Milking Frequency Research Articles

Effect of milk replacer feeding rate and frequency of preweaning dairy calves in the southeastern United States: Glucose metabolism

The objective of this experiment was to examine the effect of milk replacer (MR) feeding rate (FR) and frequency (FF) on glucose metabolism before and after weaning during summer and winter in the subtropical climate of the southeastern United States. Holstein calves (n = 48/season) were enrolled at 8 d of age (DOA) in the summer (June to August, body weight = 40.6 ± 0.7 kg) and winter (November to January, body weight = 41.9 ± 0.8 kg). In each season, calves were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement including 2 FR [0.65 (low) or 0.76 kg of solids/d (high) of a 26% CP and 17% fat MR] and 2 FF [2× (0700 and 1600 h) or 3× (0700, 1600, and 2200 h)]. Calves were managed similarly and housed in polyethylene hutches bedded with sand. Milk replacer (12.5%) was fed based on treatments until 42 DOA when FR was reduced by half and offered 1×/d (0700 h) for 7 d. Plasma was collected weekly at 1400 h for analyses of glucose and insulin concentrations in all calves. Pre- and postprandial glucose and insulin concentrations of a subset of calves (n = 10/treatment per season) were measured on 20 DOA. A subset of calves (n = 8/treatment per season) was subjected to an intravenous glucose tolerance test (GTT) on 27 and 57 DOA and insulin challenge on 28 and 58 DOA at 1030 h. Average ambient temperature was 26.1 ± 2.2°C in summer and 12.9 ± 5.4°C in winter. During the preweaning period in both seasons, feeding high increased plasma glucose concentrations compared with low, and increasing FF reduced basal insulin concentrations. Compared with 2×, feeding 3× did not affect postprandial glucose but lowered insulin in the summer, whereas in the winter, increased glucose from 30 to 180 min but lowered insulin from 240 to 420 min after MR feeding. Following GTT before weaning in both seasons, 3× reduced insulin increment and area under the curve compared with 2× without affecting glucose disposal. After weaning, treatment did not affect glucose disposal or insulin responses after GTT during winter, but calves fed 3× had faster glucose disposal and stronger insulin responses than 2× during summer. In both summer and winter, preweaned calves fed 3× had greater decrement and area under the curve of plasma glucose after insulin challenge, suggesting enhanced peripheral tissue insulin response compared with 2×. This effect persisted after weaning only during summer. Increasing FR had no effect on metabolic responses in both seasons. In conclusion, increasing MR FF from 2 to 3 times per day reduced insulin secretion but enhanced insulin response on peripheral tissues of preweaned calves regardless of season.

Promoting Human Milk and Breastfeeding for the Very Low Birth Weight Infant.

Provision of mother's own milk for hospitalized very low birth weight (VLBW) (≤1500 g) infants in the NICU provides short- and long-term health benefits. Mother's own milk, appropriately fortified, is the optimal nutrition source for VLBW infants. Every mother should receive information about the critical importance of mother's own milk to the health of a VLBW infant. Pasteurized human donor milk is recommended when mother's own milk is not available or sufficient. Neonatal health care providers can support lactation in the NICU and potentially reduce disparities in the provision of mother's own milk by providing institutional supports for early and frequent milk expression and by promoting skin-to-skin contact and direct breastfeeding, when appropriate. Promotion of human milk and breastfeeding for VLBW infants requires multidisciplinary and system-wide adoption of lactation support practices.

Farm-level factors associated with lameness prevalence, productivity, and milk quality in farms with automated milking systems

Impaired locomotion (lameness) may negatively affect the ability and desire of cows to milk voluntarily, which is a key factor in success of automated milking systems (AMS). The objective of this study was to identify factors associated with herd-level lameness prevalence and associations of lameness and other farm-level factors with milking activity, milk yield, and milk quality in herds with AMS. From April to September 2019, 75 herds with AMS in Ontario, Canada, were visited, and data on barn design and farm management practices were collected. Data from AMS were collected, along with milk recording data, for the 6-mo period before farm visits. Farms averaged 98 ± 71 lactating cows, 2.3 ± 1.5 robot units/farm, 43.6 ± 9.4 cows/robot, 36.4 ± 4.9 kg/d of milk, a milking frequency of 3.01 ± 0.33 milkings/d, and a herd average geometric mean SCC of 179.3 ± 74.6 (× 1,000) cells/mL. Thirty percent of cows/farm (minimum of 30 cows/farm) were scored for body condition (1 = underconditioned to 5 = over conditioned) and locomotion (1 = sound to 5 = lame; clinically lame ≥3 out of 5 = 28.3 ± 11.7%, and severely lame ≥4 out of 5 = 3.0 ± 3.2%). Clinical lameness (locomotion score ≥3) was less prevalent on farms with sand bedding, with increased feed bunk space per cow, and on farms with non-Holstein breeds versus Holsteins, and tended to be less prevalent with lesser proportion of underconditioned cows (with body condition score ≤2.5). Severe lameness occurrence (farms with any cows with locomotion score ≥4) was associated with a greater proportion of underconditioned cows and in farms with stalls with greater curb heights. Herd average milk yield/cow per day increased with lesser prevalence of clinical lameness (each 10-percentage-point decrease in clinical lameness prevalence was associated with 2.0 kg/cow per day greater milk yield) and greater milking visit frequency per day, and tended to be greater with increased feed push-up frequency. Lesser herd average somatic cell count was associated with lesser clinical lameness prevalence, herd average days in milk, and proportion of overconditioned cows, and somatic cell count tended to be lesser for farms with sand bedding versus those with organic bedding substrates. The results highlight the importance of minimizing lameness prevalence, using of sand bedding, ensuring adequate feed access and feed bunk space, and maintaining proper cow body condition to optimize herd-level productivity and milk quality in AMS herds.

