Milk production performance and inter-relationship among traits of economic importance in buffaloes maintained at commercial dairy farms

S K Hamid, M Farooq, M A Mian, M Syed and S Jamal

Faculty of Animal Husbandry and Veterinary Sciences,
NWFP Agricultural University, Peshawar, Pakistan
durraniff@yahoo.com or durranif@hotmail.com

Abstract

The present study was undertaken in Peshawar division by collecting data from 130 commercial dairy farms to investigate milk production performance and inter-relationships among various traits of economic importance in buffaloes.

Average peak milk yield, lactation yield, yield per day of calving interval, lactation length, dry period and calving interval were 10.5±0.27 kg, 2004±30.13 kg, 4.83±0.26 kg, 279±2.31 days, 136±2.01 days and 415±4.04 days, respectively. Peak milk yield (r=0.91; p=0.001) and lactation length (r=0.20; p=0.001) were positively correlated with lactation yield. First derivative of the regression slope for peak milk yield, lactation yield and yield per day of calving interval revealed 16.9 kg, 2663 kg and 5.59 kg, respectively to be the optimal limits for higher most economical milk production. The positive sign of second derivative for lactation yield and yield per day of calving interval suggested improvement in net profit with increase in lactation yield or yield per day of calving interval. Better milk production performance of buffaloes was observed in district Peshawar as compared to that in district Charsadda. Similarly, buffaloes maintained in farms located in peri-urban area performed better as compared to those in rural areas. Longer dry period (196±2.1 days) and calving interval (458±9.2 days) was found for buffaloes maintained in district Charsadda than those in district Peshawar (88.4±1.4 days and 391±6.9 days, respectively). In urban areas farmers were following 100% stall-feeding practice, in peri-urban areas 30.2% and in rural areas only 3.67%. A higher proportion of the farmers (89.9%) in the rural areas were growing their own fodder as compared to urban areas (3.55%). Similarly, a higher proportion of the farmers (70.4%) in urban areas were found to give dry roughages to their buffaloes as compared to farmers in rural areas (2.10%). A higher proportion of the farms in urban areas were in poor condition (47.3%) as compared to rural areas (16.2%).

It was concluded from the study that buffaloes maintained in farms located in urban and peri-urban areas had better performance than those in rural areas. Improvement in peak and lactation yield and growing own fodder crops would increase profit.

Key Words: Buffalo, management, milk production, optimization, rural, urban

Introduction

Buffaloes possess tremendous unexploited potential for milk and meat production (Cockrill 1980) with average milk yield per lactation ranging from 1671 to 3988 liters (Syed et al 1996). A higher milk yield of 3700 kg per lactation period of 300 days has also been reported in nearly 14 percent of the registered buffaloes under progeny testing program in Pakistan (Asghar et al 1997). Buffaloes, because of their higher milk fat content than cattle, are extensively reared in Pakistan on small scale for family consumption of milk, with the surplus milk being sold to compensate the family budget. However, during recent years, rearing of buffalo as a commercial dairy animal on larger scale has been popularized in Pakistan and the number of commercial dairy farms has shown a tremendous increase. Buffaloes have always been criticized for poor reproduction performance in the country. This could be attributed to silent heat in buffaloes, increased length of dry period and deliberate delay in serving the buffaloes showing heat signs following parturition. Asghar et al (1997) reported an average calving interval and dry period of 513 days and 190 days, respectively. Farmers commonly share the opinion that their animals will become dry soon after they are re-bred and customarily attempt to postpone breeding for obtaining higher and prolonged lactation. The potentials for milk production should, therefore, be exploited through proper breeding plans and selection of outstanding animals. This could be possible when a higher number of animals become available, allowing regular replacement of uneconomical animals showing poor performance.

Pakistani buffaloes are "riverain" type and thrive best in irrigated areas with an ample sources of water and green fodder (Wahid 1976). Peshawar division being an irrigated area with ample water supply and green fodder could not be a better place for rearing buffaloes on small or larger scale. However, proper documentation of various production traits of buffaloes and feeding practices followed on commercial dairy farms is required for developing future strategies. The present study was planned to investigate production performance and study inter-relationships among peak yield, lactation yield, length of lactation, calving interval and yield per day of calving interval.

