Milking Frequency Research Articles

Interactions between prolactin and local regulation of the mammary gland.

Interactions between prolactin and local regulation of the mammary gland.

Association between non-skimmed milk consumption and metabolic dysfunction-associated fatty liver disease in US adults: insights from NHANES data

PurposePrevious studies on the association between non-skimmed milk consumption and non-alcoholic fatty liver disease (NAFLD) have reported inconsistent findings, with some suggesting an increased risk and others indicating a protective effect. Moreover, as the research focus has shifted globally from NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD), there remains limited evidence on the relationship between non-skimmed milk consumption and MAFLD. The objective of this cross-sectional study was to investigate this association using data from the National Health and Nutrition Examination Survey (NHANES).MethodsIn this U.S. population-based study, adults with complete information on non-skimmed milk consumption and MAFLD diagnosis from the 2017-March 2020 Pre-Pandemic NHANES were included. MAFLD was defined using the controlled attenuation parameter (CAP). The association between non-skimmed milk consumption and MAFLD was assessed using weighted multivariable logistic regression, adjusting for potential confounders. Subgroup and sensitivity analyses were conducted to evaluate effect modifications and robustness.ResultsThe study involved 3,758 participants in total, 1,423 (37.87%) of whom had MAFLD according to the diagnosis. Frequent non-skimmed milk consumption was independently associated with higher MAFLD risk. Compared to the “Rarely” group (< 1 time/week), the “Sometimes” group (≥ 1 time/week but < 1 time/day) had an odds ratio (OR) of 1.67 (95% CI: 1.32–2.12, P = 0.004), and the “Often” group (≥ 1 time/day) had an OR of 1.36 (95% CI: 1.06–1.75, P = 0.046). Stratified analysis revealed that the association was significantly modified by education level (P for interaction = 0.010), with a stronger association observed among participants with higher education levels. Sensitivity analysis yielded consistent results, further supporting the robustness of the association.ConclusionOur findings suggest a significant association between frequent non-skimmed milk consumption and risk of MAFLD, particularly in highly educated individuals. These results highlight the importance of dietary modifications, specifically reducing non-skimmed milk intake, as a potential preventive strategy for MAFLD, especially in high-risk populations.

Can dietary palmitic supplementation and milking frequency modify the cheesemaking properties of milk?

Palmitic acid (PA) supplementation and greater milking frequency can increase milk production and fat yield in dairy cows. However, the technological effects of those practices on cheesemaking still need to be determined. This work aimed to evaluate, with Holstein dairy cows, the effects of dietary PA, thrice-daily milking frequency, and their interaction on cheese yield and composition. Before cheesemaking, milks were standardized to a casein-to-fat ratio of 0.78% (SE: 0.02) and targets of 3.27% (SE: 0.03) and 4.20% (SE: 0.05). Rennet coagulation properties of standardized milk, cheese composition, curd draining properties, free fatty acid (FFA) content, and proteolysis during ripening were analyzed. Dietary PA supplementation modified the milk fatty acid profile but did not affect coagulation and draining properties, cheese composition, or proteolysis. The moisture-adjusted yield and fat and protein recoveries were also similar between treatments. The greater milking frequency did not affect process performance. However, increasing milking frequency led to a significantly higher FFA content in cheese at the end of ripening of 1.4 (SE: 0.2) mEq/kg versus 0.8 (SE: 0.2) mEq/kg of cheese fat for thrice- and twice-daily milkings, respectively. Consequently, dietary supplementation of PA to dairy cows had only a limited effect on the cheesemaking process under the standardized conditions tested. However, the effects of FFA on cheese sensory properties should be considered if the milking frequency is increased.

The Association of Delayed Milk Ejection and Milk Production in Dairy Cows Milked by an Automated Milking System.