Milk consumption and gastrointestinal symptoms in preschool girls with different lactase genotypes

AIM: To analyze the frequency of milk consumption and subjective symptoms of intolerance to dairy products in the population of three- to six-year-old girls (born and resident in Samara) based on the genotype of the lactase gene.
 MATERIALS AND METHODS: We included 103 preschool girls ranging three to six years of age. Parents were questioned about the frequency of milk consumption by the child (per week), as well as the presence of gastrointestinal symptoms in their children (abdominal pain, bloating, flatulence and diarrhea) and the suspected association of symptoms with milk consumption (according to the parents). Buccal samples were taken from all girls to determine the polymorphism of the lactase genes (determination of C/T-13910 variant of the MCM6 gene).
 RESULTS: A significant relationship between the frequency of milk consumption and the variant of the polymorphic locus of the lactase gene, MCM6 [C 13910T; which affects the expression of the lactase gene (LCT)] has not been established. There is no correlation in the enlarged gradation of frequent milk consumption (47 times a week) and rare milk consumption (23 times a week or less): of 53 girls with the CC genotype 27 (51%) often drink milk, 26 (49%) rarely drink milk; of 39 girls with CT genotype 23 (59%) often consume milk, 16 (41%) rarely consume milk; of 11 girls with the TT genotype, 8 (73%) often consume milk, 3 (27%) rarely consume milk (c2 1.94, p = 0.379). There was no significant relationship between the frequency of milk consumption, subjective symptoms of lactose intolerance (abdominal pain, bloating, flatulence and diarrhea) and the genotype; these symptoms were found only in four girls carrying the C allele (CC and CT genotypes) though not detected in girls with TT genotype.
 CONCLUSION: In girls of 36 years old, there is no relationship between the frequency of milk consumption, subjective symptoms of lactose intolerance and genotype of lactase gene.

Effects of dietary and health factors on nutritional status of children in pastoral settings in Borana, southern Ethiopia, August\u2013October 2015

BackgroundChildhood undernourishment is a major public health problem globally, and being responsible for higher mortalities in children and enormous health costs in sub-Saharan Africa. However, scarcity of data on the magnitude of malnutrition and its underlying causes, especially in the pastoral system, limits the effectiveness of potential interventions. This study addresses the nutritional status and factors associated with malnutrition among children in Borana pastoral system, southern Ethiopia.MethodsA community based cross-sectional study, using multistage cluster sampling, was conducted from August to October 2015. Dietary diversity score (DDS), milk and meal frequencies, anthropometric measurements, and socio-economic variables were recorded for 538 children aged 6–59 months. Multivariable generalized linear model (GLM) with log link function was applied to ascertain determinants of malnutrition. The strength of association was assessed based on prevalence ratio (PR).ResultsPrevalence of underweight, stunting, and wasting were 28.3 % (95 % CI: 24.4–32.1), 41.1 % (95 % CI: 36.7–45.1), and 9.8 % (95 % CI: 7.3, 12.4), respectively. Children who consumed more diverse foods were at a lower risk of being underweight (PR = 0.72, 95 % CL: 0.59–0.88), stunted (PR = 0.80, 95 % CL: 0.68–0.93) and wasted (PR = 0.42, 95 % CL: 0.27–0.66). Intake of increased milk frequency was also associated with lower risk of underweight (PR = 0.86, 95 %CL: 0.76–0.97), stunting (PR = 0.83, 95 %CL: 0.75–0.91) and wasting (PR = 0.73, 95 %CL: 0.56–0.96). The risk of underweight (PR = 1.02, 95 %CL: 1.01–1.03), stunting (PR = 1.01, 95 %CL: 1.00–1.02) and wasting (PR = 1.01, 95 %CL: 1.00–1.04) had increased with age, and no difference was observed between boys and girls. Children who lived far away from health care facilities were 1.2 and 2.4 times more likely to be stunted and wasted, respectively than those residing near a health care facility. Ownership of toilet and living close to market were associated with reduced stunting, whereas illness was associated with increased risk of underweight.ConclusionsThe high prevalence of stunting among pastoral children is a serious public health concern and calls for urgent action. Association of nutritional status of children with dietary intake, and health status, access to health services and toilet availability underlines the need for improved nutrition practices, health care facilities and sanitary conditions in the study area.

