Total Milk Research Articles

The Protein Composition of Bovine Milk from Once-a-Day and Twice-a-Day Milking Production Systems in New Zealand

An increasing number of dairy farmers in New Zealand (NZ) have adopted a once-a-day (OAD) milking production system, and little is known about the impact of this production system on milk protein composition. The objective of this study was to evaluate the effect of OAD milking on the protein composition in milk from individual cows. Milk was sampled in early, mid-, and late lactation from cows kept at Massey University farms Dairy No. 1 (OAD milking) and Dairy No. 4 (TAD milking) in Palmerston North, NZ. The yields of total milk and milk solids, the proximate composition, and the protein composition were determined. Results showed that OAD milking yielded less milk and milk solids than TAD milking. However, no significant differences in protein, fat, and lactose contents were found. While the proportions of total casein (CN), total whey proteins, αs1-CN, β-CN, and β-lactoglobulin were not affected by the milking frequency, milk from a OAD milking system contained higher proportions of αs2-CN and κ-CN and lower proportions of α-lactalbumin. These proteins also changed differently throughout the milking season in a OAD milking system than in a TAD milking system. These changes in the protein composition of the milk observed in a OAD milking system could have implications for its processing properties and product quality.

Association Between Genetic Polymorphism of Mutation (G5736A) in the BMP-15 Gene with Productive Performance of Local and Shami Goats

The study was conducted at the ruminant research station of the Agricultural Research Department / Ministry of Agriculture on a sample consisting of 44 local goats and 52 Shami goats, while the laboratory part was conducted in Scientific Progress Laboratory, for the period from 12/20/2021 to 9/1/2022. The nucleotide sequencing technique was used to detect mutations in The second exon region of the (BMP15) gene to determine the relationship of the resulting genotypes to economic traits (growth, milk production and litter size). The results showed that there are two genotypes, the wild (GG) and the hybrid (GA), as the percentage of individuals carrying the wild genotype was (90.91, 67.31) % compared to the hybrid individuals (9.09, 32.6) % respectively, in the local and Shami goat samples, and the allelic frequency of the wild allele G in both groupss was (0.95, 0.66)% compared to the mutant allele A (0.05, 0.34)%. for both groupss goats, the wild type individuals were superior in birth weight and did not show any significant effect of this mutation on the rest of the growth traits (19.03, 21.0) kg, as for the characteristics of milk production, the individuals carrying the wild genotype also excelled in the characteristic of total milk production in both groupss. (467.4, 490.4) kg compared to individuals carrying the hybrid genotype GG (422.1, 457.1) kg respectively, While no significant effect of the mentioned mutation appeared in litter size for both groups.

A study of the Relationship of Polymorphisms of the PPARGC1A Gene with Milk Production and its Components, in Holstein Friesian Cows

This research was done at a Molecular Genetics lab at the College of Agriculture at the University of Basrah. The objective of this study is to determine how Holstein Friesian cows’ PPARGC1A genetic polymorphism affects milk production and its constituent parts. For milk production and quality standards, 59 Holstein Friesian cows from Taj Al-Nahrain station in Al-Diwaniyah are employed. Blood was drawn for genomic DNA, and the PPARGC1A gene was amplified using PCR. The samples were then transferred to the Korean firm Macrogene for DNA sequencing analysis. Morning milk 50ml samples were collected once each week., and after taking the samples during the milking process, they were evaluated for quality using the Julie Z7 milk analyzer. Association analysis was performed using SPSS statistical software. According to the current study’s findings, the stage of milk production had a significant impact on both daily and total production (p ≤0.05). The results also shows that there is a significant differences (p≤0.05) of stage of milk production on the chemical composition of milk, while there are no significant differences between Genetic Polymorphisms in daily and total milk production. The results show that hap1 is superior on hap2 in the chemical contents of milk, except for the percentage of milk fat, which has not reach a significant level.

