in cows fed FI and CO (75.0 mg/dL) than those fed GC (70.8 mg/dL). Ruminal volatile fatty acids and the pH did not differ. Fine grinding of REC increased the feed efficiency relative to CO and GC. Coarse grinding of REC ensiled for 40 days reduced the total tract starch digestibility relative to FI and GC.

Inclusion of Azolla pinnata as an unconventional feed of Zaraibi dairy goats, and effects on milk production and offspring performance.

This study investigated the effects of using sun-dried Azolla (Azolla pinnata) meal (SDAM) protein to replace sunflower meal protein in the diets of Zaraibi goats dams on nutrient digestibility, milk yield, composition, and economics. A total of 15 Zaraibi goats (32.23 ± 0.2 kg) were randomly divided into three equal groups, R1, R2, and R3 which were fed based on average milk production. The basal ration was a concentrated feed mixture containing 0, 10, and 20% SDAM which replaced 0, 25, and 50% of sunflower meal protein in the respective groups. Nutrient digestibility and feeding values were improved with R3 goats, which had the highest level of azolla (20%) R3 versus R2 and R1 goats. The total volatile fatty acid (TVFA) concentration in the in-rumen liquor was elevated by increasing the level of azolla up to 20% in R3 goats. The results revealed significantly higher (P<0.05) mean milk yield in the SDAM groups in comparison to R1 (1184, 1131 and 1034 respectively). The beneficial effects of the tested groups were observed in milk composition, milk fat, milk protein, and non- fats solids. Whereas the milk fat yield was higher in the SDAM group in comparison with the control group (40.84, 37.20, and 33.92). Ration inclusion of SDAM improved economic feed efficiency (relative feed cost and relative daily profit) and had a significant effect on the yield of milk constituents. In general, using up to a level of 20% SDAM in place of sunflower meal for feeding lactating Zaraibi goats improved milk production, milk fat yield, and cost-benefit ratio. This study recommended that, inclusion of sun-dried azolla meal up to 20%, as an unconventional feed for Zaraibi dairy goats and offspring, improved milk production and economically feed efficiency.

Heat shock protein 90 alpha family class B member 1 (HSP90AB1) gene polymorphism and its effect on milk production traits in friesian holstein cattle

Increasing temperature caused by climate change is main contributor of heat stress in dairy cattle. Heat stress has a major impact on the milk production efficiency in dairy cattle. The HSP90AB1 gene is involved in overcoming heat stress response in cattle. The purpose of this study is to find single-nucleotide polymorphism (SNP) of HSP90AB1 gene and its relationship to milk production traits in Friesian Holstein (FH) cattle. In this study, 50 FH blood samples were used. Allele Specific Polymerase Chain Reaction (AS-PCR) method was used to successfully identify three genotypes: CC, CT, and TT. The CT genotype is the most common in the sample population. When compared to the C-allele, the T-allele is more common. Hardy-Weinberg (HW) analysis using Chi-Square method revealed that the population was not equilibrium (P&lt;0.05). Association study between genotypes and milk production trait was not significant (P&gt;0.05), but the CC genotype had a trend of higher mean milk yield in the first and second lactation. It was determined that the HSP90AB1 gene could be used as molecular marker for FH cattle heat stress response, in order to increase milk production capacity.

Effect of Asparagus racemosus Supplementation on Milk Yield and Composition During Summer Stress in Jersey Crossbred Cows

The experiment was conducted at the Livestock Farm Complex, Veterinary College and Research Institute (VCRI), Tamil Nadu Veterinary and Animal Sciences University (TANUVAS), Orathanadu, Thanjavur, India to study the impact of Asparagus racemosus supplementation on milk yield and composition in Jersey crossbred cows during April–May, 2020 was studied. Twelve lactating crossbred cows were randomly assigned into two groups, as control and experiment. Experimental animals were given 200 mg kg-1 body weight of Asparagus racemosus root powder. The research carried out for the period of 30 days. The amount of milk produced was recorded daily. The composition of each animal’s milk was analysed on weekly basis. The overall mean milk yield 6.38±0.13, 7.73 ±0.17 L, mean fat percentage 3.88±0.07, 4.68±0.12, mean protein percentage 3.46±0.02, 3.64 ±0.03, mean lactose percentage 3.65±0.04, 3.74±0.04, and mean solid non-fat percentage 7.73±0.06, 8.09±0.06 were obtained for control and experimental group respectively. The mean milk yield, fat percentage, milk protein percentage, lactose percentage and Solid Not Fat percentage were highly significant (p&lt;0.01) in the experimental group as compare to control group. Supplementation with Asparagus racemosus substantially improved milk yield and milk composition in the present study. It can be used to alleviate the environmental heat stress in lactating Jersey crossbred cows.

Observational study on associations between resilience indicators based on daily milk yield in first lactation and lifetime profitability.

