Evolution of mammals: lactation helps mothers to cope with unreliable food supplies.

Aufgrund ihrer vielfältigen Anpassungen in Ökologie und Verhalten stellen die Carnivora eine geeignete Gruppe dar, um die Muster innerhalb der sozialen Evolution der Säugetiere zu studieren. Insbesondere Arten mit unterschiedlicher sozialer Organisation der beiden Geschlechter bieten die Möglichkeit, geschlechtsspezifische Kosten und Vorteile zu untersuchen, um die Determinanten und Mechanismen von Sozialität aufzuzeigen. Die Mangusten (Herpestidae) sind eine Gruppe kleiner Raubtiere, in der Studien zu einer kleinen Anzahl von hochsozialen Arten mit kooperativer Jungenaufzucht entscheidend zum Verständnis des Gruppenlebens und der Verteilung des Fortpflanzungserfolgs unter Gruppenmitgliedern bei Säugern beigetragen haben. Im Gegensatz dazu ist über die Sozialsysteme ihrer nächsten Verwandten, der Eupleridae (Madagassische Raubtiere) viel weniger bekannt. Diese Gruppe bietet jedoch ein großes Potenzial zur Untersuchung der Geschwindigkeit und Mechanismen der sozialen Evolution der Raubtiere in vergleichender Perspektive, weil sie sich für mehr als 20 Millionen Jahre isoliert auf Madagaskar entwickelt hat.
\nIn dieser Dissertation lege ich die soziale Organisation, Lebenslaufstrategie und genetischen Eigenschaften des madagassischen Schmalstreifenmungos (Mungotictis decemlineata) im Kirindy-Wald/CNFEREF, einem tropischen saisonalen Trockenwald im Westen Madagaskars, dar. Als Grundlage für zwischenartliche Vergleiche bewerte ich des weiteren in einer umfassenden Betrachtung den Wissensstand über die Sozialsysteme und Lebenslaufstrategien der Herpestiden und Eupleriden und setze diese in Beziehung zu den Vorhersagen sozio-ökologischer Theorie.
\nWährend meiner Feldstudien in den Jahren 2011 bis 2014 fing ich 63 Schmalstreifenmungos in Lebendfallen, vermaß und markierte diese und nahm Gewebeproben für genetische Untersuchungen. Von insgesamt 40 Individuen (20 Männchen, 20 Weibchen), die ich mit Radiosendern versehen hatte, sowie von den mit ihnen assoziierten Artgenossen sammelte ich durch systematische Radiotelemetrie und Zensus räumliche, demografische und Verhaltensdaten. Zur Charakterisierung der sozialen Organisation von M. decemlineata analysierte ich die Zusammensetzung sozialer Einheiten im Hinblick auf Geschlecht und Alter der Individuen und ihre Streifgebietsgröße und –verteilung. Außerdem analysierte ich das Geschlechterverhältnis, Mortalität und Reproduktionsmerkmale der Population. Des weiteren analysierte ich mitochondriale DNA und Mikrosatelliten der 63 beprobten sowie 33 weiterer Individuen aus einer vorherigen Studie zwischen 2000 und 2010. Die Mikrosatelliten-Analyse basierte auf 13 Loci der Fossa (Cryptoprocta ferox), die in vorläufigen Tests erfolgreich amplifizierten. Um die lokale genetische Struktur und Abwanderungsmuster aufzudecken, analysierte ich die Haplotypendiversität von Männchen und Weibchen. Basierend auf der Mikrosatellitenanalyse untersuchte ich Verwandtschaft innerhalb der Geschlechter und sozialer Einheiten sowie Elternschaften und Geschwisterverhältnisse.
\nMännchen und Weibchen lebten in kleinen gleichgeschlechtlichen sozialen Einheiten. Insgesamt beobachtete ich neun weibliche Einheiten und 13 Assoziationen von Männchen in 497 h, sammelte 10,411 Verhaltensscans und 1,879 Triangulationspunkte. Weibliche Einheiten basierten auf Matrilinien. Ihre Mitglieder waren enger verwandt als unter Zufallsbedingungen erwartet und umfassten durchschnittlich zwei adulte Weibchen, ein Juveniles und ein Junges. Weibliche Einheiten behaupteten eigene Territorien. Ihre Streifgebietsgröße (90% Kernel, arithmetisches Mittel: 30.4 ha) stand nicht in Zusammenhang mit der Zahl ihrer Mitglieder, war aber größer während der kargen Trockenzeit als zur Regenzeit. Männchen bildeten Assoziationen von bis zu vier Individuen, die sich während der Paarungszeit auflösten und in ihrer Zusammensetzung zwischen Jahren variierten. In der großen Mehrheit waren assoziierte Männchen nicht näher miteinander verwandt als durch Zufall erwartet. Die Streifgebiete der einzelnen Männchen (90% Kernel, arithmetisches Mittel: 63.9 ha) überlappten stark mit solchen von mit ihnen assoziierten und nicht-assoziierten Männchen und mit denen von bis zu 4 weiblichen Einheiten. Es wanderten mehr Männchen als Weibchen ab, bestätigt durch höhere Haplotypendiversität bei Männchen als bei Weibchen. Die Lebenslaufstrategien waren überwiegend langsam, wobei Männchen in jüngerem Alter abwanderten als Weibchen. Die Mortalitätsraten unterschieden sich nicht signifikant zwischen den Geschlechtern. Beobachtungen lassen jedoch darauf schließen, dass besonders allein umherstreifende Männchen anfällig gegen Prädation waren. Der Fortpflanzungserfolg der Weibchen, gemessen an der Zahl der lebend erschienenen Jungen zeigte keine signifikante Ungleichverteilung, aber Post-partum-Mortalität beschränkte die erfolgreiche Fortpflanzung auf dominante Tiere. Die Verteilung der Vaterschaften, das Geschlechterverhältnis der Adulten zugunsten der Männchen und das Paarungsverhalten deuteten auf gemäßigte Promiskuität hin, wobei einige Männchen Junge in verschiedenen weiblichen Einheiten innerhalb derselben Paarungssaison zeugten.
\nSchlussfolgernd lässt sich sagen, dass die Muster der Verteilung von Männchen und Weibchen in M. decemlineata wichtigen Vorhersagen sozio-ökologischer Theorie folgten. Vorteile bei der Vermeidung von Fressfeinden bestimmten die Vergesellschaftung von Individuen in beiden Geschlechtern. Verwandtschaft war hingegen keine bestimmende Determinante der Sozialität unter Männchen. Die sexuelle Segregation in M. decemlineata schien stark mit Fortpflanzungsstrategien zusammenzuhängen, die sich im Umherstreifen der Männchen, daraus resultierender Aktivitätsunterschiede und in sexueller Belästigung der Weibchen durch die Männchen und darauf folgender Aggression der Weibchen ausdrückten. Bei Weibchen resultierte gelegentliche Abwanderung wahrscheinlich aus der Kosten-Nutzen-Abwägung zwischen philopatrischem Gruppenleben und der Möglichkeit der eigenen Fortpflanzung in unbesetzten Territorien.
\nIn vergleichender Perspektive zeigt die Sozialität von M. decemlineata ein höheres Niveau als es für mehrere Arten der Klade der ‚solitären Herpestiden‘ beschrieben wurde. Allgemeine Muster des Paarungssystems deuten jedoch auf einen vergleichsweise ursprünglichen Zustand innerhalb der Säugetierevolution hin. Die Merkmale der Sozialstruktur und des Paarungssystems bieten Ansatzpunkte für weitere Forschung und Vergleiche mit den Herpestiden, z. B. im Hinblick auf die Intensität und Mechanismen weiblicher Konkurrenz und Determinanten des Fortpflanzungserfolgs sowie einer möglichen Rolle der Partnerwahl.

