Hasil untuk "Dairying"

Tao Luo, Nannan Jiang, Chaoqun Wu et al.

ABSTRACT: Adipose tissue remodeling is essential for mammary gland development and functional restoration. The dry period represents a pivotal phase characterized by extensive tissue remodeling as the gland transitions from pregnancy to lactation. However, the morphological and molecular mechanisms underlying mammary adipose tissue remodeling during this stage remain poorly understood. In this study, we investigated adipose remodeling in the mammary gland of dairy goats during this transitional period. An integrative multi-omics approach combining transcriptomics, lipidomics, and metabolomics was employed to comprehensively characterize the molecular changes of mammary tissue. Histological analysis and transmission electron microscopy revealed a substantial increase in both the proportion and size of adipocytes at 4 wk before prepartum. RNA sequencing of isolated mammary adipose cells indicated that the p38 mitogen-activated protein kinase (MAPK) pathway may play a key regulatory role in this process. To further dissect its function, we established an immortalized goat mammary preadipocyte cell line. Pharmacological inhibition of p38 MAPK significantly impaired adipocyte differentiation and hypertrophy. Furthermore, our findings suggested that p38 MAPK modulates adipogenesis in mammary adipocytes through downstream effectors, including apolipoprotein E. These findings highlight a critical role for the p38 MAPK signaling pathway in orchestrating mammary adipose tissue remodeling during the dry period. This work provides novel insights into the molecular regulation of mammary gland renewal and offers potential targets to manipulate mammary gland development in ruminants.

Le Van Trong, Ha Thi Phuong, Le Thi Huyen

The ability to accurately identify key growth stages is critical for proper rice management, Since management practices are directly tied to plant developmental processes, a sound understanding of rice growth is essential for effective cultivation. This study was conducted to evaluate the growth and yield performance of seven rice varieties (BT, CUDH1, NU986, ST25, TBR225, TX111, and VNR20) during different growth stages (Root establishment and Greening up,Tillering, Panicle initiation, Flowering, and Dough stage) in Thanh Hoa province, Vietnam. Results indicated that CUDH1 and TX111 exhibited superior performance, with greater plant height, higher leaf area index (LAI) throughout most growth stages, and enhanced dry matter accumulation. These characteristics reflect strong photosynthetic capacity and robust growth potential, ultimately leading to the highest recorded yields: CUDH1 (8.25 t ha-1) and TX111 (8.02 t ha-1). The NU986 (7.73 t ha-1) and BT (7.32 t ha-1) also achieved relatively good yields, though improvements in cultivation techniques are recommended to fully exploit their potential. Conversely, ST25 (6.97 t ha-¹), VNR20 (7.05 t ha-¹), and TBR225 (7.18 t ha-¹) exhibited lower plant height and dry matter accumulation, thus making them more suitable for high-quality rice production or areas prone to lodging. the conclusion, varietal selection tailored to specific production goals and local ecological conditions is a critical factor in improving the efficiency and sustainability of rice production systems.

T.S. Sundaram, C. Giromini, R. Rebucci et al.

ABSTRACT: In vitro meat cultivation, a cutting-edge innovation in food science, may represent a more sustainable and ethical source of animal proteins compared with conventionally grown meat. An important challenge for meat cultivation lies in eliminating the use of fetal bovine serum (FBS) in cell culture media due to ethical concerns. Milk whey is a nutrient-rich liquid portion of the milk, derived as a byproduct of dairy industry. Similar to FBS, whey contains proteins that are crucial for nutrition, cell adhesion, and biomolecular transport. In this study, we investigated whether whey proteins (WP) can replace FBS in supporting muscle cell cultivation, using the C2C12 myoblast model. Accordingly, under serum-free conditions, cells were treated with 2 WP mixtures, grouping high (β-LG 1.25%, α-LA 1.25%, BSA 1.25%) and low (β-LG 0.07%, α-LA 0.15%, BSA 0.15%) selected concentrations of individual proteins that positively affected cell growth in a preceding dose–response study. Cells cultured in only basal Dulbecco's Modified Eagle Medium were included as a negative control, and cells cultured in 10% FBS as a positive control. Cells were maintained in the treatment media for 48 h (d 1 and 2) to support myoblast proliferation. Subsequently, all the treatments were replaced with a standard low mitogenic 2% horse serum (HS) medium until full differentiation (d 6). The treatment effects on morphology, viability, and lactate dehydrogenase release were assessed after d 1, 2, and 6, respectively. The results showed that WP stimulated cell proliferation under serum-free culture conditions, similar to the FBS control, and subsequently facilitated myotube formation when the WP or FBS treatments were switched to HS medium. After differentiation, these cells also exhibited increased expression of cell differentiation markers such as creatine kinase and citrate synthase and underwent morphological changes from spindle-shaped cells to fused elongated myotubes, in contrast to the negative control. This study demonstrates that WP are a promising and sustainable alternative for considerably replacing FBS-based growth supplements for use in cultivated animal products.