Relationships between milk protein concentrations at different phases of first to fourth lactation and subsequent calving intervals in Holstein cows

So far, no study has been conducted on the effect of milk protein concentrations (MP%) in different time periods of lactation on subsequent calving intervals (CI). The purpose of this study was to evaluate the association between MP% at different stages of the first to fourth lactations and subsequent calving intervals in primiparous and multiparous Holstein dairy cows. Test day records (3X milking frequency) of milk yield measured on primiparous (n = 503793) and multiparous (n = 389237, 257347, 156035 and 87750 for parity 2, 3 and 4, and 5 respectively) Holstein dairy cows collected during 1984–2019 were obtained from Animal Breeding Center of Iran. To investigate the relationship between MP% at different time intervals of lactation and subsequent calving intervals (up to fifth parity), each lactation was divided into four time periods (≤50d, 50 < d ≤ 100, 100 < d ≤ 200 and 200 < d ≤ 305). At each period, protein concentrations were also divided into three classes: 1–3%, 3–5%, 5–7%. There was a negative relationship between MP% in the first 50 days of first lactation in primiparous and multiparous dairy cows and subsequent calving intervals in a way that calving intervals decreased as MP% increased and the shortest calving intervals were observed for the third class of milk protein concentrations. After the first 50 days of first lactation, the shortest subsequent calving intervals were detected for the second class of MP% and the CI increased non-significantly when MP% increased to 5–7. In general, due to the significant relationship between MP% and subsequent CI, this relationship can be further considered in breeding programs in dairy cattle.

Early breast expression for very low birth infants admitted to neonatal intensive care unit: the challenges of cesarean deliveries

Aim of the study In preterm infants, the use of human milk is associated with unique benefits. However, successful breast feeding rates and prolonged breastfeeding duration is often reduced in preterm infants. Nevertheless, early initiation of breast expression after birth is believed to be one of the major variables that should improve the odds of successful breastfeeding. Hence, we aimed to assess correlation between timing of milk expression initiation and volume produced in regards to mode-of-delivery. Materials and methods Prospective, observational study. Mothers delivering infants weighing < 1500 g measured 24-h milk volumes on days 1–7, 14, and 21. Results Mothers delivering vaginally (N = 11) expressed milk sooner (3.82 ± 5.03 h) than mothers in the cesarean group (N = 42; 11.5 ± 9.1 h). There were no significant differences in daily number of expressions (i.e. day 1 3.6 ± 1.6 versus 2.5 ± 2.1, p = .125) or daily volume (i.e. day 1 – 7.5 ± 6.1 ml versus 11.6 ± 22.9 ml, p = .563), until day 6 from which, both were lower in the cesarean group (i.e. day 21 – number − 6.0 ± 1.3 versus 4.6 ± 1.7, p = .029; volume – 796 ± 465ml versus 435 ± 368ml, p = .018). Expressed volume initially did not correlate with earlier expression, however, latter expressed volume inversely correlated with earlier expression. In multivariate-analysis, mode of delivery, gestational age, and daily number of expressions were correlated with volumes on day 21 (p = .001). Conclusions Earlier human-milk expression is related to volumes on the second and the third week of lactation. This is overwhelmed by delivery mode, and by frequent milk expression from day 2. When early milk expression is not possible, more frequent milk expression might help increasing volumes.

Factors related to dietary habits, energy drink consumption, and physical activity in marginalized Palestinian schools: A cross-sectional study.

Background: The current study assessed different dietary habits, energy drinks intake, body mass index (BMI) and physical activity and associated factors among Palestinian adolescents attending marginalized schools. Methods: A cross-sectional study targeted a random sample of 1480 students in the sixth andninth grades attending 20 marginalized public schools in the West Bank area of the occupied Palestinian Territories (oPt). Students were interviewed in-person by trained senior dental students about their dietary habits, physical activity, fathers’ employment and mothers’ level of education. Weight and height were measured, and BMI percentile was calculated. Descriptive statistics were generated for the study’s main variables and the dependent variables were compared by grade, gender, mothers’ level of education and father’s employment. Results: A total of 1282 students (98% response) completed the questionnaire. Of them, 6% were ‘underweight’ (fifth percentile or under) and 34% were ‘overweight’ or ‘obese’ (85thpercentile or over). Ninth graders had more added sugar than 6th graders (P=0.002), less frequent milk consumption (P<0.001), more frequent energy drink consumption (P=0.001),and less physical activity (P<0.0001). Frequency of carbonated and sweetened drink consumption was associated with being overweight or obese (P=0.016, P=0.001). Frequency of carbonated drinks consumption was higher among children of mothers with a high school level of education or less (P<0.001). In addition, children of mothers educated to high school level or below were associated with being underweight (P=0.05). Conclusion: Dietary habits and physical activity get worse between the ages of 12 and 15. Mothers’ level of education is an important factor in being overweight or underweight. Energy drink consumption among boys and milk consumption among girls are two challenges that need to be addressed urgently and adequately.