This retrospective cohort study examined the association between delayed milk ejection (DME), defined as bimodal milk flow, and milk yield in dairy cows milked with an automated milking system (AMS). Additionally, we identified risk factors for DME. Using data from a farm milking approximately 1350 cows, we analyzed 689,484 individual milking records and 194,142 daily cow observations over 350 days with generalized linear mixed models. Cows with DME generally had higher daily milk yields, regardless of lactation number. However, first-lactation cows early in lactation and older cows (≥third lactation) late in lactation produced less milk when experiencing DME. In contrast to the higher daily milk yield, cows produced less milk per milking when experiencing delayed milk ejection. However, more frequent milkings contributed to higher daily milk yield, even with more instances of delayed milk ejection. Risk factors for DME included lactation number, stage of lactation, milking frequency, and milking interval. These findings underscore the complexity of DME in AMS and suggest that optimizing individualized milking protocols could improve milk yield efficiency. Understanding the interplay of cow characteristics and milking management may enhance AMS performance and dairy herd productivity.

Providing concentrate feed outside of the milking robot increases feed intake in dairy cows without reducing motivation to visit the robot.

Providing concentrate feed outside of the milking robot increases feed intake in dairy cows without reducing motivation to visit the robot.

Efeito da frequência de ordenha no perfil diário de ruminação de vacas leiteiras

ABSTRACT: Rumination monitoring assesses dairy cows’ health, reproduction, and welfare status. The present study evaluated whether increasing the milking frequency affects dairy cows’ milk yield and daily rumination profile. The database was obtained from cows monitored using collars equipped with a rumination sensor. Cows were milked two (n = 9 and 379 cows) or three (n = 14 and 704 cows) times daily. Increased milking frequency improved (P ≤ 0.05) milk yield from 36.0 to 41.6 kg/cow/d. However, the milking frequency did not affect (P &gt; 0.05) daily rumination or the proportion of diurnal rumination. Diurnal rumination (from 7 to 19 h) generally represents 46.3% of daily rumination. Cows milked twice daily showed a significant decrease in rumination rate, especially during the second daily milking, compared to cows milked three times daily. Thus, milking frequency affects milk yield and reduces rumination during milking. However, it does not affect daily rumination and the proportion of diurnal rumination and can be used as an acidosis marker regardless of milk frequency.

Effect of milking interval and lactation stage on withdrawal period: Exemplified with a bovine oxytetracycline lactation physiologically based kinetic model.

Effect of milking interval and lactation stage on withdrawal period: Exemplified with a bovine oxytetracycline lactation physiologically based kinetic model.

Assessment of preferences and frequency of milk and selected dairy products consumption by mothers and their children aged 1 to 3 years.

Early childhood is a time of developing eating habits and taste preferences, which is most influenced by the family environment. Milk and dairy products play an important role in the diet of post-infant children, as they provide many nutrients that condition the proper growth and development of the young body. Assessment of the preferences for milk and selected dairy products and the frequencies of their consumption by mothers and their children aged 1 to 3 years. The study was conducted in 2019 in a group of women (n=94) aged 20-40 years who have a child aged 1-3 years and do not exclude milk and dairy products from their own or their child's diet. The study applied the Computer-Assisted Web Interview (CAWI) method using a survey including food frequency questionnaire (FFQ) developed on the basis of the Dietary Habits and Nutrition Beliefs Questionnaire (KomPAN) for research on dietary views and habits and questions about the preferences of mothers and their children regarding milk and selected dairy products. Products that were preferred by mothers and children were also consumed significantly more often in both groups (p≤0.05). Preferences for selected dairy products in the group of mothers and their children were also similar. The most popular products in both groups were: yoghurt, cottage cheese and rennet cheese, with the latter being preferred by significantly more mothers than children (p<0.001). The frequency of consumption of selected dairy products among women and children was similar, namely the most frequently consumed dairy products were: milk, yoghurt and rennet cheese, and the least frequently consumed were buttermilk and kefir. Considering the achieved results, it seems reasonable to conduct activities encouraging the consumption of fermented milk products, especially kefir and buttermilk, which have many beneficial health properties and which are the least preferred by mothers and their children aged 1-3 years, and therefore the least consumed.

