Delay in Progesterone Decline Before Parturition is Connected with Failure of Passive Immune Transfer in Tropical Composite Beef Calves

A shortage of nutrients during the final period of gestation can decrease secretion of colostrum, which is critical to newborn calf survival. The physiological mechanism modulating the nutritional control of colostrum secretion is poorly understood. Because the decline in progesterone before parturition is required for lactogenesis to occur, the objective was to evaluate the correlation between prepartum progesterone in cows and plasma immunoglobulin-G1 (IgG1) concentration in neonatal calves. From 135 pregnant cows, successful data on both prepartum progesterone and calf IgG1 was collected from 59 cow/calf pairs (animal ethics approval SA2018/05/638). The cow/calf pairs were classified into three categories according to the transfer of passive immunity: low (n = 19), medium (n = 18), or high (n = 22). Plasma IgG1 was 1025, 2395, and 3347 mg/dL for the low, medium, and high groups, respectively. Plasma progesterone 1 day prepartum was 18.3, 14.2, and 12.4 nmol/L for the low, medium and high groups, respectively. This indicates that calves with failure of passive transfer were born from cows with higher prepartum progesterone, compared to calves with high IgG1 (P = 0.05). Non-linear modelling of the progesterone data indicated the moment that progesterone started to decline (change-point). Change-point was 0.8, 2.5, and 2.4 days before parturition for the low, medium, and high groups, respectively. There was a delay in progesterone decline in the Low group compared with the High group (P < 0.05). These results corroborate the hypothesis that the delay in progesterone decline before parturition is responsible for the failure of IgG1 transfer from cows to calves.

Quarter variation and correlations of colostrum albumin, immunoglobulin G1 and G2 in dairy cows

A high variation in immunoglobulin G1 (IgG1) concentration in first milked quarter colostrum has been reported, but BSA quarter colostrum variation is not known. The occurrence of serum albumin in milk has been attributed to increased blood-milk barrier penetration. Reports of serum albumin binding to the Fc Receptor of the neonate, the receptor thought to be responsible for IgG1 transcytosis, suggested that a correlation with the appearance of IgG1 in colostrum of dairy cows was likely. The objective of the study was to establish the quarter colostrum concentration and mass of immunoglobulins and serum albumin. First colostrum was quarter collected within 4 h of parturition from healthy udders of 31 multiparous dairy cows. Individual quarter colostrum weight was determined and a sample of each was frozen for subsequent analysis. Concentrations of immunoglobulin G1, G2, and BSA were measured by ELISA and total mass of components was calculated. In addition, colostrum was also analysed for L-lactate dehydrogenase activity. Analysis of concentration and mass of BSA, immunoglobulin G1, G2 established that the quarter variations were different by cow, quarter and quarter within cow. Partial correlations corrected for colostrum weight indicated that BSA and IgG2 concentration and mass are closely correlated while that of BSA and IgG1 concentration and mass exhibited no correlation suggesting that BSA and IgG1 may have different transport mechanisms. Interestingly, immunoglobulin G1 and G2 concentration and mass exhibited strong correlations suggesting that also some unknown mechanism of immunoglobulin G2 appearance in colostrum is occurring. Finally, no measured protein exhibited any correlation with the activity of lactate dehydrogenase in colostrum.

Effects of thermally activated natural zeolite on faecal consistency score and performance of Holstein calves from birth to 6-month of ages

Natural Zeolite are characterized by framework of linked tetra hydration enclosing open cavities in the form of channels, and cages which are commonly occupied by water molecules and cations (Tomlinson, 1998). Various applications of natural and synthetic zeolites in animal nutrition, and in other uses to cope with environmental problems are widely known (Sadeghi et al., 2004; Nikkhah and Sadeghi, 2004; Tomlinson, 1998). Heat processing changes the structure of this clay and makes it as a material with Cation Exchange and adsorption properties. To our knowledge, little information is available concerning the effect of thermally activated natural zeolite on plasma IgG1 concentration, and performance of Holstein calves from birth to 6-month ages. This study was conducted to determine the effect of T-zeolite on faecal score and performance of Holstein calves from birth to 6-month ages.

Specific reaginic antibody IgG1-induced changes of airway smooth muscle cells

It was found that 1) an administration of both immunoglobulin G1 (IgG1) or immunized serum caused an immediate depolarization and an increase in the isometric force of airway smooth muscle (ASM) cells, followed by a sustained hyperpolarization and a return of the tone to the base-line values; 2) an IgG1 concentration-dependent relationship was found between a peak depolarization, a peak hyperpolarization, and a peak isometric force; for these events 50% effective dose (ED50) was found to be 0.17, 0.14, and 0.25 microgram/ml of IgG1, respectively; 3) both electrical and contractile responses to ovalbumin of ASM cells sensitized with IgG1 were also dependent on the concentration of IgG1; the ED50 values of this relationship were 0.27 and 0.25 micrograms/ml of IgG1, respectively; 4) amiloride (10(-8) to 10(-5) M) pretreatment and a sodium-deficient environment attenuated sensitized-induced electrical and contractile changes as well as the response of ASM to ovalbumin (0.1%); and 5) pretreatment of ASM with diphenhydramine (10(-5) M) or FPL 55712 (10(-6) M) had no effect on sensitization-induced changes in membrane potential but attenuated electrical and contractile response of ASM to ovalbumin (0.1%).