Effect of the Milking Frequency on the Concentrations of Ammonia and Greenhouse Gases within an Open Dairy Barn in Hot Climate Conditions

Knowledge of how different management strategies affect gas production from livestock buildings can be helpful for emission predicting purposes and for defining mitigation strategies. The objective of this study was to statistically assess whether and how measured concentrations of ammonia (NH3), methane (CH4) and carbon dioxide (CO2) were influenced by milking frequency. Concentrations of gases were measured continuously by using infrared photoacoustic spectroscopy in the breeding environment of an open dairy barn located in Sicily in hot climate conditions. Data were acquired by specific in-field experiments carried out in 2016 and 2018, when milking sessions occurred twice a day (2MSs) and three times a day (3MSs), respectively. The number of the milking cows was 64 in both 2MSs and 3MSs. The results showed that concentrations of NH3, CH4 and CO2 were statistically influenced by the number of milking sessions. From 2MSs to 3MSs, NH3 concentrations were enhanced (p &lt; 0.001) due to the higher cow’s activity. Conversely, gas concentrations of CH4 and CO2 were lower for 3MSs compared to those for 2MSs due to the effect of the different feeding frequency. Overall, the milking frequency influenced barn management and cow behaviour by modifying the level of gas concentrations in the barn environment.

Milk Consumption and Bone Mineral Density in Adults: Using Data from the Korea National Health and Nutrition Examination Survey 2008-2011.

BackgroundMilk consumption is associated with bone mineral density (BMD), but reports are limited in terms of participant age, sex, and number of study subjects. We investigated the association between milk consumption and BMD in South Korean adults (≥20 years).MethodsWe analyzed men and women aged ≥20 years who participated in the Korean National Health and Nutrition Examination Survey, 2008–2011. We used linear regression to calculate the mean BMD and 95% confidence interval (CI) based on the frequency of milk consumption. Multivariate logistic regression analysis was used to estimate the odds ratios (ORs) and 95% CI for T-scores ≤-2.5 (osteoporosis) in both men aged ≥50 years and postmenopausal women.ResultsIn total 8,539 subjects were studied. Drinking milk more than once a day was associated with higher BMD in the total femur and femoral neck in men aged <50 years and lumbar spine in men aged ≥50 years, compared to less than once a week. It was also associated with lower ORs for osteoporosis of the femoral neck and lumbar spine in men aged ≥50 years (OR, 0.35; 95% CI, 0.125–0.979 and OR, 0.34; 95% CI, 0.143–0.804, respectively). In postmenopausal women who consumed milk 2–6 times weekly, higher BMD and lower OR for osteoporosis were observed in the total femur (OR, 0.23; 95% CI, 0.055–0.958).ConclusionThis study suggests that frequent milk consumption could potentially reduce osteoporosis incidence in South Korean adults. Further prospective study is necessary to elucidate the effect of milk consumption on BMD.

Effects of feeding level, milking frequency, and single injection of cabergoline on feed intake, milk yield, milk leakage, and clinical udder characteristics during dry-off in dairy cows

Abrupt and gradual dry-off strategies by reducing feeding level (normal vs. reduced energy density), reducing milking frequency (twice vs. once daily), and administration of a dopamine agonist after last milking (i.m. saline vs. cabergoline injection) were investigated (2 × 2 × 2 factorial arrangement) for their effects on feed intake, milk yield, energy balance, milk leakage, and clinical udder characteristics in 119 Holstein cows. In the last week before dry-off, cows were assigned to 1 of 4 combinations of feeding level and milking frequency. Within 3 h after last milking, cows were injected with either saline or a dopamine agonist (cabergoline; Velactis, Ceva Santé Animale; labeled for use only with abrupt dry-off, i.e., no preceding reduction in feeding level or milking frequency before last milking). After dry-off, all cows were fed the same diet for dry cows, and data collection continued for a week. Dry matter intake (DMI) was recorded in automated feed bins and milk yield in an automatic milking system where additional concentrate was fed. Clinical udder characteristics and milk leakage were scored 10 times during the week before and the week after dry-off. Before dry-off, total DMI decreased with reduced feeding level compared with normal feeding level, but did not differ between milking frequencies. The combined effect of reduced DMI and diet energy concentration resulted in a 47% lower net energy intake with reduced feeding level compared with normal feeding level during the week before dry-off. Milk yield was approximately 30% lower during the week before dry-off when either feeding level or milking frequency was reduced compared with no change in feeding level or milking frequency, whereas milk yield was 45% lower when both feeding level and milking frequency were reduced. The net energy balance during the week before dry-off was negative with reduced feeding level and more negative when combined with twice-daily milking. After dry-off, udder engorgement was reduced in the 3 gradual dry-off treatments compared with abrupt dry-off. Cabergoline injection after last milking resulted in least udder engorgement and signs of milk leakage for 48 h, but also resulted in abrupt reduction of DMI lasting approximately 24 h irrespective of treatment before dry-off. In conclusion, gradual cessation of lactation by reducing milking frequency to once daily without reducing the feeding level decreased milk yield before dry-off in high-yielding dairy cows and reduced udder engorgement after dry-off without inducing negative energy balance during the period of dry-off. In contrast, reduced feeding level induced negative energy balance, which may compromise welfare due to metabolic stress and hunger. No clear differences in risk of milk leakage after dry-off were observed between abrupt and gradual dry-off management strategies. Use of cabergoline led to fewer signs of milk leakage and reduced udder engorgement during the first days after dry-off, which may positively affect welfare at dry-off. However, the mechanism behind and the welfare consequences of the concomitant abrupt decrease in DMI lasting approximately 24 h needs further investigation to complete our understanding of dopamine agonist use for dry-off.

