What Makes ICC$ Ideal?
Who is it ideal for? What does commercial mean anyway?
Most dairies around the world strive to produce high quantities of high component, low somatic cell score milk from cows that are healthy, breed easily, and can accomplish this over many lactations. Yet, the types of farming situations throughout the world can vary greatly. ICC$ recognizes genetics that excel in any farming situation, regardless of barn style or milking system.
The description of a commercial cow or a commercial farm is quite simple: it's one that generates revenue from the sale of milk and/or meat products. Progressive and successful commercial dairies have a business model that is sustainable and profitable for many years. Genetics and improving our cattle with genetic selection is a strategy to enhance revenue, control expenses and improve the long-term success of the farm.
Today's commercial dairies are innovative, utilize technology and produce the majority of milk in the world, all while providing the high quality of cow care expected by consumers.
Why are There so Many Choices?
ICC$, PREF$, HLTH$, FYFT$, MABL$, CABL$ ... How do I know which one to use?
We now have genetic evaluations for 40-some different cow characteristics. Each one of these traits is related to another, and sometimes that relationship is antagonistic. Thus, the best way to accomplish genetic progress for all traits of interest is to combine them into an index. An index delivers the desired amount of progress for all traits.
Within the ICC$ sub-indexes, each trait is categorized according to its impact on primary management areas: milk-to-feed ratio, health care, reproduction, milking systems, and calving or maternity operations. ICC$ is the total summation of the five management sub-indexes. Selection based on ICC$ as a whole aids in genetic improvement in all areas at a balanced rate. A producer who wants to target a single management area for genetic improvement can identify high-ranking bulls for a single sub-index. Or, a producer can first select by high-ranking ICC$ and then put added pressure on the sub-index choice.
What's the Big Deal About Body Condition Score?
Producers often use body condition score (BCS) to assess the body fat or condition on certain parts of a cow, because a cow's body condition is an indicator of a balanced ration and overall transition health and reproductive efficiency. In fact, many researchers are studying BCS and have found strong correlations between BCS changes and health, production and efficiency.
Body condition scoring is especially useful assessing changes from pre to post calving. Why? Because following calving a cow goes through ha state of negative energy balance (when a cow's daily energy requirement cannot be met by the energy she consumes in a day), and she tends to lose body condition. Adequate body condition during this period of lactation is critical, as research shows transition health is strongly correlated to health throughout lactation. Furthermore, research studies done in multiple countries have concluded loss in body condition leads to lameness, as opposed to the old paradigm that a lame cow becomes skinny.
Genetic selection for optimal BCS will raise the average BCS of cows at the time of calving and the benefits will carry through the peak production period of lactation. Simply stated, a cow off to a good start has more opportunity to finish the lactation strong and healthy. Therefore, Genex is proud to offer a genetic index that incorporates BCS evaluations. The ICC$ index includes BCS as 6% of the Health (HLTH$) sub-index.
Why Does Size Matter?
Why is a bigger cow not better? What is meant by a medium-sized cow?
For more than 30 years, data has supported that a medium-sized cow has the lowest risk of being culled. A medium-sized cow is defined as:
• Fresh heifers: 1150-1250 lbs post-calving body weight and 52-56 inches tall at 21-24 months of age
• Mature cows: 1400-1600 lbs at peak milk and 56-58 inches tall
During recent years, leaders of a multi-university research project on feed efficiency have documented that larger cows are less feed efficient. Dr. Kent Weigel, Professor of Dairy Science at the University of Wisconsin; Mike VandeHaar, Professor of Dairy Nutrition and Metabolism at Michigan State University; and Mark Boggess, Director of USDA-ARS U.S. Dairy Forage Research Center, in a letter to the editor published by Progressive Dairymen, state, "USDA-ARS Animal Improvement Program, Animal Genomics and Improvement Laboratory complies extensive data for Holsteins and shows the genetic correlation between body size and milk yield to be -0.1 along with negative correlations between fat, protein and body size." Additionally, "a -0.28 genetic correlation between metabolic weight and gross efficiency indicates cows with larger body size are less efficient when it comes to feed utilization." Furthermore, "larger and larger cows are exacerbating challenges with practical dairying in many important areas: reduced reproductive fitness, increased injury and lameness, (and) wear and tear on facilities and housing."
