Effects of targeted clinical examination based on alerts from automated health monitoring systems on herd health and performance of lactating dairy cows.

Our objectives were to compare the proportion of lactating dairy cows diagnosed with health disorders (HD) and herd performance when using a health monitoring program designed to rely primarily but not exclusively on alerts from automated health monitoring (AHM) systems or a health monitoring program based primarily on systematic clinical examinations, milk yield monitoring, and visual observation of cows. In a clinical trial, at ∼30 d before expected parturition, nulliparous and parous Holstein cows, stratified by parity and days in gestation, were randomly assigned to the high-intensity clinical monitoring (HIC-M; n = 625) or automated monitoring (AUT-M; n = 624) treatment. Cows were fitted with a neck-attached rumination and physical activity monitoring tag, and individual daily milk yield data were collected from parlor milk meters. For cows in HIC-M, clinical examination was conducted daily until 10 d in milk (DIM) and then in response to milk yield reduction alerts or visual observation of clinical signs of HD over the course of 21 DIM. For cows in AUT-M, clinical examination until 21 DIM was because of health index (HI) score alerts and reduced milk yield alerts. The HI score alerts used were generated based on the manufacturer's settings for the system for the last 2-h period before cows were selected for examination. Visual observation of clinical signs of HD was used for identifying cows potentially missed by automated alerts. Binomial and quantitative data were analyzed by logistic regression and ANOVA with repeated measures, respectively. The percentage of cows diagnosed with at least 1 HD during the experimental treatments risk period tended to be greater and the incidence rate ratio of HD diagnosed was greater in the HIC-M than in the AUT-M treatment. We found no difference between treatments for cows that exited the herd up to 60 or 150 DIM, but more cows tended to exit the herd from 61 to 150 DIM in the HIC-M than in the AUT-M treatment. No differences were detectable between treatments in daily or total milk yield to 21 DIM or in weekly mean milk yield and total milk yield to 150 DIM. More cows were inseminated in estrus for first service if in the HIC-M treatment and had no HD diagnosed than if in the HIC-M treatment but with HD diagnosed, or in the AUT-M treatment and had no HD diagnosed. Cows in the AUT-M treatment with HD diagnosed did not differ from other groups. No differences between treatments were observed in pregnancies per artificial insemination or pregnancy loss for first service. Despite a reduction in the risk of diagnosis of HD, no evidence indicated that a health monitoring program that relied on AHM system alerts to select cows for clinical examination reduced herd performance compared with a more intensive program that included systematic clinical examinations of all cows for the first 10 DIM, reduced milk yield alerts, and visual observation. However, to obtain the same herd performance as with the HIC-M treatment, the AUT-M treatment required use of visual observation. In conclusion, a health monitoring program designed to rely primarily on targeted clinical examination based on alerts from automated health monitoring systems might be a feasible alternative to programs that rely more on clinical examination, provided that visual observation is used to identify cows not detected by automated alerts.

Invited review: Muscle protein breakdown and its assessment in periparturient dairy cows.

Mobilization of body reserves including fat, protein, and glycogen is necessary to overcome phases of negative nutrient balance typical for high-yielding dairy cows during the periparturient period. Skeletal muscle, the largest internal organ in mammals, plays a crucial role in maintaining metabolic homeostasis. However, unlike in liver and adipose tissue, the metabolic and regulatory role of skeletal muscle in the adaptation of dairy cows to the physiological needs of pregnancy and lactation has not been studied extensively. The functional integrity and quality of skeletal muscle are maintained through a constant turnover of protein, resulting from both protein breakdown and protein synthesis. Thus, muscle protein breakdown (MPB) and synthesis are intimately connected and tightly controlled to ensure proper protein homeostasis. Understanding the regulation of MPB, the catabolic component of muscle turnover, and its assessment are therefore important considerations to provide information about the timing and extent of tissue mobilization in periparturient dairy cows. Based on animal models and human studies, it is now evident that MPB occurs via the integration of 3 main systems: autophagy-lysosomal, calpain Ca2+-dependent cysteine proteases, and the ubiquitin-proteasome system. These 3 main systems are interconnected and do not work separately, and the regulation is complex. The ubiquitin-proteasomal system is the most well-known cellular proteolytic system and plays a fundamental role in muscle physiology. Complete degradation of a protein often requires a combination of the systems, depending on the physiological situation. Determination of MPB in dairy cows is technically challenging, resulting in a relative dearth of information. The methods for assessing MPB can be divided into either direct or indirect measurements, both having their strengths and limitations. Available information on the direct measures of MPB primarily comes from stable isotopic tracer methods and those of indirect measurements from assessing expression and activity measures of the components of the 3 MPB systems in muscle biopsy samples. Other indirect approaches (i.e., potential indicators of MPB), including ultrasound imaging and measuring metabolites from muscle degradation (i.e., 3-methylhistidine and creatinine), seem to be applicable methods and can provide useful information about the extent and timing of MPB. This review presents our current understanding, including methodological considerations, of the process of MPB in periparturient dairy cows.