COMPARISON OF BREASTMILK PRODUCTION FROM MOTHERS OF PREMATURE AND MATURE BABIES DURING THE FIRST WEEK IN NICU SILOAM HOSPITALS KEBON JERUK

Background: The principal goal for infants especially preterm is the provision of the mother’s own milk (MOM), but on the other hand it is difficult to get MOM for preterm babies due to delayed of lactogenesis II and mother’s stress. Milk production and adequacy, for mothers of both healthy breastfeeding term infants and non-nursing preterm infants, have been shown to have a significant relationship with milk production 4-6 days after birth. This research aim to describe the comparison of milk production between mothers of premature and mature babies during the first week in NICU SHKJ. Methods: This is an observational descriptive with comparative study of mother’s milk production of preterm (&lt;37 weeks) and term (&gt;37 weeks) babies during the first week of life in NICU Siloam Hospitals Kebon Jeruk from 1st January until 31st December 2018. We documented the milk production from mothers breastmilk expression every 3-4 hours since 4-6 hours after delivery until day 7. Results: From 181 babies during 2018, we got 31 preterm and 77 term babies that we could documented from birth until day 7. The average breastmilk production of the preterm vs term mothers in each expression from day 1-7 were 0,81 vs 1,61 ml; 3 vs 3,65 ml; 6,66 vs 6,94 ml;21,5 vs 26,6 ml; 34,1 vs 46,4 ml; 45,92 vs 46 ml; 48,88 vs 50,4 ml/x expression.Conclusions: Expressing milk for a preterm or unwell baby requires commitment by the mother and effective support from staff. Commence breast milk expression as soon as possible after birth, at least within the first six hours, followed by frequent, regular and effective breast milk expression to stimulate adequate breast milk production may provide MOM for babies even for preterm babies in NICU with almost similar amount.

P75 Disaggregating Nutrition Education Evaluation Data to Assess Racial Equity in Program Outcomes

<h3>Background</h3> A legacy of structural discrimination has contributed to increased rates of poverty, food insecurity, and obesity among African American Americans compared to White Americans. Supplemental Nutrition Assistance Program - Education (SNAP-Ed) is intended to ameliorate food insecurity and obesity and must consider whether it meets the needs of African Americans at increased risk of those conditions. <h3>Objective</h3> To assess whether educational outcomes from participation in the Louisiana State University SNAP-Ed program were equivalent for African American participants compared to White participants. <h3>Study Design, Settings, Participants</h3> Change in eating behaviors following SNAP-Ed participation were evaluated with pre/post surveys. Outcomes measured included change in frequency of consuming fruits, vegetables, whole grain and dairy products, and sugar sweetened beverages after SNAP-Ed participation. Data from 2 prior evaluations were combined and stratified by race (n = 434, 66% African American). Paired <i>t</i> tests for change in dietary behaviors were conducted across race categories using Stata 16.1. <h3>Results</h3> Outcomes did not differ between African American and White participants for most behaviors. However, frequency of fruit juice consumption increased significantly among African Americans (mean increase 0.27 on a Likert scale of 1-5, <i>P</i> = 0.005), but not among White participants (0.12 increase, <i>P</i> = 0.191). Frequency of low-fat milk (0.24, <i>P</i> = 0.053) and whole grain pasta consumption (0.33, <i>P</i> = 0.001) increased among White participants with marginal significance, but not among African American participants (mean increase 0.11, <i>P</i> = 0.247 and 0.16, <i>P</i> = 0.102, respectively). <h3>Conclusion</h3> SNAP-Ed must consider whether it adequately serves African Americans given the historical structural discrimination they have faced. Though most outcomes from LSU SNAP-Ed participation were not significantly different between African American and White participants, the consumption of fruit juice, low fat milk, and whole grain pasta changed differently in African American participants. This study serves as an example for future equity-focused evaluations. Further research should assess what may contribute to racial differences in behavior change outcomes of SNAP-Ed participation.

Genetic Parameters Estimation of Milking Traits in Polish Holstein-Friesians Based on Automatic Milking System Data.

Simple SummaryThe automatic milking system provides a large amount of information characterizing the course of each cow milking, which is not available in the conventional system. From a breeding point of view, it is interesting to establish the genetic variability of these traits, as well as to establish the relationship between them. The aim of our study was to estimate heritability and genetic correlations for milk yield (MY), milking frequency (MF), and speed (MS) for 1713 Polish Holstein-Friesian primiparous cows milked in barns with an automatic milking system. Our study conclusively indicated that it is possible to carry out effective selection for milking speed, which provides an opportunity to increase the number of cows per milking robot, and thus increase the profitability of production in the herd. We proved that selection for milk yield and daily milking frequency is also feasible. Our research showed a high, positive genetic correlation between milking frequency and milk yield, which allows us to conclude that preferring breeding cows with a natural tendency to frequent visits to the milking robot should indirectly improve the genetic basis of milking.The automatic milking system (AMS) provides a large amount of information characterizing the course of each milking cow, which is not available in the conventional system. The aim of our study was to estimate heritability and genetic correlations for milk yield (MY), milking frequency (MF), and speed (MS) for 1713 Polish Holstein-Friesian primiparous cows milked in barns with an AMS. Daily heritability indicators estimated using second-order Legendre polynomials and Random Regression Models showed high variation during lactation, ranging 0.131–0.345 for MY, 0.153–0.322 for MF, and 0.336–0.493 for MS. The rates of genetic correlation between traits ranged: 0.561–0.929 for MY-MF, (−0.255)−0.090 for MF-MS, (−0.174)−0.020 for MY-MS. It is possible to carry out effective selection for milking speed, which provides an opportunity to increase the number of cows per milking robot, and thus increase the profitability of production in the herd. The results proved that selection for milk yield and daily milking frequency is also feasible. The research showed a high, positive genetic correlation between milking frequency and milk yield, which allows us to conclude that preferring breeding cows with a natural tendency to frequent visits to the milking robot should indirectly improve the genetic basis of milking.

