Late puberty is the major factor in buffalo heifers leading to low reproductive efficiency resulting in economic losses. Very little information was available about the reproductive potential based on quantitative investigation of primordial follicles and their relation with the ovarian size and weight which directly affects the attainment of puberty.

The present study was designed to determine the number of primordial follicles in non - cycling 3 - 4 years buffalo heifers and results were based on the specific selection of the animals after confirmation of age by dentition, general physical examination, the reproductive status after slaughter. This was achieved by the collection of 12 samples (ovaries) from six animals, two animals belonging to each age group of 3 years, 3 1/2 years and 4 years.

In the heifer Al, the right ovary was more round in shape than left but somewhat softer in consistency than the left ovary. In the heifer A2, the left ovary was somewhat flattened than right ovary which was firmer in consistency than the left ovary and surface was nodular in both ovaries. In the heifer Bi the left ovary was less oval than the right one but was harder in consistency than right ovary. In the heifer B2 the left ovary was more oval in shape than right and somewhat nodular and softer in consistency than right ovary. In the heifer Cl, the left ovary was oval and right elliptical in shape having smooth surface throughout while the right ovary was harder in consistency than left one. In the heifer C2, both ovaries were almost similar in shape which were more oval almost round and right ovary was quite hard and its palpation was almost impossible.

The average weights of ovaries in two non cycling buffalo heifers of Group A (3 years) were 3.30 ± 0.50 gm for the left and 3.90 ± 0.10 gm for the right ovaries (Table 3). The average weights of ovaries in two non cycling buffalo heifers of Group B (3 1/2 years) were 2.70 ± 0.30 gm for the left and 2.90 ± 0.30 gm for the right ovaries (Table 3). The average weights of ovaries in two non cycling buffalo heifers of Group C (4 years) were 2.40 ± 0.40 gm for the left and 2.70 ± 0.70 gm for the right ovaries (Table 3).

The average size of the ovaries of Group A heifers (3 years) was 2.61 ± 0.53 cm x 1.64 ± 0.40 cm x 1.53 ± 0.13 cm in length, width and thickness respectively for the left ovaries and same for the right ovaries was 2.61 ± 0.35 cm x 1.88 ± 0.10 cm x 1.65 ± 0.01 cm (Table 5). The average size of the ovaries of Group B heifers (3 1/2 years) was 2.39 ± 0.13 cm x 1.58 ± 0.10 cm x 1.31 ± 0.13 cm in length, width and thickness respectively for the left ovaries and same for the right ovaries was 2.39 ± 0.05 cm x 1.55 ± 0.21 cm x 1.34 ± 0.09 cm (Table 6). The average size of the ovaries of Group C heifers (4 years) was 2.18 ± 0.08 cm x 1.41 0.16 cm x 1.35 ± 0.0cm in length, width and thickness respectively for the left ovaries and same for the right ovaries was 2.56 ± 0.50 cm x 1.48 ± 0.16 cm x 1.26 + 0.02 cm (Table 7). The mean volume i.e. length x width x thickness for the left and right ovaries of the heifers belonging to Group A was 6.39 ± 0.66 cm3 and 8.05 ± 0.71 cm3 respectively and the same for the heifers belonging to Group B was 5.03 ± 1.08 cm3 and 4.99 ± 0.90 cm3 respectively and for the heifers belonging to Group C was 4.18 ± 0.63 cm3 and 4.86 ± 1.38 cm3 respectively.

The average number of primordial follicles for the left ovaries was 22108 ± 1099 and the same for the right ovaries was 22920 ± 106 in the heifers belonging to Group A (Table 25). The average number of primordial follicles for the left ovaries was 21105 ± 1304 and the same for the right ovaries was 21956 ± 1835 in the heifers belonging to Group B (Table 26). The average number of primordial follicles for the left ovaries was 1620 ± 282 and the same for the right ovaries was 1231 ± 53 in the heifers belonging to Group C (Table 27). In the ovaries of heifers belonging to Group A the mean diameter of the oocyte nuclei was 12.0 ± 1.15u, where as the same in the Group B and Group C were 11.04 ± 1.05u and 11.00 ± 0.02u respectively. The total number of growing follicles in both left and right ovaries of the heifer Al was 123 and the same number of the heifer A2 was 175 with an average of 149 ±26 in both the ovaries of heifers Al and A2 belonging to Group A (Table 28).

The total number of growing follicles in both left and right ovaries of the heifer Bi was 128 and the same of the heifer B2 was 152 with an average of 140 ± 12 in both the ovaries of heifer Bi and B2 belonging to Group B (Table 28). The total number of growing follicles in both left and right ovaries of the heifer Cl was 47 and the same of the heifer C2 was 15 with an average of 31 ± 16 in both the ovaries of heifers C1 and C2 belonging to Group C (Table 28).

The number of primordial follicles was counted per ovary and compared with the relative size and weight of ovary and age of the heifer a poitive corelation was found to be existed between ovarian size/weight and primordial follicle number perovary of heirfers of three age groups and hence the possible factors responsible for culling or selection of such animals were observed for the improvement of buffalo dairy herd.

CONCLUSION and SUGGESTIONS

It is concluded from the results of present study that the ovarian weight and size have a significant effect On the number of primordial follicles since the weight cannot be assessed through rectal palpation and when the average ovarian weight and size were analyzed statistically a +ve correlation of 0.94 was found between these two factors. Hence it is concluded that the normal ovarian weight can he compared with the normal ovarian size while performing the examination of genitalium per rectum and hence by measuring the ovarian size per recturm in heifers its reproductive potential i.e. the number of primordial follicles per ovary can be estimated which would he helpful in selecting or culling virgin buffalo heifers who have not attained puberty. While performing the specific genital examination it is suggested that the following parameters must he considered.

1) The age of heifer for selection must he upto 3 1/2 years.

2) Per rectal examination it must he confirmed that the genitalium has no any segmental aplasia.

3) The ovaries must he oval in shape with somewhat nodular surface, soft, flexible consistency.

4) The ovarian size must he 2.61 + 0.53 x 1.64 ± 0.40 x 1.52 ± 0.12 cm for the left ovaries and 2.61 ± 0.35 x 1.88 ± 0.10 x 1.65 ± 0.01 cm for the right ovaries in length, width and thickness respectively.

5) The ovaries must never have any tumour which can he differentiated from the developing functional structure i. e. follicles and corpus luteum and if the ovarian tumour are confused with functional structures then these animals may he kept under observation for 21 days to find any developmental stage of functional structure.

6) Probably the heifers approaching puberty or in some cycling stage may have 3 - 8 transverse wrinkles upon their external vaginal lips.

It is anticipated that these conclusions and suggestions will serve a useful purpose in selecting or culling those buffalo heifers which have not attained puberty till 3 to 4 years of age and hence will be helpful to make necessary improvements in buffalo dairy herds.