Whole Period Of Lactation Research Articles

Качество клетчатки и эффективность ее использования в рационах голштин-холмогорских коров

Abstract. The purpose of the research is to determine the optimal level of fibre and its fractions, neutral detergent fibre (NDF) and acid detergent fibre (ADF), in the ration of cows with milk yield 6–7 thousand kg according to the period of the physiological cycle. The scientific and economic experiment was carried out with two groups of cows, control and test, 10 animals in each other, during the whole period of lactation. The ration of control group cows corresponded to the economic one. The analysis of the crude fibre in feeds doesn't identify a reasonably accurate content of the fibre and its fractions. Therefore, the research includes the elaborated method of fractionation of structural carbohydrates (Van Soest et al.). As a result of the research, the optimal level of the crude fibre and its fractions (NDF and ADF) was determined in the cow rations according to the periods of the physiological cycle. It was established that the level of the crude fibre should be 20.5 %; NDF – 40.0 %; ADF – 25.0 % during the first phase of lactation (14–100 days). For the period of the second phase of lactation (101–200 days) the content of the crude fiber – 22,5 %, NDF – 41,3 %, and ADF – 26,3 %. For the period of the third phase of lactation (201–305 days) the level of the crude fibre should be 25,0 %; NDF – 45,5 %; ADF – 25,4 %. The novelty of the research is that we determined the requirements of the milk cows for the crude fibre, NDF and ADF according to the physiological periods in the conditions of the Arctic region. Separation of the fibre into fractions makes it possible to reveal more fully its composition, and consequently to show more precisely digesting of each fraction in the gastrointestinal tract of ruminants and to determine the role of fibre in providing of animals by energy.

МОРФОФУНКЦИОНАЛЬНЫЕ СВОЙСТВА ВЫМЕНИ, ЭКСТЕРЬЕРНЫЕ ОСОБЕННОСТИ И МОЛОЧНАЯ ПРОДУКТИВНОСТЬ КОРОВ РАЗНЫХ ПОРОД

The authors have carried out comprehensive research of morphological and functional features of the mammary gland of the Black-Motley and Ayrshire cattle breeds, which belong to the specialized dairy cow breeds; described conformation features of the Black-Motley and Ayrshire cattle, estimated milk productivity of these breeds; studied morphological and functional properties of the udder, as well as histostructure of the mammary gland of cows, depending on the breed. It has been noted that cows of the Black-Motley breed tend to rather of a dairy type as compared to the Ayrshire breed. The conformation shortcomings of Ayrshire cows include the chest and pelvis narrowness, those of the Black-Motley breed - the lack of firmness in legs and hooves. When used under the conditions of intensive milk production technology, Ayrshire cows are inferior to Black-Motley cows in total milk yield and milk fat. 42 kg more milk per 100 kg of live weight has been obtained from Black-Motley cows. Cows of both breeds have a bulky and proportionally developed udder. Morphological and functional features of the udder of Ayrshire and Black-Motley cows do not differ much. The glandular tissue in the mammary gland of both breeds is well developed. At the beginning of lactation, it amounted to more than 80% of the total udder tissue, which indicates its strong development and characterizes the Black-Motley and Ayrshire cattle as highly productive dairy breeds. The front and the rear parts of the udder of the Ayrshire cattle are developed equally in the main structural elements especially in the total area of milk alveoli, while Black-Motley cows feature more developed rear parts with more visible glandular tissue and larger alveoli. The vascularization degree of the udder parts of both breeds is almost equal. There was almost no developed adipose tissue in the udder of both Ayrshire and Black-Motley breeds observed over the whole period of lactation. Among the studied animals of both breeds, the content of adipose tissue was 0.17-0.49%. In the mammary gland of the Ayrshire cows the greater amount of milk stones was detected than that in their Black-Motley age mates. This may be caused by the fact that the Finnish Ayrshire cattle are probably less adapted to being housed in the dairy plant.

Ефективність використання кормосумішей у літній період у зв’язку з переведенням корів на безприв’язне боксове утримання

У роботі наведені результати досліджень у виробничих умовах сільськогосподарського підприємства щодо ефективності двократного, частково триразового та триразового доїння корів у зв’язку з їх переведенням із прив’язного утримання на безприв’язне боксове та введенням зеленої маси у склад кормосуміші.

Efficiency of the transfer of cows for tieless maintenance and their feeding under intensive technology of milk production

The paper presents the results of research in the working conditions of an agricultural enterprise that studies the efficiency of double, triple and triple partly milking of cows in connection with their transfer from a fixed content to a tieless box and the addition of some green mass into the contents of the feed mix. The purpose of our research was to determine the efficiency of different ratios of green and conserved feeds in the ration of dairy cows during summer period; to study the effect of the frequency of milking on the milk productivity of the Black-and-White breed cows in the conditions of cows’ transfer to the tieless maintenance at the intensive technology of milk production. The investigation was carried out in the conditions of the agro-firm № 10 of the state enterprise “Illich Agro-Donbas”, Mariupol district, Donetsk region. The dairy cows of the Ukrainian Black-and-White breed were used in our experiment that was conducted in accordance with the generally accepted methods of the research on cattle feeding. Before the beginning of the research the cows were kept on a leash all- year- round. The experiment was carried out and during the experiment the technology of maintenance and milking of the cows in the control group remained unchanged, the cows-analogues of the second group were transferred to the new, reconstructed livestock house for the tieless maintenance, for the first hundred days of lactation the cows were milked three times a day and they were milked twice a day till the end of the lactation. The cows of the third group were under tieless conditions of maintenance and they were milked three times a day throughout the lactation period. The feeding conditions for the cows were the same, that is, the animals were fed with the balanced feed mixtures at the silage-concentrate type of feeding. The partial replacement of the brought up (mown) green feeds of the field forage production in the ration of dairy cows in stalls and under unleashed pen maintenance by high quality silage met the physiological requirement of the cows in dry matter and at the same time it increased the concentration of energy in 1 kg of the ration. The following results were obtained. When keeping the cows tied and tieless at the partial replacement of the brought up (mown) green feeds of the field forage production in the ration of lactating cows by the high quality silage better provides their physiological requirements in dry matter and at the same time it increases the energy concentration in 1 kg of the ration. The use of partly both three-time milking (for the first hundred days of lactation) and three-time milking (during the whole period of lactation) increased the milk productivity of the cows by 7.0 and 11.4%, with the simultaneous decrease in the feed costs per a unit of produce by 7.2 and 11.8%, respectively. The lactation activity of the cows that were milked twice a day was more fluent and uniform and the intensity of milk yield was significantly higher as compared with the cows of groups 2 and 3 by 29.4% and 26.5%, respectively. The economic efficiency of milk production was higher in group 2 and 3, the profit in the above groups exceeded the profit of group 1 by 4.7% and 5.4%, respectively.