Materials and methods

The present study was conducted by collecting data from 130 commercial buffalo farms located in Peshawar division to investigate production. Information was collected on herd size (number of lactating, dry and pregnant animals and calves), housing condition, type and amount of fodder and concentrate given to the animal, feed supply source, calving date, peak milk yield, date the animal dried, lactation yield and length, dry period, criterion for drying buffaloes and fate of buffalo after lactation was terminated. A similar study regarding cost of milk production and net profit from a buffalo was also undertaken on the same farm at the same time. Profit per buffalo worked out in that particular study was utilized here for predicting standard limits of economic importance.

Data analysis

The data were analyzed using relevant statistical procedures namely, univariate, General Linear Model (GLM), Pearson's correlation, regression analysis, Chi-square test, Fisher Exact Test and quadratic functions. A 95% confidence interval around the mean for peak milk yield and lactation yield was constructed as follows to work out the proportion of buffaloes falling above and below the upper and lower limits of confidence interval;

95% CI = μ^± t _0.05 (σ^/Ön)

Where, "μ^" was the sample mean, "σ^" the sample standard deviation, and "n" the number of observations.

To study the effect of farm location and district of production on peak milk yield of buffaloes at commercial dairy farms, the following statistical model was constructed adopting the procedure of Steel and Torrie (1981);

Y_ijk= μ + a_i + b_j e_ijk

Where, "Y_ijk" was the response variable, "μ" the population mean, constant to all observations, "a_i" the effect of i-th district of production; i= Charsadda, Nowshehra and Peshawar, "b_j" the effect of j-th farm location; j= Urban, Peri-urban and Rural area, and "e_ij" the residual term associated with each Y_ijk, assumed to be distributed normally and independently with mean zero and variance Iσ².

The association among various parameters namely lactation yield, peak milk yield, calving interval, yield per day of calving interval and lactation length was worked out using the following regression model;

Y_ij=ß₀ + ß_iX_i + e_ij

Where, "ß₀" was the intercept, "ß_i" the partial regression coefficients for the independent variables used in the model, and e_ij = the residual term. Traits of economic importance were optimized using the following quadratic equation:

Y = ß₀ + ß₁X_i + ß₂X²_i

Where, "Y" was response variable, "ß₀" the intercept, "ß₁" first slope of the regression line, "ß₂" second slope of the regression line and "Xi" the independent variables. Standard limits for various traits of economic importance were developed taking first and second derivative of the regression slopes.

Correlation among peak milk yield, lactation yield, length of lactation, dry period, calving interval and yield per day of calving interval was worked out using the formula,

     r_X,Y = Cov (X, Y)/σ_xσ_Y

Comparison among various practices and supply sources of fodder was made using the following form of Chi square test;

    x^{2 =} Ó (O-E)²/E

 

Where "E" were expected events and "O" were observed events. In some cases, where expected numbers in the cells of most of the contingency tables were less than 10 and chi-square Test was not effectively applicable, the following form of Fisher's Exact Test was used for comparison:

Probability of any observed set of entries = [(a+b)! (c+d)! (a+c)! (b+d)!] / [n! a! b! c! d!]

Where a, b, c and d were the observed numbers in four cells of contingency table and "n" the total number of observations (Fisher 1970).

Results and discussion

Peak milk yield

Average peak milk yield of buffaloes maintained in commercial dairy farms was 10.5±0.27 kg (Table 1). Peak milk yield in the present study was higher than that reported by Singh et al (1990; 9.61±0.18 kg) and Dahama and Malik (1991; 8.08±0.78 kg) in Nili-Ravi buffaloes. The findings of the present study suggest a relatively better milk production performance of buffaloes in the study area. This could probably be due to the presence of higher yielding animals at the farms as most of the animals were selectively purchased and maintained on the basis of their higher milk yielding capabilities.

Peak milk yield was significantly correlated with lactation yield (r=0.91) indicating that buffaloes attaining higher peak yield were having higher milk yield in lactation. However, this may not always be true and an optimal limit for peak milk yield may be more relevant in this respect. Keeping in view the prediction of an optimal limit for peak milk yield (PMY), a quadratic relationship was worked out between peak milk yield and 305-day lactation yield (LY): 

Taking derivative of the first regression slope (Equation II), a peak yield of 16.9 kg was found to be the optimal limit for higher milk production under present circumstances. The negative sign of the second derivative (PMY¢¢ = -6.99; equation III) suggested a decline in predicted 305-day milk yield when peak milk yield exceeded the limit of 16.9 kg, thus, 16.9 kg was found as the critical maximum limit for peak milk yield. The actual peak milk yield in the present study was lower (10.5 kg) than the predicted optimal peak milk yield (16.9 kg). Thus, efforts should be made to obtain the predicted optimal limit of peak milk yield, resulting in increase of 709 kg in predicted 305-day milk yield shifting it from 2004 kg to 2714kg.