Introduction. The article analyses current trends in milk production and consumption in the world, taking into account the latest factors of product competitiveness in the global milk market and the growing interest of consumers in plant substitutes for animal milk. According to the Food and Agriculture Organization of the United Nations, world dairy production continues to grow, with Asia experiencing the largest increase since 2019. The next decade will create great opportunities for the dairy industry in the world. The increase in demand will be accelerated by the globalization of the industry, which will form consolidation in order to efficiently use resource potential, ensure a sustainable supply of milk and stable profits for producers. Purpose. The purpose of the article is to study current trends in milk production and consumption in the world, taking into account the latest factors of product competitiveness in the global milk market and the growing interest of consumers in plant substitutes for animal milk. Method (methodology).The methodological basis of the study is scientific work on the current state and trends in production and milk consumption in the world. Dialectical, systemic and synergetic approaches were used at all stages of the study; methods of general scientific knowledge: comparison, analysis and synthesis, induction and deduction. Statistical analysis was used as specific methods. Results. The results of the study allowed us to draw conclusions about the social significance of dairy production. Globalization with a significant impact on domestic and international trade in the dairy industry will accelerate in the coming years, as more and more consumers seek to include dairy products in their daily diet to promote good quality and healthy natural products. One of the current trends in the world food market is a significant increase in consumption of plant foods. At present, each country faces a difficult task to develop an effective strategy for the development of natural dairy products in such conditions. The development of the world dairy market is influenced by various factors that determine the volume of production and consumption of dairy products, associated primarily with global changes in consumer preferences, increasing demand for goods in cheaper price segments, population growth, especially in developing countries, as well as economic development and overall welfare of mankind. In the context of globalization, an important factor in the world market is the economic policy of major countries that export and import milk and dairy products. In recent years, trade wars have begun to intensify, in particular between key players in the global market, which negatively affects the market for natural milk and dairy products and hinders its development. as well as with economic development and the general growth of human well-being. In the context of globalization, an important factor in the world market is the economic policy of major countries that export and import milk and dairy products. In recent years, trade wars have begun to intensify, in particular between key players in the global market, which negatively affects the market for natural milk and dairy products and hinders its development. As well as with economic development and the general growth of human well-being. In the context of globalization, an important factor in the world market is the economic policy of major countries that export and import milk and dairy products. In recent years, trade wars have begun to intensify, in particular between key players in the global market, which negatively affects the market for natural milk and dairy products and hinders its development.

