The Relationship Between Coat Color and Reproductive Performance of Dairy Cows in Algeria

The objective of the current study was to analyze the reproduction parameters of 48 dairy cows (29 Montbeliardes and 19 Normandes) and their relationship to coat color. Cows were imported from European countries and raised in the semi-arid region of Sétif in Algeria. The findings showed that the cows of the Montbéliarde breed were more fertile and of greater reproduction efficiency, compared to Normandes. Regarding the Montbéliarde breed, the intervals between calving and calving to conception were respectively 378.34 and 98.65 days, which were shorter than those of the Normandes breed (67 and 22 days, respectively). Normandes cows registered a higher number of services per conception (1.54 ± 0.9), compared to Montbeliarde cows (1.34 ± 0.55). Calving to the first service interval of the Normandes (76 days) was longer by 5 days than that of the Montbéliarde breed. The coats of Montbéliarde cows (51%) were whiter than those of Normandes (48%). A darker hair coat probably assured protectivity against thermal stress and greater efficiency of reproduction. The interval between calving in Montbéliarde cows was significantly affected by coat color; the interval between calving of cows with a colored coat was shorter (358 days) than whiter cows (400 days). For Normandes, cows with a colorful coat required fewer services per conception number (1.44). Hair works as a temperature regulator and may affect reproduction performances. The results of the current study suggest the possibility of integrating coat color into animal selection. It can be assumed that colored coats for Montbéliarde and Normande breeds appear to be related to their reproductive efficiency (interval between calving and number of services per conception, respectively).

Stock status, environmental factors and reproduction efficiency of the anchovy sprat population (Clupeonella Engrauliformis Borodin) in modern conditions

Until the end of the XX century, anchovy sprat was the leading object of marine fishing in the Caspian Sea. At the beginning of the XXI century, there was a mass death of this species, as well as an outbreak of the number of mnemiopsis comb - a powerful consumer of feed zooplankton. There was a redistribution of keel clusters in the sea. The main part of the fishing stock of keels began to be distributed in the Middle Caspian Sea. The main object of marine fishing has become an ordinary sprat. In recent years (2015-2020), there has been an increase in the number of anchovy sprats. The materials of keel surveys also confirm the annual growth in the number of juvenile sprats. This paper presents the results of recent years of observations, shows the dynamics of the number and biomass of the population, the parent part of the herd, total fertility. The efficiency of spawning and the survival coefficients of the generation in early ontogenesis are shown. Environmental factors that have a direct impact on the formation of the anchovy sprat stock are described.

Evolution and extinction can occur rapidly: a modeling approach

Fossil record of Earth describing the last 500 million years is characterized by evolution discontinuity as well as recurring global extinctions of some species and their replacement by new types, the causes of which are still debate. We developed a model of evolutionary self-development of a large ecosystem. This model of biota evolution based on the universal laws of living systems functioning: reproduction, dependence of reproduction efficiency and mortality on biota density, mutational variability in the process of reproduction and selection of the most adapted individuals. We have shown that global extinctions and phases of rapid growth and biodiversity stasis can be a reflection of the emergence of bistability in a self-organizing system, which is the Earth’s biota. Bistability was found to be characteristic only for ecosystems with predominant sexual reproduction. The reason for the transition from one state to another is the selection of the most adapted individuals. That is, we explain the characteristics of the Earth’s fossil record during the last 500 million years by the internal laws of Earth’s ecosystem functioning, which appeared at a certain stage of evolution as a result of the emergence of life forms with an increased adaptive diversification associated with sexual dimorphism.

ANALYZING STOCK STATUS OF MAIN COMMERCIAL FISH IN KUIBYSHEV RESERVOIR IN 2000–2018 AND EFFECTIVENESS IN FISHING

The article presents a review of the main commercial fish stocks of the Kuibyshev Reservoir based on the long-term research data (2000–2019). The Kuibyshev Reservoir is the leading fishery reservoir in the Republic of Tatarstan, Mari El, Chuvashia, Ulyanovsk and Samara Re-gions. There have been given the data of regular observing species, sex, size-weight and age composition of fish, their reproduction efficiency, distribution, abundance and reproduction of aquatic biological resources, their habitat, as well as control over their fishing and conservation. The analysis of the influence of environmental factors (level and temperature regimes) and fishing on the fish stocks formation is presented. Based on the presented materials, there have been shown the data about the stocks of the main commercial fish species of the Kuibyshev Reservoir (bream, zander, pike, carp, catfish, sterlet) and of the small-sized ordinary fish stocks, the optimal development of which will bring the catches up to 10 thousand tons and more. It has been inferred that for rational fishing in the reservoir, it is necessary to develop a strategy for the integrated effective development of biological resources of the reservoir on an ecosystem basis for better use of the bioproduction capabilities of its biological resources.