ПРОИЗВОДСТВО ТОВАРНОГО МОЛОКА И КОНКУРЕНТОСПОСОБНЫЕ КАЧЕСТВА МОЛОЧНОГО СЫРЬЯ В РЕСПУБЛИКЕ БАШКОРТОСТАН

The article considers the indicator of marketability of milk, which directly affects the formation of competitiveness of raw milk produced in the Republic of Bashkortostan, and raw materials for further export and production of dairy products. The factors and features influencing the indicator of the volume of commercial milk production in the Russian Federation and the analyzed region, the quality of milk are revealed. The volume of commercial milk production is the main key indicator of the development of dairy cattle breeding, since it is commercial (and not all raw) milk that is the resource base for the industrial production of dairy products and only commercial milk can be reliably accounted for. To date, in the republic, the share of commercial milk from the total milk yield is only 51%, with the average Russian indicator of 73.7%. Based on this, possible ways to solve the problem of increasing the volume of commercial milk production in the Republic of Bashkortostan, as well as the impact of modernization of production facilities, state subsidies and investments in the development of the industry are considered. Statistical information on the state of the dairy industry in the region is provided.

Lifetime dairy product consumption and breast cancer risk: a prospective cohort study by tumor subtypes

BackgroundPrevious literature on dairy products and risk of breast cancer is inconsistent, and the relationship may depend on the life-period of dietary assessment. ObjectiveWe examined dairy consumption from adolescence through later adulthood and incidence of breast cancer by menopausal status and tumor molecular subtypes in the Nurses’ Health Study (NHS), a prospective cohort study. MethodsWe analyzed data from 63,847 females in the NHS collected from 1980 to 2018. Average intake of dairy products during adulthood was assessed by validated semiquantitative food frequency questionnaires throughout follow-up. Participants recalled adolescent dietary intake in 1986. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) relating dairy product consumption to breast cancer risk overall, by menopausal status, and by subtypes. ResultsWe documented 5733 incident cases of invasive breast cancer during 32 y of follow-up (n = 5298 postmenopausal). Lifetime, adolescent, adulthood, and postmenopausal total dairy and milk intakes were not associated with overall breast cancer risk (nonsignificant HRs comparing highest with lowest quintile range = 0.97–1.08), although there was a suggestive positive association between adolescent milk intake and breast cancer risk (HR: 1.09; 95% CI: 1.00, 1.18). Higher lifetime and premenopausal cheese intakes were associated with modestly lower risks of breast cancer (comparing highest with lowest quintile, HR for lifetime cheese intake: 0.90; 95% CI: 0.82, 0.98; HR for premenopausal cheese intake: 0.89; 95% CI: 0.79, 1.00). Results varied by tumor subtype and some evidence for heterogeneity was observed for an association between premenopausal milk intake and breast cancer (HR for estrogen receptor [ER]-positive: 0.84; 95% CI: 0.72, 0.99; ER-negative: 1.36; 95% CI: 1.00, 1.84; P heterogeneity = 0.04). ConclusionsThese findings suggest that overall dairy consumption was not associated with risk of breast cancer. However, heterogeneity was observed for type of dairy food, period of life, and tumor subtypes.

Optimizing selection strategy for enhancing reproduction efficiency in Indian crossbred goats using milk productivity as a selection criterion.

The present study was aimed at optimizing the selection strategy for enhancing reproductive efficiency and milk productivity of Alpine × Beetal crossbred goats. The data set included 2949 milk trait records across parities and 1389 milk records from first parity and corresponding reproductive traits. The traits included for analysis were 150-day milk yield (150DMY), days in milk (DIM), peak yield (PY) and total milk yield (TMY). The litter size (LS) and litter weight (LW) were used for specifically formulating selection plan using indirect selection. The least squares mean for lactation traits during the first parity were 150DMY: 195.32 ± 2.09 kg, DIM: 236.42 ± 3.04 days, PY: 1.82 ± 0.02 kg, TMY: 269.62 ± 4.52 kg. Notably, Alpine × Beetal goats demonstrated genetic superiority pan India for milk productivity as compared to other native goat breeds. The least squares mean for 150DMY across all parities was 236 ± 3.13 kg. An animal model employing average information restricted maximum likelihood was used for (co)variance component estimation to get the genetic parameters. The analysis revealed total heritability estimates for 150DMY, DIM, PY and TMY as 0.18 ± 0.06, 0.04 ± 0.04, 0.12 ± 0.06 and 0.08 ± 0.05, respectively. Repeatability estimates for 150DMY, DIM, and TMY were 0.28 ± 0.04, 0.21 ± 0.03 and 0.37 ± 0.03, respectively. Bivariate analysis of 150DMY with reproductive traits revealed heritability for LS and LW as 0.05 ± 0.01 and 0.10 ± 0.01, respectively using Gibbs sampling. Strong and positive genetic correlations of 150DMY with other production and reproduction traits was observed, such as DIM (0.72), PY (0.98), TMY (0.88), LS (0.57) and LW (0.33). Moderate heritability and repeatability estimate of 150DMY, along with its positive correlation with production and reproductive traits suggested it as a suitable selection criterion for early selection and overall genetic progress of lactation traits. The genetic trend analysis showed an overall improvement in all these traits, with observed gain of 98.4 g per year for 150DMY, 0.04 days per year for DIM, 0.5 g per year for PY and 220.5 g per year for TMY. We observed that selecting based on 150DMY would lead to a favourable indirect improvement for LW as 79 g and LS 0.04 units per generation. We, therefore, recommend employing 150DMY as the single trait selection criteria to enhance both milk productivity and reproductive potential of Alpine × Beetal goats.

