Abstract
The effects of rations (fed at 1% of BW) containing highly degradable intake protein (DIP) vs rations with fishmeal (FM), a more undegradable intake protein (UIP), were studied. Thirty-nine Brahman bulls (301.7d; 202.7kg) were allotted to one of two treatments. The sources of protein were soybean meal (SBM) in Control (C) and fish meal in the FIS treatment. Bulls assigned to the FIS treatment had higher (p<0.01) total weight gain (81.2[plus or minus]1.4 vs 71.2[plus or minus]2.2kg), higher (p<0.01) ADG (0.97[plus or minus]0.02] vs 0.85[plus or minus]0.03kg), and better (p<0.05) feed efficiency (7.6:1 and 8.6:1 feed consumed : BW gain) than C bulls. Age did not differ between treatments at first motile spermatozoa, but FIS were heavier (p<0.02) than C bulls (338.6[plus or minus]12.0 vs 304[plus or minus]10.0kg, respectively). Age and weight at puberty did not differ between treatments. There were no differences in testis growth, luteinizing hormone or testosterone concentrations between treatments. Testicular and epididymal traits were analyzed for one testicle. Parenchyma and testicular weights were not affected by treatment. Daily sperm production (DSP) and daily sperm production/g of parenchyma (DSPG) did not differ (p>0.05) between treatments. The FIS-fed bulls had heavier (p<0.05) epididymis than C but similar (p>0.05) epididymal sperm reserves. Sire and diet had significant (p<0.05) affects on the distribution of epididymal sperm reserves. Thirty-six Brahman heifers (332[plus or minus]4d; 201[plus or minus]4kg) were allotted to three treatments: Coastal bermudagrass hay plus 0.45kg of corn:0.45kg of GM/head/day (HAY), rye-ryegrass pasture overseeded on a Coastal bermudagrass sod (PAS) and the same pasture plus 0.45kg of corn:45kg FM/head/day (FIS). After a 116-d period FIS and PAS-fed heifers had similar (p>0.05) BW (317[plus or minus]6 vs 306[plus or minus]7kg, respectively), but were heavier (p<0.05) ADG (1.0[plus or minus]0.06kg) than heifers on PAS (0.9[plus or minus]0.02kg) and HAY-fed heifers the lowest (0.47[plus or minus]0.02kg). Treatment did not affect (p>0.05) ovarian follicular population or volume...
Rocha, Antonio M. (1993). Effects of ruminally undegradable intake protein on growth and peripuberal reproductive and metabolic parameters in male and female Brahman cattle. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1530770.