A review of strategies aimed at adapting livestock to volatile climatic conditions in Nigeria

Despite their crucial importance, limited information exists about how livestock are affected by climate change in Nigeria. Changing climatic patterns are manifested through occurrences like abrupt temperature increase, dwindling rainfall pattern, rise in spells of drought and flood. These conditions exert different effects across the geographical landscape of the country, which can broadly be classed as Semiarid, Sahel and Derived Savannah, respectively as well as Forest and Montane. Livestock provide humans with the full complement of amino acids, which are the only known natural suppliers of Vitamin B12 and equally supply iron, calcium, iodine and zinc. In addition, livestock accounts for 40% of Agricultural Gross Domestic Product and significantly contributes to enhancing rural livelihood. Stress conditions are induced in livestock by harsh weather conditions that reduce the feed available to them as well as impede growth rate and reproduction efficiency and disease incidence which may eventually result in death. In the light of the livestock benefits to humanity, it is necessary to devise means of making their climate resilient. Some of the proven strategies include animal genetic improvement for stress tolerance, growing disease resistant, early maturing and drought tolerant crops, selecting for and rearing climate tolerant animal species and breeds. Malgré leur importance cruciale, il existe peu d'informations sur la manière dont le bétail est affecté par le changement climatique au Nigéria. Le changement des modèles climatiques se manifeste par des événements tels que l'augmentation brutale de la température, la diminution des précipitations, l'augmentation des périodes de sécheresse et d'inondation. Ces conditions exercent des effets différents sur le paysage géographique du pays, qui peuvent être globalement classés comme semi-aride, sahélien et savane dérivée, respectivement, ainsi que forêt et montagne. Le bétail fournit aux humains le complément complet d'acides aminés, qui sont les seuls fournisseurs naturels connus de vitamine B12 et fournissent également du fer, du calcium, de l'iode et du zinc. En outre, l'élevage représente 40% du produit intérieur brut agricole et contribue de manière significative à l'amélioration des moyens d'existence ruraux. Les conditions de stress sont induites chez le bétail par des conditions météorologiques difficiles qui réduisent les aliments disponibles pour eux et entravent le taux de croissance, l'efficacité de la reproduction et l'incidence des maladies qui peuvent éventuellement entraîner la mort. À la lumière des avantages de l'élevage pour l'humanité, il est nécessaire de concevoir des moyens de rendre leur résilient climatique. Certaines des stratégies éprouvées comprennent l'amélioration génétique animale pour la tolérance au stress, la culture de cultures résistantes aux maladies, à maturation précoce et à la sécheresse, la sélection et l'élevage d'espèces et de races animales tolérantes au climat.

Effects of Premating Calcium and Phosphorus Supplementation on Reproduction Efficiency of Grazing Yak Heifers

Reproductive efficiency is the main factor limiting yak production on the Tibet Plateau. The purpose of this study was to investigate the effect of supplementation with calcium chloride (CaCl) and monocalcium phosphate (MCP) for 30 days before breeding on body weight (BW) change, serum bone metabolism biomarkers, conception rate, and calving rate of grazing yaks. Ninety 3 year old yak heifers (153.05 ± 6.56 kg BW) were assigned to three treatments (n = 30 per treatment): grazing without supplementation (CONT), grazing plus calcium chloride supplementation (CaCl), and grazing plus monocalcium phosphate supplementation (MCP). Compared with the CONT group, supplementation with CaCl increased the serum concentrations of osteocalcin and decreased the alkaline phosphatase (ALP) levels (p < 0.05); supplementation with MCP increased the average daily gain (ADG), serum concentrations of phosphorus (P) and osteocalcin, conception rate, and calving rate (p < 0.05), whereas it decreased the serum concentrations of hydroxyproline, ALP, and calcitonin (p < 0.05). Both CaCl and MCP supplementation had no effect on serum calcium (Ca) concentration. The ADG, conception rate, and calving rate were higher in the MCP group than in the CaCl group (p < 0.05), while the serum concentrations of hydroxyproline and calcitonin were lower (p < 0.05). It could be concluded that premating supplementation with MCP increased the body weight gain and subsequent conception and calving rate of grazing yaks. Supplementation with MCP had a positive effect on body condition and bone metabolism, thus providing a better estrous condition for grazing yak heifers, which could contribute to enhancing reproduction efficiency.