Search Results (19)

Modeling milk yield in dairy cows is essential for improving management decisions, but traditional lactation curve models often fail to capture individual variability. Machine learning approaches offer greater flexibility; however, their performance in small, within-herd datasets and their reliance on explicit cow identification remain unclear, particularly in grazing systems. This study aimed to evaluate whether routinely measured biological traits can substitute for cow identification in machine learning models for predicting daily milk yield within a herd under limited data conditions. The dataset comprised 62 lactations from 48 Holstein–Friesian cows in a grazing system. Two machine learning models were developed: one including cow identification (With ID) and another excluding cow identification but incorporating milk quality traits, body weight, and body condition score (Without ID). Both models were compared with the Wood lactation model fitted to individual cows. The With ID and Without ID models achieved $R^2$ values of 0.97 and 0.93 and RMSE values of 1.2 and 1.6 ${\mathrm{kg} \mathrm{d}}^{-1}$, respectively. Both machine learning models outperformed the Wood model fitted individually to each cow ($R^2$ < 0.90; RMSE > 2.03 ${\mathrm{kg} \mathrm{d}}^{-1}$), which represents an implicitly cow-specific approach. The model including cow identification therefore served as a machine learning analogue to this benchmark. Importantly, the trait-based model closely matched the performance of the cow-specific model. These results demonstrate that machine learning models based on routinely measured traits provide a practical approach for predicting within-herd milk yield from small datasets, while retaining much of the accuracy of cow-specific models. Full article

Lactoferrin (LF) is an iron-binding immunoprotein of the mammary gland whose levels increase during mastitis and may be influenced by the metabolic status of the cow. During early lactation, dairy cows are exposed to a negative energy balance (NEB) and the associated increase in susceptibility to mastitis. However, the extent to which the metabolic profile influences LF secretion in milk during the postpartum period remains unclear. The objective of this study was to assess the associations between metabolic status and milk LF contents in Holstein cows (n = 122) in the first twenty days of lactation. Based on the milk LF contents, the cows were categorized into two groups: LF-LOW (≤123 mg/L; n = 81) and LF-HIGH (>123 mg/L; n = 41). Serum indicators of energy and nitrogen metabolism, hepatic function, and selected macro-/microelements were measured; urine electrolytes and net acid–base excretion (U-ABB) were assessed; and milk composition, including somatic cell count (SCC), was determined. LF-HIGH cows showed higher SCC (p = 0.0516) and serum glucose (p < 0.001), together with lower serum triglycerides (p = 0.0101) versus LF-LOW cows. Milk beta-hydroxybutyric acid (BHB) content was lower in the LF-HIGH group (trend, p ≈ 0.062). LF-HIGH also exhibited significantly greater natriuresis (p = 0.0078) and a more negative U-ABB (p < 0.001), indicating higher acid–base load. In conclusion, elevated LF contents during the postpartum period were associated with the activation of local mammary gland immune defence and concurrent compensatory metabolic processes related to NEB, rather than with pronounced alterations in basic milk composition. Milk LF content may therefore be considered as a specific indicator of immunometabolic compensation during the early postpartum period, rather than as a general marker of overall cow health. Full article

This study aimed to evaluate the effect of the supplementation with rumen-protected fat from soybean or palm and thermally processed soybean on the feed intake, digestibility of nutrients, milk production, and milk content of ewes. Twenty-five Pantaneiras ewes, 3–6 years old, 39.8 ± 3.51 kg body weight, and 65 ± 4 days in milk, were distributed into five treatments (5 ewes in each) in a completely randomized design continuous trial, over 56 days. The treatments consisted of daily supplementation with soybean-based rumen-protected fat (SPF; 30 g/d), palm-based rumen-protected fat (PPF; 30 g/d), a blend of soybean and palm rumen-protected fats (Blend; 30 g/d), thermally processed soybean (TPS; 124 g/d), and a control without supplementation. We performed a daily evaluation of feed intake and milk production, and every 14 days, we evaluated the nutrient digestibility, milk composition, and fatty acid profile. The protein and casein content were lower in the SPF treatment. Supplementation with PPF resulted in a higher saturated fatty acid content, while supplementation with TPS resulted in higher monounsaturated and polyunsaturated fatty acid contents. The supplementation with SPF resulted in higher milk fatty acid functionality. Feeding ewes SPF or TPS enhanced nutrient intake and digestibility, leading to increased milk production and an improved milk fatty acid profile. In contrast, supplementation with PPF resulted in a less favorable fatty acid composition. Full article

