Lactation Persistency in Bulgarian Murrah Buffalo Cows

With the objective to establish the lactation persistency and its variability as affected by different factors, the study assigned 953 lactations of 310 Bulgarian Murrah buffalo cows bred on the farm of Agricultural Institute – Shumen within the period 1967-2009. The main method of measurement was the mean post-peak milk yield reduction. The data were processed by the conventional statistical procedure, as well as by the software products LSMLMW and MIXMDL. The persistency of milk yield after reaching peak was established to be relatively high (89.22%). Its variance is to a great extent explained by the factors days in milk (P<0.001) and parity (P<0.001), defining favorable effect of increased lactation length, and adverse effect of advancement in lactation order. The significant effect of season of calving (P<0.001) is expressed in higher lactation persistency in the autumn and winter calvers. The other environmental factor, period, and the genetic factor (individual) are significant at P<0.01, while the effect of productivity level is not. The portion of the peak yield was estimated to be 15.75% of the lactation productivity, the percentage of the greatest yield drop – 11.38%, the persistency ratio between the first and second lactation half – 73.60%

Effect of weaning on some plasma metabolites in buffalo calves fed diets with or without supplemental chromium picolinate

The objective of this study were 2 fold: to determine whether the weaning (abrupt transition from liquid to solid diet) at the age of 90 days causes stress in buffalo calves, and if so, to alleviate the negative effect of stress by chromium picolinate supplementation (400 μg daily). All buffalo calves were separated from their mothers immediately after birth. Chromium supplementation started 3 days before the weaning and was terminated 5 days later. Plasma cholesterol and indol levels declined significantly after weaning in both groups. Both the weaning and supplemental chromium had no effect on plasma urea level. Our results indicate that when the negative emotional arousal, caused by the interruption of the physical contact mother – calf, is avoided, as it is in our case, then the abrupt transition from liquid to solid feed at 90 d of age has no stress-inducing effect. Supplemental chromium reduced plasma cortisol levels both before and following the weaning, but had no significant effect on the determined metabolites since its effect is more pronounced during extreme stress load

Physiological indices in buffaloes exposed to sun.

ABSTRACT Ten lactating buffaloes were kept in a barn or exposed to direct solar radiation (air temperature 30.2 0 C) for 12 h. Rectal temperature (RT) and respiratory rate (RR) were measured at 8 h, 11 h, 15 h and 20 h. Both RT and RR increased significantly at temperature -humidity index (THI) -77.83, showing that the lactating buffaloes are sensitive to heat stress and are not able to maintain their core temperature within the thermoneutral zone. The same THI had no significant effect on rectal temperature elevation when the buffaloes were kept in barn. The obvious heat stress, assessed by the rate of RT and RR elevations, was not accompanied with an enhancement of plasma cortisol level. The unchanged plasma cortisol level in the buffaloes under heat is interpreted within the context of the hormonal integration and the modulating effect of hypothalamic-pituitary-adrenal axis on the other endocrine glands involved in the thermal homeostasis maintenance. These data demonstrate that lactating buffaloes need protection against the direct solar radiation