Optimization of dairy cows diets for crude protein

The influence of the composition of the diet on the productive indicators of cows, in particular on the chemical composition of milk, is analyzed. A reduction in the supply of succulent feed to 46.6% of the total energy nutrition and an increase in the proportion of concentrates (up to 53.4% of the exchange energy) for dairy cows were unacceptable. During the study, the level of milk productivity of black-andwhite cows increased very slightly – by 0.7 kg head /day. It is possible that in the first days of the change of the cow's diet, the total gross milk yield increases, but this period does not last long, and soon cows with acidosis and other metabolic disorders appear on the farm. The increase in the level of concentrated feed in the farm negatively affected the physico-chemical composition of milk, which became unsorted. A negative consequence of the change in the diet of cows was a deterioration in the quality of milk. Thus, the ratio of «fat – protein» has changed in the opposite direction, the urea content has increased (to 48.58–52.97 mg / 100 ml), the titrated acidity of milk has increased (to 19.49–21.04 °T) and the content of somatic cells in milk (to the level of 354.41–450.54 thousand / cm3) in cows of all lactations.

Strategy for Developing Dairy Farming for All-Business Cooperatives in Tandangsari, Sumedang Regency

The livestock sector has proven itself to be a crisis-resistant sector. The Ministry of Agriculture stated that the total national milk demand in 2019 reached 4,332.88 thousand tons. One of the dairy cattle center areas that has developed and become the focus of the Sumedang Regency Government is Tanjungsari District. The breeders joined the Tandangsari KSU. The supply and demand for pure milk has fluctuated at KSU Tandangsari in the last five years. The problems in the dairy cattle business at KSU Tanjungsari are currently related to production factors as inputs in the development of a dairy cattle business including livestock seeds, feed availability, land as living space for livestock, livestock production facilities (procurement of equipment and maintenance of livestock production), labor (breeders), as well as the cost of production.The goal of preparing the RIP is to formulate alternative strategies for developing a dairy cattle business. By identifying strengths and weaknesses, as well as opportunities and threats based on internal and external factors that affect the dairy cattle business at KSU Tandangsari.The strategy for developing a dairy cattle business is the S-O (1) strategy. Development of cattle population to increase production, (2). Building a place (factory) for processing dairy products, W-O strategy (1). Build a cow nursery, (2). Establishing cooperation with third parties in producing processed HPT, strategy S-T (1). Increasing the quality and quantity of beef cattle, (2). Moving the location of the fresh milk business activity center (MCU), W-T strategy (1). The application of appropriate technology is increased by breeders, (2). Establish cooperation with financial institutions in capital facilities.

The relationship between creamatocrit and cumulative percentage of total milk volume: a cross-sectional study in mothers of very preterm infants in Bangkok, Thailand