Observational study on associations between resilience indicators based on daily milk yield in first lactation and lifetime profitability.

Resilience is the ability of cows to be minimally affected by disturbances, such as pathogens, heat waves, and changes in feed quality, or to quickly recover. Obvious advantages of resilience are good animal welfare and easy and pleasant management for farmers. Furthermore, economic effects are also expected, but these remain to be determined. The goal of this study was to investigate the association between resilience and lifetime gross margin, using indicators of resilience calculated from fluctuations in daily milk yield using an observational study. Resilience indicators and lifetime gross margin were calculated for 1,325 cows from 21 herds. These cows were not alive anymore and, therefore, had complete lifetime data available for many traits. The resilience indicators were the natural log-transformed variance (LnVar) and the lag-1 autocorrelation (rauto) of daily milk yield deviations from cow-specific lactation curves in parity 1. Good resilience is indicated by low LnVar (small yield response to disturbances) and low rauto (quick yield recovery to baseline). Lifetime gross margin was calculated as the sum of all revenues minus the sum of all costs throughout life. Included revenues were from milk, calf value, and slaughter of the cow. Included costs were from feed, rearing, insemination, management around calving, disease treatments, and destruction in case of death on farm. Feed intake was unknown and, therefore, lifetime feed costs had to be estimated based on milk yield records. The association of each resilience indicator with lifetime gross margin, and also with the underlying revenues and costs, was investigated using analysis of covariance (ANCOVA) models. Mean daily milk yield in first lactation, herd, and year of birth were included as covariates and factors. Natural log-transformed variance had a significantly negative association with lifetime gross margin, which means that cows with stable milk yield (low LnVar, good resilience) in parity 1 generated on average a higher lifetime gross margin than cows that had the same milk yield level but with more fluctuations. The association with lifetime gross margin could be mainly attributed to higher lifetime milk revenues for cows with low LnVar, due to a longer lifespan. Unlike LnVar, rauto was not significantly associated with lifetime gross margin or any of the underlying lifetime costs and revenues. However, it was significantly associated with yearly treatment costs, which is important for ease of management. In conclusion, the importance of resilience for total profit generated by a cow at the end of life was confirmed by the significant association of LnVar with lifetime gross margin, although effects of differences in feed efficiency between resilient and less resilient cows remain to be studied. The economic advantage can be mainly ascribed to benefits of long lifespan.

Estimation and analysis of cow-level cumulative lifetime break-even on financial resiliency.

A dairy farm's ability to generate positive profit is dependent on the cow's response to management decisions made in conjunction with input cost management. Therefore, farm managers consider a multifaceted set of choices, managing their herd not as a homogeneous group of animals, but justifying the influence of individual cows on the farm's financial performance. We combined cow-level performance records from Minnesota DHIA and farm-level financials from the University of Minnesota Center for Farm Financial Management database FINBIN (https://finbin.umn.edu/) from 2012 to 2018 to evaluate farm- and cow-level profitability. The objective of this study was to evaluate individual cow performance matched with farm-level input expenses allocated to the cow level to measure a dairy farm's ability to be profitable over time, considering input and milk price fluctuations. Conventional Minnesota dairy farms were divided into 2 groups-financially resilient and non-resilient-based on their adjusted net farm income ratio over time. Yearly farm-level expenses and revenues were allocated to cows based on performance measures provided in monthly DHIA test data, and a cumulative lifetime break-even was calculated for all cows with consecutive farm data from 2012 to 2018. Herd-level and cow-level characteristics were analyzed to test for statistical difference between resilient and non-resilient farms as well as cows who achieved their break-even versus those that did not for resilient and non-resilient farms. Results showed that resilient farms had statistically different and lower expenses than non-resilient farms, with lower heifer raising expenses ($1,839.32 vs. $1,886.20), lifetime feed expenses ($4,197.07 vs. $4,975.39), and lifetime non-feed expenses ($2,761.63 vs. $4,502.67). Resilient farms had 38.3% of cows reach break-even, whereas non-resilient farms had 25.2% of cows break even. On average, cows who achieved their break-even remained in the herd for approximately 1 yr longer for both resilient farms (1,011 d for cows who break even and 627 d for those that do not) and non-resilient farms (1,033 d for cows who break even and 683 d for those that do not). Cows on resilient farms who achieved their lifetime break-even had an average lifetime profit of $1,613.48, which was $3,095.10 higher than the lifetime profit of -$1,481.62 of cows who never reach their break-even. Cows who reached their break-even on non-resilient farms had a lifetime profit of $1,270.51, which was $3,854.11 higher than the lifetime profit of -$2,583.60 for those who did not break even. Therefore, financially resilient dairy farms were utilizing a low-input, low-output model that proved to be successful and resulted in maintained profitability across volatile and fluctuating commodity prices.