Motivation of milking high productivity cows under the conditions of robotic sys-tems

Scientific research was carried out at the TDV “Terezine” farm of Bila Tserkva district, Kyiv region, on a newly created dairy farm for 500 cows with robotic milking systems of the De Laval Company. The herd of cows has been housed in a room with new volume-planning and technological solutions of 36 m wide and 10.5 m high. In the center of the room are eight robotic systems where the animals enter for milking at their request. The article highlights the research results into the structure of the milking herd of a dairy farm. It has been established that at the farm with robotic milking systems for 500 cows, there are animals with 1–6 lactations. The most significant part of the herd consists of cows of the first lactation (142 heads) and the smallest one - of the sixth lactation (11 heads). The parts of cows of the third, fourth, and fifth lactation are, respectively, 3rd – heads, 4th – 45 heads, and 5th – 28 heads. Such a structure of the herd indicates that the cows are highly productive. We studied the milking frequency of cows of different ages under robotic milking depending on the lactation period and their productivity. It has been shown that the technology of milking cows using robotic milking systems radically differs from that of milking on traditional machines. It was found that first-born cows had the lowest number of milking times per lactation (2.17 times), and cows of the second lactation had the highest (2.24 times) with a gradual decrease in the third (2.21 times) and the fourth (2.18 times). The decrease in the frequency of milking in the third and fourth lactation is because as the age of lactating cows increases, milk productivity increases, and, accordingly, the size of the udder, which does not require frequent release. Studies have proven that the higher the daily milk yield, the more often the cow comes to be milked. So, the first-born cows with an average daily milk yield of 10–20 kg go to milking 2.12 times, and with a productivity of 20–30 kg, the number of milking increases by 0.1 time, and with daily milk yields of 31–40 kg and 41–50 kg, the need in milking increases by 0.35 and 0.43 times. It has also been established that the need for milking is 0.52 times higher in animals of second lactation than in first-born cows. It has also been established that when the daily productivity of cows increases, the intervals between milking are shortened. With a daily milking of 10–20 kg, the average interval between milking is 10.5 hours, and with a milking of 40 kg and above – 7.3 hours. The most extended interval between milking is observed at night between the evening and morning milking. Based on the obtained research results, the farm's work schedule is suggested to be adjusted.

Regulation of gene expression in milk secretory pathways during secretory activation in Holstein cows

Increased transcription of genes involved in lactose synthesis is a key feature of secretory activation of the mammary gland. We determined which genes are transcriptionally regulated during the transition from colostrum to milk in cows and whether more frequent milking of one udder half would increase milk yields and alter gene expression. We enrolled 12 Holstein cows immediately after calving, harvested colostrum, then randomly assigned one udder half to 12 h (2X) or 6 h (4X) milking intervals for 48 h after first milking. After 48 h, all quarters were milked twice daily until d7, when final quarter milk yields were collected. Yields and composition of colostrum and milk were recorded for each 12 h interval. After each milking, a strip sample of hind milk was collected for isolation of RNA from milk fat and quantification of selected transcripts via qPCR. Milk, milk fat, total protein, and lactose yields increased significantly over the initial 48 h and at d7 after calving. Quarters on 4X treatment produced more milk than the contralateral 2X quarters. Genes upregulated concomitantly with milk yields encoded α-lactalbumin (LALBA), β-1,4-galactosyltransferase (B4GALT1), fatty acid synthase (FASN), β casein (CSN2), and folate receptor α (FOLR1). Downregulated genes encoded monosaccharide transporters (SLC2A3, SLC2A8, SLC35A2) and enzymes involved in galactose synthesis (HK1, PGM1, GALE). Three genes were initially downregulated but later upregulated at d7 (LPIN1, SLC2A1, UGP2). Notably, milking frequency had no effect on gene expression. Sequential upregulation first of genes encoding the former enzymes, then of UGP2, may be necessary for copious milk production. However, the local effects of milking frequency on milk production during lactogenesis do not appear to be controlled by transcription of these genes related to lactose synthesis.