BackgroundHuman hindmilk contains higher concentrations of fat than foremilk and is more desirable for growth in preterm infants who can tolerate limited volumes of breastmilk. There is currently no clear demarcation between foremilk and hindmilk. This study characterized the change in breastmilk’s fat content from the start to end of milk flow and defined this demarcation.MethodsMothers of infants born at ≤ 32 weeks gestational age and ≥ 14 days after childbirth in a University hospital in Bangkok, Thailand between July, 2011, and April, 2012 were included in this cross-sectional study. Breastmilk samples were sequentially collected from the start to end of milk flow in 5-mL aliquots using breast pumps. The fat content of each aliquot from each breast was determined through creamatocrit. The average creamatocrit of foremilk and hindmilk were compared in predefined foremilk to hindmilk ratios of 20:80, 25:75, 33:67, and 50:50. Creamatocrit of the first and last aliquots were compared for mothers who expressed low- (≤ 25-mL per breast) and high-volumes (> 25-mL per breast) of breastmilk.ResultsOf the 25 mothers enrolled, one was excluded due to unsuccessful creamatocrit measurement. The last aliquot of breastmilk had a significantly higher creamatocrit than the first from the same breast (median [interquartile range] of 12.7% [8.9%, 15.3%] vs. 5.6% [4.3%, 7.7%]; test statistic 1128, p < 0.001). Mean creamatocrit in hindmilk portions (9.23%, 9.35%, 9.81%, and 10.62%, respectively) was significantly higher than foremilk portions (6.28%, 6.33%, 6.72%, and 7.17%, respectively) at all predefined ratios. Creamatocrit increased by 1% for every 10% incremental increase in expressed breastmilk volume until the breast was emptied. Low-volume mothers had a significantly higher creamatocrit in the first aliquot compared with high-volume mothers (U = 437, p = 0.002). No significant difference in breastmilk volume was observed between mothers with and without breastfeeding experience.ConclusionsFat content in breastmilk increased on an incremental basis. More fluid definitions of foremilk and hindmilk should be adopted. Mothers should prepare their breastmilk into aliquots based on the required feeding volume of their infant. Hindmilk aliquots can be prioritized over foremilk aliquots to ensure infants obtain optimal caloric intake.

DNA methylation of GDF-9 and GHR genes as epigenetic regulator of milk production in Egyptian Zaraibi goat

BackgroundDNA methylation is an epigenetic mechanism that takes place at gene promoters and a potent epigenetic marker to regulate gene expression.ObjectiveThe study aimed to improve the milk production of Zaraibi goats by addressing the methylation pattern of two milk production-related genes: the growth hormone receptor (GHR) and the growth differentiation factor-9 (GDF-9).Methods54 and 46 samples of low and high milk yield groups, respectively, were collected. Detection of methylation was assessed in two CpG islands in the GDF-9 promoter via methylation-specific primer assay (MSP) and in one CpG island across the GHR promoter using combined bisulfite restriction analysis (COBRA).ResultsA positive correlation between the methylation pattern of GDF-9 and GHR and their expression levels was reported. Breeding season was significantly effective on both peak milk yield (PMY) and total milk yield (TMY), where March reported a higher significant difference in PMY than November. Whereas single birth was highly significant on TMY than multiple births. The 3rd and 4th parities reported the highest significant difference in PMY, while the 4th parity was the most effective one on TMY.ConclusionThese results may help improve the farm animals' milk productive efficiency and develop prospective epigenetic markers to improve milk yield by epigenetic marker-assisted selection (eMAS) in goat breeding programs.

Combined mechanistic and genetic modelling to benchmark body reserve traits as proxies of dairy cows’ lifetime efficiency in grass-based production systems

Improving lifetime lactation efficiency of dairy cows by selection is difficult due to the complexity of this trait and the existence of genotype-by-environment interactions. This study aimed at assessing the relevance of traits derived from body reserves as lifetime efficiency indicators under contrasting nutritional environments. Given the absence of large-scale datasets covering a panel of feeding regimes, phenotypes were simulated for populations of 20 000 dairy cows using a mechanistic bioenergetic model. Ten phenotypes were computed for third-lactation cows. Analysed phenotypes comprised total milk production, lactation efficiency, BW at calving (BWcalv), DM intake (DMI) and interval between first insemination and conception. Five traits described levels and changes of body reserves at different periods during lactation. Lifetime lactation efficiency was computed for all cows (Life_Eff). Three nutritional environments were defined considering a grass-based production system with seasonal calving: a high non-limiting scenario (HS) mimicking ad libitum access to feed and two limiting environments with moderate (MS) and low (LS) feed offer. Variance components were estimated for all traits within and between environments using REML. Heritabilities estimated for milk production, lactation efficiency, BWcalv and DMI were moderate in the different environments (0.27–0.35 ± 0.04). The heritability of body reserve levels and dynamics were moderate in the HS and MS scenarios (0.23–0.30 ± 0.03) and lower in the LS scenario (0.14–0.25 ± 0.03). The heritability of Life_Eff was low in the HS environment (0.07 ± 0.01) and slightly increased in the limiting environments. All genetic correlations estimated between environments were moderate to high (≥0.66 ± 0.07), suggesting low to moderate genotype-by-environment interactions. Estimated genetic correlations were moderate between Life_Eff and body reserve levels (from 0.39 to 0.51 ± 0.08) and moderate but negative between Life_Eff and change in body reserves traits (−0.27 to −0.37 ± 0.09) in the HS environment. The genetic correlations between Life_Eff and body reserve levels increased to higher values in the limiting environments. In contrast, genetic correlations between Life_Eff and the changes in body reserves were closer to zero. In conclusion, this study showed that body reserve levels were relevant proxies of lifetime irrespective of the environment. In contrast, changes in body reserves that reflected energy mobilisation in early lactation were less informative about lifetime efficiency in environments with severe feed restrictions.