Ultrasonographic assessment of change in omasal position during the last month of gestation and first month of lactation in buffaloes.

INTRODUCTION: This study was aimed to determine the effect of advanced pregnancy on the topography and size of the omasum in 22 healthy Murrah buffaloes. The omasum was scanned 15-20 days before and after parturition, as per the standard procedure. The dorsal and ventral margins of the omasum were identified and marked at each intercostal space (ICS). The dorsal and ventral limits up to the dorsal midline were measured. The omasum was scanned in 6th to 11th ICS during advanced pregnancy and 7th to 11th ICS after the parturition. Irrespective of the pregnancy, the dorsal and ventral margins of the omasum were located farther dorsal and close to the spine in the 6th, 7th and 11th ICS. Except in one buffalo, the omasum was scanned in four consecutive ICS during the advanced pregnancy. After parturition the omasum was scanned in four and five consecutive ICS in 17 and five buffaloes, respectively. The mean dorsal and ventral limits of the omasum increased significantly (P .

INTRODUCTION: Cette étude visait à déterminer l'effet d'une gestation avancée sur la topographie et la taille de l'omasum chez 22 buffles de Murrah en bonne santé. L'omasum a été scanné 15 à 20 jours avant et après la parturition, selon la procédure standard. Les marges dorsale et ventrale de l'omasum ont été identifiées et marquées au niveau de chaque espace intercostal (EIC). Les limites dorsale et ventrale jusqu'à la ligne médiane dorsale ont été mesurées. L'omasum a été scanné du 6ème au 11ème EIC pendant la gestation avancée et du 7ème au 11ème EIC après la mise-bas. Indépendamment de la gestation, les marges dorsale et ventrale de l'omasum étaient situées plus loin dorsalement et plus près de la colonne vertébrale dans les 6ème, 7ème et 11ème EIC. Sauf chez un buffle, l'omasum a été scanné dans quatre EIC consécutifs au cours de la gestation avancée. Après la mise-bas, l'omasum a été scanné dans quatre et cinq EIC consécutifs chez 17 respectivement 5 buffles. Les limites dorsales et ventrales moyennes de l'omasum ont augmenté de manière significative (P.

Replacement of grain maize with spineless cactus in the diet of dairy goats.

Spineless cactus (Nopalea cochenillifera) is widely used in animal feed in semi-arid regions, due to the adaptive characteristics to such conditions and for having high levels of soluble carbohydrates. This research article describes the effect of replacing grain maize with spineless cactus in the diet of dairy goats on dry matter intake, water intake, milk yield, milk physicochemical characteristics and diet production costs. Eight multiparous Anglo Nubian goats were fed diets in which grain maize was replaced with spineless cactus at four levels (0, 33, 66, and 100%) in a double 4 × 4 Latin square design. Milk yield was measured and samples collected in the last three days of each period for physicochemical analysis and for determining nutrient intake. Diet production costs were also determined. Replacing maize with spineless cactus did not influence dry matter intake. Water intake via the drinker decreased linearly in response to the increasing levels of spineless cactus in the diet. The replacement of maize with spineless cactus did not change milk yield or physicochemical parameters. Total feed cost and the percentage of revenue losses from feed decreased with the replacement. Therefore, spineless cactus can fully replace grain maize in the diet of dairy goats, as it does not change dry matter intake or milk yield, but rather reduces feed costs and the drinking-water intake of goats.

Assessment of Maternal Macular Pigment Optical Density (MPOD) as a Potential Marker for Dietary Carotenoid Intake during Lactation in Humans.