The results of the present study revealed that 17.7% of the buffaloes had peak milk yield above the mean by more than 3 standard deviations (Table 2). Almost 55% of the buffalo population produced milk below the mean by less than 1 standard deviation. Only 5% of the population produced milk around the mean by 1 standard deviation. In a selection program, buffaloes falling above the mean by more than 3 standard deviations should be selected as dams of the sires. If such sires are re-bred to outstanding dams (falling above the mean by more than 2 standard deviations), milk production potentials of the progeny could be improved many fold. The population of buffaloes falling above the mean from 1 to less than 3 standard deviations could be used as dams of the dams in a selection program. Buffaloes falling below the mean should be culled immediately from the herd for better milk production in future.

District distribution and location of the farm had a significant effect on peak milk yield (Table 3), with  higher peak milk yield in Peshawar (11.4±0.39 kg) as compared to those in district Charsadda (9.58±0.27 kg). Buffaloes in farms located in peri-urban areas gave higher peak milk yield (12.1±0.19 kg) as compared to those in rural areas (8.28±0.10 kg) (Table 4). The higher peak milk yield by buffaloes in Peshawar district and peri-urban areas could be attributed to highly productive animals and better quality of feed as compared to buffaloes maintained in the rural areas.

Lactation yield

The lactation yield in the present study was higher than that reported by Ismaiel (1990; 1337kg) and Syed et al (1996; 1671±31.4 kg). The better milk production  of buffaloes in the study area as compared to the reported findings could probably be due to rigorous culling and regular induction of highly productive buffaloes in the herds under study. Farmers were usually selling their animals after completing one lactation length and were keeping exceptionally out-standing animals at the farm for rebreeding.

Lactation yield is an important trait that significantly influences net profit obtained from the buffalo milk produced. A quadratic relationship was found between lactation yield (LY) and net profit per buffalo (NF; equation IV.).

Taking the derivative of the first regression slope (Equation V), the LY of 2663 kg was found to be the optimal limit for obtaining higher net profit under present situation. The positive sign of the second derivative (LY¢¢; equation VI) suggested that 2663 kg was the minimal limit and an increase beyond this limit in lactation yield will increase net profit per buffalo maintained at commercial dairy farms. The optimal limit worked out for LY was higher than the actual average lactation yield (2004 kg).

Distribution of buffaloes falling above or below the mean in terms of standard deviation regarding lactation yield, is given in Table 2. The data are similar to those observed for peak milk yield.

District distribution of buffaloes and location of the farm had a significant effect on lactation yield (Table 3). The results were similar to those observed for peak milk yield and the interpretation equally similar.

Lactation length

The average lactation length was shorter than that reported by Parkash and Tripathi (1990; 307±8.0 days) and Sharma and Singh (1990; 373±5.8 days) but longer than that reported by Ismaiel (1990; 260 days). The shorter lactation period in the present study than the standard 305-day length of lactation could be attributed to the decision making of drying the animal when the milk yield was reduced to an uneconomical level. Buffaloes were usually discarded from the herd or dried off when their milk production was below 4 kg/day. The effect of district and farm location on lactation length was similar to what was observed for milk yield.

Yield per day of calving interval

Yield per day of calving interval is a function of total milk produced by a buffalo in a lactation between two successive calving. Average yield per day of calving interval was 4.83±0.26 kg with a coefficient of variation of 26.84% (Table 1). Nadir et al (1999) reported a smaller yield per day of calving interval (4.11 kg) in buffaloes maintained at commercial dairy farms in Pakistan than the present findings. The higher yield per day of calving interval in the present study could be attributed to the higher yielding animals at the farms. In fact farmers maintaining commercial buffalo farms were regularly purchasing higher yielding animals to cope with the higher demand of buffalo milk in the area.

