Buffalo is important dairy animal in Pakistan. It contributes 75% milk and more than 50% meat production of the country. The population is growing at the rate of more than 5 percent per year. In spite, of its great contribution towards the economy of famer, it has some inherent problem of late maturity, long calving and silent heat. In the present study, effect of energy on early sexual maturity and other physiological has been investigated.
For this purpose, 21 buffalo heifers of about one year age and similar body weight were selected and divided into three groups. Three total mixed rations (A, B and C) with three energy levels were randomly allotted to these groups. The ration A contained 80% of energy of the National research council, (NRC) requirement while, B and C contained 100% and 120% of the recommended levels of energy. Dietary protein was equal in the entire entire ration. These rations were offered for a period of 18 months. Feed intake, growth rate, feed efficiency, hematology such as, such as, pH, erythrocytic sedimentation rate (ESR), packed cell volume (PCV), hemoglobin concentration (HB), erythrocytic count (RBC s count) and total leukocytic count, blood metabolites such as pH, glucose creainine, blood urea nitrogen. Serum proteins, (total proteins, algbumin, globulin and A / G ratio), serum electrolytes, (sodium, chloride and calcium) and progesterone were studied.
Results show that the average intake was 8.35=0.94 kg per day. Feed intake was highest during summer and lowest during winter but age of animals and energy levels had no effect on feed intake of the animals. The highest weight was recorded in buffalo heifers of group B kept on medium plan of nutrition with 100% energy level. While, lower weight gain was recorded in group c of buffalos fed on high- energy diets with 120% daily growth rate for first year of trial was studied. Highest growth rate was observed in group. ā€œBā€ with medium energy level as compare to other groups. Marked increase in weight gain was found during spring, but this gain was decreased during summer. The weight gained by the growing buffalo heifers increased as age of the animal progressed. The feed efficiency was better in group, ā€œBā€ of medium energy level.
In addition to these parameters, the hematological values were also studied. The overall value of blood coagulation time was 5.77=1.32 minutes in growing buffalo heifers on all types of rations. In present study, buffaloes receiving low energy rations had highest blood coagulation time than those fed on medium energy and high energy rations. Lowest coagulation time was observed during summer, while highest values were recorded during winter. It was also observed that coagulation time was increased as animal attained the puberty. The average erythrocytic count was 6.01-0 .72 milion/ul in growing buffalo heifers. A significant increase in count was found during spring than winter. Autumn and summer on erythrocytic count. The erythrocytic count during young age was lowest as compared to post-pubertal stage.
ESR values were increased in group of buffaloes fed on medium energy level with 100% energy level. There was marked increase in ESR values after the attainment of puberty. The overall PCV was 34.3=0.43%, in heifers. PCV values were highest in ā€“group of buffalo heifers offered medium energy ration, while lowest values were recorded in group of buffaloes fed on low energy ration. An increasing trend of PCV was seen during winter, whereas, these decreased during hot day. The packed cell volume was lower during young age and these as age progressed.
The overall hemoglobin concentration was 11.23=0.76 g/dl in different of buffalo heifers. Higher levels of hemoglobin were found in group of buffaloes on high energy levels with 120% energy level highest values were observed during autumn, while lowest during summer. Hemoglobin concentration showed variation during different stages of age with higher values at post-pubertal stage and lower at pre-pubertal stage. The average total leukocytic count was 12.59=43 thousand/ul in growing buffalo heifers. Energy levels had no effect on total leuiocytic count. Low total leukocytic count was observed in autumn. TLC also increased with advancement of age. The pH value was highest in buffalo heifers fed on low energy diet as compared to other groups kept on medium and high-energy diets. The values of pH were affected by different seasons of the year as pH values reached at its peak during winter but during hot days of year. Age had significant effect on pH value. Before puberty pH, value was higher. An average level of glucose was 59.65=2.6 mg/dl in buffalo heifers.