Iodine monitoring models contribute to avoid adverse birth outcomes related more than adequate iodine intake

BackgroundIodine plays an important role in pregnancy. How to maintain adequate iodine intake amongst pregnant women in each trimester of pregnancy to prevent adverse birth outcomes in central China is a challenge for clinical practice.Methods870 pregnant women and their infants were enrolled in the study. Urinary iodine concentration (UIC) was measured using an inductively coupled plasma mass spectrometry (ICP-MS). Maternal and newborn information were obtained during follow-up. Multinomial logistic regression models were established.ResultsMedian UIC of pregnant women was 172 ± 135 μg/L which is currently considered to be sufficient. Multivitamin supplements containing iodine, iodized salt intake and frequent milk intake were significantly associated with higher UIC. Multivariate logistic regression analysis showed that multivitamin supplements containing iodine and milk consumption were risk factors for more than adequate iodine (UIC ≥ 250 μg/L). Iodine-rich diet was significantly related to heavier birthweight, larger head circumference and longer femur length of the newborns while more than adequate iodine intake (UIC ≥ 250 μg/L) was a risk factor for macrosomia. Logistic regression models based on potential risk factors involving iodine containing supplements and iodine-rich diet were established to predict and screen pregnant women with high risk of more than adequate iodine intake among local pregnant women in different trimesters and guide them to supplement iodine reasonably to prevent the risk.ConclusionsMultivitamin supplements containing iodine and milk consumption were risk factors for maternal UIC ≥ 250 μg/L which was a risk factor for macrosomia. Iodine monitoring models were established to provide guidance for pregnant women to reduce the risk of more than adequate iodine intake, thereby contributing to reduce the risk of having a macrosomia.

Characterization of the liver proteome in dairy cows experiencing negative energy balance at early lactation

Negative energy balance (NEB) is associated with metabolic disorders in early lactation dairy cows. Therefore, our objective was to characterize the liver proteome in cows experiencing either NEB or positive energy balance (PEB). Forty-two multiparous Holstein dairy cows were milked either 2 or 3 times daily for the first 30 days in milk (DIM) to alter EB, and were classified retrospectively as NEB (n = 18) or PEB (n = 22). Liver biopsies were collected from 10 cows (n = 5 from each milking frequency) at 17 ± 3 DIM (NEB, n = 6; PEB, n = 4). The liver proteome was characterized using label-free quantitative shotgun proteomics and Ingenuity Pathway Analysis used to identify key affected canonical pathways. Overall, 2741 proteins were identified, and 68 of those were differentially abundant (P ≤ 0.05 and FC ± 1.5). ENO3 (FC = 10.3, P < 0.01) and FABP5 (FC = -12.5, P = 0.045) were the most dramatically upregulated and downregulated proteins, respectively, in NEB cows. Numerous mitochondrial proteins (NDUFA5, NDUFS3, NDUFA6, COX7A2L, COX6C, and COA5) were differentially abundant. Canonical pathways associated with NEB were LPS/IL-1 mediated inhibition of RXR function, oxidative phosphorylation, and mitochondrial dysfunction. Additionally, cows experiencing NEB had less hepatic IL10 transcript abundance than PEB. Together, NEB was associated with altered hepatic inflammatory status, likely due to oxidative stress from mitochondrial dysfunction. SignificanceOur manuscript describes the associations of negative energy balance with the liver proteome in early lactation dairy cows, when metabolic stress and the incidence of diseases is increased. Specifically, we found associations of negative energy balance with shifts in hepatic protein abundance involved in fatty acid uptake, impaired anti-inflammatory responses, and mitochondrial dysfunction. Moving forward, differentially abundant proteins found in this study may be useful as either biological markers for disease or therapeutic targets to improve metabolic adaptations to lactation in postpartum dairy cattle.

