SQuim \% W Grazing Gazette penn: College of Agricultural Sciences m cooperation with USOA/ARS MONITORING BODY CONDITION IS IMPORTANT TO GRAZIERS Mike O’ Connor and Larry Muller Penn State Consistently maintaining high dry matter intake for cows on pas ture is a major challenge to gra ziers. Not only does low or vari able dry matter intake affect milk yield, but it will result in weight loss, especially in early lactation. Research studies have uniform- Item No. Cows Days to Ist ovulation Days to Ist heat DMI, Ib/day 4% milk yield, Ib/day BW change. Ib/day Energey balance, Mcal/day ly shown that cows that foil to consume levels of dry matter after calving lose more weight and body condition, produce less milk and the onset of estrous cycles is significantly delayed. As an example, the table documents the relationship between energy sta tus, body weight loss, dry matter Engineered For Life On The Faim. I ~~ ' ' Choose from a wide range of standard or custom Lester wood frame agricultural buildings. Each features value engineered Uni-Frame® construction. Top quality materials. The industry's leading warranty. LESTER intake, and milk yield with the onset of estrous cycles. Cows were classified into three groups based upon the interval to first ovulation: (1) before 40 days. (2) between 40-60 days, and (3) no evidence of ovulation by 63 days. The cows that had not cycled by 63 days postpartum consumed less dry matter per day, produced less milk during the first nine weeks, and a larger percentage of the milk that was produced came from body reserves compared to cows that cycled early. Previously, most Onset of Estrous Cycles Early Late 25 14 22 43 47 73 41 39 74 70 -1.8 -1.8 ■4.4 -4.1 people believed that high milk yield was the major factor causing anestrus (failure to cycle). How ever, in this study, energy balance was the major factor. Average energy balance during the first nine weeks was lower for the anestrous cows (-5.6 Meal/ cow/day) compared to groups 1 | $ 5 > > *«»»«» W«*| Very Late 15 110 33 63 -2.7 -5.6 Stop By And See Us At AG PROGRESS DAYS and 2, respectively (-4.4 and -4.1 Mcal/cow/day). It was concluded that the more negative energy balance was attributed to the nega- - live energy balance during the first three weeks postpartum. Body weight loss during the first two weeks of lactation was also related to onset of ovarian activity. Cows ovulating earlier lost less body weight than cattle that ovu lated later. Although this information was obtained from research conducted in a conventially fed herd with no pasture, the concepts apply to pas tured herds as well. It is much easier to monitor dry matter intake in a convential fed herd. In addi tion to monitoring milk yield on a tegular basis, graziers should take time to score and record body con dition throughout the year but especially during the pasture season. Cattle should be evaluated for body condition at calving, 30 and 60 days into lactation, during mid lactation and at the end of lacta tion. It is important to record the actual score for each cow at each time period and calculate the aver age change in condition between each period during lactation. Dur ing early lactation cows will gen erally lost one-half a condition score. A change greater than one half a point but less than one point mi the 1 to 5 scale from calving to 30 days may be a sign of inadequ ate dry matter or energy intake or a ration imbalance. An average loss greater than one point is more serious and the onset of estrous cycles and conception rate will likely be adversely affected. If the average loss is in excess of one condition score, then several cows must have lost severe weight. Most of the current information a's4\ % And the support of the nation's leading building company. Reap the benefits of quality, affordable storage. Call your local Lester dealer or 1 -800-826-4439 today. on W. sth St. tu>!i been obtained from research and field studies with nongrazing In general, high producing cows in our various grazing stu dies at Penn State have been lower in body condition score than cows in confinement, and have tended to less condition during the grazing season. These trends existed even when grain has been fed with grain to milk ratios of 1 to 4 and 1 to 3. We often hear and see lower than desired body condition in high producing cows on pasture. This situation indicates an inadequate energy intake and a loss of body reserves to support the high level of milk production. Several factors are likely related to the less than adequate body condition. 1. Inadequate pasture DMI and/ or low quality pasture. 2. Extra energy needed for maintenance. Cows that are graz ing expend more energy to graze than cows in confinement This requirement is greater depending on the distances cows walk to and from pasture, the available pasture ' (cows walk more with sparse pas tures). and heat stress. Cows may required from 2 to 4 lb of comme al (grain) per day just to meet the energy needs of activity. This maintenance energy can be viewed as a “fixed cost” that must be met before energy is used for milk production. 3. Inadequate supplemental energy to complement the energy intake from pasture. Although the degree of change in body condition is most impor tant, we should set targets for body condition scores at specified periods. Cows should calve with a score 3+ to 4-. It is important to attain this condition score by the end of the previous lactation an<f maintain period. If body condition loss and low body condition is die prob lem, then consider the following; 1. Routinely monitor body coni dition, record the scores, and make necessary adjustments. 2. Keep the “feed bunk” bull, or in grazing terms, provide adequate available pasture that is high in quality. The major reason to move to a pasture-based system is to utilize as much high quality, low cost pasture as possible. A grazing management system that can max imize DMI and energy intake is the key to the success or failure of a pasture-based system. 3. Provide adequate supplemen tal energy, particularly to the early lactation cows. This additional energy meets the activity require ment and the energy for milk pro duction and minimizes condition loss. Cows fed only high quality pasture obtain enough energy to produce about 40-45 pounds of milk. In order to obtain milk pro duction close to the genetic poten dal of the cows, grain is needed at a grain to milk ratio of 1:3 to 1:4 for early lactation cows. Consider added fet, similar to what we do with nongrazed herds. Com silage is an excellent supplemental for age to provide energy and to com pliment the nutrients in pasture. Producers who feed the grain and forage as a TMR can likely expect better utilization of energy and body condition status. 4. During the summer heat stress and pasture slump, consider less grazing to reduce the energy needed for activity and mainte nance. Numerous producers have success in the milk pail and with body flesh by just grazing during the cooler evenings, and keep cows in the bam durine the day. (Turn to Pago ElO) Contact The Lester Dealer Nearest You Today For A Quote Or More Information »ENNSYLVANIA Winterford Annville ROBERT R. H.R. WEAVER SMITH BUILDING , & SONS SYSTEMS (814) 825-5828 (717) 838-3753 (800)287-3753 MARYLAND Street, MD GOMPF Downingtown CONST M&S BUILDING C O.. INC. SYSTEMS, INC. (410) 692-5350 (610) 524-4221 Manheim CRAFT-BILT BROTHERS, CONSTRUCTION INC. (717) 653-4023 (41Q) 756-4457 Nazareth MEW JERSEY NAZARETH Mt. Holly, NJ BUILDING MATTSON SYSTEMS, ENTERPRISES, INC. INC. (800) 322-9605 (609) 261-3600 (610) 837-7700 ESTER* Taneytown, MD RASCHE
Significant historical Pennsylvania newspapers