Claudia F. Viana, Ana C.C. Lopes, Rosemary S. Conrrado et al.

ABSTRACT: Despite buffalo milk being an important food worldwide, not much is known about factors that influence its quality on Brazilian buffalo milk farms. It ranks second in total volume of milk production, with cow milk in first place, but a lack of minimum legal parameters for buffalo milk is another problem faced by some countries as it happens in Brazil, where the buffalo population represents less than 1% of dairy cows, even though the Brazilian buffalo herd is one of the largest in Latin America, with a successful dairy processing chain. This study investigated the composition and SCC of buffalo milk produced in a high-altitude tropical region in the state of Minas Gerais, Brazil, where buffalo calving naturally happens from February to May. A total of 2,211 samples of raw milk were analyzed for compositional parameters (fat, protein, lactose, TS, and SNF) using Fourier-transform infrared spectra and for SCC using flow cytometry. Official climatological data were also collected. Descriptive, multivariate statistics and principal component analysis were used. The highest fat, protein, solids nonfat, and total solids concentrations were recorded during the summer and spring seasons, 6.01 and 6.31 g/100 g for fat, 4.23 and 4.18 g/100 g for protein, 9.93 and 9.92 g/100 g for SNF, and 15.95 and 16.23 g/100 g for TS, respectively. Lactose, however, had the lowest concentration observed in the same seasons, 4.76 and 4.75 g/100 g, respectively. The component with the highest correlation to SCC was lactose, with the highest SCC values during spring, which was similar to the SCC during the fall. The concentrations of buffalo milk components were influenced by the season, with an opposite trend when compared with cow milk. However, buffalo milk SCC was usually lower than the counts reported for cow milk in the same region. Upcoming studies must include data as well as weighted averages to estimate the financial effect of this oscillation during the year and for milk quality payment.

Gunvantsinh Rathod, Suresh Sutariya, Ram Kumar et al.

ABSTRACT: Mozzarella cheese is widely used for pizza applications, and it is generally shredded either in conversion plants or in pizzerias. The shreddability of mozzarella cheese is influenced by a variety of factors, and it is critical to understand how different mozzarella cheese types and storage conditions (temperature and age) affect this property. Three batches each of 3 types of mozzarella cheese (low-moisture mozzarella [LMM], low-moisture part-skim mozzarella [LMPS], and reduced-fat mozzarella [RFM]) representing 3 different fat levels were procured directly from a commercial manufacturer and stored at 2 different temperatures (1.67 and 4.44°C) and evaluated for shreddability at 2- and 3-wk storage. Shreddability parameters such as stiction (peak force) and work of grating were significantly affected by fat content and storage time, whereas the weight of the shred obtained after each cycle was significantly affected by fat content and storage temperature. Along with shreddability, other tests, such as texture profile analysis (TPA), wire cutting, stretchability, and dynamic shear rheology (DSR) were performed to understand their relationship with shreddability. Textural parameters were significantly affected by fat content and storage time, whereas wire cutting parameters were significantly affected by fat content, storage time, and temperature. Stretchability and dynamic shear rheology parameters were significantly affected by fat content followed by storage time and temperature. Further shreddability parameters, such as stiction and work of shear had a positive significant correlation, whereas the weight of shreds had a negative significant correlation with unmelt (TPA) and melt parameters (stretchability and DSR). Overall, fat content had the greatest effect on shreddability followed by storage time and temperature. Considering the high correlation of shreddability with other textural parameters, textural parameters can be used to predict shreddability of mozzarella cheese.

A. Legarra, I. Aguilar

ABSTRACT: Unknown parent groups (UPG) model missing parentships according to breed, year, and pathway of selection. Genetic evaluations need a sensible definition of rules to form UPG to ensure their accurate estimation. With more complex evaluations, systematic rules are needed to form UPG. We propose several methods to ascertain informativity and join consecutive UPG within breed and pathway. First, a pseudocount of records based on descendants with record can be easily computed from a pedigree and a list of animals in records by propagating fractions of one from the flagged animals to ancestors through the pedigree, from youngest to oldest. Then, 2 rules are proposed: the first joins UPG forward in time until records appear, and the second joins consecutive UPG backward in time to achieve a minimum pseudocount. Finally, a simplified model estimates the precision of contrasts of UPG. Computations are feasible even for very large datasets. We illustrate with 2 examples from all-breed US traditional BLUP evaluation for yield and health traits. For yield traits, the number of pseudorecords is very high, and joining UPG occurs mainly in small breeds. Joining or not results in very similar estimated breeding values and genetic trends. For health traits, joining UPG occurs for all breeds, and more intensely for small breeds. Joining or not joining UPG resulted, for some trait-breed combinations, in quite different genetic trends and estimated breeding values. The approximated contrasts across all pairwise UPG show that the joining strategies achieve more precision, in the form of lower SE.