Genetic relationships between reproductive and production traits in Jersey crossbred cattle

The study aimed to estimate the genetic parameters of different reproductive traits namely age at first calving (AFC), calving interval (CI), days open (DO) and number of service per conception (NSPC) and their associations with productive traits including 305-day milk yield (305DMY), total lactation milk yield (TLMY) and lactation length (LL) of Jersey crossbred cattle maintained at Kalyani, Nadia, West Bengal, India. Genetic parameters of reproductive traits and their correlations with productive traits were estimated by Restricted Maximum Likelihood method and Bayesian approach. Using both analytical approaches, the estimates of heritability for AFC, CI, DO and NSPC ranged from 0.12 −0.15, 0.05–0.08, 0.08–0.09 and 0.04–0.06, respectively. Low proportion of variances associated with permanent environmental effect of animals (c2 effect) were detected for CI (0.08–0.10), DO (0.09–0.11) and NSPC (0.05–0.06) in both the methods. Repeatability measures for all the reproductive traits considered in this study were low to moderate in nature, which ranged from 0.09 to 0.17. Genetic correlations between different reproductive traits were positive and low (0.05) to high (0.98) in magnitude except AFC-NSPC. Low and negative genetic correlations of AFC with 305DMY and TLMY were favourable and indicated animals with high milk yield had early age of maturity. Positive genetic correlations between CI, DO and NSPC with all production traits implied the antagonism relationships among these traits, therefore in any breeding program for improvement of production traits via selection, the reproductive traits should be taken into account as well.

PSX-22 Effects Of Milk Replacer Supplementation with Beta-Glucans on Male Dairy Calf Performance

Abstract The objective of this randomized controlled trial was to determine the performance effects of milk replacer supplemented with a feed additive high in beta-glucans for male dairy calves. Holstein male calves (n = 147) were enrolled in a 76-day randomized block trial in two blocks. Upon enrollment, calves were assigned to one of the four following treatments: Control with no beta-glucan supplementation (BG0; n = 36; BW = 48.32 ± 3.73 kg), 1 g· animal-1· d-1 (BG1; n = 38; BW = 48.29 ± 2.89kg), 3 g· animal-1· d-1 (BG3; n = 37; BW = 48.31 ± 3.23 kg), and 5 g· animal-1· d-1 (BG5; n = 36; BW = 48.47 ± 3.00 kg) of beta-glucans. The beta-glucan supplement was blended with milk replacer (24% CP, 20% fat; 130 g/L) and fed to calves during the morning milking. Calves were individually housed, had unlimited access to water, and a pelletized calf starter (20% CP). Calves were fed 5 L/d of milk replacer divided into two equal meals until d 15; milk feeding plan increased until d 35 (8 L/d), on d 36, milk allowance was gradually reduced until weaned on d 56 (2.5 L/d). Calf starter intake and body weight were recorded weekly until d 77. Disease treatment was recorded daily. A mixed linear model determined the effect of treatment on calf starter intake and average daily gain. The model included treatment if the calf was ever treated with antibiotics for respiratory disease and/or diarrhea, study period, and a treatment by period interaction. Block was considered a random factor. The total milk replacer intake was 5.73 ± 0.08, 5.71 ± 0.08, 5.73 ± 0.01, 5.73 ± 0.01 L/d for BG0, BG1, BG3 and BG5, respectively. Calf grain intake by treatment was 58.10 ± 12.02, 54.58 ± 8.11, 56.86 ± 11.8, 56.73 ± 15.52 for BG0, BG1, BG3 and BG5, respectively. Overall, 55% and 71% of all calves were treated at least once for diarrhea, and respiratory disease respectively. The percentage of animals treated for diarrhea by treatment were 45.00, 57.50, 50.00, and 32.50% for BG0, BG1, BG3, and BG5, respectively. For respiratory disease, the percentage of animals treated was 72.5, 72.5, 70.0, and 70.00 for BG0, BG1, BG3, and BG5 treatments, respectively. There was a significant interaction between treatment and study period where the control group had greater starter intake during the postweaning period (BG0 = 0.78 ± 0.01, BG1= 0.82 ± 0.01, BG3 = 0.81 ± 0.02, BG5 = 0.82± 0.01 kg/d; P &amp;lt; 0 .001). No treatment or treatment by study period effects was observed for average daily gain (P = 0.79, P = 0.89, respectively). Future research should investigate the effects of beta-glucans on blood metabolites and palatability throughout the calf-rearing period.