What Determinants Are Related to Milk and Dairy Product Consumption Frequency among Children Aged 10-12 Years in Poland? Nationwide Cross-Sectional Study.

Due to their high nutritional value, milk and dairy products should be a permanent element of a properly balanced diet for children and adolescents. The study aimed to identify (i) the frequency of milk and dairy product consumption by children aged 10-12 years in the opinion of children and their parents and (ii) the determinants related to the consumption of these products (including lifestyle, nutrition knowledge, and the nutritional status of children's as well as parents' nutrition knowledge). A cross-sectional study was conducted with 12,643 primary school students aged 10-12 and 7363 parents. Dietary data were collected using the Food Frequency Consumption and Nutritional Knowledge Questionnaire (SF-FFQ4PolishChildren® and KomPAN®). Anthropometric measurements were taken and body mass index (BMI) and waist/height ratios (WHtR) were calculated. A logistic regression model was used to assess the likelihood of the frequent consumption of dairy products in the opinion of both the children and their parents, and the quality of the obtained models was assessed using model fit statistics and the Hosmer and Lemeshow test. The frequency of consuming milk and milk products (every day and more) was low in the opinion of children aged 10-12 years (29.6%). According to their parents, the frequency of the consumption of dairy products was slightly higher (44.8%). Six factors associated with the frequency of milk and dairy product consumption were identified independently. These included schoolchildren and their parents' nutrition knowledge, physical activity, sleep, gender, and place of residence. More of these products were consumed by children with greater nutrition knowledge-both their own and their parents'-higher physical activity, longer sleep duration, males, and those living in the city. Family eating habits, particularly eating meals together, also played an important role in the consumption of milk and dairy products. According to the parents, the children in older grades were less likely to consume dairy products more frequently. The obtained results suggest an insufficient consumption of milk and dairy products. The identification of modifiable factors, such as nutrition knowledge, physical activity, sleep duration, and eating meals with the family, suggests the need to improve the existing strategies, including activities encouraging nutritional education for both schoolchildren and their parents.

Effects of Early Lactation Milking Frequency in an Automated Milking System on Cow Performance.

Automated milking systems (AMS) are increasingly adopted for dairy cow production, promoting individualized cow management dependent on factors like lactation stage, age, and productivity. The study objective was to investigate the effects of early lactation milking frequency on cows milked via AMS. Multiparous Holstein cows blocked by parity and due date were randomly assigned to treatments (n = 8 per treatment): three (3X) or six (6X) milkings per day (MPD). The experimental phase (EXP) was defined as 4 to 29 days in milk (DIM). The AMS settings were programed so 3X cows were limited to three MPD while 6X cows were allowed six MPD. Afterwards was the carry over phase (CO) ranging from 30 to 90 DIM; all cows were allowed up to six MPD. Measurements by the AMS included bodyweight, milk yield (MY), and pellet intake. Weekly composite milk samples were analyzed for macronutrient composition and fatty acid (FA) profile. Coccygeal blood was sampled at 3, 8 ± 1, and 13 ± 1 DIM; concentrations of blood plasma analytes were quantified. Greater MPD was achieved for 6X cows versus 3X cows during EXP, but similar during the CO. Daily MY was non-separable during the EXP while 6X cows in their third or greater lactation group (3 + LG) had greater MY than 3X cows of the same LG during the CO. Milk fat content and 4% fat-corrected MY were both greater for 6X, 3 + LG cows during the EXP compared to 3X, 3 + LG cows. Milk FA methyl esters (FAME) proportions were different between MPD groups, with 6X, 3 + LG cows having the lowest short, even-chain FA from de novo or post-absorptive origin. Differences in analytes indicated that 6X, 3 + LG cows experienced metabolic stress and incorporated greater FA from adipose tissue. Greater early lactation MPD in AMS may shift cow nutrient partitioning to support greater production in 3+ parity cows.