Profitable dairy farming requires continuous appraisal and adaptation of production systems in response to changing market and agricultural policy conditions. Geopolitical and climate events have exemplified the exposure of farm incomes to the increased volatility associated with often-global market factors. In this context, bio-economic models can be a useful tool for researchers seeking to understand the financial resilience of different production systems to these changing circumstances. The AFBI Dairy Systems Model is presented and used to simulate the impacts of alternative price scenarios for Northern Ireland-based dairy systems. The whole farm model consists of four interdependent components, comprising farm system, animal nutrition, feed supply and financial sub models. The model is used to evaluate how fluctuations in milk, concentrate, fertiliser, contractor, and electricity prices, as well as interest rate changes, affect three distinct production systems. The financial performance of all systems was sensitive to variations in milk and concentrate prices but relatively insensitive to variations in fertiliser, contractor, and electricity prices and interest rate changes. The profitability of a low-output system was less exposed to variations in prices. In contrast, a high-output system was more exposed to price variations. However, a medium-input system was the most profitable across the majority of price scenarios investigated. Full article

Methane (CH₄) is the second largest greenhouse gas (GHG) after carbon dioxide (CO₂), and ruminant production is an important source of CH₄ emissions. Among the six types of livestock animal species that produce GHGs, cattle (including beef cattle and dairy cows) are responsible for 62% of livestock-produced GHGs. Compared to beef cattle, continuous lactation in dairy cows requires sustained energy intake to drive rumen fermentation and CH₄ production, making it a key mitigation target for balancing dairy production and environmental sustainability. Determining how to safely and efficiently reduce CH₄ emissions from dairy cows is essential to promote the sustainable development of animal husbandry and environmental friendliness and plays an important role in improving feed conversion, reducing environmental pollution, and improving the performance of dairy cows. Combined with the factors influencing CH₄ emissions from dairy cows and previous research reports, this paper reviews the research progress on reducing the enteric CH₄ emissions (EMEs) of dairy cows from the perspectives of the CH₄ generation mechanism and emission reduction strategies, and it summarizes various measures for CH₄ emission reduction in dairy cows, mainly including accelerating genetic breeding, improving diet composition, optimizing feeding management, and improving fecal treatment. Future research should focus on optimizing the combination of strategies, explore more innovative methods, reduce EME without affecting the growth performance of dairy cows and milk safety, and scientifically and effectively promote the sustainable development of animal husbandry. Full article

Maintaining teat-end integrity in dairy cows is essential to preventing intramammary infections (IMIs) in dairy cows, yet the relationship between hyperkeratosis, teat conformation, and mammary health remais underexplored. This study evaluated the relationship between teat-end hyperkeratosis, teat conformation traits, microbial colonization, and somatic cell count (SCC) in milk from 170 cows on ten commercial dairy farms in Santa Catarina, Brazil. During two farm visits, milk and teat-end swab samples from paired teats (one with hyperkeratosis, one without) were analyzed for microbial growth and SCC. SCC data were transformed into somatic cell scores (SCS). Results showed no significant association between hyperkeratosis and mastitis microorganisms, although environmental microorganisms tended to be more frequent in hyperkeratotic teats (p = 0.0778). Major microorganisms in milk were significantly associated with higher SCC (p = 0.0132). No relationship was observed between teat conformation traits and hyperkeratosis. These findings suggest that hyperkeratosis may subtly influence the teat canal to environmental bacterial colonization, underscoring the need for improved milking management practices to minimize hyperkeratosis and associated mastitis risks. Full article