Ana Blanco-Doval, Raquel Sousa, Luis Javier R. Barron et al.

ABSTRACT: Mare milk has a unique protein composition that makes it a preferred option for adult and infant nutrition. Several functional properties have been attributed to this milk, but with little current evidence. In fact, knowledge on mare milk composition is still limited. In particular, studies addressing the performance of mare milk proteins during human gastrointestinal digestion are scarce, which limits the understanding of mare milk nutritional quality and functionality. For this reason, the present study describes the digestibility of mare milk proteins and the release of peptides as affected by management and lactation stage, factors which are known to affect milk composition. Mare milk samples from 3 different farms collected during 6 mo of lactation (n = 54) were subjected to a static in vitro gastrointestinal model to measure peptide release and protein digestibility. In the present study, a detailed description of protein and individual amino acid behavior during the digestion process was given. For the first time, digestion of the 2 equine β-lactoglobulin isoforms (I and II) was described individually. In addition, it was found that lactation stage and management system can significantly affect protein digestibility and peptide release during gastrointestinal digestion of mare milk. Presumably, differences in the composition of mare milk influence the protein structure and enzyme accessibility, which might have an impact on digestion behavior. Although no specific bioactive peptides were identified, several precursors of previously described bioactive peptides were found. These findings could support the idea of mare milk as a food with added value.

Kelechi A. Ike, David P. Casper, William P. Hansen et al.

ABSTRACT: Galacto-oligosaccharide (GOS) is a prebiotic isolated from whey. This study evaluated the optimal inclusion rate for improving the growth and health performance of neonatal calves. Eighty-eight 2 to 5-d old Holstein bull calves were blocked by initial BW and randomly allocated to 1 of 4 treatments using a randomized complete block design. Treatments comprised a 22:20 (CP:fat) AA-balanced milk replacer (MR) with GOS added at the rate of 0 g/d (control or GOS0), 2 g/d (GOS2), 4 g/d (GOS4), and 8 g/d (GOS8). Calves received 0.283 kg MR in 1.9 L fed 2×/day for the first 14 d, then increased to 0.42 kg in 2.84 L fed 2×/d through d 35, followed by 0.42 kg MR in 2.84 L fed 1×/d through d 42, followed by weaning. The GOS inclusion rate remained constant as the milk volume increased. Calves fed GOS at 2, 4, and 8 g/d demonstrated similar growth performance compared with calves fed GOS0. Calves fed GOS4 demonstrated a carryover effect into postweaning resulting in a tendency for increased BW (82.5, 83.0, 85.3, and 83.1 kg for GOS0, GOS2, GOS4, and GOS8, respectively), BW gains (37.8, 38.2, 41.3, and 38.6 kg), and ADG (687, 696, 751, and 701 g/d). The ADG was increased by 9.3% when feeding calves GOS4 compared with calves fed GOS0. Calf starter DMI was greater at 7 (1.73,1.86, 1.95, and 1.83 kg/d) and 8 (2.34, 2.50, 2.60, 2.49 kg/d) wk of age for calves fed GOS4 compared with calves fed GOS0, with the remaining treatments being intermediate and similar. Feed conversion (0.552, 0.529, 0.563, and 0.545 kg/kg) was greater for calves fed GOS0 and GOS4 g/d compared with calves fed GOS2, with calves fed GOS8 being intermediate and similar. Body frame gains were similar for calves fed all GOS inclusion rates. A treatment by week interaction at wk 2 indicated that calves fed GOS2 demonstrated a greater number of of days with a fecal score = 0 than calves fed the remaining treatments, indicating less scours. In conclusion, supplementing GOS to a MR at 4 g/d fed to neonatal calves improved growth performance without compromising health conditions.

R.B. Standish, A.D. Wright, N.L. Whitehouse et al.