Pregnancy and lactation can change the maternal nutrient reserve. Non-invasive, quantitative markers of maternal nutrient intake could enable personalized dietary recommendations that improve health outcomes in mothers and infants. Macular pigment optical density (MPOD) is a candidate marker, as MPOD values generally reflect carotenoid intake. We evaluated the association of MPOD with dietary and breastmilk carotenoids in postpartum women. MPOD measurements and dietary intake of five carotenoids were obtained from 80 mothers in the first three months postpartum. Breastmilk samples from a subset of mothers were analyzed to determine their nutrient composition. The association between MPOD and dietary or breastmilk carotenoids was quantitatively assessed to better understand the availability and mobilization of carotenoids. Our results showed that dietary α-carotene was positively correlated with MPOD. Of the breastmilk carotenoids, 13-cis-lutein and trans-lutein were correlated with MPOD when controlled for the total lutein in breastmilk. Other carotenoids in breastmilk were not associated with MPOD. Maternal MPOD is positively correlated with dietary intake of α-carotene in the early postpartum period, as well as with the breastmilk content of lutein. MPOD may serve as a potential marker for the intake of carotenoids, especially α-carotene, in mothers in the early postpartum period.

Herd-level associations between somatic cell counts and economic performance indicators in Brazilian dairy herds.

The aims of the present study were to provide a portrait of the techno-economic status of dairy herds in Minas Gerais, Brazil, particularly with respect to bulk-tank somatic cell count (BTSCC) data, and to examine the herd-level associations of BTSCC with various economic performance indicators (EPI). Data from 543 herds, 1,052 herd-year records in total, spread over 3 years (2015-2017), from the South and Southwest mesoregions of Minas Gerais State were provided by the Brazilian Support Agency to Micro and Small Companies Division Minas Gerais (SEBRAE). Herds had an average of 82 lactating cows per herd, milk yield of 17 L/cow per day, and availability of financial information via routine monthly economic surveys. The EPI data (revenue, gross margin, GM; net margin, NM; profit; break-even point; and operational profitability) of each herd was measured monthly by SEBRAE personnel, and herd-year averages of all variables were computed. Bulk-tank data (SCC, total bacterial count, content of crude protein and fat) taken by producers or dairy processors were recorded by SEBRAE personal; and corresponding herd-year averages were calculated and included in the SEBRAE database. There were 209 selected herds, which passed all edit checks, and which had data for all 3 years. The EPI (all expressed on a per-cow basis, $/cow per year) were analyzed, including the effects of region, year, log (ln) BTSCC, production level, and herd size, together with the random effect of herd nested within region. A high proportion of herds (94.6%) presented data records (herd-years) with an average BTSCC > 200 × 103 cells/mL: 37.8% of herd-year records had BTSCC between >200 and ≤400, 14.5% with BTSCC between >400 and ≤500, 25% with BTSCC between >500 and ≤750, and 17.3% with BTSCC >750. For each unit increase in ln BTSCC, revenue declined by $228.5/cow per year, GM by $155.6/cow per year, and profit by $138.6/cow per year. Herds with cows of lower production (<14 kg/d) presented lower GM ($286.8/cow per year) compared with herds containing cows producing ≥14 kg/d (≥14 and <19 kg/d = $446.5, and ≥19 kg/d = $601.9). The small-scale milk producers (<39 lactating cows) presented lower revenue ($1,914.9/cow per year) and GM ($274.5/cow per year) and consequently a negative profit (-$224.1/cow per year) compared with other herd size categories (≥39 lactating cows). The reduction in milk yield was 641 L/cow per lactation for each unit increase in ln BTSCC; this represented 9.4% of the milk yield per lactation, assuming an average milk production of 6,843.3 L/cow per lactation of cows from herds that had BTSCC ≤ 200 × 103 cells/mL. Consequently, we found a negative association of BTSCC with profit; profit declining from $227.0 to -53.1/cow per year when the BTSCC increased from 100 to 750 × 103 cell/mL. In short, the lower the BTSCC, the greater the revenue, GM and NM, profit, and operational profitability of the herds. The reduction of milk yield was the main factor associated with higher BTSCC.

Welfare assessment in dairy cows using hair cortisol as a part of monitoring protocols.