Since Azerbaijan's independence in 1991, milk production has increased significantly. This study investigated the milk and dairy product consumption behavior of students at Azerbaijan State Agricultural University (ADAU) in Ganja. It fills a gap in research on milk consumption patterns among university students in Azerbaijan. Data were collected via a survey conducted with 418 students from various departments in March-April 2024, using a 22-item survey focusing on demographics, consumption habits, and purchasing behaviors. The majority of participants (64.1% male, over 90% single) were aged 17-22. Although students consumed milk, the frequency was relatively low. Both male and female students predominantly preferred plain milk, with street milk being the most common choice. Students primarily associated milk consumption with health benefits, which positively influenced their preferences. However, no single dominant factor limiting milk consumption was identified. Key factors affecting purchasing decisions included price, expiry date, place of purchase, and calorie content. The study suggests that government incentives to support milk and dairy product consumption in retail outlets, both on campus and in urban areas, could be beneficial. Additionally, organizing awareness-raising scientific activities and incorporating relevant undergraduate courses into the curriculum may promote healthier consumption behaviors among students.

This study examined the trend and variability in milk production and consumption in different countries of the South Asian region from the year 2000 to the year 2017. An exponential growth function was fitted to estimate compound annual growth rates (CAGR) in milk production and consumption. Cuddy-Della Valle indices were constructed to examine the extent of instability. The study reveals that the growth rate of milk consumption in Afghanistan and Nepal was higher than that of milk production, indicating an increasing trend of net imports in these countries. In Bhutan, milk growth (CAGR) was negative for both production (-0.69 percent) and consumption (-0.67 percent), indicating a weak performance in the livestock sector during the study period. However, in this South Asian region, the positive CAGR in milk production varied from 1.38 percent in Iran to 5.20 percent in Sri Lanka, with total consumption growing at almost the same rate as production in these two countries. In the South Asian region, all countries showed low milk production and consumption variability, except Sri Lanka, where medium instability was observed in both milk production and consumption during this period. In Afghanistan, milk production grew at an annual compound rate of 1.86 percent, slightly less than milk consumption, which grew by 2 percent compound annual growth rate.

