Elena Bolocan | Research and Development Institute for Cattle Husbandry (original) (raw)

Papers by Elena Bolocan

Research paper thumbnail of Seasonal Variations of some Hematological and Biochemical Parameters of the Carpathian Romanian Buffaloes. I. The Winter Period

usab-tm.ro

Aim of this study was to investigate the blood parameters in Carpathian Romanian Buffaloes in ord... more Aim of this study was to investigate the blood parameters in Carpathian Romanian Buffaloes in order to establish their physiological ranges. Eight buffaloes from Şercaia-Braşov area were screened for hematological and biochemical profile during the winter ...

Research paper thumbnail of Strategia protejarii bovinelor în perioadele caniculare

Research paper thumbnail of Influenţa temperaturilor ridicate asupra comportamentului alimentar la bovine │ The influence of high temperatures on feeding behaviour in cattle

Cattle exposed to high environmental temperatures develop behavioural strategies meant to ease th... more Cattle exposed to high environmental temperatures develop behavioural strategies meant to ease their thermoregulatory process. The animals eat less in order to reduce the metabolic heat production; also, they prefer grain concentrates and silage rather than hay. In a favorable physical environment, Romanian Black Spotted heifers spend about 6,5 hours per day eating and about 8 hours ruminating. The total feeding time decreased by 32% under severe thermal stress (36-420C) and by 10% when heifers were exposed to 30-360C. Feeding and other general activities were shifted to the cooler early morning, late evening, or night hours. Water intake lasts usually about 8-9 min. per day. When heifers have been exposed to heat stress, the total drinking time increased by 43- 210%.

Research paper thumbnail of Effects of heat stress on sexual behavior in heifers │Studiul comportamentului sexual la juninci în condiţii de stres termic

Lucrări Ştiinţifice Zootehnie Şi Biotehnologii, Universitatea De Ştiinţe Agricole Şi Medicină Veterinară a Banatului Timişoara, 2009

High ambient temperatures affect the secretion of sexual hormones in cows and heifers. As a resul... more High ambient temperatures affect the secretion of sexual hormones in cows and heifers. As a result, the frequency of silent estrus can reach a high level during summer. In order to analyze the effects of heat stress on sexual behavior in Black and White Romanian heifers, a research has been conducted on four groups of animals in the pre- and post-AI interval. During spring, in conditions of thermal comfort and under the stimulating influence of increasing photoperiod, 83.3% of the heifers showed clear signs of estrus. Exposure to temperatures of 36-42○C by day and 21-31○C by night caused anoestrus: the heifers did not respond to repeated estrus-induction treatment. When hot days (33-38○C) alternated with tolerable temperatures by night (18-21○C), a normal expression of estrus was noticed in 16.7% of the animals, while 33.3% experienced weak estrus and 50% did not exhibit sexual behavior. In conditions of moderate thermal stress, with peaks of daily temperature ranging from 28 to 34○C, clear signs of estrus were detected in 25% of the heifers and weak symptoms in 41.7%, while 33.3% had silent heat, clinically diagnosed. The circadian profile of behavior changes in heat-stressed heifers, whose sexual activity shifts to night time and to the early hours of the morning.

Research paper thumbnail of Photostimulation of heifers growth and reproductive performance in winter

balnimalcon.nku.edu.tr

The decline of fertility in cattle during winter has been attributed mainly to microclimatic fact... more The decline of fertility in cattle during winter has been attributed mainly to microclimatic factors and inadequate food quality. More recent studies indicate that the diminished daylength has also a strong negative effect upon sexual activity. Though cattle reproduction is not photoperiodically induced, as in other species, light plays an important role in stimulating endocrine functions and subsequent behaviour. Exploring this area of research, we have subjected Romanian Black and White heifers during autumn-winter to an artificial illumination régime of 14 hours per day. The physiological and behavioural response was complex. As light stimulates the sympathetic nervous system and the secretion of growth hormone, aroused appetite and better feed efficiency have been noticed; the weight gain increased with 17%. Subsequently, the sexual maturity occurred earlier. Prolonged photoperiod has exerted a pregnant influence upon the hypothalamic-pituitary-gonadal circuit. Heifers showed standing estrus, intensely expressed. Conception rate after the first A.I. increased significantly (62,5%); pregnancy percentage after three A.I. cycles reached the maximum level of 100%. These results point out that artificial prolonged photoperiod during late autumn and winter could contribute to a satisfactory development of heifers and improves considerably reproductive performance, by reducing the frequency of anovulation, silent heats and embryos mortality.

Research paper thumbnail of Research regarding the dynamics of body development and feed consumption in youth buffaloes in Romania

balnimalcon.nku.edu.tr

The study was performed on a number of 10 exemplar youth buffaloes, aged 8 months, at the beginni... more The study was performed on a number of 10 exemplar youth buffaloes, aged 8 months, at the beginning of the study with a mean weight of 176 kg. The main periodic determinations performed were: weighing each animal separately monthly; measuring the main body components: stature, the oblique length of the trunk, the thoracic perimeter, the width of the chest, the perimeter of the shinebone, the width of the loins, the spiral perimeter of the leg, the length of the buttock; daily weighing of the remains of each type of feed. Using the results of the periodic measurements, a series of body indices was calculated, which provide further information concerning the growth tendencies of the youth buffaloes. The progressive increase in body weight from 225.1 to 289 kg was noticed during the 3-month study on the 10 animals included. Another observation concerned the variation in food consumption from one month to the other, as follows: during the first month the consumption was 4.44 UNC/kg, but decreased during the second month by 8.33%, only to rise again in the last month of the study reaching 4.72 UNC/kg, which means 6.3% increase.

