Date: February 28, 2003
BODY SIZE VS. REPRODUCTION
Brazilian researchers used Nelore (a pure Bos indicus breed prevalent in Brazil) in a selection study. Three lines were established: control (C); closed select (SC); and select open to outside sires (SO). Breeding stock in the two select lines were selected for increased 550-day-old weight. After 16 years, C females had decreased 4 lb and 0.25 in, SC females increased 67 lb and 1.6 in, and SO increased 84 lb and 1.5 in. There were no significant differences among lines in body condition score at start of breeding, date of calving, or calving rate.
CHOOSING VACCINE NEEDLES
There are three primary factors that determine the right vaccination needle: route of administration; body weight; and viscosity of the injected solution. Subcutaneous administration calls for a ½ to 1 inch needle, intramuscular 1 to 1 ½, and intravenous 1 ½. For thin liquids, such as saline solution, cattle less than 300 lb need 18 gauge (SQ), 18-20 (IM), and 16-18 (IV). From 300 lb to 700 lb the sizes are 16-18, 16-18, and 16. For over 700 lb the sizes are 16, 16-18, and 14-16. For thicker materials, such as oxytetracycline, the gauge of the needle should be slightly larger (numerically smaller). The smallest size that can be used without bending is usually best.
WINTER PASTURE FOR COW SUPPLEMENTATION
Arkansas workers studied British-Continental crossbred cows for three years in three groups. One group was fed 3 lb (first year) or 6 lb (second and third years) 3 times a week of a 20% crude protein supplement. The other two groups were grazed on winter pasture for 7 hours/day at 10 cows /acre, one group for 2 days/week and the other for 3 days/week. All groups were on dormant bemudagrass pasture and ad lib grass hay. The studies began in early January and ended in late April to early May. Winter pasture was a mix of wheat, rye, and annual ryegrass. Limit-grazed cows had lower body condition the first year but higher the next two years. There was no significant difference among the three groups in conception rate or calf birth weight and gain.
WHAT HAY FEEDER IS BEST?
Michigan researchers studied four types of hay feeders: (1) cone, 8 ft diameter and 4 ft high; (2) ring, 8 ft diameter and 6 ft high; (3) trailer, 7 ft X 20 ft and; (4) cradle, 6 ft X 12 ft with a built-in trough under the rack on both sides . All feeders provided about 15 linear inch/cow. The amount and nutrient content of hay actually consumed per cow was very similar, except the amount was slightly higher for the trailer. However, hay wasted was: cone, 3.5 %; ring, 6.1 %; trailer, 11.4 %; cradle, 14.6 %. Also, for the cradle, cows entered the feeder more frequently and there were about three times more agnostic interactions (I think that means fights).
MODIFIED-LIVE VACCINE FOR PREGNANT COWS
Pfizer is marketing Bova-Shield FP TM 4 + VL5 , a modified-live vaccine for IBR, BVD, PI3, and BRSV, plus Camphylobacter and Lepto, that is safe for pregnant females.
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