From the evolutionary point of view, the priority problem for an individual is not longevity, but adaptation to the environment associated with the need for survival, food supply, and reproduction. We see two main vectors in the evolution of mammals. One is a short lifespan and numerous offspring ensuring reproductive success (r-strategy). The other one is development of valuable skills in order compete successfully (K-strategy). Species with the K-strategy should develop and enhance specific systems (anti-aging programs) aimed at increasing the reliability and adaptability, including lifespan. These systems are signaling cascades that provide cell repair and antioxidant defense. Hence, any arbitrarily selected long-living species should be characterized by manifestation to a different extent of the longevity-favoring traits (e.g., body size, brain development, sociality, activity of body repair and antioxidant defense systems, resistance to xenobiotics and tumor formation, presence of neotenic traits). Hereafter, we will call a set of such traits as the gerontological success of a species. Longevity is not equivalent to the evolutionary or reproductive success. This difference between these phenomena reaches its peak in mammals due to the development of endothermy and cephalization associated with the cerebral cortex expansion, which leads to the upregulated production of oxidative radicals by the mitochondria (and, consequently, accelerated aging), increase in the number of non-dividing differentiated cells, accumulation of the age-related damage in these cells, and development of neurodegenerative diseases. The article presents mathematical indicators used to assess the predisposition to longevity in different species (including the standard mortality rate and basal metabolic rate, as well as their derivatives). The properties of the evolution of mammals (including the differences between modern mammals and their ancestral forms) are also discussed.

One of the main ways to overcome the existing problem of providing the country’s population with proteins of animal origin is, among other things, to increase the production and consumption of milk and dairy products. Based on this, consideration of the existing problems of the functioning of the dairy subcomplex of the agro-industrial complex of the country is extremely relevant. The purpose of the study is to assess the current state of the subcomplex and to develop practical recommendations for improving the efficiency of its functioning. The research was based on the application of methods: analysis and synthesis, induction and deduction, factor and economic and statistical comparative analysis, analytical and logical generalisations, etc. In contrast to the existing positive trend of growth in milk production in the world, in dairy farming in Ukraine, there is a constant reduction in the number of cows and milk production. Over the past 10 years alone, the number of cattle in the country has decreased by 1.952 million heads, including cows by 0.958 million heads, and milk production in 2020 amounted to 9.263 million tons of milk (17.64% less than in 2010). There was a reduction in the number of milk processing enterprises. Thus, in 2020, there were only 192 of them left (of which 178 worked) or only 29.86% of their number in 1990. All this resulted in the fact that the actual consumption of milk per capita in 2020 was only 53.13% of the scientifically based standards of consumption of milk and dairy products. According to the results of the research, it was established that the decrease in the number of cows, without considering the growth of their productivity in farms of all categories, reduced the production of dairy raw materials. The results of the research allow identifying the main factors that affect the reduction in the production of milk and its derivatives. After analysing the state and trends in the development of dairy farming, it can be argued that the increase in the production of quality and safe milk and its supply for processing requires the cooperation of farms and households. Together, they can ensure the stability of production of the necessary volumes of milk, appropriate quality and safety and ensure the supply of significant volumes of raw materials to large processors. Possible areas and innovative technologies of animal husbandry and milk production and processing require further research

