NIPPLE FEEDING OF SUPPLEMENTAL PROTEIN TO CALVES

Abstract

Forty-eight Holstein bull calves initially averaging 90 kg were used in a 2 × 2 factorial design to compare two levels and two methods of feeding supplemental protein. The basal ration, which was fed free choice, consisted of shelled corn, minerals, vitamins and urea and provided 10.5% CP on a DM basis. Supplemental protein as 50% CP soyaflour was fed at levels of 228 g (H) and 126 g (L) per day. The soyaflour was fed either with the basal ration (C) or twice per day (in equal amounts) from a nipple bottle (N) after being mixed with approximately 2 liters of lukewarm water. Calves were housed in individual pens with wire mesh floors and fed for 70 days. The soyaflour slurry was vigorously consumed by calves. No significant differences (P <.05) occurred in any of the performance parameters. However, a trend toward reduced weight gains and DM intake was observed among calves fed treatment LN. A nitrogen metabolism trial was conducted concurrently utilizing the same calves. Calves fed the high level of protein retained more (P <.05) nitrogen and excreted more (P <.05) urine urea nitrogen than calves fed the low level of protein. Increases in levels of plasma urea nitrogen following feeding were greater (P <.05) and occurred later (P <.05) in nipple-fed compared to conventionally fed calves. A subsequent trial was conducted with 10 calves to determine extent of closure of the reticular groove. Post-feeding levels of both blood glucose and rumen strontium indicated a high degree of groove closure with bottle feeding.