Yield per day of calving interval was  positively correlated with lactation yield (r=0.85; p=0.001) and negatively correlated with calving interval (r=0.46; p=0.001).  Yield per day of calving interval is the most important trait from an economic point of view. However, its optimization is one of the pre-requisites for generation of more revenues. Yield per day of calving interval was predictable with much accuracy from net profit per buffalo per day. A quadratic relationship was found (equation VII) between yield per day of calving interval and net profit per buffalo per day.

 

Taking the derivative of the first regression slope (Equation VIII), YDCI of 5.59 kg was found to be the optimal limit for obtaining higher net profit under the present situation. However, the positive sign of the second derivative (YDCI¢¢; equation IX) suggested 5.59 kg to be the minimal limit and any decline in YDCI beyond 5.59 kg would adversely effect net profit per buffalo. The optimal limit set for YDCI was higher than the actual average YDCI found in the present study was lower (4.83 kg).

Farm location and district-wise distribution of buffaloes had a significant effect (p<0.001) on yield per day of calving interval, the trends being in line with those for peak milk yield (Tables 3 and 4).

Dry period

The average dry period in the study area (Table 1) was shorter than that reported by Ismaiel (1990; 154 days), Juma et al (1994; 149 days) and Syed et al (1996; 190 days). The smaller dry period in the present study could be attributed to higher yielding capability of the buffaloes in the area. The trends for effects of district and farm location were similar tot those found for peak milk yield (Tables 3 and 4).

Calving interval

Length of calving interval observed in the present study (Table 1) was shorter than that reported by Nadir et al (1999; 528 days), and Syed et al (1996; 533 days) and longer than that reported by Juma et al (1994; 400 days). From an economic point of view 365 days is considered the ideal length of calving interval. The higher calving interval in the study area could probably be due to poor reproductive management and silent heat problem in buffaloes. Also, the deliberate delay in re-breeding of buffaloes by the farmers could be one of the reasons. The majority of the farmers, especially in rural areas, were of the view that early re-breeding would result in a drastic decrease in milk yield. Trends for effect of district and farm location were similar to those found for peak milk yield (Tables 3 and 4).

Feeding practices

Feeding practices and fodder given to the buffaloes revealed that 44.6% of the farmers were doing stall feeding and 56.4% had stall cum grazing feeding practice (Table 5).  In urban areas farmers were following 100% stall-feeding practice, in peri-urban areas 30.2% and in rural areas by 3.67%. A higher proportion of the farmers (96.3%) used grazing cum stall-feeding practices at the commercial dairy farms in rural areas. 

As shown in Table 6, a higher proportion of the farmers (89.9%) in the rural areas were growing their own fodder as compared to urban areas (3.55%). Availability of land was the obvious determining factor in this case.

The amount of dry and green fodder given to buffaloes revealed that a higher proportion of the farmers (45%) were giving mixed fodder (green+dry) and a smaller proportion (18.1%) were giving green fodder only (Table 7). Similarly, a higher proportion of the farmers (70.4%) in urban areas were found to give dry roughages to their buffaloes as compared to farmers in rural areas (2.10%). On the other hand, a higher proportion of the farmers (31.6%) in the rural areas were giving green fodder to the farmers than those in urban areas (2.10%). The smaller proportion of the farmers giving green fodder to their buffaloes in urban areas could be attributed to higher prices of green fodder in the market and lower land availability in the urban areas for cultivation of fodder crops for their animals.

Overall farm condition

Overall farm condition was assessed from the point of view of space given to animals, cleanliness, hygienic conditions, sanitary conditions and clean milk production. On an overall basis 43.7% of the farms were found in good condition, 27.0% in poor and 29.4% in bad conditions (Table 8). A higher proportion of the farms in urban areas were in poor condition  as compared to rural areas. In peri-urban areas,  24.6% of the farms were found in bad conditions and 45.2% in good condition (Table 8). The higher proportion of the farms under poor conditions in urban population could be attributed to the congestion, poor sanitary conditions and location of the farms in densely populated areas.

Conclusions

• Distribution of buffaloes regarding lactation yield in terms of standard deviation around the mean revealed that 30% of the buffaloes were falling above the mean by more than 3 standard deviations. About 18% were between 1 and 3 standard deviations while the rest were below 1 standard deviation.
• Peak yield affected lactation yield, however peak yield of more than 16.6 liters resulted in a decline in lactation yield.
• Majority of the farmers were purchasing fodder from the market and were feeding mostly dry roughages to their buffaloes

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