Milk and dairy products are an important food in the human diet. The present investigation was carried out to determine concentrations of lead, cadmium, zinc, copper and iron in milk and dairy products and evaluate the potential health risks of metals to humans via consumption of milk and dairy products. A total of 77 samples of milk and dairy products (22 raw milk, 20 kareish cheese, 21 butter and 14 rice pudding) were collected from farms, individual farmers and dairy shops in Beni-Suef governorate, Egypt. Pb, Cd, Zn, Cu and Fe concentrations in milk and dairy products ranged from 0.044–0.751, 0.008–0.179, 0.888–18.316, 0.002–1.692 and 1.3208–45.6198 ppm respectively. Pb concentration in all samples exceeded the maximum permissible limit (0.02 mg/kg) established by codex standard. Pd and Cd intake through milk and dairy products consumption were 1.27 and 0.33 μg/kg bw/day, which represent 35.3 and 39.8 % of the tolerable daily intake. Dairy products are poor sources of iron, copper and zinc, and milk contributes little to the total iron and zinc intake. Target hazard quotient values of less than 1 indicate a relative absence of health risks associated with the consumption of milk and dairy products.

Considering that pollutants transformed to human body through food consumption, food safety is of great concern to consumers. Because consumption of milk contaminated with heavy metals poses serious threats to consumer's health. This study was conducted to evaluate the concentration of heavy metals and its risk with the consumption of milk and milk products in Aswan Province . A total of 20 samples of raw fresh buffalo, cow, sheep and goat milk and 16 samples of milk products of Kareish cheese, Domiati cheese, Mish and Samna were analyzed for the presence of heavy metals of Cadmium (Cd) and Lead (Pb) and trace elements of Copper (Cu) and Zinc (Zn) via Atomic Adsorption Spectrophotometer (AAS). The results showed that the concentration of total heavy metals differed between different areas, it was the highest in Edfu but the least in Toshka. With the analysis of metals concentration in milk of different species, the results showed higher concentration of total metals in sheep and goat milk combined with low content of Cd and high content of Zn and Cu than that of cow and buffalo milk. Comparing the Cd, Pb, Cu and Zn concentrations in locally manufactured milk products with the permissible upper limit of EOS (1993), the results are within the permissible limit. The health risk assessment of metals was assessed on the basis of determining of EDI and THQ for inhabitants through the consumption of contaminated milk and milk products. The EDI of Cd and Pb contributed to 59.7% and 20.48% of PTDI, while Zn contributed to 0.0345 to 2.582% and 0.0475 to 3.55% of RDA for male and female, respectively, but the Cu contributed to 0.0555 to 7.466 % of RDA. The results also showed that THQ of all metals under studies are less than one via the consumption of milk and milk products which means that inhabitants in Aswan Governorate will not exposed to health risk from the consumption of raw milk and milk product.

Questionnaires were administered to 163 individuals to determine the factors which influence the choice and consumption of milk and milk products among consumers in three socio‐economic groups within Lilongwe, the capital city of Malai. Another set of questionnaires was sent to 206 individuals in Salima area to assess the factors that limit the consumption of goat and sheep milk in comparison with cow milk.Whole pasteurized cow milk was the product most frequently purchased due to its flavour, taste and lower price as compared to other products. Generally, the study indicated that incomes and product prices are the most important factors influencing the choice and consumption of cow milk and milk products. Milk intolerance seems to play a very minor role. Unavailability of particular products at a particular time when the product is wanted also poses a problem. With regard to goat and sheep milk, unavailability is the major problem influencing the consumption, followed by the fact that it is not traditional to milk and consume goat and sheep milk.

