The most profitable age for first calving is between twetjty-'fpur> and twenty-six months. Heifers that calve later produce slightly more milk during their first lacta tion. However, increased costs of raising late-calving heifers, the delay in recovering investment costs, and reduced production per day of herdlife outweigh the slight increase in milk yield. If heifers are managed well, they are large enough to breed at fifteen months and calve at twenty-four months of age. A heifer reaches puberty when normal sexual behavior is exhi bited and ovulation occurs. Onset of puberty is more closely related to body weight than to age. Heif ers reach puberty when body weight is 30% to 40% that of aver age adult weight. Occasionally, the first few estrous cycles occur without behavior signs of heat. These are called silent heats. On the other hand, some of the first standing heats are followed by anovulation (no ovulation). Frequency of silent heat and anovulation decreases as heifers experience more cycles. For these reasons and because they are not yet lirgc enough, heifers should not be toed when they first reach puberty. If growth is slowed down by underfeeding, disease, or para sites puberty is delayed. With regard to nutrition, low dietary energy levels can lead to ovarian inactivity. Inadequate protein intake and nutritional problems leading to anemia can cause silent or irregu lar heats. Deficiencies of pho sphorus, vitamin A and E may also affect reproduction. Heifers approaching breeding age should be watched closely for heat to insure that they are cycling. A vet erinarian can examine heifers to PAUL B. ZI BLOCKING CHUTE • For safe and easy grooming, washing and clipping cattle • Expanded metal floor stays cleaner and gives more traction • Assembles and disassembles quick and easy • Can easily be moved and loaded by one person PAUL B. ZIMMERMAN, MC. Call or Writ* For Additional Information And Your Noarost Doalor Dairy Heifer Reproductive Management . Seminar determine which ones are cycling and also determine if there are any congenital reproductive abnormalities. There are numerous advantages to artificial insemination and dairymen should consider breed ing their heifers to the bctlei AI bulls. The most important advan tage is the improved genetic merit of the calves sired by AI bulls. Daughters of AI sires have at least 900 pound milk production advan tage over daughters of non-AI sires. A successful AI program involves routine heat detection and timely insemination. Although the average interval between heats for heifers is twenty days there is a normal range of eighteen to twenty-four days. Because considerable variation exists between animals, dairy far mers should record all heat dates on a chart so that they can antici pate future heats. To monitor heats accurately, heifers must be clearly identified with neck chains, large ear tags, or freeze brands. Heifers should be checked for heat twice a day. If heat detection is routine and frequent, heifers should be inseminated twelve hours after the beginning of stand ing heat. When the onset of heat cannot be accurately determined, heifers should be bred soon after standing heat is noticed. Dairy men who cannot^routinely check for heat should consider using heat synchronization and a con centrated AI breeding program for selected months during the year. Heat detection aids, such as heat mount detectors, crayon or chalk markings, surgically altered bulls or androgenized heifers equipped with chin-ball markers, can make heat detection easier and more efficient. When selecting AI sires to breed heifers, primary emphasis should be placed on production merit. From among these bulls, the choice should be further nar rowed to those bulls with the least expected calving difficulty. Thirty-five to fifty days after inse mination heifers should be exa- 295 Woodcorner Rd. Lltitz. PA 17543 IMilaWoatofEphrata Phone:7l7-735-1121 Franklin County Extension The 1989 Executive Committee of the Franklin County (PA) Cooperative Extension Association was selected at the recent Board of Director’s reorganizational meeting In Chambersburg. They are (seated, I. to r.): Michael John of Waynesboro - President; Philip Lobaugh of Chambersburg • vice President; (standing left to right): Dana Mey ers of Chambersburg - secretary; Joel Rotz of Chambersburg - director; and Mark Cayman of Waynesboro - director. John Hart serves as treasurer. The executive committee, along with the Board of Directors, is responsible for funding and direct ing the Penn State Cooperative Extension educational programs for Franklin County. KEY-AID DISTRIBUTORS INC 225 Wood Comer Road, Lititi, PA 17543 Call Toll Free: In PA 1-800-2KEYAID (1-800-253-9243) Elsewhere 1-800-4KEYAID (1 -800-453-9243) Local calls 738-4241 Hours: Mon - Thur 7:30 A.M.-5:00 P.M. Fri 7:30 - 9:00 Saturday 7:30 A.M.-12:00 Noon (Eastern Time) mined for pregnancy. Accurate breeding records are important for predicting calving dates. Heifers close to calving should be observed frequently. They should be moved to the calv ing area several clays to a week before the anticipated calving date. The best calving area is a level, LOCK IN PROTECTION mma against WITH PILIGUARD PINKEYE - 1 A Quality Schering Animal Health Product VACCINE 1 SHOT EQUALS SEASON LONG V PROTECTION 644 or less per dose Available In 10 or 50 dose vials 10 dose vial @ $6.40 / 12 or more $5.60 50 dose vial @ $29.25 / 12 or more $27.00 ORDERS OVER $30.00 YOU PAY NO FREIGHT WE SHIP UPS EVERYDAY uncasnr farming, snuraay, narcn n, dmimuj dry, easily accessible grassy pas ture. A good alternative is a large, dry, well bedded maternity pen. Maternity pens should be kept clean and reserved solely for calv ing. Selecting sires for calving ease, raising heifers to adequate size and using proper calving management practices will minimize calving problems. PINK-EYE In Cattle
Significant historical Pennsylvania newspapers