Resilience is the ability of cows to be minimally affected by disturbances, such as pathogens, heat waves, and changes in feed quality, or to quickly recover. Obvious advantages of resilience are good animal welfare and easy and pleasant management for farmers. Furthermore, economic effects are also expected, but these remain to be determined. The goal of this study was to investigate the association between resilience and lifetime gross margin, using indicators of resilience calculated from fluctuations in daily milk yield using an observational study. Resilience indicators and lifetime gross margin were calculated for 1,325 cows from 21 herds. These cows were not alive anymore and, therefore, had complete lifetime data available for many traits. The resilience indicators were the natural log-transformed variance (LnVar) and the lag-1 autocorrelation (rauto) of daily milk yield deviations from cow-specific lactation curves in parity 1. Good resilience is indicated by low LnVar (small yield response to disturbances) and low rauto (quick yield recovery to baseline). Lifetime gross margin was calculated as the sum of all revenues minus the sum of all costs throughout life. Included revenues were from milk, calf value, and slaughter of the cow. Included costs were from feed, rearing, insemination, management around calving, disease treatments, and destruction in case of death on farm. Feed intake was unknown and, therefore, lifetime feed costs had to be estimated based on milk yield records. The association of each resilience indicator with lifetime gross margin, and also with the underlying revenues and costs, was investigated using analysis of covariance (ANCOVA) models. Mean daily milk yield in first lactation, herd, and year of birth were included as covariates and factors. Natural log-transformed variance had a significantly negative association with lifetime gross margin, which means that cows with stable milk yield (low LnVar, good resilience) in parity 1 generated on average a higher lifetime gross margin than cows that had the same milk yield level but with more fluctuations. The association with lifetime gross margin could be mainly attributed to higher lifetime milk revenues for cows with low LnVar, due to a longer lifespan. Unlike LnVar, rauto was not significantly associated with lifetime gross margin or any of the underlying lifetime costs and revenues. However, it was significantly associated with yearly treatment costs, which is important for ease of management. In conclusion, the importance of resilience for total profit generated by a cow at the end of life was confirmed by the significant association of LnVar with lifetime gross margin, although effects of differences in feed efficiency between resilient and less resilient cows remain to be studied. The economic advantage can be mainly ascribed to benefits of long lifespan.

The effect of activity on some milking parameters in holstein cows

The study was conducted on 41-second lactation Holstein cows of German origin. The shelter type is a semi-open field type and the research period is 12 months. The activities in the first 100 days of lactation per day were 451.4 ± 133.5, and in the second 100 days, it was determined at 420.78 ± 118.0. The activities are divided into 3 parts within 24 hours (at night, during the day between two milkings, and in the evening). While there was no statistical difference between days 100 and 200 of lactation, the lowest activity was recorded at night and the highest activity during the day. The conductance, milk flow, and milking duration of the milk were within the normal range in the first 100 and 200 days and no statistical difference between them could be determined. Mean daily milk yield was 28.28 ± 3.86 kg for the first 100 days and 25.15 ± 3.61 kg for the following 100 days, and the difference was found to be significant (P&amp;lt;0.001). To investigate the influence of the daily activity numbers taken into account as factors on the milking parameters, 4 groups were formed for the 100th and 200th days. Accordingly, the effect of activity on milk conductivity, milking duration, and milk yield could not be determined in the first 100 days; its effect on milk flow rate proved significant (P&amp;lt;0.05). No effect of activity on milking parameters was observed in 200 days of lactation. It is assumed that the inclusion of the housing type, lactation number, and lactation period as well as the seasonal effect in activity studies in cows will contribute positively to animal welfare in herd management.

Supplementation strategies for lactating F1 Holstein x Zebu cows on deferred pastures

The objective of this study was to evaluate the effects of different concentrate supplementation strategies to lactating F1 Holstein x Zebu cows managed on deferred signal grass pasture on milk yield, composition and body weight gain. Thirty-six F1 Holstein x Zebu cows with average days in milk of 102 ± 10 and body weight of 501 ± 19 kg were allotted to a 4 x 5 completely randomized factorial design, with four feeding strategies and five weeks of evaluation. The treatments consisted of four nutritional strategies: deferred pasture as a source of roughage + 700 grams of protein supplement (PDPI); deferred pasture as a source of roughage + 1,200 grams of protein supplement (PDPII); deferred pasture + 15 kilograms of corn silage (natural basis) + 1,200 grams of protein supplement (PDSP) and corn silage (ad libitum) + 700 grams of protein supplement (CSS). There was no interaction (P = 0.99) between supplementation strategies and test days on milk yield and chemical composition. The mean milk yield of cows managed on PDPI, PDPII and PDSP was 11.50 kg/day (P &gt; 0.05), which was 14.30% lower than that of cows managed on CSS. Fat content (P &lt; 0.01), protein (P &lt; 0.01), lactose (P &lt; 0.01), defatted dry extract (DDE) (P&lt; 0 .01), total solids (P &lt; 0.01) and milk casein (P &lt; 0.01) were affected by different supplementation strategies. F1 Holstein x Zebu cows on deferred Urochloa decumbens cv. Basilisk pasture and supplemented with concentrate maintains milk production at 11.50 kg with normal composition, maintaining satisfactory body weight and condition score.