Improving infant formulas: on the way to approaching breast milk

Breast milk is the gold standard of infant feeding during the first year of life that ensures adequate physical and psychological development. The composition of human milk changes all the time in the process of one feeding as well as throughout the whole period of lactation. The ingredients of breast milk promote the normal growth of the baby, affect postnatal differentiation of tissues, the formation of the central nervous system (CNS), auditory and visual analyzers, development of the intestinal microbiota of the infant. Breastfeeding contributes to a strong psycho-emotional bond between mother and child which provides the best conditions for further development of the mind, intelligence and behavioral characteristics.

Sulfadimethoxine residues in rabbit muscle after extended oral treatment at therapeutic dosage

Sulfadimethoxine is extensively used in rabbit breeding for preventive and curative purpose and residues are sometimes observed in carcasses at slaughter. It has been suggested this is due to dosage and/or duration of treatment not being in compliance with the manufacturer?s recommendations, which probably induces residue levels in the meat above the maximum residue limit (MRL) value of 100 ?g/kg. In order to test this hypothesis, a study was carried out on gravid rabbits and their progeny. The animals were subjected to an extended treatment with sulfadimethoxine at therapeutic level in the feed. The feed was supplemented before pelleting with a commercial veterinary product containing 20 g of trimethoprim and 93 g of sulfadimethoxine per kg. On the basis of the dosage indicated for this commercial veterinary product, the incorporation level in the feed was 5 kg/ton (i.e. 465 g of sulfadimethoxine/ton), providing oral daily therapeutic treatment of the animals of ca. 12.5 to 50 mg of sulfadimethoxine per kg bodyweight. The mothers were treated during the last 21 d of pregnancy and during the whole period of lactation (35 d). The animals were sacrificed after a wash-out period of 12 d with blank feed. The young rabbits received the supplemented feed after weaning during the first 40 d of the fattening period. These animals were also sacrifi ced after a wash-out period of 8, 12, 15 or 20 d, respectively, with a blank feed. A sample of the leg muscle was taken for analysis. An HPLC analytical method was used to determine the sulfadimethoxine concentrations in tissue, with a LLOQ (Lower Limit Of Quantification) of 50 ?g/kg of muscle (trimethoprim was not considered in this study). Sulfadimethoxine concentrations above the MRL value of 100 ?g/kg were registered only in muscle from 1 out of 8 mothers and in 2 out of 8 young rabbits sacrificed 12 d after cessation of the treatment. For other young rabbits sacrificed on the 8th, 15th or 20th d after cessation of treatment, Sulphonamide concentrations in muscle always remained below the MRL value (8 animals per slaughtering time). These results show that oral treatment of rabbits with veterinary products containing sulfadimethoxine administered for a long period at the daily therapeutic level of 12.5 to 50 mg/kg does not seem to induce the accumulation of this molecule in muscle.

Lactation and Stress: Protective Effects of Breast-feeding in Humans

Whilst most research on breast-feeding has been designed to assess its importance for infant health or to find a human nutrient replacement for infant formula, the effects of breast-feeding on maternal health have received little scientific attention. In several animal studies lactation has been shown to be associated with a marked blunting of physiological and behavioral responses to physical and psychological stress. However, the literature on the effects of lactation on stress in humans remains limited. This review focuses primarily on recent findings on the effects of breast-feeding on neuroendocrine and behavioral responses to acute stress exposure in lactating women. The available data suggest that breast-feeding suppresses the hypothalamic-pituitary-adrenal (HPA) axis response to physical and psychosocial stress. However, lactation in women, in contrast to lactating rats, does not seem to result in a general restraint of the endocrine stress response during the whole period of lactation. Recent data strongly suggest that the blunted HPA axis response to stress in women seems to be counterbalanced if the acute stressor, at least when of a psychosocial nature, occurs later than 1 h after suckling. Further elucidation of the underlying psychobiological mechanisms involved in suppressed stress responses during lactation will no doubt lead to new insights into improved health sequelae of breast-feeding in women and to a better understanding of the psychobiology of human stress protection in general.

Milk-fat globule membranes: chemical composition and phosphoesterase activities during lactation

SummaryThe morphology, protein and glycoprotein composition, amino-acid analysis, phospholipid and carbohydrate contents and 3 phosphoesterase activities of the milk-fat globule membranes were studied in 4 cows during their whole period of lactation. No differences were found in the morphology and the overall chemical composition. However, glycoprotein composition varied with the cow and, for each cow, with the stage of lactation. The differences were more marked for membranes obtained from colostrum. Acid phosphomonoesterase was practically unchanged during the whole period of lactation, while alkaline phosphomonoesterase and phosphodiesterase increased as lactation proceeded.