Relation between milk quantity and reproduction

IN ITALY THE NUMBER OF LACTATION SINCE 1995 TILL 2003 HAS BEEN RIDUCED FROM 3,5 TO 2,5,IN THE SAME PERIOD THE PERCENTAGE OF COWS AT FIRST PARITY INCREASED FROM 27 TO 34[percent],AS MORE THE MILK PRODUCTION INCREASES THE STAYNG OF DAIRY COWS IN THE FARM DECREASES. THERE ARE MANY FIGURES THAT CLESARLY SHOW THIS RATIO. THE NEGATIVE ENERGY BALANCE RIDUCES FERTILITY, REDUCES LUTEINIZING HORMONE (LH), REDUCES INSULIN AND INSULINE GROWTH FACTOR THAT HAVE A NEGATIVE EFFECT ON OOCYTE DEVELOPMENT. IT IS A LONG SPEECH THAT DESERVES MUCH ATTENTION REGARDING A CERTAIN KIND OF GENETIC IMPROVEMENT

The onset of pregnancy may be associated with hormonal changes and decline in milk yield of buffaloes. To investigate this, forty lactating buffaloes from 1st to 23rd weeks post-conception were selected. The animals were assigned to three treatments: PRT, PRS, NPRTand three milk yielding groups HMY, 66 to 75 l/week, n[equal]12 MMY, 56 to 65 l/week, n[equal]16 LMY, 46 to 55 l/week, n[equal]12). Milk samples were collected on alternate weeks and analyzed with ultrasonic milk analyzer. EIA was used for milk progesterone concentrations. Group means were compared and correlation analysis was conducted. Progesterone concentrations increased in almost similar pattern with the advancing weeks post-conception. The high and low yielder showed greater progesterone concentrations in the supplemented than the animals on traditional ration (P0.001). Progesterone concentrations correlated positively with fat ([percent]), negatively with milk yield, protein ([percent]) and lactose ([percent]). Decline in milk yield became drastic when progesterone concentrations rose above 6.44 ng/ml. The pregnant animals on traditional ration exhibited a sharper decline in milk yield with the increasing progesterone concentrations as compared to pregnant animals with supplemented ration. It is concluded that concentrates supplementation induced a raise in progesterone levels. Progesterone concentrations and milk yield showed an inverse relationship.

a pressure difference at the teat end combined with milk stasis and a poor immune system that releases toxic steroids will result in poor maintanance of the corpus luteum due to the lack of progestrone and prostaglanda resulting in low preg rates pre embryonic failure, mastitis, heel warts, hyperkeratosis, excessive NEFA mobilizATION AND THE LIST GOES ON. SO YES, HIGHER MILK YIELDS WILL RESULT IN DISEASE IF WE DO NOT PARALLEL HARVEST

There is no such thing. It is common sense that if you have better feeding regimes, management and have balance in positive and negative energy balance nothing will happen. all such problems arise with poor nutrient intake and extra nutrients draiin out in milk.

Thanks for your comments on this topic. Generally We agree that excessive milk production has negative impact on reproduction and longevity except Mr. Raza. He suggests that If we feed animal properly There is no reproduction and pregnancy problem. But as we know it is almost imposssible to prevent 0.5 body condition loss in cows which give more than 40 litres milk per day and first thing animal gives up is reproduction. Another reason for reduced reproduction parameters in high milk yield cows is over blood flow from liver to supply enough metabolites for high milk production causes destruction of steroid hormones such as oestrogen and progesterone in the liver. As a result of these factors silent oestrus, inactive ovariums and high embrionic losses common in high milk yields cows. Although we can reduce these risks by good feeding management and using feed additives like fatty acids The reality in the world through last 15-20 years milk production per cow increased consideraby but reproduction parameters decreased relatively. I am looking forward to your further comments and criticism My Regards

It is quite interesting. It is a fact that such conditions are noticed in high yielding cows. While reviewing the ration of such cows and examining the dietary nutrients one can understand that there will be a shortfall of glucose arriving at the udder. Glucose is the important nutrient for milk synthesis whaich is used for lactose formation and NADPH for milk fat synthesis. The availability of glucose through propionic conversion has limitations as the acetic :propionic ratio is 2.2:1. To increase propionic acid more grain needs to be fed. This may lead to pH lowering and associated problems. The recent advent of inert fats feeding which supply energy by splitting fatty acids to acetyl coA by releasing energy. However acetyl Co A cannot be converted to glucose. Unless enoguh glucose is not supplied it may predispose to the hormonal problems.

I agree with Mr Yusaf Ziya. His comments are comprehensive,self explanatory and understable

Relation between milk quantity and reproduction array of explaination paves the way to assess the nutritional statuus of tha animal and more over in high yielding animals liver is being taxed much for clearing the metabolites which in turns solicts for higher amount energy for clearing the metabolites and ultilmately ther is energy shory fall

I do not agree with Hassan Raza as his statement is true only for cattle or buffaloes producing only upto 10 liters of milk per day and getting moderate level of feed, where the loss of nutients through milk production is not drastic to affect fertility. Yousuf Cakir has explained the phemenon excellantly that a very high milk yielding cow has to loose most of her metabolites in milk yield and nothing is left for maintianing fertility. In addition the role of exessive blood supply to through the liver for milk synthesis results in loss of steroid hormones. In fact the animals has to live and face the challenges of harsh environment, disease stress, milk production stress and other body functions. A lower milk production can be maintained by a non-improved dairy animal, while keeping moderate body condition score. With the improvement in genetics for milk produciton, the animal changes its priorities for various body functions. Milk yield is given higher priority followed by health status and fertility. The biological target for body condition is lowered, meaning that the animal will continue to increase milk yield with the increasing nutrient status, without increasing the body conditions. So we can not see a genetically improved dairy animal to have a better body condition. So, we come to know that a genetically improved animal will not accomulate adipose tissue in form of enhanced body condition, resulting in a poor body condition. On the other hand, a moderate body condition is required to support ovarian cyclicity. In addition appropriate blood glucose levels are required for supporting estrus induction as found on our recent study on local and improved dairy cows. The higher milk yield utilizes more glucose for milk synthesis and little is left for supporting fertility. Another factor is the leptin which is a permissive factor for reproductive cyclicity. And leptin is produced only when the body condition is at moderate level. Again higher milk yield resulting in poor body condition will weaken the leptin signals resulting in cessation of reproductive activities. So, we can say that improved milk yield will resutl in poor fertility and breeding may be expected at some delayed stage.

Dear all I have done a lot of field trials in high yielding dairies and the situation is actually in Germany 2.2 lactations....19 500 kg life yield per cow....more or less the heifer growing periode is longer than the production periode in milk...The main reason is the toxic pressure in the liver. All the efforts in cow comfort are forcing the milk yield...but not fertility. In the trials we have seen by managing the toxins the SCC especially the higher laktation numbers runs down between 300 000 and 400 000. In a two years term the lifetime efficiancy increase from 13 kg milk per life day to 16 kg. This benchmark includes all relavant parameters in milk production mainly fertility. The service time cut down nearly three weeks. Normaly the better second lactation cows leave the farm. Now we can see that this better ones stay in the farm. The effect in managing the toxin risk is an increased digestability in NDF and Protein. 200 000 SCC is exhausting 5 -7 [percent] of the feed energy. In the last 30 years we have a better fertility by the heifers and 20 [percent] less fertility in cows. So we have to support the liver function and inactivate the toxins.