ABSTRACT: The purpose of this experiment was to determine if nicotinic acid (NA) effects on dairy cows and rumen microbial characteristics are forage-type dependent (corn silage, CS; grass silage, GS). Four late-lactation (DIM = 225 ± 12 d) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The main effects were a CS (66.10% CS) based diet or a GS (79.59%) based diet with or without 12 g/d NA. Each experimental period lasted for 28 d. Milk production and milk components, blood metabolites, apparent total-tract nutrient digestibilities, minutes rumen pH were below 5.8 as an indicator of ruminal acidosis, and body temperature changes were analyzed as indicators of heat stress. Nicotinic acid supplementation did not improve apparent total-tract nutrient digestibility. Feeding a GS-based diet improved NDF and hemicellulose digestibility. Feeding a CS-based diet increased the apparent total-tract digestibility of fat, and minutes rumen pH below 5.8 for a greater proportion of the time. The CS-based diet also improved milk yield, milk fat and protein yields, and ECM yield; however, somatic cell count and BHB were also increased. Supplementing NA tended to decrease nonesterified fatty acids, especially when combined with GS where DMI was low. There was a trend for the total protozoa population to increase when GS and NA were fed but decreased when CS and NA were fed. Nicotinic acid tended to decrease rumen protozoal populations of Dasytricha, but increased populations of Ophryoscolex and Diplodiniinae with GS diets and decreased with CS diets. Entodiniinae were increased with CS but NA had no effect. Body temperature was increased when a CS-based diet was fed when compared with a GS-based diet. More research is needed to determine how NA can affect rumen microbial protein synthesis and what kind of diets will provide the optimum effect.

Mary Beth de Ondarza, Vinícius Carneiro de Souza, Ermias Kebreab et al.

ABSTRACT: Supplemental dietary rumen available fats show promise as enteric methane (eCH4) mitigators for lactating dairy cows. However, concerns include variability in eCH4 response and possible negative effects on dairy cow performance. Successful implementation of this mitigation option requires better prediction of responses specifically to rumen available fatty acids (FA) as well as understanding the modulating effects of other dietary and animal characteristics. Using meta-analytic and meta-regression techniques, 35 published studies with diet definition were used to assess changes in eCH4 emissions and lactation performance associated with supplemental fat, specific supplemental rumen available FA types, and other dietary characteristics. Enteric CH4 (g/d) was reduced by 3.77% per percentage unit of supplemental rumen available ether extract (EE). Supplemental rumen available PUFA (C18:2 and C18:3) and UFA (C18:1, C18:2, C18:3) mitigated eCH4 (g/d) emissions in dairy cows by 6.88 and 4.65% per percentage unit increase, respectively. The anti-methanogenic effects of PUFA, MUFA and MCFA increased with correspondingly greater basal dietary levels of each FA type. Higher rumen-degradable starch (RDS; >18% DM) in the basal diet promoted greater reductions in eCH4 yield (eCH4/DMI, g/kg) with supplemental rumen available PUFA and UFA. Both milk fat percentage and yield (kg/d) were reduced with rumen available fat supplementation with a reduction of 7.8% and 6.0%, respectively, relative to control diets. Our results highlight the importance of determining basal levels of the rumen available FA before providing supplemental rumen available FA as an option for enteric eCH4 mitigation. Dairy nutritionists can use estimates generated from this analysis to predict changes in eCH4 emissions and dairy cow performance associated with dietary supplementation of rumen available EE and specific rumen available FA types for the purpose of eCH4 mitigation.

A. Birkinshaw, M. Sutter, M. Nussbaum et al.

ABSTRACT: As the call for an international standard for milk from grassland-based production systems continues to grow, so too do the monitoring and evaluation policies surrounding this topic. Individual stipulations by countries and milk producers to market their milk under their own grass-fed labels include a compulsory number of grazing days per year (ranging from 120 d for certain labels to 180 d for others), a specified amount of herbage in the diet, or a prescribed dietary proportion of grassland-based forages (GBF) fed and produced on-farm. As these multifarious policy and label requirements are laborious and costly to monitor on-farm, fast economical proxies would be advantageous to verify the proportion of GBF consumed by the cows in the final product. With this in mind, we employed readily available mid-infrared spectral data (n = 1,132 spectra) from routine milk controls to develop binary classification models for 4 main feed groups from a primarily forage-based diet: total GBF (≥50% [n = 955], ≥75% [n = 599], ≥85% [n = 356]), pasture (≥20% [n = 451], ≥50% [n = 284], ≥70% [n = 152]), fresh herbage (pasture + fresh herbage indoor feeding; ≥20% [n = 517], ≥50% [n = 325], ≥70% [n = 182]), and whole plant corn (fresh + conserved; ≥10% [n = 646], ≥30% [n = 187]), with the latter as a negative control. We compared 4 machine learning methods to assess which statistical model performs best at discriminating these classes. Three of these models have not yet been tested for herd-level dietary proportion classification, and all 4 follow completely different approaches: least absolute shrinkage and selection operator (LASSO), partial least squares discriminant analysis (PLS-DA), random forest (RF), and support vector machines (SVM). Seasonality has been a missing element from previous dietary herbage proportion classification models. As grazing and fresh herbage indoor feeding are highly dependent on the season, we developed an indicator to incorporate seasonality in a consistent, unbiased manner into our models. We also tested 3 sets of covariates. The first set included only mid-infrared spectra derived data, the second included mid-infrared spectra derived data plus seasonality indices and the third included mid-infrared spectra derived data, seasonality indices and additional herd specific information (DIM, breed, and parity). Of the 4 machine learning algorithms tested for the binary classification of GBF proportion at herd level, LASSO and PLS-DA performed best according to evaluation metrics; however, the RF and SVM models were not far behind the best performing model evaluation metrics in each feed category. Our best performing model, the LASSO model containing seasonality indices and herd specific information, classified total GBF ≥50% with an accuracy of 78.6%, precision of 85.1%, sensitivity of 90.6%, specificity of 14.1%, and F1 score (harmonic mean of precision and sensitivity) of 87.7%; this was very similar to the PLS-DA model. Our results suggest that in general, LASSO and PLS-DA machine learning algorithms perform better for dietary GBF classification than RF or SVM algorithms.