Effects of concentrate supplementation strategies during the transition period and milking frequency in early lactation on seasonal winter-calving organic dairy cows

At the start of lactation, a severe energy deficiency can have negative impacts on dairy cows’ performance and health. The objective of this 3 × 2 factorial study was to compare the effects of three concentrate (C) build-up strategies during transition period (C-21; C1; C+21) and two milking frequencies (M) during 1st week of lactation (once vs. twice-daily milking; M1 vs. M2) on feed intake, milk yield, energy supply, body weight, body condition score, metabolic status, health, and fertility parameters.During the three years of study, data were collected for 66 transition periods (N) from 37 individual animals (21 Holstein Friesian (HF) and 16 Austrian dual purpose Simmental animals (SI); 8 primiparous cows in each breed). Four weeks (1st Nov., ±57.2 days) before expected calving date the animals were allocated randomly (balanced for parity, breed, calving date, insemination index in the previous breeding season and genetic merit) to one of three concentrate supplementation strategies (C) during the transition period (C-21; C+1; C+21; N=22 group−1). Within these three C groups, half of the cows were either milked once (M1) or twice (M2) during 1st week of lactation, and from 8 DIM onwards all cows were milked twice a day. All animals were offered a high-quality forage basal diet comprising hay and grass silage from four weeks before expected calving date until 98th days in milk (DIM). In group C-21 the concentrate supplementation started 21 days (-21 days) before expected calving date and was increased (DIM -21 to -15) from 1.8 kg dry matter (DM) to 2.6 kg DM (DIM -14 to 1) until parturition; during the first 14 DIM concentrate supplementation was daily increased by 0.26 kg DM cattle−1 from 2.6 to 5.9 kg DM and from 15 DIM onwards concentrate supply depended on actual milk yield of the individual cow. In group C+1 no concentrate was fed pre-partum, and from lactation day 1 onwards the same concentrate building up strategy and allocation was made as described for group C-21. In group C+21 the concentrate supplementation did not start until 21 DIM and from this point on the same concentrate build-up-strategy was implemented as described for group C+1, but with each phase delayed by 21 days.Pre-calving feed and net energy intake (NEL) as well as net energy balance (EB) was significantly higher in C-21 compared to groups C+1 and C+21. During the first seven weeks of lactation C+21 groups (P<0.001) showed the significant lowest NEL intake, and for energy-corrected-milk (ECM) yield a tendency (P=0.067) for an interaction between C and M was found. In C-21 and C+1, cows in M1 had significantly lower ECM yields compared to cows in groups M2 (C-21: 22.5 and 25.0 kg/d; C+1: 20.3 and 26.1 kg/d in M1 und M2, respectively); in C+21, ECM yield differed only numerically between M1 (22.1 kg/d) and M2 (23.9 kg/d). Cows in M1 showed in all C groups higher milk protein contents and higher somatic cell counts compared to M2; no significant C x M interactions were found. Within all concentrate supplementation strategies, cows in M1 showed higher EB during lactation weeks 1 to 7, within C groups the differences between M1 and M2 were significant in C-21 (C-21M1 +4.8 and -4.2 MJ NEL/d) and C+1 (C+1M1 +7.8 and -4.7 MJ NEL/d), in C+21 groups only numerical differences were found (C+21M1 -2.1 and C+21M2 -8.1 MJ NEL/d). During the first six weeks of lactation, the lowest blood glucose concentrations were detected in C+21 (2.80 in C+21M1 and 2.68 mmol/l in C+21M2). For nonesterified fatty acids concentration (NEFA) a significant interaction between C and M treatment was found (PCxM<0.001), within C-21 and C+1 groups cows in M1 showed significantly lower NEFA concentrations compared to M2 groups, in C+21 NEFA concentration were higher in M1. The significant highest ß-hydroxybutyric acid concentrations (BHBA) were found in C+21 groups with 0.80 and 0.92 mmol/l in M1 and M2, respectively, between C-21 and C+1 no significant BHBA concentration differences were found in both milking groups. Cows in M1 require fewer veterinary treatments, were significantly earlier inseminated, but the first service conception rate and the total number of services per conception varied not significantly between groups. In conclusion, a delayed concentrate supplementation to 21 DIM (C+21) reduced energy intake and showed negative effects on EB and metabolic parameters. Once a day milking up to 7 DIM (M1) had no effect on energy intake, reduced ECM yield and improved EB and metabolic parameters in the first seven weeks of lactation. Also M1 reduced total number of veterinary treatments, led to earlier inseminations, had no effects on the other measured reproduction parameter, and increased somatic cell counts (SCC).

Assessing effects of dietary and milking frequency changes and injection of cabergoline during dry-off on hunger in dairy cows using 2 feed-thwarting tests