Impact of Economic Crisis and Socio-Demographic Factors on Milk and Milk Product Consumption of Undergraduates: A Case Study of Eastern University, Sri Lanka

Milk consumption is influenced by a wide range of factors, including gender, age, income, education, ethnicity, health condition, and presence of children in the household. The current study was designed to investigate the effects of the recent economic crisis and socio-demographic factors on the milk and milk product consumption patterns of undergraduates. The questionnaire survey was used as the primary data collection tool. The survey was conducted with a representative sample of undergraduates (n=238) using a self-structured online questionnaire. The collected data was analyzed using descriptive and inferential statistics. As per the results, the majority of undergraduates in the sample size consume raw milk (83%). Therefore, cattle milk was the most widely consumed type of raw milk (84%). Ice cream is the most popular milk product (99%) in sample size. Despite the economic crisis, the majority of undergraduates (53%) maintain steady milk consumption habits. However, the milk consumption of undergraduates during the financial crisis was significantly associated with factors including locality (p=0.017), family size (p=0.014), monthly family income (p=0.000), parental educational level (p=0.000), and employment status (p=0.014). Further, this study investigated the fact that the purchasing frequency of milk and milk products was not associated with socio-demographic backgrounds (P&gt;0.05).

Exploring the Multifaceted Influences on Childhood Nutritional Status: A Study Conducted in South Punjab, Pakistan.

Introduction The double burden of malnutrition (DBM) in Pakistan is a rising concern affecting school-going children, marked by coexisting under- and over-nutrition within the same population. Key influences include shifts in dietary habits, socioeconomic status, and lifestyle changes due to rapid urbanization. With a focus on Multan, Pakistan, the study seeks to assess the proportion of underweight and overweight students while identifying the risk factors and sociodemographic characteristics associated with this incidence. The aim is to guide future health interventions addressing this multidimensional health challenge. Materials and methods This study, adopting a descriptive cross-sectional research design, collected data from female teenage students through interviews and anthropometric measurements. A total of 300 participants were randomly selected from a comprehensive school list representing diverse urban and rural settings. Participants' weight and height were measured to calculate their body mass index (BMI), categorizing them into underweight, normal weight, and overweight groups. The relevant risk factors were collected through an interview questionnaire. Collected data were analyzed using IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp., Armonk, New York, United States), with the results stratified according to socioeconomic, dietary, and psychosocial factors and compared across different weight categories. Results The study collected data from 300 students, revealing a correlation between socioeconomic status, dietary habits, and BMI. Parental occupation significantly affected nutritional status, with children of laborers primarily falling within normal and underweight categories. Dietary habits like frequency of fast food and milk or dairy consumption showed notable associations with nutritional status. Psychosocial factors such as peer or teacher comments about weight and outdoor sports participation also influenced the students' nutritional status. However, factors like family income, video game hours, and the presence of pets at home did not show significant associations with nutritional status. Conclusions The study illustrates a multi-faceted association between socioeconomic status, dietary habits, and BMI among schoolchildren in Multan, Pakistan, emphasizing the need for comprehensive interventions.

The Shift to Less Frequent Milk Consumption and the Rise of Alternative Milk: United States, Aged 2+ Years, 2009–March 2020

The Shift to Less Frequent Milk Consumption and the Rise of Alternative Milk: United States, Aged 2+ Years, 2009–March 2020

High Concentrations of Immunoglobulin G Against Cow Milk Proteins and Frequency of Cow Milk Consumption Are Associated With the Development of Islet Autoimmunity and Type 1 Diabetes—The Trial to Reduce Insulin-dependent Diabetes Mellitus (IDDM) in the Genetically at Risk (TRIGR) Study