The take-home message: ending the trend toward selection for larger size should be a priority. Once we have stabilized the genetic trend, we can design our selection indexes to be size neutral and maintain a medium-sized cow for multiple generations.
Why are the Polled Gene and Fertility Haplotypes Given Consideration?
Dehorning cattle presents financial costs to the producer in terms of labor. It is also a setback to cattle in regards to growth. ICC$ considers these costs and gives bulls with the polled gene a slight advantage over bulls without the gene.
In the Fertility and Fitness (FYFT$) sub-index, the polled condition refers to fitness. Fitness traits refer to a class of qualitative trait loci (a single gene or haplotype) that has a measurable economic value. Also among these are the fertility haplotypes. By including the haplotypes in FYFT$ and ICC$ producers have a simple and trouble-free way to manage their economic impact and their effects of days open and abortions without having to evaluation each mating.
What's With the Focus on Fertility?
DPR, CCR, HCR ... Why so many fertility measurements?
We can improve female fertility indirectly be selecting for bulls with high Productive Life or by selecting for traits such as Daughter Pregnancy Rate (DPR), which would yield a more desired genetic response. Newer traits such as Cow Conception Rate (CCR) and Heifer Conception Rate (HCR) give producers the option to specifically select for fertility improvement in their milking herd or heifer population. The Fertility and Fitness (FYFT$) sub-index accounts for 15% of the overall ICC$ index. Within FYFT$, DPR has a trait weighting 53%, HCR is 35% and CCR is 6%.
Graph 1 shows the genetic trend for both cow DPR and sire DPR by birth year. Both lines indicate a steep decline from around the 1960s all the way to the mid-2000s. At that point we were able to stabilize female fertility through DPR emphasis in genetic programs. To date we have only barely began to make up ground.
CCR and HCR became part of the U.S. Lifetime Net Merit (LNM$) and TPI® indexes in December 2014, but at the same time an increase in the overall weighting on yield traits was implemented as a reflection of the increased milk price and lower feed costs of 2013 and 2014. Because of the antagonistic relationship between yield and fertility, a producer should only expect a very slight difference in genetic progress for female fertility with LNM$ or TPI.
Also, time has shown milk price fluctuations are happening more quickly and with greater magnitude. It's important that our selection indexes are less sensitive to price cycles. By continuing to emphasize a balanced approach to genetic improvement for milk yield and fertility, the result will be an optimization of milk yield and total number of replacement animals. With more replacement, comes the opportunity to make better management decisions.
Why is it Time to Move On?
Why did Genex create ICC now? Why is now the time to change to ICC$?
Without a doubt, LNM$ has been a very successful genetic selection tool for Genex members and producers globally. The science-based and economic approach to trait weightings in LNM$ are what made it successful. While changes to LNM$ are typically mirrored in TPI in subsequent months, the primary difference between the two indexes is the greater value placed on conformation and final score, which has a different economic significance if you are merchandising seedstock cattle.
While progressive producers worldwide have found value in LNM$ and TPI, more recently they have been loud and clear in proclaiming their need for a better way to identify cattle and genetics that excel in the commercial cow environment. Their requirements were clear on two points: (1) a balanced cow that is high-producing, feed efficient, healthy, mobile and fertile, and (2) flexibility based on the individual farm's needs.
Genex responded to this grassroots feedback by developing ICC$. In its creation, Genex used the same science-based and economic principles proven to be successful and incorporated data like BCS from other countries. In addition to providing producer flexibility through sub-indexes, Genex monitors and projects genetic trends and evaluates new traits to determine when changes need to be made to ICC$. ICC$ will live up to its name. ICC$ will produce the balanced ideal commercial cows desired by producers all around the globe ... cows that lead to farm profitability, efficiency and sustainability.