Selection of dairy goats using milk recording and multivariate analysis in a family farming system

Although dairy control is a widely used tool in herds with numerous animals (mainly cows), it is often neglected in small farms. The aim of the present work was to select the most suitable animals for milk production using dairy control and multivariate statistics. Results indicate a great dispersion of the data as a consequence of milk production variation from each goat. These results demonstrate the need to identify and select the most productive animals in order to have a selected and controlled flock. The analysis of hierarchical conglomerates showed that the herd can be divided into three groups: Cluster 1 is integrated by 31 goats with the highest productive parameters, above the herd average and together produce 59.1% of the accumulative milk yield; Cluster 2 consists of 24 animals whose production parameters are close to the current average of the herd and accumulates 27.7% of milk production and Cluster 3 groups animals with the lowest production. From the results obtained, it was possible to make the selection of the 55 most productive animals for milk production. This represents 64.70% of the herd and they are responsible for 86.8% of the total milk production.

Effect of Adding Choline Chloride to the Diet in Milk Production of Holstein Cows

This study aimed to show the effect of adding choline chloride to the feed on milk production during the summer in central Iraq. This study was conducted at Al-Khalis cows station in Diyala Governorate during the period from 21/6 to 21/9/2022, where 25 Holstein cows between the ages of 3-5 years used, the cows were divided into five treatments, so that treatment T1 represents the control treatment (without adding Choline chloride), while treatments T2 and T3 add untreated and formaldehyde-treated choline chloride, respectively, to the concentrated feed with an amount of 35 g /cow /day, T4 and T5 add untreated and formaldehyde-treated Choline chloride, respectively, with an amount of 70 g /cow /day, It is noted from the results that there is a significant effect of the treatment of adding Choline chloride treated with formaldehyde T3 during the ninth and thirteenth weeks in the daily milk. In the ninth week, the average milk production was 14.50 kg / cow/day compared to 9.88 kg/cow/day in the control treatment, and the rest of the treatments were T4 and T5 were 11.25 and 10.00 kg/cow/ day respectively. In the thirteenth week milk yield was 12.50 kg/cow/day compared to 7.20 kg/cow/day in the comparison treatment, and the rest of the treatments T2, T4, and T5 were 8.75, 8.50, and 8.60 kg/cow/day, respectively. While the monthly and total milk production and the amount of fat and protein in milk for cows, there were no significant differences between the treatments, we conclude from the current experiment that adding Choline chloride treated with formaldehyde in an amount of 35 g / cow/day to the feed increases the daily milk production in some weeks for this experiment in the season Summer when the average Temperature Humidity Index for this season is 79 and cows are under heat stress.