Welfare of dairy cows can be assessed using welfare assessment protocols consisting of resource, management and animal-based measures. Welfare Quality® Assessment Protocol is one of the best-known protocols, which depends almost entirely on animal-based measures. To gain more objective and rapid welfare assessment, new techniques have been developed to measure welfare of animals, such as hair cortisol concentration. As cortisol is released in response to stress, it has long been used as a biomarker of stress in animals. While the precise mechanism of cortisol incorporation into hair is unknown, hair cortisol concentration seems to be a marker of long-term systemic cortisol concentration. Hair cortisol is, therefore, a potential marker of chronic stress and is not likely to be affected by acute stress. Studies on cattle show connections between hair cortisol concentration and factors such as pregnancy, parity, diseases, ectoparasites, body condition score, environmental changes, stocking density and milk yield. Hair cortisol concentration appears to be affected by time of sampling, cow age and breed, UV radiation, season, body region of sampled hair and hair colour. Its concentration also depends on sampling and analytical methods. Hair cortisol is a promising non-invasive tool to evaluate welfare of dairy cows, however, more research is needed to determine the extent of effects on its concentration and the appropriate method of sampling and analysis. Correlations between Welfare Quality® Assessment Protocol scores and pooled hair cortisol concentrations have not yet been found, and more research is needed with larger sample size, a standardized protocol of hair sampling, processing and analysis. With proper attention to detail, hair cortisol levels in pooled hair samples might come to be used as a reliable indicator of dairy animal welfare.

Forecasting the milk yield of cows on farms equipped with automatic milking system with the use of decision trees.

The purpose of this paper was to utilize the decision trees technique to determine the factors responsible for high monthly milk yield in Polish Holstein-Friesian cows from 27 herds equipped with milking robots. The applied statistical method-the decision tree technique-showed that the most important factors responsible for monthly milk yield of dairy cows using robots were, in descending order of importance: milking frequency, lactation number, month of milking, and type of lying stall. At the same time, it has been ascertained that the highest monthly milk yield (47.24 kg) can be expected from multiparous cows kept in barns with a deep bedding that were milked more frequently than three times per day. On the other hand, the lowest milk production (13.56 kg) was observed among dairy cows milked less frequently than two times a day, with an average number of milked quarters lower than 3.97. The application of the decision trees technique allows a breeder to select appropriate levels of environmental factors and parameters that will help to ensure maximized milk production.

Reactive stress-coping styles show more variable reproductive expenditure and fitness outcomes.

Stress-coping styles dictate how individuals react to stimuli and can be measured by the integrative physiological parameter of resting heart-rate variability (HRV); low resting HRV indicating proactive coping styles, while high resting HRV typifies reactive individuals. Over 5 successive breeding seasons we measured resting HRV of 57 lactating grey seals. Mothers showed consistent individual differences in resting HRV across years. We asked whether proactive and reactive mothers differed in their patterns of maternal expenditure and short-term fitness outcomes within seasons, using maternal daily mass loss rate to indicate expenditure, and pup daily mass gain to indicate within season fitness outcomes. We found no difference in average rates of maternal daily mass loss or pup daily mass gain between proactive and reactive mothers. However, reactive mothers deviated more from the sample mean for maternal daily mass and pup daily mass gain than proactive mothers. Thus, while proactive mothers exhibit average expenditure strategies with average outcomes, expenditure varies much more among reactive mothers with more variable outcomes. Overall, however, mean fitness was equal across coping styles, providing a mechanism for maintaining coping style diversity within populations. Variability in reactive mothers' expenditures and success is likely a product of their attempts to match phenotype to prevailing environmental conditions, achieved with varying degrees of success.

Individual dairy cow management: achievements, obstacles and prospects.

This review deals with the prospects and achievements of individual dairy cow management (IDCM) and the obstacles and difficulties encountered in attempts to successfully apply IDCM into routine dairy management. All aspects of dairy farm management, health, reproduction, nutrition and welfare are discussed in relation to IDCM. In addition, new IDCM R&D goals in these management fields are suggested, with practical steps to achieve them. The development of management technologies is spurred by the availability of off-the-shelf sensors and expanded recording capacity, data storage, and computing capabilities, as well as by demands for sustainable dairy production and improved animal wellbeing at a time of increasing herd size and milk production per cow. Management technologies are sought that would enable the full expression of genetic and physiological potential of each cow in the herd, to achieve the dairy operation's economic goals whilst optimizing the animal's wellbeing. Results and conclusions from the literature, as well as practical experience supported by published and unpublished data are analyzed and discussed. The object of these efforts is to identify knowledge and management routine gaps in the practical dairy operation, in order to point out directions and improvements for successful implementation of IDCM in the dairy cows' health, reproduction, nutrition and wellbeing.

