Effects of breed, age, parity, body weight and body condition on productive and reproductive performance of buffalo cows at Rajshahi district of Bangladesh

The present study was to evaluate the reproductive and productive performance (RPP) of Indigenous (n=145) and Nili-Ravi cross-bred (n=55) dairy buffalo in relation to age, parity, body weight and body condition. A total of 200 buffalo cows were randomly selected and interviewed to collect data on reproductive and productive performance of buffalo cows of Rajshahi district by using pre-tested questionnaire during the period from January 2015 to December 2015. The average mean ± SD value of reproductive and productive performances were as age at puberty (AP), age at first calving (AFC), gestation length (GL), post-partum heat period (PPHP), milk yield per day (MYPD), lactation length (LL), birth weight of calf (BWC) and calving interval (CI) were recorded as 25.05±4.00 months, 35.26±4.14 months, 308.28±12.46 days, 84.00±25.95 days, 3.59±0.56 litre, 202.76±33.54 days, 28.79±4.23 kilogram and 461.36±15.41 days, respectively. Nili-Ravi crossbred buffalo cow had shown better RPP than Indigenous. The genotype of buffalo cows had significant effect (p<0.05) on most of the RPP except AP, AFC and CI. Age of buffalo had also significant effect (p<0.05) on GL, PPHP and BWC and middle age (4 to < 7yrs) observed good RPP. The best RPP were recorded in 2 parity than others and also significant effect (p<0.05) on GL, MYPD and BWC. Body weight and body condition of buffalo had significant effect (p<0.05) on PPHP, BWC and MYPD. The body weight of >350 kg and very good body condition groups were observed better reproductive performance. It could be concluded that the buffalo owners of these areas do not follow any scientific method of buffalo husbandry; they just follow traditional rearing systems. Very recently, a few farmers started farming of the mostly Indigenous buffalo cows for dairy purpose at Rajshahi region of Bangladesh.


Introduction
Buffalo cow rearing is one of the most important occupations. The success of any dairy farm depends upon efficient productive and reproductive performances of a dairy animal. Different genetic and non-genetic factors influence its performance potential (Boro et al., 2020). Productive performance is determined to a great extent by the milk yield at first lactation and the farm, followed by the age at first calving (Ilieva and Peeva, 2007). The importance of livestock production has increased in Bangladesh as witnessed by the growth of the subsector over the last few decades in Bangladesh (FAO, 2005). The buffalo hold strategic place in overall livestock economy of Bangladesh and serve three important purposes viz. milk production, meat and draught power (Ghaffar et al., 1991). Cattle and buffalo supplies about 99% of the total milk produced in the country, 50.2% of the total milk consumes and 98% of the draught power requirement of the country. Contribution of cattle to national economy is not static rather varies depending upon population size and location. The domestic buffalo is an important animal in the agricultural economy of many tropical and subtropical countries and being an integral part of farming system (Suhail et al., 2009). Buffalo is contributing 12.1% to the world, 38.0% in

Materials and Methods 2.1. Study areas and population
To conduct the study at the districts of Bangladesh namely Rajshahi was selected. Two hundred (200) buffalo cows were randomly selected to collect data regarding reproductive and productive performance of those buffalo cows with separate questionnaires during the period from January 2015 to December 2015.

Selection of Animals
Different breeds of buffalo cows from different places upto 6 parities an absolutely for dairy and drought purpose was considered and selected for the present study. A total 200 buffalo cow were selected from greater Rajshahi district (Kakonhat, Nawhata, Kasiadanga, Damkura, Puthiapara, Godagari, Rajabari, Courtstation and Rajshahi city) in Bangladesh.

Method of data collection
A questionnaire was developed for proper recording the reproductive and productive performance of buffalo cows. The data were collected directly from the buffalo cow owners/farmers/attendant who was responsible for the rearing of buffalo cows. During data collection careful attention was given to attained accurate and reliability of data during the period from January 2015 to December 2015. The data were collected from the randomly selected areas by the researcher every three (3) months interval in year. After collecting the information, data were prepared for analysis.

Grouping of experimental animals
To achieve the goal, animals were grouped according to the following considering factors: Genotype or Breed: The buffalo cows were classified broadly in Indigenous and Nili-Ravi cross. Group I: Indigenous (n=145) Group II: Nili-Ravi cross (n=55) Age group: Age of the buffalo cows were measured by examination of teeth and counting number of horn ring and birth record kept by the farmers/register book. After confirmation of age of these buffalo cows then divided in the following groups: Group I: <4 yrs (n=53) N Group II: 4 to < 7yrs (n=118) Group III: > 7yrs (n=29) Parity: The buffalo cows those did not give any calf considered as heifer (P 0 ), those gave 1 st calf considered as parity 1 (P 1 ), those gave 2 nd calf considered as parity 2 (P 2 ), those gave 3 rd calf considered as parity 3 (P 3 ) and so on. The buffalo cows were divided in the following groups: Group I: 1 st calving (n=52) Group II: 2 nd calving (n=93) Group III: >3 rd calving (n=55) Body Weight: The body weight of each buffalo cow was recorded in kg and the body weight was measured by means of a measuring tape applying the formula of Rahman et al. (2004).
Live body weight = 300 G2 × L pounds Where, L = Length from the point of shoulder to pin bone in inches G = Chest girth in inches Then, the body weights were converted from pound to kg, dividing by 2.2 The selected cows were classified according to their body weight such as Group I: <250 kg (n=63) Group II: 250 -350 kg (n=127) Group III: > 350 kg (n=10) Body condition: Buffalo cows of different body condition were considered for the study and BCS were determined by Nicholson and Butterworth (1986) with some modified technique. The buffalo cows were divided in the following groups considering body conditions: Group I: Poor (n=32) Group II: Medium (n=95) Group III: Good (n=73)