Evaluation of Impact of Chelated Mineral Mixture Formulation Supplementation on Milk Quantity and Milk Quality Parameters in Lactating Dairy Cows under Field Conditions

Background: The primary aim of the present study is to evaluate the effect of chelated organic mineral mixture “HimChelate” (Developed by Himalaya Wellness Company) on milk production, fat percentage, solids not fat (SNF) and milk somatic cell counts in lactating dairy cows. Methods: A total of eight lactating dairy cows were randomly selected in one group (G) supplemented with HimChelate mixed with concentrate feed and water at a dose of 30 g/day/cow. The cows were used as their controls and thus, allocated to a control pretreatment period (baseline; 7 days), followed by a treatment period (30 days) and after the treatment period (7 days). The impact of HimChelate supplementation on milk production and quality parameters viz, fat and SNF percentages were before supplementation (baseline), during the supplementation period of HimChelate daily up to 4 weeksand after supplementation of HimChelate (1 week) were accessed to evaluate the efficacy of HimChelate. Result: The mean milk yield in G on the baseline and during the treatment period, i.e., weeks 1, 2, 3 and 4, was 10.64±1.34 and 10.72±1.36, 10.76±1.35, 10.79±1.37 and 10.73±1.40, respectively. The sum milk yield was increased moderately in G during the treatment period compared with that on the baseline throughout the treatment period, i.e., 0.58 L (week 1), 0.93 L (week 2), 1.20 L (week 3) and 0.68 L (week 4). The impact of HimChelate on assessment parameters, such as milk yield, fat and SNF in dairy cows showed that mean milk yield (L) was increased by 1.03% following supplementation of HimChelate at 30 g (G) once daily per cow, respectively. Conversely, fat and SNF percentages were increased by 4.41% and 0.25% following the supplementation of HimChelate at 30 g(G). The supplementation of HimChelate 30 g once daily caused a slight reduction in milk somatic cell count (SCC) as early as day 3 (5100000 cells/mL). Conversely, the major reduction in milk SCC count was observed from day 9, i.e., 900000 cells/mL and maintained milk SCC of 300000 cells/mL from days 12 to 21. The findings of present research investigation depicted that the supplementation of HimChelate at the dose of 30 g/day/cow was better in terms of augmentation of milk production and improvement of milk quality parameters.

Detection of correct pregnancy status in lactating dairy cattle using MARS data mining algorithm

In this study, it is aimed to determine pregnancy outcomes by using multivariate adaptive regression splines (MARS) algorithm for classification type problems. For this purpose, data obtained from a private dairy farm in the Konya region of Türkiye in 2020 were used to determine pregnancy outcomes in Holstein dairy cattle. It has been determined how to perform statistical analyses on solving classification-type problems with the MARS algorithm and how to use R packages (caret and earth) by creating an R script file. After the analysis, the MARS estimation equation was created and in finding the probability of being pregnant: While lactation period, cow age, number of lactations, insemination number, and total lactation milk yield variables are important, it was seen that 7-day mean milk yield and last lactation milk yield were not significant. Using the train function of the caret package, the number of terms that produce the highest accuracy and the degree of interaction are determined. Goodness-of-fit tests of the optimum model were calculated. Within the scope of the evaluation of the generalization ability of the model, training and test sets were created, the classification success graph of the MARS algorithm, the model building phase were summarized, and the generalization ability of the established model was measured. When the pregnancy status is taken as a positive reference, the correct classification rate (sensitivity) of the animal with positive pregnancy status was found to be 0.9574. The correct classification rate (specificity) of pregnant animals was found to be 0.8370. The overall classification ratio of the training set (accuracy) was found to be 0.8777. The area under the ROC curve (AUC) was found to be 0.947, which indicates that the optimum specificity value is close to 1.

EVALUATION OF MILK YIELD PERFORMANCE OF FRIESIAN CROSSBRED COWS WITH DIFFERENT BLOOD LEVEL IN BARISHAL DISTRICT OF BANGLADESH

Friesian crossbred is the most popular dairy animal in Bangladesh though very little work has been done on production performance at various blood level on southern part of this country. The current study was carried out to investigate milk yield performance of this popular crossbred cow genotype having three different blood levels in Barisal district (Ganges tidal flood plain area) of Bangladesh. Thirty-three (33) crossbred cows were assigned in which 11 were 50% Local-50% Friesian, 11 were 25% Local-75% Friesian and 11 were 25% Local-50% Friesian- 25% Sahiwal considered for current study. Microsoft Excel was used to analyze collected data. Highest average daily milk yield of 5.74 lit. was obtained from 25% Local-50% Friesian-25% Sahiwal, followed by 5.24 lit. from 25% Local-75% Friesian and 3.96 lit. from 50% Local- 50% Friesian cows. In case of 50% Local-50% Frisian, highest average daily milk was found in 5th lactation while lowest was in 1st lactation. For 25% Local- 75% Friesian and 25% Local-50% Friesian-25% Sahiwal, highest mean milk yield per day was found in 3rd lactation while in 1st lactation it was lowest. It was concluded that among the three crossbred genotypes studied 25% Local-50% Friesian-25% Sahiwal was most efficient in term of milk production in southern part (Barisal district) of Bangladesh