Talks by Elena Bolocan

Research paper thumbnail of Soluţii tehnologice pentru creşterea competitivităţii pe piaţa europeană a exploatării bovinelor în România

Research paper thumbnail of Seasonal Variations of some Hematological and Biochemical Parameters of the Carpathian Romanian Buffaloes. I. The Winter Period

usab-tm.ro

Aim of this study was to investigate the blood parameters in Carpathian Romanian Buffaloes in ord... more Aim of this study was to investigate the blood parameters in Carpathian Romanian Buffaloes in order to establish their physiological ranges. Eight buffaloes from Şercaia-Braşov area were screened for hematological and biochemical profile during the winter ...

Research paper thumbnail of Strategia protejarii bovinelor în perioadele caniculare

Research paper thumbnail of Influenţa temperaturilor ridicate asupra comportamentului alimentar la bovine │ The influence of high temperatures on feeding behaviour in cattle

Cattle exposed to high environmental temperatures develop behavioural strategies meant to ease th... more Cattle exposed to high environmental temperatures develop behavioural strategies meant to ease their thermoregulatory process. The animals eat less in order to reduce the metabolic heat production; also, they prefer grain concentrates and silage rather than hay. In a favorable physical environment, Romanian Black Spotted heifers spend about 6,5 hours per day eating and about 8 hours ruminating. The total feeding time decreased by 32% under severe thermal stress (36-420C) and by 10% when heifers were exposed to 30-360C. Feeding and other general activities were shifted to the cooler early morning, late evening, or night hours. Water intake lasts usually about 8-9 min. per day. When heifers have been exposed to heat stress, the total drinking time increased by 43- 210%.

Research paper thumbnail of Effects of heat stress on sexual behavior in heifers │Studiul comportamentului sexual la juninci în condiţii de stres termic

Lucrări Ştiinţifice Zootehnie Şi Biotehnologii, Universitatea De Ştiinţe Agricole Şi Medicină Veterinară a Banatului Timişoara, 2009

High ambient temperatures affect the secretion of sexual hormones in cows and heifers. As a resul... more High ambient temperatures affect the secretion of sexual hormones in cows and heifers. As a result, the frequency of silent estrus can reach a high level during summer. In order to analyze the effects of heat stress on sexual behavior in Black and White Romanian heifers, a research has been conducted on four groups of animals in the pre- and post-AI interval. During spring, in conditions of thermal comfort and under the stimulating influence of increasing photoperiod, 83.3% of the heifers showed clear signs of estrus. Exposure to temperatures of 36-42○C by day and 21-31○C by night caused anoestrus: the heifers did not respond to repeated estrus-induction treatment. When hot days (33-38○C) alternated with tolerable temperatures by night (18-21○C), a normal expression of estrus was noticed in 16.7% of the animals, while 33.3% experienced weak estrus and 50% did not exhibit sexual behavior. In conditions of moderate thermal stress, with peaks of daily temperature ranging from 28 to 34○C, clear signs of estrus were detected in 25% of the heifers and weak symptoms in 41.7%, while 33.3% had silent heat, clinically diagnosed. The circadian profile of behavior changes in heat-stressed heifers, whose sexual activity shifts to night time and to the early hours of the morning.

Research paper thumbnail of Photostimulation of heifers growth and reproductive performance in winter

balnimalcon.nku.edu.tr

The decline of fertility in cattle during winter has been attributed mainly to microclimatic fact... more The decline of fertility in cattle during winter has been attributed mainly to microclimatic factors and inadequate food quality. More recent studies indicate that the diminished daylength has also a strong negative effect upon sexual activity. Though cattle reproduction is not photoperiodically induced, as in other species, light plays an important role in stimulating endocrine functions and subsequent behaviour. Exploring this area of research, we have subjected Romanian Black and White heifers during autumn-winter to an artificial illumination régime of 14 hours per day. The physiological and behavioural response was complex. As light stimulates the sympathetic nervous system and the secretion of growth hormone, aroused appetite and better feed efficiency have been noticed; the weight gain increased with 17%. Subsequently, the sexual maturity occurred earlier. Prolonged photoperiod has exerted a pregnant influence upon the hypothalamic-pituitary-gonadal circuit. Heifers showed standing estrus, intensely expressed. Conception rate after the first A.I. increased significantly (62,5%); pregnancy percentage after three A.I. cycles reached the maximum level of 100%. These results point out that artificial prolonged photoperiod during late autumn and winter could contribute to a satisfactory development of heifers and improves considerably reproductive performance, by reducing the frequency of anovulation, silent heats and embryos mortality.

Research paper thumbnail of Research regarding the dynamics of body development and feed consumption in youth buffaloes in Romania

balnimalcon.nku.edu.tr

The study was performed on a number of 10 exemplar youth buffaloes, aged 8 months, at the beginni... more The study was performed on a number of 10 exemplar youth buffaloes, aged 8 months, at the beginning of the study with a mean weight of 176 kg. The main periodic determinations performed were: weighing each animal separately monthly; measuring the main body components: stature, the oblique length of the trunk, the thoracic perimeter, the width of the chest, the perimeter of the shinebone, the width of the loins, the spiral perimeter of the leg, the length of the buttock; daily weighing of the remains of each type of feed. Using the results of the periodic measurements, a series of body indices was calculated, which provide further information concerning the growth tendencies of the youth buffaloes. The progressive increase in body weight from 225.1 to 289 kg was noticed during the 3-month study on the 10 animals included. Another observation concerned the variation in food consumption from one month to the other, as follows: during the first month the consumption was 4.44 UNC/kg, but decreased during the second month by 8.33%, only to rise again in the last month of the study reaching 4.72 UNC/kg, which means 6.3% increase.