Reproductive and productive traits of buffalo cows studied
The following reproductive and productive traits of buffalo cows were studied in this study. Age at puberty: The age at which a heifer first shows estrus sign and behavior may be defined as age at puberty (Hafez, 1993). It measured in month (m) and total number of observation was 200. Age at first calving: The actual age of buffalo at the time of its first calving. It is defined as the age when a buffalo heifer first calving a newborn calf. It measured in month (m) Gestation length: It is defined as the period between fertilization and birth or the period during which an embryo develops. It is calculated in days (d). Post partum heat period: It is considered as the interval between date of calving and the date of first insemination or first heat show after parturition. It was calculated in days (d).
Calving interval: It is the period between two successive calving i.e. the period between the calving of the first calf to the calving of immediate next calf and was expressed in days. Average daily milk yield: It refers to the average milk yield of buffalo during the lactation. This was measured in litre/day by using the following formula: Average milk yield (lit./day)= Lactation yield/205 days Lactation length: It is the number of days a buffalo remain in milk from the date of calving to the date of dry. It express in days or months: Birth weight of calf: It is defined as the weight of calf during the period of birth. It is calculate in kilogram (kg).

Data management and analysis
The data obtained from the questionnaire was entered into the Microsoft Excel 2007 and transferred to SPSS version, 17.0. Data were statistically analyzed to calculate the effect of reproductive and productive traits of buffalo cows. Various standard statistical procedures had been adopted in the study. The standard error of mean for the reproductive traits was calculated with help of a computer package programme (SPSS) version 17.0. Mean of different traits were then tested by using analysis of Variance (ANOVA) by Duncan Multiple Range Test (DMRT). Data were presented as Mean±SE. P<0.05 was considered as significant. Simple ANOVA was performed considering the age of buffalo cows and to observe the significant differences among the mean values, Duncan's multiple range test (DMRT) was performed to observer significant differences of reproductive traits in different genotype, age, parity, body weight, body condition of buffalo cows.

Effects of genotypes on reproductive and productive performance of buffalo cows
The effects of genotype on reproductive and productive performance of buffalo cows are summarized in Table 1 and Figure 2

Effects of age group on reproductive and productive performance of buffalo cows
The effects of age groups on reproductive and productive performance of buffalo cows are presented in Table 2 and Figure 3.

Effects of parity on reproductive and productive performance of buffalo cows
To determine the variation of reproductive and productive parameters of buffalo cows due to parity effects are shown in Table 3 and Figure 4. The lower value of almost reproductive traits of age at puberty, age at first calving, gestation length, post partum heat period, birth weight of calf and calving interval (

Effects of body weight on reproductive and productive performance of buffalo cows
The effects of body weight on reproductive and productive performances of buffalo cows are furnished in Table  4 and Figure 5.

Effects of body condition on reproductive and productive performance of buffalo cows
The effects of body condition score on reproductive and productive performance of buffalo cows are presented in Table 5 and Figure 6. Effects of good body condition resulted the lower value of reproductive traits of age at puberty (

The reproductive performance of buffalo cows in Rajshahi district of Bangladesh
Problems that create from infertility are usually overlooked by the farmers, imbalance and undernourished feed management of dairy and buffalo cows and their calves, unavailability of pasture land, inadequate veterinary services and unawareness of farmers in herd health management are the burning issues, which seriously affects the farm economy in Bangladesh (Shamsuddin et al., 2001). In the present study, we found significant (p<0.05) difference on gestation length and post partum heat period of reproductive traits of Rajshahi district. Cuong (1983) concluded that age of puberty of local Murrah and their crosses buffalo in Vietnam were 36, 30, 34 months. The present study shown that the average age at puberty of buffalo cows were 25.05±4.00 months, which is lower than the other study. The result is quit difference due to breed of buffalo, feed quality, environmental and managemental practices as well as data error. Shah et al. (1987) mentioned that the average age at first calving of rural Nili-Ravi buffalo was 45.84±0.19 months in Punjab. The average age at first calving reported by Bhalaru and Dhillon (1987) was about 42.36 months in Nili-Ravi buffaloes. Gupta et al. (1994) and Boro et al. (2020) found that age at first calving for Murrah buffaloes were 45.8 months and 43.69±0.46 months, respectively. Singh and Dhillon (1975)