P. Piantoni, M.A. Abeyta, G.F. Schroeder et al.

ABSTRACT: Intestinal hyperpermeability and subsequent immune activation alters nutrient partitioning and thus, decreases productivity. Developing experimental models of intestinal barrier dysfunction in heathy cows is a prerequisite in identifying nutritional strategies to mitigate it. Six cannulated Holstein cows (mean ± standard deviation, 37 ± 10 kg/d milk yield; 219 ± 97 d in milk; 691 ± 70 kg body weight) were used in a replicated 3 × 3 Latin square design experiment with 21-d periods (16-d wash-out and 5-d challenge) to evaluate either feed restriction or hindgut acidosis as potential models for inducing intestinal hyperpermeability. Cows were randomly assigned to treatment sequence within square and treatment sequences were balanced for carryover effects. Treatments during the challenge were (1) control (CTR; ad libitum feeding); (2) feed restriction (FR; total mixed ration fed at 50% of ad libitum feed intake); and (3) resistant starch (RS; 500 g of resistant starch infused in abomasum once a day as a pulse-dose 30 min before morning feeding). The RS (ActiStar RT 75330, Cargill Inc.) was tapioca starch that was expected to be resistant to enzymatic digestion in the small intestine and highly fermentable in the hindgut. Blood samples were collected 4 h after feeding on d 13 and 14 of the wash-out periods (baseline data used as covariate), and on d 1, 3, and 5 of the challenge periods. Fecal samples were collected 4 and 8 h after the morning feeding on d 14 of the wash-out periods and d 5 of the challenge periods. By design, FR decreased dry matter intake (48%) relative to CTR and RS, and this resulted in marked reductions in milk and 3.5% FCM yields over time, with the most pronounced decrease occurring on d 5 of the challenge (34 and 27%, respectively). Further, FR increased somatic cell count by 115% on d 5 of the challenge relative to CTR and RS. Overall, FR increased nonesterified fatty acids (159 vs. 79 mEq/L) and decreased BHB (8.5 vs. 11.2 mg/dL), but did not change circulating glucose relative to CTR. However, RS had no effect on production or metabolism metrics. Resistant starch decreased fecal pH 8 h after the morning feeding (6.26 vs. 6.81) relative to CTR and FR. Further, RS increased circulating lipopolysaccharide binding protein (4.26 vs. 2.74 µg/mL) compared with FR only on d 1 of the challenge. Resistant starch also increased Hp (1.52 vs. 0.48 µg/mL) compared with CTR, but only on d 5 of the challenge. However, neither RS or FR affected concentrations of serum amyloid A, IL1β, or circulating endotoxin compared with CTR. The lack of consistent responses in inflammatory biomarkers suggests that FR and RS did not meaningfully affect intestinal barrier function. Thus, future research evaluating the effects of hindgut acidosis and FR using more intense insults and direct metrics of intestinal barrier function is warranted.

J.M.D.R. Jayawardana, N. Lopez-Villalobos, L.R. McNaughton et al.

