Summer-to-Winter Production Ratio
A tool to Evaluate the Efﬁciency of the Hot Season Management by Dairy Farms
Israel Flamenbaum – Cool Cows
Ephraim Ezra – Israel Cattle Breeders Association (ICBA)
Due to the harsh summer conditions in Israel, the use of cooling methods in dairy farms has become an important tool for increasing milk production efﬁciency. A Summerto-
Winter Production Ratio, which uses data from the “Israeli Herdbook”, was developed as an indicator of the efﬁciency with which farm managers reduce the summer’s negative impact on cows’ performance. This parameter is applied in the present research to evaluate the achievements of Israeli dairy producers to overcome the detrimental effects of the hot season on cows’ performance. Increased summer milk yield and fertility, and reduced seasonality of milk supply to the dairy industry are some of the main goals of the Israeli dairy sector. In the last three decades, new cooling methods and summer management practices were developped and largely introduced to dairy farms all over the country. The Extension Service of the Israeli Ministry of Agriculture in cooperation of the Israel Cattle Breeders
Association (ICBA) have cooperated for many years to take advantage of the “Israeli Herdbook” data, and use it to evaluate the efﬁciency of the different cooling methods, through ﬁeld experiments and large scale surveys.
The “Summer-to-Winter Production Ratio” which has been developed, is based on the monthly yields measured by the Milk Recording System. The ICBA computer creates“virtual” production curve for cows that have calved in the summer (July – September) and winter (January – March) season and calculates a “seasonal average” of production for every herd.
The resulting ﬁgures are the basis for calculating the “Summer-to-Winter production ratio”. This ratio can be used by the individual farmer to evaluate his efforts to reduce heat stress in the farm, as well as by farmers organizations, government agencies and dairies while making policy-making decisions.
Lately, after having used this parameter for evaluating results of surveys and experiments dealing with cooling methods, we decided to calculate this ratio annualy for each dairy farm in Israel to evaluate results of the intensive use of “summer management practices” and the introduction of cooling methods.
Using this method we have compared results of this Summer-to-Winter production ratio between the years 1994 and 2004 in order to learn about the changes and advances in Israeli dairy farms with relation to improving cows’ performance in summer.
The following report presents the Summer-to-Winter production ratio for average corrected* daily yields of ECM (Economic Corrected Milk) obtained in summer and winter.
The higher this ratio is (close or above 100%), means that summer production is relatively good, and that the farm is dealing well with the summer heat-stress (or that it is one of those fortunate farms located in highlands, which beneﬁts from a relatively mild summer).
672 dairies participated in this survey, 184 of which are Kibbutz (cooperative, large scale dairies) and 488 (moshav, family farms, relatively small sized dairies). In table 1 Summer and Winter averages of corrected ECM daily yield and the Summer-to-Winter production ratio for the two kinds of dairy farms in 1994 and 2004 are presented.
Results show a signiﬁcant improvement in Summerto-Winter production ratio in the last 10 years.
First-calvers have almost closed the gap and reached production levels in 2004 very similar to winter ﬁrst-calvers. For adult cows, summer production levels in 2004 reached 90% of winter levels, and for cooperative farms this rate was almost 10% more than the 1994 level.
Distribution of dairy farms regarding the Summer-to-Winter ratio, for the two dairy production sectors, is presented in table 2.
Data in table 2 show that 93 farms (almost 15% of the total farms in Israel) have a Summer-to-Winter ratio greater than 100%. A large portion (nearly 40%) of the farms, achieve a ratio ranging between 91- 96%. A relatively higher percentage of family farms, compared to cooperative farms, have Summer-to-Winter production ratios below 90% (25% and 16%, respectively). This possibly represents poorer installations and/or implementation of summer management and cooling methods in farms of this sector.
The inﬂuence of the geographical region, and level of winter ECM production on Summer-to-Winter production ratios was also studied in this survey.
To determine the inﬂuence of the geograﬁcal region on cows’ performance, the 2004 Summer-to-Winter ratio was calculated for two groups of cooperative dairy farms located in the Jordan Valley (a relatively hot area) and a group of dairy farms located in the highlands of Israel (relatively cool). Data concerning these two groups and the average of all of the cooperative dairy sector is presented in table 3.
To examine the inﬂuence of milk production level in the Summer-to-Winter production ratio, we compared results of dairy farms from both sectors in which the winter average production exceded 37 kg ECM/d and those whose average winter production was below 31 kg ECM/d. Results are presented in table 4.
Figures in tables 3 and 4 show that hot climate conditions and high winter level of production have a negative impact on the ability of the individual dairy farm to reach high Summer-to-Winter production ratio.
The data presented in these tables indicate that the parameter of the Summer-to-Winter production ratio must be implemented carefuly, and that operative steps must take into account important factors that can inﬂuence this ratio.
In conclusion, this article presents the use of the Summer-to-Winter production ratio as a parameter to evaluate the efﬁciency of milk production achieved in the summer in relation to winter levels. This ratio can be used to verify the effects of the implementation of anti heat-stress measures.
Furthermore, this index pinpoints to the professional and economical achievements that can be obtained by cooperation between Extension Services and the “Herdbook” data-bank, for the beneﬁt of both the Israeli dairy farmers and the consumer.