The production of farm bulk milk with low bacterial counts is a key quality index used by industry to help ensure the production of high-quality dairy products. The primary metrics used to determine the microbiological quality of bulk tank milk on a farm are the total bacteria count (TBC) and thermoduric bacteria count. To maintain TBCs and thermoduric counts at the lowest attainable levels, i.e., TBC ≤ 15,000 cfu/mL and thermoduric bacteria ≤ 200 cfu/mL, it is imperative that milk quality management is treated as a multi-faceted endeavor. Milking equipment cleaning, pre-milking teat preparation, milk filtration, cooling and storage, milking equipment maintenance and management of a cow’s environment and diet must each be managed with best practice in mind if farm bulk milk is to consistently attain low TBCs and thermoduric counts. This is especially important when using chlorine-free cleaning protocols, which are more complex than traditional chlorine-based cleaning methods and if not implemented correctly do not offer the confidence of achieving required hygiene standards. Full article

The objective of this study was to determine the enteric methane (CH₄) emission factor (EF) at the national level for Peruvian dairy cattle following the IPCC Tier II (2006, 2019) methodology. Data were collected from seven regions of Peru and classified according to the type of feeding as intensive, semi-intensive or extensive. It included farm information (geolocation) and livestock information for two seasons of the year. At the national level, lactating cows obtained the highest EF with 117 kg CH₄/head/year, followed by heifers from 15 to 24 months of age (91 kg), non-lactating cows (74 kg), heifers from 12 to 15 months of age (67 kg), calves (62 kg) and pre-weaned calves (16 kg). Additionally, the highest EF was reported for lactating cows in the intensive system (151.8 kg CH₄/head), which is 46.8 kg CH₄/head more per year than that reported in the semi-intensive and extensive systems in the same animal category. The combined uncertainty in all animal categories was low to very low (between 9.4 and 18.72%), except for that of lactating cows, which was low to medium (22.24 and 26.72%). These results allowed us to find the EF that exerts the most pressure according to the level of intensity in Peruvian dairy farming. Full article

The dairy industry’s contribution to global warming has been thoroughly examined. However, it is important to raise public awareness of emission hotspots and the possibility of mitigation in dairy supply chains. This study assessed the Carbon Footprint (CF) of five dairy products through a cradle-to-grave Life Cycle Assessment approach and evaluated the carbon sink potential of some practices. The functional units were 1 kg of fresh raw milk, yogurt, fresh cheese, mozzarella cheese, and aged cheese. The data collected were related to an extensive dairy farm, a cheese-factory, two markets, a delivery service, and a court of consumers. The CFs were 4.39, 5.10, 9.82, 8.40, and 15.34 kg CO₂ eq. for fresh raw milk, yogurt, mozzarella cheese, fresh cheese, and aged cheese, respectively. The hotspots of the dairy supply chain considered herein refer to farm activities and energy consumption, whereas conservative agriculture practices and rotational grazing sequestered 1.60 ± 0.80 kg CO₂ eq. per kg of dairy product consumed. The CF was reduced by 0.14 kg CO₂ eq. for 1 kg of dairy product delivered at home compared to direct purchasing at a market. The carbon sink capacity of dairy farms appeared as a primary mean for mitigating climate change in the dairy supply chain. Full article

Dairy cow longevity is associated with three key areas: animal welfare, the economy, and the environment. In pastoral dairy systems, cows are exposed to environmental hardships and variations in feed supply associated with the seasonal growth of pastures. The objectives of this study were to generate base parameters for longevity and evaluate the effect of season and decade of birth on herd life (HL) and length of productive life (LPL) for dairy cows in pasture-based production. Records from the Dairy Herd Improvement Database at the Instituto Nacional para el Control y Mejoramiento Lechero (Uruguay) were extracted. The dataset contained 313,146 cows born between 1 January 2000 and 31 December 2019, classified by decade and season of birth. HL and LPL were calculated for each cow. The effects of season of birth, decade of birth, and the interaction between them on HL and LPL were evaluated using a generalized mixed model. The mean HL was 73.4 and mean LPL was 42.0 months. Cows born in spring had longer LPL and HL (p < 0.001). Cows born in the 2010s had significantly shorter HL (12.8 months) and LPL (9.14 months) (p < 0.001). In conclusion, the season and decade of birth have an impact on the longevity of cows in pastoral-based systems. This study is the first to demonstrate the effect of season of birth on long-term longevity. Full article