ABSTRACT: The objectives of this study were to estimate the genetic and phenotypic correlations and heritabilities for milk production and fertility traits in spring-calved once-daily (OAD) milking cows for the whole season in New Zealand and compare those estimates with twice-daily (TAD) milking cows. Data used in the study consisted of 69,252 first parity cows from the calving seasons 2015–2016 to 2017–2018 in 113 OAD and 531 TAD milking herds. Heritability estimates for production and fertility traits were obtained through single-trait animal models, and estimates of genetic and phenotypic correlations were obtained through bivariate animal models. Heritability estimates of production traits varied from 0.26 to 0.61 in OAD and from 0.13 to 0.63 in TAD. Heritability estimates for fertility traits were low in both OAD and TAD milking cow populations, and estimates were consistent (OAD: 0.01 to 0.10 and TAD: 0.01 to 0.08) across milking regimens. Estimates of phenotypic and genetic correlations among production traits were consistent across populations. In both populations, phenotypic correlations between milk production and fertility traits were close to zero, and most of the genetic correlations were antagonistic. In OAD milking cows, genetic correlations of milk and lactose yields with the start of mating to conception, 6-wk in-calf, not-in-calf, and 6-wk calving rate were close to zero. Interval from first service to conception was negatively genetically correlated with milk and lactose yields in OAD milking cows. Protein percentage was positively genetically correlated with 3-wk and 6-wk submission, 3-wk in-calf, 6-wk in-calf, first service to conception, 3-wk calving, and 6-wk calving rate in the TAD milking cow population, but these correlations were low in the OAD milking cow population. Further studies are needed to understand the relationship of protein percentage and fertility traits in the OAD milking system. The phenotypic correlations between fertility traits were similar in OAD and TAD milking populations. Genetic correlations between fertility traits were strong (≥0.70) in cows milked TAD, but genetic correlations varied from weak to strong in cows milked OAD. Further research is required to evaluate the interaction between genotype by milking regimen for fertility traits in terms of sire selection in the OAD milking cow population.

V. Landi, A. Maggiolino, A. Cecchinato et al.

ABSTRACT: Due to its geographical position and a highly variable orography, Italy is characterized by several climatic areas and thus, by many different dairy cow farming systems. Brown Swiss cattle, in this context, are a very appreciated genetic resource for their adaptability and low metabolic requirement. The significant heterogeneity in farming systems may consist of genotype by environment (G × E) interactions with neglected changes in animals' rank position. The objective of this study was to investigate G × E for heat tolerance in Brown Swiss cattle for several production traits (milk, fat, and protein yield in kilograms; fat, protein, and cheese yield in percentage) and 2 derivate traits (fat-corrected milk and energy-corrected milk). We used the daily maximum temperature-humidity index (THI) range, calculated according to weather stations' data from 2008 to 2018 in Italy, and 202,776 test-day records from 23,396 Brown Swiss cows from 639 herds. Two different methodologies were applied to estimate the effect of the environmental variable (THI) on genetic parameters: (1) the reaction norm model, which uses a continuous random covariate to estimate the animal additive effect, and (2) the multitrait model, which splits each production pattern as a distinct and correlated trait according to the first (a thermal comfort condition), third (a moderate heat stress condition), and fifth (a severe heat stress condition) mean THI value quintile. The results from the reaction norm model showed a descending trend of the additive genetic effect until THI reached the value of 80. Then we recorded an increase with high extreme THI values (THI 90). Permanent environmental variance at increasing THI values revealed an opposite trend: The plot of heritability and the ratio of animal permanent environmental variance to phenotypic variance showed that when the environmental condition worsens, the additive genetic and permanent environmental component for production traits play a growing role. The negative additive genetic correlation between slope and linear random coefficient indicates no linear relationship between the production traits or under heat stress conditions, except for milk yield and protein yield. In tridimensional wireframe plots, the extreme margin decreases until a minimum of ∼0.90 of genetic correlation in the ECM trait, showing that the magnitude of G × E interaction is greater than the other traits. Genetic correlation values in Brown Swiss suggest the possibility of moderate changes in animals' estimated breeding value in heat stress conditions. Results indicated a moderate G × E interaction but significant variability in sire response related to their production level.

T.T. Lott, N.H. Martin, J. Dumpler et al.

ABSTRACT: Growing interest in the manufacture of extended shelf-life (ESL) milk, which is typically achieved by a high-temperature treatment called ultra-pasteurization (UP), is driven by distribution challenges, efforts to reduce food waste, and more. Even though high-temperature, short-time (HTST) pasteurized milk has a substantially shorter shelf life than UP milk, HTST milk is preferred in the United States because consumers tend to perceive UP milk as less desirable due to the “cooked” flavor associated with high-temperature processing. While ESL beyond 21 d may be possible for HTST, the survival and outgrowth of psychrotolerant aerobic spore-forming bacteria can still be a limitation to extending shelf life of HTST milk. Microfiltration (MF) is effective for reducing vegetative microorganisms and spores in raw milk, but it is unclear what the effects of membrane pore size, storage temperature, and milk type (i.e., skim vs. whole) are on the microbial shelf life of milk processed by both MF and HTST pasteurization. To investigate these factors, raw skim milk was MF using different pore sizes (0.8 or 1.2 μm), and then MF skim milk and standardized whole milk (MF skim with heat-treated [85°C for 20 s] cream) were HTST pasteurized at 75°C for 20 s. Subsequently, milk was stored at 3°C, 6.5°C, or 10°C and total bacteria counts were measured for up to 63 d. An ANOVA indicated that mean bacterial concentrations between storage temperatures were significantly different from each other, with mean maximum observed concentrations of 3.67, 5.33, and 8.08 log10 cfu/mL for storage temperatures 3°C, 6.5°C, and 10°C, respectively. Additionally, a smaller difference in mean maximum bacterial concentrations throughout shelf life was identified between pore sizes (<1 log cfu/mL), but no significant difference was attributed to milk type. An unexpected outcome of this study was the identification of Microbacterium as a major contributor to the bacterial population in MF ESL milk. Microbacterium is a psychrotolerant, thermoduric gram-positive, non-spore-forming rod with a small cell size (∼0.9 μm length and ∼0.3 μm width), which our data suggest was able to permeate the membranes used in this study, survive HTST pasteurization, and then grow at refrigeration temperatures. While spores continue to be a key concern for the manufacture of MF, ESL milk, our study demonstrates the importance of other psychrotolerant, thermoduric bacteria such as Microbacterium to these products.