Survival Analysis On The Reproductive And Production Performances Of Dairy Cow In Bogor

The aim of this study was to analyze the reproductive performance (empty period) and production (peak time of milk production) of 87 dairy cows (Friesian Holstein) at X dairy farm Bogor using survival analysis. The analysis results based on the Kaplan-Meier curve showed that the median total idle time, primiparous cow, multiparous cow, cow that gave birth in the rainy and dry seasons were 210; 335; 231; 272; and 397 days. The median value of the total peak milk production, primiparous cow, multiparous cow, cow that give birth in the rainy and dry seasons is 41; 41; 39; 41; 41 days. The Cox Proportional Hazard regression results on idle time showed that the multiparous cow was 1.84 times more likely (P&lt;0.05) to have a shorter idle period than the primiparous cow. Cows that gave birth during the rainy season had a 1.80 times shorter chance than cows that gave birth during the dry season, although they were not statistically significantly different (P=0.043). The regression results on peak milk production showed no difference between cows and primiparous cows. Meanwhile, cows that gave birth during the rainy season experienced peak lactation 1.26 times and tended to be faster than cows that gave birth during the dry season, although this was not statistically significant. The study's conclusions show that it was necessary to improve the management of reproduction and production of X dairy farm in Bogor.

Analysis of milk production and calving records in semi-intensively managed dairy herd in Zambia

This study was undertaken to provide empirical evidence for some reproductive performance traits in a dairy herd managed under a semi-intensive production system in Zambia. Milk production and calving records on 106 milking cows were analysed over a 12-year period involving Friesian, Jersey, Friesian x Jersey, Friesian x Simmental and Jersey x Sussex breeds. With an average parity order of 4.4, the average total milk production per lactation, average daily milk production, calving interval, and calving rate were 1,996 ± 493.5Kg, 7.9 ± 2.6Kg, 473.1 ± 138.5 days, and 77.2% respectively. Milk production was significantly higher from mid November to April compared to other months and this corresponds to the significant seasonal effect observed. A significant breed effect was found with total milk yield per lactation and average milk yield. There were significant parity effects on average daily milk production and calving interval. However, there was no significant breed effect on the calving interval. The correlation of average milk yield with calving interval was -0.26, and the parity order with average milk yield was 0.65. Friesian x Jersey crossbred showed heterosis for milk production (48.3%) and calving interval (11.4%). Breeding strategies can, therefore, be targeted at using Jersey x Friesian crossbred for the emergent smallholder farmers.

49 The Effect of Increasing Standardized Ileal Digestible Methionine Intake During Lactation on Whole-Body Nitrogen Utilization of Primiparous Sows

Abstract Seventy-five primiparous Yorkshire × Landrace and Yorkshire sows were used to determine the effect of increasing dietary standardized ileal digestible (SID) methionine (Met) intake on whole-body nitrogen (N) utilization during lactation. Upon farrowing (190.2 ± 18.0kg initial body weight), sows were assigned to 1 of 7 dietary SID Met levels (n = ~10), ranging from 70% to 130% of estimated SID Met requirements (0.182 to 0.338% SID Met) via the addition of DL-Met. All other indispensable amino acids were supplied above estimated requirements (1.19% SID lysine, 19.74% crude protein) and additional cysteine was supplied to minimize Met utilization for transsulfuration. Litters were standardized to 13 ± 2 piglets within 48 hours of birth and feed was offered according to a standard feeding curve (NRC, 2012). The N balance periods were between days 5 to 9 (early; N1) and 17 to 21 (Peak; N2) of lactation where total urine was collected via urinary catheters and feces was grab-sampled; titanium dioxide was used as an indigestible marker for determining apparent total tract N digestibility. In N1 and N2, 5.22 and 6.87 kg/d of experimental diet was offered in three equal meals at 0830, 1200, and 1530 h to each sow. Milk N output (g/d) was calculated using estimated milk yield based on litter growth rate and size and analyzed milk N concentration. Contrast statements were used to assess linear and quadratic effects of dietary SID Met level. During N1, N intake increased and then decreased when dietary SID Met content surpassed 0.286% (quadratic; P &amp;lt; 0.05). Similar relationships were observed for total N excretion (urine + fecal N; P &amp;lt; 0.05) resulting in no SID Met effect on N retention (77.1 ± 6.6, -12.5 ± 10.4, and 89.5 ± 8.9 g/d for total, maternal, and true milk protein N retention, respectively) or apparent N utilization efficiency (N retention/N intake×100; 53.2 ± 3.4%). During N2, as SID Met increased, N intake tended to increase (205.5 to 210.2 ± 5.7g/d; linear; P = 0.078), total N excretion tended to decrease (87.3 to 78.7 ± 6.2 g/d; linear; P = 0.087), and total N retention increased (117.9 to 131.4 ± 8.0g/d; linear; P &amp;lt; 0.05). True milk protein N output increased with SID Met (100.3 to 112.5 ± 8.1 g/d; linear; P &amp;lt; 0.05) and maternal N retention decreased and then increased when dietary SID Met content surpassed 0.260% (quadratic; P &amp;lt; 0.05). Apparent N utilization efficiency increased with increasing dietary SID Met (57.5 to 62.5 ± 1.2%; linear; P&amp;lt; 0.05). Therefore, in early lactation, SID Met intake had minimal effects on N utilization, indicating that the requirement for lactating primiparous sows may be equal to or less than 0.182% SID Met. During peak lactation, the supply of SID Met needed to maximize true milk protein N and apparent N utilization efficiency may be greater than 0.338%, which does not take into consideration the non-protein partitioning of dietary Met.