The indicators of recent years demonstrate stability and high results in milk production at agricultural enterprises. The relevance is confirmed by the fact that milk production and its optimization are key aspects of the economic development of the agricultural sector of Ukraine in the post-war period, because dairy farming is a system-forming branch of agriculture that opens up new opportunities for the formation of promising business development vectors. The purpose of the article is to analyse the problems and prospects of economic aspects of the efficiency of resource use and optimization of milk production in agricultural enterprises of Ukraine in the post-war period. The research used the following methods: induction and deduction, synthesis, theoretical generalization, statistical analysis, comparative analysis, modelling. The links of inconsistency between resources, production of dairy products and the capabilities of enterprises, state policy, the level, and norms of consumption of milk and dairy products by the population in the post-war period are studied. Accordingly, the dynamics of production, export, sales, stages of production, peculiarities of cooperation and import of basic dairy products were considered. A direct connection between the production and consumption of milk, the dependence of the demand and consumption of milk and dairy products on the level of total income of households has been established. Based on this, the work presents a full description of the dairy industry in Ukraine, the volume of milk production in the pre-war period and prospects for development in the post-war period. A systematic study of the market properties of various types of dairy products of Ukraine using SWOT and PEST analysis is given in general. In order to improve the state of the market of milk and dairy products of Ukraine, appropriate proposals have been formulated. The practical value of the work lies in the fact that its results can be used as a basis for the development of technologies for the use of milk production resources in the post-war period, as well as in the work of specialists in the agro-industrial and economic sectors

Vitamin concentrates with vitamins A and D are used for fortification of fluid milk. Although many of the degradation components of vitamins A and D have an important role in flavor/fragrance applications, they may also be source(s) of off-flavor(s) in vitamin fortified milk due to their heat, oxygen, and the light sensitivity. It is very important for the dairy industry to understand how vitamin concentrates can impact flavor and flavor stability of fluid milk. Currently, little research on vitamin degradation products can be found with respect to flavor contributions. In this review, the history, regulations, processing, and storage stability of vitamins in fluid milk are addressed along with some hypotheses for the role of vitamin A and D fortification on flavor and stability of fluid milk.

Purpose: Understanding the main factors affecting the environmental impacts of milk production and consumption along the value chain is key towards reducing these impacts. This paper aims to present detailed spatialized distributions of impacts associated with milk production and consumption across the United States (U.S.), accounting for locations of both feed and on-farm activities, as well as variations in impact intensity. Using a Life Cycle Analysis (LCA) approach, focus is given to impacts related to (a) water consumption, (b) eutrophication of marine and freshwater, (c) land use, (d) human toxicity and ecotoxicity, and (e) greenhouse gases. Methods: Drawing on data representing regional agricultural practices, feed production is modelled for 50 states and 18 main watersheds and linked to regions of milk production in a spatialized matrix-based approach to yield milk produced at farm gate. Milk processing, distribution, retail, and consumption are then modelled at a national level, accounting for retail and consumer losses. Custom characterization factors are developed for freshwater and marine eutrophication in the U.S. context. Results and discussion: In the overall life cycle, up to 30% of the impact per kg milk consumed is due to milk losses that occur during the retail and consumption phases (i.e., after production), emphasizing the importance of differentiating between farm gate and consumer estimates. Water scarcity is the impact category with the highest spatial variability. Watersheds in the western part of the U.S. are the dominant contributors to the total water consumed, with 80% of water scarcity impacts driven by only 40% of the total milk production. Freshwater eutrophication also has strong spatial variation, with high persistence of emitted phosphorus in Midwest and Great Lakes area, but high freshwater eutrophication impacts associated with extant phosphorus concentration above 100 µg/L in the California, Missouri, and Upper Mississippi water basins. Overall, normalized impacts of fluid milk consumption represent 0.25% to 0.8% of the annual average impact of a person living in the U.S. As milk at farm gate is used for fluid milk and other dairy products, the production of milk at farm gate represents 0.5% to 3% of this annual impact. Dominant contributions to human health impacts are from fine particulate matter and from climate change, whereas ecosystem impacts of milk are mostly due to land use and water consumption. Conclusion: This study provides a systematic, national perspective on the environmental impacts of milk production and consumption in the United States, showing high spatial variation in inputs, farm practices, and impacts.