Yu Gao, Ying Ma, Lina Pan et al.

ABSTRACT: Yak milk is rich in essential milk proteins of nutritional and therapeutic value. In this study, whey proteins of milk from 3 yak breeds (Gannan, GN; Huanhu, HH; Maiwa, MW) in China were comprehensively identified and compared using a data-independent acquisition quantitative proteomics approach. A total of 632 proteins were identified in yak milk whey samples, in which immune-related proteins were abundant. Compared with other milks, more proteins were involved in oxidation-reduction process and with ATP binding. In addition, we identified 96, 155, and 164 differentially expressed proteins (DEP) for GN versus HH, GN versus MW, and HH versus MW, respectively. “Phagosome” and “complement and coagulation cascades” were the most significant pathways for DEP of GN versus HH and GN or HH versus MW yak milk based on the Kyoto Encyclopedia of Genes and Genomes pathway analysis. Protein-protein interaction network analysis showed that DEP for the 3 comparisons had significant biological interactions but were associated with different functions. The results provide useful information on yak milk from different breeds in China, and elucidate the biological functions of yak milk proteins.

Andreas W. Oehm, Andrea Springer, Daniela Jordan et al.

Fasciola hepatica and Ostertagia ostertagi are internal parasites of cattle compromising physiology, productivity, and well-being. Parasites are complex in their effect on hosts, sometimes making it difficult to identify clear directions of associations between infection and production parameters. Therefore, unsupervised approaches not assuming a structure reduce the risk of introducing bias to the analysis. They may provide insights which cannot be obtained with conventional, supervised methodology. An unsupervised, exploratory cluster analysis approach using the k–mode algorithm and partitioning around medoids detected two distinct clusters in a cross-sectional data set of milk yield, milk fat content, milk protein content as well as F. hepatica or O. ostertagi bulk tank milk antibody status from 606 dairy farms in three structurally different dairying regions in Germany. Parasite–positive farms grouped together with their respective production parameters to form separate clusters. A random forests algorithm characterised clusters with regard to external variables. Across all study regions, co–infections with F. hepatica or O. ostertagi, respectively, farming type, and pasture access appeared to be the most important factors discriminating clusters (i.e. farms). Furthermore, farm level lameness prevalence, herd size, BCS, stage of lactation, and somatic cell count were relevant criteria distinguishing clusters. This study is among the first to apply a cluster analysis approach in this context and potentially the first to implement a k–medoids algorithm and partitioning around medoids in the veterinary field. The results demonstrated that biologically relevant patterns of parasite status and milk parameters exist between farms positive for F. hepatica or O. ostertagi, respectively, and negative farms. Moreover, the machine learning approach confirmed results of previous work and shed further light on the complex setting of associations a between parasitic diseases, milk yield and milk constituents, and management practices.