BackgroundThe Trial to Reduce IDDM in the Genetically at Risk (TRIGR) (NCT00179777) found no difference type 1 diabetes risk between hydrolyzed and regular infant formula. However, cow's milk consumption during childhood is consistently linked to type 1 diabetes risk in prospective cohort studies. ObjectiveOur primary aim was to study whether humoral immune responses to cow’s milk and cow’s milk consumption are associated with type 1 diabetes in TRIGR children. MethodsTRIGR comprised 2159 children with genetic susceptibility to type 1 diabetes born between 2002-2007 in 15 countries. Children were randomized into groups receiving extensively hydrolyzed casein or a regular cow’s milk formula and followed until age 10. Type 1 diabetes related autoantibodies and antibodies to cow’s milk proteins were analyzed. Infant formula intake was measured by structured dietary interviews and milk consumption with a food frequency questionnaire. Associations of milk antibodies and milk consumption with the risk to develop type 1 diabetes were analysed by Cox survival model. ResultsCow’s milk antibody levels both in cord blood [HR for islet autoimmunity 1.30 (95% CI 1.05-1.61); type 1 diabetes 1.32 (1.02-1.71)] and longitudinally from birth to 3 years [islet autoimmunity 1.39 (1.07-1.81); type 1 diabetes 1.43 (1.04-1.96)] were associated with increased risk of developing type 1 diabetes. The amount of regular infant formula was associated with a reduced islet autoimmunity risk in the regular infant formula group [0.92 (0.85-0.99)]. Furthermore, frequent liquid milk consumption after infancy was associated with an increased risk of islet autoimmunity or type 1 diabetes. ConclusionsElevated cow's milk antibody levels and high consumption of liquid milk after infancy are related to type 1 diabetes development in children with an increased genetic susceptibility to type 1 diabetes. Enhanced antibody levels to cow’s milk may provide a biomarker of immune system prone to develop islet autoimmunity. Trial registry numberNCT00179777

Milk consumption and stunting among children aged 6-59 months in Surabaya, Indonesia

Background: Stunting impairs child growth and development, affecting millions of children under five years worldwide. Consumption of milk provides important macronutrients and micronutrients that support growth. Objectives: To assess milk consumption and its associations with stunting in children aged 6-59 months in Surabaya City, Indonesia. Method: This case-control study compared milk consumption between children aged 6-59 months with stunting (cases) and normal children (controls). Data were obtained from questionnaires and anthropometric databases from five primary healthcare centres in Surabaya city. Data from 94 subjects were analysed using Chi-square and multivariate logistic regression. Results: Children with stunting had a significantly later age of milk introduction, less frequent daily milk consumption and a lower amount of daily milk consumption than controls (p&lt;0.05). Age of milk introduction ≥18 months was a risk factor associated with stunting (p&lt;0.05, crude OR= 3.0, 95% CI 1.2-7.4). Daily milk consumption less than twice a day (p&lt;0.05, crude OR=3.8; 95% CI 1.4-10.5) and amount of milk less than 500 ml (p&lt;0.05, crude OR=2.9; 95% CI 1.2-6.8) were risk factors associated with stunting. After adjusting for other confounding variables, odds of stunting were found to be dominantly higher statistically in children with daily milk consumption of less than twice a day (p&lt;0.05, adjusted OR= 3.4, 95% CI 1.0-11.5). Conclusions: This study concluded that milk introduction at the age beyond 18 months, frequency of daily consumption of less than twice a day and an amount of less than 500 ml a day are significantly associated with higher odds of stunting.