We investigated the single and combined effects of 2 feeding levels (normal lactation diet vs. energy-reduced diet, both fed for ad libitum intake) and 2 daily milking frequencies (twice vs. once) during 1 wk before the dry-off day (d 0), as well as an intramuscular injection of either a dopamine agonist (cabergoline; Velactis, Ceva Santé Animale; labeled for use only with abrupt dry-off, e.g., no reduction in feeding level or milking frequency before the last milking) or saline after the last milking on d 0 on the feeding motivation of clinically healthy, loose-housed, pregnant, lactating Holstein cows. From d 0, all cows were fed the same dry-cow diet for ad libitum intake. Cows were subjected to 2 feed-thwarting tests, a test in the home pen using their diets (test A: d -6, -1, and 1; during 35 min when the feed bins were filled, but locked) and another test carried out in an adjacent pen in which access to concentrate provided in a familiar plastic box was blocked by a wire-mesh lid (test B: d -5 and 2). In test A, we recorded how often cows attempted to feed per 35 min, whether cows vocalized during the 35-min period, and latency to feed within 300 s after feed bins were unlocked. In test B, we recorded latency to approach either of 2 familiar boxes (the wire-mesh box and an identical open box with a small portion of concentrate) within 600 s and how often cows directed behaviors toward the wire-mesh box (number of occurences/5 min). On d -6 (test A), no clear differences in feeding motivation among treatments were found. On d -5 and -1, cows fed the energy-reduced diet displayed a higher probability of vocalizing (test A), were more than 50% quicker to feed (test A), were approximately 5× quicker to approach a box (test B), and directed 60% more behavior toward the wire-mesh box (test B) than cows fed the normal diet. Moreover, cows fed the energy-reduced diet attempted to feed approximately 75% more on d -1 compared with d -6 (test A). On d 2 (test B), cows previously fed the normal diet directed 40% more behavior toward the wire-mesh box than cows previously fed the energy-reduced diet. Reducing feeding level, either before or on the dry-off day, resulted in consistently increased feeding motivation, interpreted as a sign of hunger. No clear effects of change in milking frequency, singly or combined with reduced diet energy density, on feeding motivation were found before d 0. Whereas, on d 2, cows previously milked twice daily were quicker to approach a box than cows previously milked once daily. Cows injected with cabergoline attempted to feed more, but showed lower probability of vocalizing compared with saline-injected cows (d 1; test A), irrespective of treatment before d 0. The effects of cabergoline on feeding motivation are not easily interpreted and warrant further investigation. From a hunger perspective, reducing milking frequency rather than diet energy density seems to be a less negative management to reduce milk production before dry-off.

Comparison of sire breeding values for milk yield traits based on daughters milked once or twice daily in New Zealand

Abstract Context In New Zealand, cows are usually milked twice a day (TAD), but in ~8% of herds, cows are milked once a day (OAD) for the entire lactation. If a genetic correlation (rg) of the same trait expressed in two environments (such as TAD and OAD) is substantially &lt;1.0, then the genetic merit assessed from TAD herds may not be reliable for predicting genetic merit in OAD herds. Initial evaluation of sires has been undertaken from progeny test herds with TAD milking, and the best sires have then been made widely available for use in TAD or OAD herds. Aim The study was designed to test formally whether sire re-rankings occur in widely used sires at different milking frequencies. Methods Regression coefficients and rank correlations (rS) for estimated breeding values (EBVs) of 242 widely used sires (86 Holstein-Friesian, 96 Jersey and 60 crossbred) were calculated for yields of milk, fat and protein, and for somatic cell score (SCS). The rS values were contrasted with expected rank correlations (rE) between TAD and OAD EBVs assuming rg = 1.0 between true BVs expressed at the two milking frequencies and accounting for the fact that sires were highly selected. Key results Within and across breeds, regression coefficients of OAD on TAD EBVs for the same traits were &lt;1.0, but rS values between TAD and OAD EBVs of the same sires were strong (&gt;0.75) for milk yield, moderate–strong for fat and protein yield (0.55–0.77), and moderate for SCS (0.41–0.65). Estimates of rS were higher than their critical rE values, indicating no significant sire re-ranking across milking frequencies. Conclusions On the basis of the results, a separate selection program to generate sires for use in OAD herds is not justified. Implications Farmers operating under OAD systems can rely on genetic evaluation of sires evaluated in TAD systems and used in the OAD population. However, producers should recognise that the realised productive and economic advantage of daughters of elite sires born in OAD herds is diminished relative to that expected in TAD herds.

ЛАКТАЦИОННАЯ ДЕЯТЕЛЬНОСТЬ КОРОВ-ПЕРВОТЕЛОК В УСЛОВИЯХ РОБОТИЗИРОВАННОГО ДОЕНИЯ

Studies have been conducted to assess the lactation productivity of Kholmogory breed Tatarstan type first-calf cows with robotic milking systems. The frequency of milking distribution during the day was observed: in the interval of 4-6 hours, the minimum number of milking occurs (6.4 %), in the interval of 12-14 hours, the maximum number (10.7 %). Most milking (34.7 %) is carried out in 6-8 hours after the previous one. More frequent milking (after 4-6 hours) is rarely observed is in 6 % of cases. 48.6 % of milking occurs after the 8-12 hour interval. For an interval of more than 12 hours occurs for 10.7 % of milking. With an increase in the milking interval, the milk yield also increases. At 4-6 hour interval, the milk yield is 5.2 kg, at 6-8 hour is 6.0 kg. An increase in the milking interval by 2 hours is accompanied by an increase in the single milk yield by 0.8-1.3 kg. During the first month, the cows were milked the least number of times, which was 75, or 2.4 times per day; during the second month, they were milked 86 times (2.8 per day). By the 4th month, milkings reached a peak of 93 times (3 per day). By the 5th month, a decline was observed (by 11 % compared to the 4th month). The peak milk production takes place during the second month of lactation, 681.3 kg. By the third month, a decline was observed by 4.8 %, to 648.1 kg. The maximum decrease in milk production, by 12.4 %, occurred between the 5th and 6th month of the tested lactation period.