Heather W. Neave, Karin E. Schütz, Dawn E. Dalley

ABSTRACT: Dairy cows are motivated to access dry lying surfaces and will seek protection from wind and rain, but winter conditions may limit these opportunities when cows are managed outdoors. The primary aim of this observational study was to determine the effects of weather and paddock soil conditions on lying behavior of dairy cows managed outdoors during winter and fed crop in situ, a practice occurring in New Zealand with year-round grazing of dairy cows. A secondary aim was to characterize eating and ruminating behaviors during winter weather and paddock soil conditions. Four groups (99 nonlactating, pregnant cows each) were managed on 4 outdoor paddock areas on the same farm; the groups were fed pasture silage and grazed either kale (2 groups) or fodder beet (2 groups). Behaviors were recorded using validated leg-based (lying behavior) and ear-based (eating and ruminating time) accelerometers on 30 focal cows in each group over 32 d. Soil depth and wetness were scored daily at 25 points along 4 transects within each paddock area using recognized technical measures (penetrometer, soil volumetric water content), which were compared with practical tools for farmer use (ruler, moisture meter, percentage of sites in paddock scored as dry, wet, sodden, or with surface water pooling). Rainfall occurred most days during the study (mean 1.6 mm/d; maximum 12.2 mm/d), resulting in wet and muddy paddocks (mud depth with ruler: mean 6 cm, maximum 18 cm; paddock sites scored as wet or sodden: mean 34%, maximum 100%; paddock sites with surface water pooling: mean 27%, maximum 100%). Group lying time was 9.6 ± 2.3 h/d (mean ± standard deviation); however, 21% of cows consistently lay less than 8 h/d (to a minimum of 4.9 h/d). A mixed regression model tested the effects of daily weather and paddock soil conditions on daily lying time, with group as the observational unit, day as repeated measure, crop type as a fixed effect, crop type interactions with explanatory variables, and random intercepts of group and paddock within group. Lying time was less on the day of and day after rainfall (24 and 29 min/d less for 1 mm increase in rainfall, respectively). Two days after rainfall, lying time rebounded to about 1 h longer than before the rainfall. On the day after the heaviest rainfall event, group average lying time was only 2.5 ± 1.9 h/d (mean ± standard deviation); in 2 groups, 30% and 38% of cows, respectively, did not lie down at all for 24 h. Lying time decreased with deteriorating paddock soil conditions, especially with increasing surface water pooling, suggesting that this may be a useful measure to estimate the quality of the lying surface. Descriptively, ruminating time appeared to decrease with increased surface water pooling, possibly due to decreased lying time. Our results demonstrated that dairy cows could experience periods of short or no lying time during inclement weather and muddy paddock soil conditions. Prior rainfall and surface water pooling may be useful measures to determine if lying time, and thus animal welfare, are compromised.

D. Chapman, I. Pinxterhuis, S. Ledgard et al.

As the pressure intensifies to reduce nitrogen (N) losses to the environment from pasture-based dairy systems, interest in reducing N-fertiliser inputs and returning to grass–clover mixtures, where more N for pasture growth is supplied by biological N fixation (BNF), have been revived. However, the following question then arises: is BNF fundamentally different from fertiliser N with respect to N losses, especially nitrate-N leaching risk? The present paper addresses this question by reviewing empirical evidence in the context of N-cycling processes and the efficiency of N use for herbage production. Nitrate leaching data from studies comparing different sward treatments at the same level of total N inputs (fertiliser plus BNF) provide no evidence to suggest that leaching differs when N is supplied solely by fixation in mixtures, by fixation plus fertiliser in mixtures, or solely as a fertiliser to grass monoculture. Increasing clover content in mixed grass–clover pastures is likely to increase N leaching due to a lower ratio of soluble sugar and starch to N in herbage than the common companion grass species perennial ryegrass, and, therefore, a higher partitioning of N eaten to urine. Counteracting this effect, mixed grass–clover pastures may offer some potential for increasing N-use efficiency and reducing the whole-farm N surplus compared with grass-dominant pasture receiving high rates of N fertiliser. While there are undeniable benefits for the productivity of dairy systems from maintaining strong grass–clover mixtures, it is the total amount of N entering the system, rather than the form of N (BNF or fertiliser), that influences nitrate leaching rates.

P. Rathod, S. Dixit

Dairying in Bundelkhand region continues to play a central role in providing livelihood security and coping mechanism to mitigate risks of the resource poor farmers. However, the development of this key sector has not progressed to the desired extent in comparison to other regions of Uttar Pradesh and also across other states. Thus, an attempt was made to study the present status and issues in dairying, analyze strengths, weaknesses, opportunities, threats (SWOT) and propose strategies for dairy sector development in Bundelkhand region of Uttar Pradesh using primary and secondary data in this study. The study identified various issues and constraints, viz. presence of low yielding non-descript cattle, low milk yield, less breedable population, dependency on grazing and crop residues utilization, lack of veterinary services, dominance of middle men in marketing, poor scientific knowledge etc. in the region. Further, it was found that this region of Uttar Pradesh is facing a tentative annual loss of rs. 1,619 crores due to Anna pratha. There is also a need to calculate the losses like crop damage, indiscriminate animal breeding, high cost of production for unproductive animals, lack of milk availability leading to poor human nutrition, etc. Hence, there is a need to focus on short and long term strategies based on strengths, weaknesses, opportunities, threats (SWOT) of dairy sector in Bundelkhand region. A need based research and extension activities by different organizations in the region may be emphasized for the benefit of farming community.