Combination of Sensor Data and Health Monitoring for Early Detection of Subclinical Ketosis in Dairy Cows.

Subclinical ketosis is a metabolic disease in early lactation. It contributes to economic losses because of reduced milk yield and may promote the development of secondary diseases. Thus, an early detection seems desirable as it enables the farmer to initiate countermeasures. To support early detection, we examine different types of data recordings and use them to build a flexible algorithm that predicts the occurence of subclinical ketosis. This approach shows promising results and can be seen as a step toward automatic health monitoring in farm animals.

Improving nutritional accuracy and economics through a multiple ration-grouping strategy.

The objective of this study was to develop a model application to systematize nutritional grouping (NG) management in commercial dairy farms. The model has 4 sub-sections: (1) real-time data stream integration, (2) calculation of nutritional parameters, (3) grouping algorithm, and (4) output reports. A simulation study on a commercial Wisconsin dairy farm was used to evaluate our NG model. On this dairy farm, lactating cows (n = 2,374 ± 185) are regrouped weekly in 14 pens according to their parity and lactation stage, for which 9 diets are provided. Diets are seldom reformulated and nutritional requirements are not factored to allocate cows to pens. The same 14 pens were used to simulate the implementation of NG using our model, closely following the current farm criteria but also including predicted nutritional requirements (net energy for lactation and metabolizable protein; NEL and MP) and milk yield in an attempt to generate more homogeneous groups of cows for improved diet accuracy. The goal of the simulation study was to implement a continuous weekly system for cows' pen allocation and diet formulation. The predicted MP and NEL requirements from the NG were used to formulate the diets using commercial diet formulation software and the same feed ingredients, feed prices, and other criteria as the current farm diets. Diet MP and NEL densities were adjusted to the nutritional group requirements. Results from the simulation study indicated that the NG model facilitates the implementation of an NG strategy and improves diet accuracy. The theoretical diet cost and predicted nitrogen supply with NG decreased for low-nutritional-requirement groups and increased for high-nutritional-requirement groups compared with current farm groups. The overall average N supply in diets for NG management was 15.14 g/cow per day less than the current farm grouping management. The average diet cost was $3,250/cow per year for current farm management and $3,219/cow per year for NG, which resulted in a theoretical $31/cow per year diet cost savings.

Symposium review: Why revisit dairy cattle productive lifespan?

Dairy cattle productive lifespan averages approximately 3 yr after first calving. Changes in the last decade in reproductive performance, genetic merit, and societal concerns regarding animal welfare and the environmental footprint of dairy products warrant a critical review of decision making regarding dairy cattle productive lifespan. The objective of this study is to provide such a review. Economic decision making drives the majority of culling decisions and, by extension, dairy cattle productive lifespan. Historically, models focused on optimizing replacement decisions for individual cows found economically optimal productive lifespans of 40 mo or more. However, cow performance and prices have changed and the average findings of these models may no longer hold. Management and housing may affect productive lifespan through improvements in health care and cow comfort. Improvements in reproductive efficiency and the availability of sexed semen are leading to an abundance of dairy heifers on many dairy farms, which often results in shorter productive lifespans in herds of fixed sizes. There is also a growing interest in the use of beef semen in dairy cattle, which does not add to the supply of dairy heifers. Acceleration of genetic gain due to genomic testing should likely result in shorter productive lifespans. Younger herds capitalize on genetic progress but have fewer efficient mature cows and have greater replacement costs. Extending dairy cattle productive lifespan might decrease the environmental footprint of milk production because fewer heifers need to be raised. Short productive lifespans, especially as a result of much forced culling early in lactation, are often signs of reduced welfare. Possible extensions of productive lifespan through improved welfare may alleviate public concerns about dairy production, although longer productive lifespans for healthy cows are not necessarily more profitable. A simple model of the economically optimal productive lifespan illustrates the tradeoffs between herd replacement cost, maturity and aging costs, genetic opportunity cost, and calf value opportunity cost. Combined, these factors suggest that an average productive lifespan of approximately 5 yr is warranted. In conclusion, increases in genetic gain, reproductive efficiency, cow comfort, and health care will increase the opportunity of herd managers to change productive lifespan to increase profitability, improve societal acceptance of dairy production, or both.

Economic and environmental effects of double cropping winter annuals and corn using the Integrated Farm System Model.