In present study, significantly different glucose levels have been observed with different energy levels. It was highest during spring and was lowest during spring and was lowest during summer. The age of animal has exhibited highly significant variations in blood glucose level in buffalo heifers. The highest values were recorded during post-pubertal stage. The average cholesterol value was 168.9=9.9 mg/dl in growing heifers, different levels of energy in rations affected the blood cholesterol of buffalo heifers. The highest values were observed in group of heifers fed on high-energy ration as compared to those fed on low energy ration having low cholesterol level. The lowest values were found during spring whiles these were highest during winter. Cholesterol levels with refer3ence to age of animals were found increased during post-pubertal stage.
The average creatinine value was 1.29=0.23 mg/dl in growing buffalo heifers. Various levels of energy in rations affected these values. The highest values were observed during autumn and spring. On the other hand, lower values were during summer and winter. The pre-pubertal values were higher, while, these values were lower during post-pubertal stage. The average blood urea nitrogen was 24.68=3.38 mg/dl in growing buffalo heifers, while, the highest value was observed in blood of growing heifers fed on high energy level. The highest values were found autumn, whereas, lowest values were noted during winter the pre-pubertal vales were great than the post pubertal phase.
An average of 6.546=0.3 mg/dl of total protein was observed in buffalo heifers in present study. It was found to be significantly increased in group fed on high-energy ration as compared to other seasons. Total protein has been observed to vary with age. The average value of serum was 4.27=0.12 g/dl in the experimental heifers. The serum albumin was significantly greater in the group of buffalo heifers kept on medium and high plan of nutrition as compared to those heifers fed on low energy ration. The highest values were recorded during spring, whereas; the values were lowest during hot days of the year. The age of animals also had significant effects on serum albumin.
The overall average value of globulin was 2.29=0.4 g/dl in buffalo heifer. The increasing trend of globulin concentration was been in buffalo fed on high-energy diet. On other hand, globulin level declined in scrum of buffalo heifers kept on low energy diet. Highest values were observed during autumn. While lowest value was found during winter. Increasing trend was seen before puberty, while, this level was decreased as animal attained the puberty. The overall average A/G ratio was 2.185=0.125 in growing buffalo heifers. Energy levels had no effect on A/G ratio. Highest A/G ratio was observed during winter. While, this ratio was lowest during autumn. A/G ratio was increased after the attainment of puberty, whereas, this ratio was low before puberty. An average concentration of sodium was 145.82=2.18 mEq/L in growing heifers in the study. Sodium concentration was not affected by defected by different energy levels. The marked increase was seen in spring while, decrease during summer. The greater sodium concentration was recorded after the attainment of puberty as compared to low concentration before. An average level of potassium was 5.125=63 mEq/L in growing heifers.
Potassium concentration was significantly affected by different energy levels in blood. Summer potassium values were the highest as compared to those of spring value. In present study, potassium concentration was observed to vary with age. The average value of chloride concentration was 357.26=5.39 mg/dl in buffalo heifers. The values were affected by different energy levels in rations. Highest values were recorded during spring i.e. 362.95mg/dl, while, lowest values were observed during summer. Higher values were found during post-pubertal stage as compared pre-pubertal stage.
The average value of serum calcium was 10.7=5.76 mg/100mg in growing buffalo heifers. The different energy level in the rations exhibited the highly significant effect in serum calcium level. The lowest calcium level was recorded during autumn, while highest levels were obtained during spring season. Serum calcium varied in different age groups. A significantly decreased level of calcium was noticed during pre-pubertal stage and increased after the attainment of puberty.
The overall serum progesterone concentration was 0.41 ng/ml in different buffalo heifers. Energy levels in ration affected the circulating level of progesterone. Higher level of progesterone, (2.03ng/ml) was observed in the group of buffalo heifers fed with high-energy ration, whereas, lower level (1.21 ng/ml) was recorded in those fed on medium energy ration progesterone concentration was highest, i.e. 2.42ng/ml during winter as compared to other season lowest values were observed during , (1.14ng/ml). Significant in increase in concentration, i.e. 1.87ng/ml was observed the attainment of puberty, while decrease i.e. 1.19ng/ml was recorded before puberty.
The buffalo heifers of group C with 120% energy ration attained the puberty at the age of 21 months and 289 days. While the buffalo heifers of groups B fed on medium energy ration reached at pubertal stage of 23 month and 8 days and buffalo heifers if group A fed on low fed on energy became mature at age of 22 months and 19 days.