Background: Various factors influence the quality and safety of milk. However, a detailed study about these factors is lacking in our area. Aim: To elucidate perceptions regarding milk hygiene, milk processing and consumption behaviors. Study design: Descriptive cross-sectional study, Place & duration of study: Mohi-ud-Din Islamic Medical College, Mirpur, AJK, from March to August 2020. Methods: Female staff, patients and attendants were included. A pre-tested and pre-validated questionnaire was used to gather responses. Questions were specifically asked about practices associated with consumption of milk and related products, familiarity with risks associated with consumption of raw milk, practices associated with boiling of milk and milk consumption. Result: There were 130 participants and 75(58%) were educated while 55(42%) were uneducated. Almost all of the educated women were aware of the importance of boiling milk. On the contrary, awareness about usage of boiled milk among uneducated women was 69% while 31% were unaware about the importance of boiling milk. About 58% of study participants consume milk regularly as compared to 42% who were not taking milk regularly. The duration of boiling of milk, for majority of participants, ranged from 05-15 minutes. Side effects experienced by the those consuming raw milk included abdominal pain (62%), diarrhea (23%) and vomiting (15%). Conclusion: The findings suggest that there is a need to encourage sterile milk handling practices and local communities should be closely involved to strengthen their understanding of milk safety. There should be campaigns involving masses to induce behavioral changes among communities about safe and hygienic habits involving handling and usage of milk and its products. The best approach to encourage people towards milk safety will be the boiling of milk. Keywords: Milk, boiling, pasteurization, hygiene, raw

BackgroundMilk is an important source of protein for many Indian households. However, milk intake is very low. Hence, it is necessary to examine production–consumption linkages of milk within the paradigm of accessibility, availability, and affordability. ObjectivesThis study examined linkages between milk consumption and production, accounting for sales and factors associated with production investments in rural Bihar, a major milk-producing state of India with very poor nutritional status. MethodsA panel of households from the Gaya and Nalanda districts of Bihar were surveyed: the first round in July and August 2019 (n = 2026 households) and the second round from December 2019 to January 2020 (n = 2001 households). Data were collected on household consumption, production, and sale of milk, as well as other foods. The study examines the consumption–production linkage of milk and the association of dietary diversity with consumption from own production, with households as the unit of analysis. Ordinary least square regression analysis of average monthly household milk consumption was used to identify factors associated with milk consumption, particularly milk production. ResultsThe median (Quartile 1, Quartile 3) per capita milk consumption per day was 83.3 (41.6, 166.6) mL in the milk-consuming households. Average monthly household milk consumption in liters was higher in milk-producing households [β: 7.1; 95% confidence interval (CI): 6.1, 8.1] than households relying on market purchases. Household milk consumption was higher in the third tertile of milk production than the first tertile of production (β: 14.3 L/wk; 95% CI: 12.1, 17.2) and lower in the highest tertile of household sale quantity (β: −8.8 L/wk in tertile 3, 95% CI: −12.7, −5) than the first tertile of household sale quantity of milk. ConclusionsThe study provides evidence that consumption of milk in rural households is associated with own production such that households with higher production consume more. However, sale preferences restrict the quantity of milk consumed in milk-producing households.

Acquisition of milk production capabilities by an ancestor of mammals is at the root of mammalian evolution. Milk casein micelles are a primary source of amino acids and calcium phosphate to neonates. To understand the role of kappa-casein in lactation, we have created and characterized a null mouse strain (Csnk-/-) lacking this gene. The mutant kappa-casein allele did not affect the expression of other milk proteins in Csnk-/- females. However, these females did not suckle their pups and failed to lactate because of destabilization of the micelles in the lumina of the mammary gland. Thus, kappa-casein is essential for lactation and, consequently, for the successful completion of the process of reproduction in mammals. In view of the extreme structural conservation of the casein locus, as well as the phenotype of Csnk-/- females, we propose that the organization of a functional kappa-casein gene would have been one of the critical events in the evolution of mammals. Further, kappa-casein variants are known to affect the industrial properties of milk in dairy animals. Given the expenses and the time scale of such experiments in livestock species, it is desirable to model the intended genetic modifications in mice first. The mouse strain that we have created would be a useful model to study the effect of kappa-casein variants on the properties of milk and/or milk products.