Dairy farms have been under pressure to reduce negative environmental impacts while remaining profitable during times with volatile milk and commodity prices. Double cropping has been promoted to reduce negative environmental impacts and increase total dry matter yield per hectare. Three dairy farms that double cropped winter annuals and corn were selected from northern and western Pennsylvania. Data were collected from recorded crop and dairy records and financial data for 2016 and 2017. Farms ranged in size from 336 to 511 ha with 233 to 663 cows. Data were used to set parameters for the Integrated Farm System Model, which was then used to simulate 8 scenarios for each farm: current operation; 0, 50, and 100% of corn hectares double cropped; 30% feed price increase with and without double cropping; and 30% feed price decrease with and without double cropping at the farm's current level of double cropping. A 20-yr time period, using weather data that was representative of the actual farms, was used in the Integrated Farm System Model simulation to produce both financial and environmental outputs. Double cropping winter annuals and corn silage increased dry matter yield per hectare by 19%, when comparing 0 to 100% of the corn area double cropped. With all corn land double cropped, net return to management per hundredweight (45.36 kg) of milk increased by 1.8%, N leached per hectare per year decreased by an average of 4.5%, and phosphorus loss was reduced by an average of 9.2% across farms. When feed prices increased by 30%, double cropping increased net return over feed cost and net return to management by 1.6 and 2.2%, respectively, across farms. When feed prices decreased by 30%, double cropping decreased net return over feed cost and net return to management by smaller amounts of 0.13% and 0.11%, respectively, across farms. Modeling indicated that double cropping winter annuals with corn silage can have both environmental and economic benefits when winter-annual silage yields are enough to cover expenses.

Symposium review: An abundance of replacement heifers: What is the economic impact of raising more than are needed?

Historically, most dairy producers raised every heifer born, to ensure a supply of future replacements. However, advancements in transition and reproductive management, coupled with widespread use of sex-sorted semen in dairy heifers and cows, have led to an oversupply of dairy replacement heifers in the United States. With current market values for prepartum heifers at $1,300 and estimated raising costs ranging from $1,700 to $2,400, dairies that continue to produce quantities of heifers in excess of anticipated needs with plans of selling the extras on the open market are likely to experience significant economic loss. Adult cow herd turnover is the key driver behind the number of heifers needed to calve; however, mortality, disease, fertility, and elective culling losses throughout the heifer-raising period determine the total number of heifers that must be retained and raised to meet anticipated needs. A convenience sample of 50 US dairy herds revealed an average heifer inventory of 102% of total milking and dry cows. In this data set, the mean annualized adult herd turnover was 39%. With a mean stillbirth risk of 5.7% in calving heifers, a culling risk of 10.2% by 13 mo of age, a reproductive failure risk of 6.8% in breeding heifers, and an additional culling risk of 6.4% in pregnant heifers, only 74% of calving events with a heifer birth yielded a heifer that entered the lactating herd. Much of this heifer removal was elective, and making the correct culling decisions at the appropriate time yields the best return for the herd. To demonstrate how a herd might approach the elective culling issue, a records-based exercise with 2 large Holstein herds was performed to estimate the cost versus benefit of 3 different elective culling approaches, using a combination of genetic potential and growth performance as the selective criteria. However, the culling of heifers results in economic losses, because the revenue received is less than the cost incurred during raising. Selective culling of heifers soon after weaning yielded the best results in both herds, but despite the predicted improvement in lactation performance of the retained group, the cost associated with removal was greater than the benefit predicted. Culling a group early and then culling a second group just before calving yielded the largest loss. Moving forward, herds should breed more carefully to produce better-quality heifers from more superior dams and sires and consider the use of beef semen in inferior animals. However, to reduce the risk of not producing an adequate supply of replacement heifers, dairies should add an additional buffer to their anticipated needs. Using the assumptions within this project, having 10% extra calving events with a heifer birth would allow the annualized adult herd turnover to rise from 39 to 43% in case economic conditions or health status of the herd should change. If these heifers are not needed, the selection criteria outline could be used to help identify more valuable animals to retain.

Food insecurity and dietary diversity among lactating mothers in the urban municipality in the mountains of Nepal.

