Determining the dietary needs of your cows - Part 1
Once our passion for dairy kicked-in; we started measuring the milk output of our desi cows. We increased their feed in the hopes that their milk output would increase in direct proportion. We did not notice any appreciable increase in milk output. We concluded that none of our cows had high milk potential. We decided to purchase a friesian cross-breed from a local farmer. The cow was giving 6-8 l/d. The farmer told us that he is unable to give ample food to the cow hence the cow is not realising its true milk potential. We thought that once we give the cow ample food it would increase it's milk. After the purchase, we did increase its feed and gave the cow not only green fodder but also ample "vanda". The cow increased its milk to 11-12 l/day. But it saturated at that limit. No amount of extra food or vanda nudged the cow further. We concluded that the cow did not have any more milking potential. We had bought the cow for Rs. 150K. So increasing its milk output to 12 l/day made this financial deal a break even for us. We were confused on the feed-milk-milking potential correlation. We decided to attack each of these variables one by one. First we decided to attack the "milking potential" variable. We bought couple of expensive cross-breed cows which were producing 27 l/day (in first lactation), we were able to maintain their milking output on our farm for 2-3 weeks. We thought we had cracked the mystery and were about to conclude that our feed formula to the cows is correct and that it was always the "gene pool" of the cow that was the problem with our existing herd; until our new cows were hit with seasonal fever which reduced their milking output. Even after the cows recovered, their milking output did not reach their peak potential and they started averaging around 21 l/day. Given below is the graph of both our exotic breed cows.
In the graphs the dip indicates when the cows caught fever. For the first cow, the fever lasted for almost 7 days for the second it lasted for 4 days. In case of the first cow, during the fever the cow's output went down from 28 l/day to 6 l/day with in a span of 5 days. It then slowly started recovering and in 4 days had come back up to 15 l/day. In 11 days it crossed 20 l/day. It then stayed between 22-23 l/day. For the second cow the impact was less drastic and prolonged; but none of the cows went back to their original output, even after several days post-fever. They were both eating well and did not show any signs of weakness, additionally their blood tests came normal. While we were struggling with this mystery, our green fodder crop was hit by parasite attack and was no longer fit for consumption by the cows. Our feed was mostly composed of green fodder (lucern, barseen) and small portions of Silage (which was bought through a vendor that Engro Foods ahd recommended). Due to green fodder shortage, we had to switch to Silage almost exclusively and soon ran out of our Silage. We bought Silage from a neighbouring farmer. Once we did that we saw a marked increase in the cow's milk output, the output graph of Cow # 1(shown in the first graph above) is shown below:
The cow had gone back to its original maximum of 27+ l/day. All of our other cows showed similar dramatic increase in milk output. Our farm average jumped from 21 l/day to as high as 24 l/d.
While we were nursing our cows back to health we got multiple advice on adding minerals, soda bicarbonate, oil, molasses etc. in cows feed. Our own experience of dramatic affect that a high quality Silage can have was also eye opening for us. Once our herd situation stabilised, we got down to doing a thorough analysis of how the feed of the cows should be structured. We read books, talked to experienced dairy farmers and consulted Nestle and Engro Foods experts. Based on our discussions we developed a food calculator; that we use on our farm to devise a food plan for our herd. Please note that nothing can substitute good sound advice from a trained and experienced dairy nutrition specialist - we don't claim to be one. We are jotting down our experience for your benefit. Please take our experience with a grain of salt. Use your best judgement to filter through out advice.
Green Fodder is composed of two major components: Water and Solids. Different fodder have different composition of water in them. Therefore cow's dietary needs should not be determined by the weight of the fodder. A common rule of thumb is to give the cow 10% of its body weight in fodder daily. This is an over simplification. By this rule, if you are exclusively feeding your cow Lucern then a cow that weighs 500Kg, should be given 50 Kg of Lucern. The fact is that this will keep your cow under-nourished It should actually be given 88Kg/day of lucern to meet its dietary need (discounting the fact that giving only one type of fodder is not a good idea because the rest of the nutrients that a cow needs will be compromised if only one type of feed is given). If you are giving Barseem then to provide the same energy as 88 kgs of Lucern, your cow should be given 117 Kg/day of Barseem. Why is more Barseem needed than Lucern ? The answer lies in the water contents of these fodder. Lucern has 80% water and 20% dry matter; whereas Barseem has 85% water and 15% dry matter. Cow's dietary needs are based on the dray matter in its diet. The ideal feed should be such that it mixes different types of fodder, silage and vanda. Additionally the cow also needs salt and minerals and other supplements in small quantities.
A cow needs 3.5% of its body weight in Dry Matter. Out of this 1% should be met through Vanda. Let us see how the maths work:
Cow Weight = 500Kg
Dry Matter Needs = 3.5% * 500 = 17.5 Kgs of Dry Matter.
1% of Dry Matter should be met through Vanda. Vanda has 90% Dry Matter in it therefore your cow should be given 5.6 Kgs of Vanda. This also covers you for ~ 16 l/d of milk. If the cow produces more milk then add 1 additional Kg of vanda for every 3 liters of milk above 16 l/day.
The remaining 2.5% (12.5 Kg) should be met through other fodder:
If you want to meet the rest of the need exclusively through Lucern then 62.5 Kgs of Lucern should be fed
If you want to meet the rest of the need exclusively through Barseem then 83.3 Kgs of Barseem should be fed.
If you want to meet the rest of the need exclusively through Corn Silage then 41.6 Kgs of Silage should be fed.
In addition to the above calculations, you should also give the cow:
50 grams of soda bicarbonate daily.
100 grams of mineral mix daily.
1-1.5 Kgs of wheat straw (bhoosa/tori) daily.
50 grams of Molasses (Gur) daily.
You can also give stomach powder to improve cow's digestive system. Additionally in summer exotic breeds are susceptible to heat stroke. So you may have to reduce some of the above feed and add oil to the cow's feed to counter the acidity that exacerbate the heat stroke condition in cows.
In our next blog we will share with you a software application (that automates all of the above information) that you can use to auto-calculate your cow's dietary needs.