Isolation and Characterization of Cow-, Buffalo-, Sheep- and Goat-Milk-Derived Extracellular Vesicles.

Milk is a complex biological fluid that has high-quality proteins including growth factors and also contains extracellular vesicles (EVs). EVs are a lipid bilayer containing vesicles that contain proteins, metabolites and nucleic acids. Several studies have proposed that EVs in cow milk can survive the gut and can illicit cross-species communication in the consuming host organism. In this study, we isolated and characterized extracellular vesicles from the raw milk of the four species of the Bovidae family, namely cow, sheep, goat and buffalo, that contribute 99% of the total milk consumed globally. A comparative proteomic analysis of these vesicles was performed to pinpoint their potential functional role in health and disease. Vesicles sourced from buffalo and cow milk were particularly enriched with proteins implicated in modulating the immune system. Furthermore, functional studies were performed to determine the anti-cancer effects of these vesicles. The data obtained revealed that buffalo-milk-derived EVs induced significantly higher cell death in colon cancer cells. Overall, the results from this study highlight the potent immunoregulatory and anti-cancer nature of EVs derived from the milk of Bovidae family members.

Effect of intramammary infection and inflammation on milk protein profile assessed at the quarter level in Holstein cows

In this study we wanted to investigate the associations between naturally occurring subclinical intramammary infection (IMI) caused by different etiological agents (i.e., Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, and Prototheca spp.), in combination with somatic cell count (SCC), on the detailed milk protein profile measured at the individual mammary gland quarter. An initial bacteriological screening (time 0; T0) conducted on individual composite milk from 450 Holstein cows reared in 3 herds, was performed to identify cows with subclinical IMI. We identified 78 infected animals which were followed up at the quarter level at 2 different sampling times: T1 and T2, 2 and 6 wk after T0, respectively. A total of 529 quarter samples belonging to the previously selected animals were collected at the 2 sampling points and analyzed with a reversed phase HPLC (RP-HPLC) validated method. Specifically, we identified and quantified 4 caseins (CN), namely αS1-CN, αS2-CN, κ-CN, and β-CN, and 3 whey protein fractions, namely β-lactoglobulin, α-lactalbumin, and lactoferrin (LF), which were later expressed both quantitatively (g/L) and qualitatively (as a percentage of the total milk nitrogen content, % N). Data were analyzed with a hierarchical linear mixed model with the following fixed effects: days in milk (DIM), parity, herd, SCC, bacteriological status (BACT), and the SCC × BACT interaction. The random effect of individual cow, nested within herd, DIM and parity was used as the error term for the latter effects. Both IMI (i.e., BACT) and SCC significantly reduced the proportion of β-CN and αS1-CN, ascribed to the increased activity of both milk endogenous and microbial proteases. Less evident alterations were found for whey proteins, except for LF, which being a glycoprotein with direct and undirect antimicrobial activity, increased both with IMI and SCC, suggesting its involvement in the modulation of both the innate and adaptive immune response. Finally, increasing SCC in the positive samples was associated with a more marked reduction of total caseins at T1, and αS1-CN at T2, suggesting a synergic effect of infection and inflammation, more evident at high SCC. In conclusion, our work helps clarify the behavior of protein fractions at quarter level in animals having subclinical IMI. The inflammation status driven by the increase in SCC, rather the infection, was associated with the most significant changes, suggesting that the activity of endogenous proteolytic enzymes related to the onset of inflammation might have a pivotal role in directing the alteration of the milk protein profile.