BACKGROUND: Adequate nutrition is essential during the lactation period for better maternal and child health outcomes. Although food insecurity and dietary monotony (defined as less diverse diet), two important determinants of undernutrition, are endemic in the rural mountains of Nepal, insufficiently examined and assessed for risk factors in mothers during lactation, a life stage of high nutritional demand. This study aimed to assess the status and factors associated with food insecurity and dietary diversity among lactating mothers residing in the mountains of Nepal. METHODS: A community-based cross-sectional study was conducted in an urban municipality in the mountainous Bajhang District of far-western Nepal. The sampling frame and strategy led to 417 randomly selected lactating mothers. Household Food Insecurity Access Scale (HFIAS) and the tool "Minimum Dietary Diversity for Women" developed by the Food and Agriculture Organization were used to measure food insecurity and dietary diversity, respectively. Additional information on socio-demographics and risk factors were collected. Multivariable logistics regression assessed correlates of study outcomes. RESULTS: Overall, 54% of the households were food insecure, and over half (53%) of the mothers had low dietary diversity. Food insecurity status (mild food insecurity AOR = 10.12, 95% CI = 4.21-24.34; moderate food insecurity AOR = 8.17, 95% CI = 3.24-20.59, and severe food insecurity AOR = 10.56, 95% CI = 3.92-28.43) were associated with higher odds of dietary monotony. Likewise, participants with lower dietary diversity were 8.5 times more likely to be food insecure than those with higher dietary diversity (AOR = 8.48, 95% CI = 3.76-19.14). The monthly income of the family was positively associated with food insecurity. Participants' (AOR = 3.92 95%CI = 1.76-8.71) or spouses' (AOR = 2.90, 95% CI = 1.07-7.85) unemployment was associated with higher odds of being food insecure. Likewise, owning a cultivable land (AOR = 0.49, 95% CI = 0.28-0.84) and participant's unemployment status (AOR = 5.92, 95% CI = 3.02-11.63), were significantly associated with increased odds of dietary monotony. CONCLUSION: The observed food insecurity and poor dietary diversity among lactating mothers, the correlates associated with these outcomes, may help local stakeholders to identify local health needs and subgroups for targeted interventions. Socioeconomically disadvantaged mothers should be specifically targeted for relevant programs and policies.

Non-invasive estimation of the costs of feeding competition in a neotropical primate.

A key goal in behavioral ecology is to investigate the factors influencing the access to food resources and energetic condition of females, which are strong predictors of their reproductive success. We aimed to investigate how ecological factors, social factors, and reproductive state are associated with energetic condition in a wild neotropical primate using non-invasive measures. We first assessed and compared urinary C-peptide levels (uCP), the presence of urinary ketones (uKet), and behaviorally assessed energy balance (bEB) in female white-faced capuchin monkeys (Cebus imitator) living in Santa Rosa, Costa Rica. Then, we assessed how these measures were associated with feeding competition, dominance rank, and reproductive state. As predicted, uCP and bEB were positively associated with each other, and bEB was negatively associated with uKet. However, we did not find a relationship between uCP and uKet. Females showed lower uCP and bEB values during periods of intense feeding competition, but this relationship was not dependent on dominance rank. Furthermore, rank was not directly associated with uCP and bEB. Urinary ketones, on the other hand, were only produced in the most adverse conditions: by low-ranking, lactating females during periods of intense feeding competition. Behavioral strategies are assumed to maximize reproductive success and not energetic condition per se, which might explain why rank was not generally associated with energetic condition in our study population. This highlights the importance of considering potential differences between reproductive success and proxies of reproductive success, such as energetic condition or food intake, when investigating predictions of socioecological models.

High oxytocin infants gain more mass with no additional maternal energetic costs in wild grey seals (Halichoerus grypus).

Maximising infant survival requires secure attachments and appropriate behaviours between parents and offspring. Oxytocin is vital for parent-offspring bonding and behaviour. It also modulates energetic balance and neural pathways regulating feeding. However, to date the connections between these two areas of the hormone's functionality are poorly defined. We demonstrate that grey seal (Halichoerus grypus) mothers with high oxytocin levels produce pups with high oxytocin levels throughout lactation, and show for the first time a link between endogenous infant oxytocin levels and rates of mass gain prior to weaning. High oxytocin infants gained mass at a greater rate without additional energetic cost to their mothers. Increased mass gain in infants was not due to increased nursing, and there was no link between maternal mass loss rates and plasma oxytocin concentrations. Increased mass gain rates within high oxytocin infants may be due to changes in individual behaviour and energy expenditure or oxytocin impacting on tissue formation. Infancy is a crucial time for growth and development, and our findings connect the oxytocin driven mechanisms for parent-infant bonding with the energetics underlying parental care. Our study demonstrates that oxytocin release may connect optimal parental or social environments with direct physiological advantages for individual development.