Randomized-controlled study assessing the effect of milking permission settings and concentrate supplementation on milking frequency and milk yield in a pasture-based automatic milking system

This study aimed to verify the impact of milking permission (MP) and concentrate supplementation (CS) on milking frequency (milkings per cow/day) and milk yield (kg per cow/day) in a farm using a pasture-based automatic milking system (AMS). Sixty-eight cows milked using this AMS unit were randomly assigned to one of 4 groups homogeneous for parity, days in milk and milk yield. Treatments used were: Frequent (F) or Restricted (R) MP, that granted cows permission to milk after 6 to 8 h or 9.6 to 14 h of the previous milking, respectively; and low (LC) or high (HC) CS of 0.5 kg or 3.5 kg per cow/day, respectively. The combination of the 2 levels of MP and the 2 levels of CS resulted in the 4 treatment combinations (FHC, RHC, FLC, RLC). This study was designed as a 2 X 2 factorial arrangement with treatment crossover: each of the 4 cow-groups was randomly assigned to one of the 4 treatment combinations for a 5-week experimental period (one pre-treatment week and 4 treatment weeks), and after each 5-week period groups crossed over to another treatment combination until they experienced all. Statistical analysis assessed the impact of MP, CS and their interaction on milk yield, milking frequency, box time, milking time and average milk flow rate. This was done using a mixed model analysis with repeated measures to account for repeated observations on the experimental unit (cow). Milk yield per cow/day and milkings per cow/day were significantly higher with the Frequent compared with the Restricted MP (1.5 kg and 0.65 respectively). Milk yield per cow/day and milkings per cow/day were significantly higher with the HC compared with the LC CS (3.1 kg and 0.25 respectively). Additionally, milk yield per cow/day was affected by the interaction of MP and CS and it was highest with the FHC (20.1 kg) treatment combination, followed by RHC (18.2 kg) treatment combination. The number of milkings per cow/day were also affected by the interaction of MP and CS. The highest estimated number of milkings per cow/day was recorded for the FHC (2.12) and the FLC (1.77) treatment combinations, followed by the RHC (1.38) and RLC (1.23) treatment combinations. Similarly, milking interval was 2.5 h longer for the RLC treatment combination compared with RHC. The shortest milking interval/milking was observed for the FHC (11 h) and FLC (12.8 h) treatment combinations. In conclusion, the study showed that allowing access to the robot between 6 to 8 h after the previous milking was sufficient (even with a minimal level of CS) to achieve acceptable milk production and milking performance in a pasture-based AMS.

Effect of low milking frequency on the concentration of antimicrobial proteins in goat milk

Effect of low milking frequency on the concentration of antimicrobial proteins in goat milk

Geometry of milk liners affects milking performance in dairy cows.

The geometry of milk liners may affect milking performance and cow comfort as the milk liner is the only part of the milking machine that comes into contact with the teat. To determine the effect of alternative shape of milk liners we compared square (SQR) vs. the conventional round (RND) teat cup liner on milking performance and comfort of dairy cows. Treatment milk liners were randomly allocated to clusters within each side of the 12 a side double up-herringbone dairy shed in a complete randomised block design over two periods. Milking performance data from a total of 10 065 (late stage of lactation and once-a-day milking frequency, LATE) and 18 048 (early stage of lactation and twice-a-day milking frequency, EARLY) milking events were automatically recorded by a DeLaval milk meter, and separately analysed for LATE and EARLY, respectively. In EARLY, cow comfort behaviour was also recorded during afternoon milking sessions. Across the two study periods, average milk flow rate, milk flow rate during 0-15, 15-30 and 30-60 s after cluster attachment, and milk flow rate at cluster take-off were higher in SQR compared to RND treatment. Proportion of time in a milking session with low milk flow rate and duration of milking session were less in SQR compared to RND treatment. However, effect of geometry of milk liner on peak milk flow rate was inconsistent across the two-study periods. Peak milk flow rate was higher (P < 0.001) in SQR than RND in LATE, but higher (P < 0.001) in RND than SQR in EARLY. Stomping and kicking behaviours of cows were similar between treatments. Results of this study suggest that square milk liners potentially improve milking performance, without adverse effect on cow comfort compared to conventional round liners. Long-term, multi-site studies are required to confirm potential teat-end health benefits associated with square milk liners and further verify these results.