Stable flies, Stomoxys calcitrans (L.), are important biting pests of dairy cattle and other livestock. These flies develop in decaying organic matter, such as soiled animal bedding. As part of a larger study of management options in organic dairy production, leftover debris from two winter housing systems, outdoor straw packs and indoor sawdust compost barns, were analyzed for the numbers and size of stable flies produced the following summer. The study was conducted at the University of Minnesota’s West Central Research and Outreach Center in Morris. During winter, independently managed groups of 20 cows were housed from November to May in replicate housing systems. After the cows were moved to summer pasture, fly traps were assembled in the leftover piles (n = 4): emergence traps to quantify stable fly emergence and Olson traps to study ambient adults. The size of the emerged flies and 30 ambient adult females were measured. The sampled females were also dissected to determine the gonotrophic age. During peak emergence in both years, straw piles produced significantly more stable flies than compost bedding, but the adults were equal in size. The Olson traps showed adults were equally abundant at both sources. Over 60% of the females dissected were previtellogenic, indicating local emergence. Compost bedding is useful in managing stable fly numbers, while straw presents a serious stable fly production liability if not disposed of properly. Full article

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. Full article

The age at first calving (AFC) is one of the most used indicators to evaluate the efficiency of rearing systems in dairy herds. The objective of the present study was to evaluate the association between AFC and different parameters of productive and reproductive efficiency in dairy cows of Holstein and Jersey breeds and their crosses, reared under pasture-based conditions. A retrospective longitudinal study was carried out with information on the performance of 77,311 cows with birth and culling dates between 1990 and 2016 from 654 specialized dairy herds located in mid and high-altitude regions of Costa Rica. Cows were classified into five classes according to their age in months at first calving (≤24, 25–27, 28–30, 31–33, ≥34). A generalized linear mixed model was used to assess the effect of AFC and breed factors on milk production (first lactation, lifetime total, and per day of life), open period (first calving and lifetime total), and herd life. The mean AFC was 29.5, 29.1, and 28.0 months for Holstein, Holstein × Jersey, and Jersey, respectively. The AFC was significantly associated (p < 0.01) with all the variables evaluated. Cows with AFC ≤ 24 presented a higher (p < 0.01) milk production (total lifetime and per day of life), as well as a longer herd life, compared to cows in classes of AFC > 28 m. The reduction in AFC contributes to a significant increase in the production and reproduction efficiency of pasture-based dairy herds. This effect was consistent across the three breed groups. Full article

The study examined the relationship between milk yield and udder morphology traits in White Fulani cows. Fifty-eight apparently healthy cows in early lactation at 2nd, 3rd, and 4th parity were used in the study. The data obtained from the cows were test day milk yield (TDMY) from single milking and udder morphology traits comprising udder length (UL), udder width (UW), udder depth (UD), fore teat length (FTL), rear teat length (RTL), fore teat diameter (FTD), and rear teat diameter (RTD). There was no significant effect of parity on TDMY or the udder morphology traits. Phenotypic correlations between TDMY, UL, UW, and UD were positive and significant. Notably, phenotypic correlations between UL and TDMY at different parities were the strongest. Teat measurements had no significant correlation with TDMY. Stepwise and principal component regressions were implemented to assess the relationship between milk yield and udder morphology traits. Interestingly, UL was the only trait that entered the reduced models. The results suggest a probable genetic correlation between milk yield and udder length. Therefore, since udder conformation traits are heritable, when selecting for udder length in White Fulani cows, a correlated response in milk yield is expected. Full article

The monitoring and measurement of animal behaviour may be valuable for improving animal production and welfare. This study was designed to develop thresholds to predict the grazing, standing, walking, and lying behaviour of dairy cows from motion sensor (IceTag) output. The experiment included 29 lactating cows grazed in a pasture-based dairy production system with voluntary cow movement in northern Victoria, Australia. Sensors recorded motion data at 1 min intervals. A total of 5818 min of cow observations were used. Two approaches were developed using (1) the IceTag lying index and steps only and (2) the IceTag lying index, steps, and motion index for each behaviour. Grazing behaviour was best predicted by the second approach, which had a sensitivity of 92% and specificity of 60%. The thresholds were then used to predict cow behaviour during two periods. On average, across both time periods, cows spent 38% of the day grazing, 38% lying, 19% standing, and 5% walking. Predicted individual cow grazing time was positively correlated with both milk production and milking frequency. The thresholds developed were effective at predicting cow behaviours and can be applied to measure behaviour in pasture-based dairy production. Full article