Effect of Seasonal Variation on Crossbred Cow Milk Composition in Southern Region of Tamil Nadu

| The study was designed to evaluate the seasonal influences on crossbred cow milk composition in an organized cattle farm, Dindigul District, Tamil Nadu, India. One hundred (n=100) samples from each season were collected from a herd of Holstein Friesian crossbred cows during summer (March-May), rainy ( June-September), autumn (October-November) and winter (December-February) and analyzed for fat, solids not fat (SNF) and total solids. Overall mean for fat, SNF and total solids of milk were 3.74, 8.258 and 11.998 per cent respectively. Fat and SNF content significantly (P<0.01) differed among seasons and highest in winter (3.819% and 8.348%) followed by autumn (3.771% and 8.282%), summer (3.739% and 8.246%) and lowest in rainy season (3.631% and 8.158%). The seasonal variation in this part of the southern region of Tamil Nadu influences the fat, SNF and total solids content of crossbred cow milk.


Journal of Animal Health and Production
December 2018 | Volume 6 | Issue 4 | Page 109 The study was carried out in an organized cattle farm, KSE Limited, Dindigul, southern region of Tamil Nadu. The herd milk samples were collected within 1-2 hour of milking of Holstein Friesian crossbred cows for a period of one year from June 2016 to May 2017. One hundred (n=100) milk samples from 18 cows were collected in each season namely summer (March-May), rainy ( June-September), autumn (October-November) and winter (December-February). The milk samples were collected in clean, dry and neatly labelled sample containers and transported to the laboratory as soon as possible under refrigerated conditions. The samples were analysed for fat, solids not fat (SNF) and total solids (TS) content. Fat content of the milk was analysed by Gerber's method (ISI, 1977). SNF was calculated by Richmond's formula as follows, SNF (%) = CLR/4 + 0.25F + 0.44 Where, CLR = Corrected lactometer reading and F = Fat per cent Here, Zeal's Lactometer was used to determine CLR and Specific gravity of milk at 29°C (Sharma et al., 2002). The total solids content was calculated by adding SNF and fat per cent.The data collected on milk fat, SNF and total solids content were statistically analysed as per the methods described by Snedecor and Cochran (1994).

results AnD DIscussIon
The mean values of milk composition on different seasons are presented in Table 1. Overall mean for fat, SNF and total solids of crossbred cow milk were 3.74, 8.258 and 11.998 per cent respectively. Fat and SNF content significantly (P<0.01) differed among seasons and highest in winter (3.819% and 8.348%) followed by autumn (3.771% and 8.282%), summer (3.739% and 8.246%) and lowest in rainy season (3.631% and 8.158%). Similar results were expressed by Sharma et al. (2002), Sudhakar et al. (2013) and Wangdi et al. (2016). The total solids content of milk were significantly (P<0.01) higher in winter than other seasons (Table 1).
Sunil Kumar et al. (2011) concluded that tropical climate is stressful for the Holstein Friesian crossbred milch animals particularly in summer season, as the ambient temperature (25°C) rises high. The animals suffer from heat stress when the thermal equilibrium is upset with increased production of body heat than its dissipation and subsequently it leads to increased water intake, reduced dry matter intake and variation in milk composition. Secondly, the green fodder availability is more in winter than summer season, which in turn increases the percentage of milk constituents (Abraham and Gayathri, 2015). The results of above workers are in accordance with our present study.
The above findings concluded that the seasonal variation in the southern part of Tamil Nadu influences the fat, SNF and total solids content of milk.

conFlIct oF Interest
There is no conflict of interest.

AutHors contrIbutIon
All the authors contributed significantly to the paper. The corresponding author along with M. Arulmuthumathavan carried the experimental trial and compiled the results. V.V. Raji and N. Muniyappan designed the protocol and helped in laboratory analysis of the milk samples.