Effects of different hay: concentrate ratios on body and testicular-epididymal biometry and metabolic profile of Santa Ines lambs

Abstract

This study was carried out to verify the effects of different hay: concentrate ratios on body, testicular and epididymal development and metabolic profile of hair sheep lambs. Twenty-nine Santa Ines lambs were used. Treatments consisted of diets with different hay: concentrate ratios (100:0-Control, 80:20- T1, 60:40-T2, 40:60-T3 and 20:80-T4). The characteristics evaluated were: body weight (BW), body condition score (BCS), hearth girth (HG), body length (BL), height at withers (HW), height at rump (HR), rump width (RW), chest width (CW), scrotal perimeter (SP), testis length (TL) testis width (TW), testis thickness (TT), cauda epididymal length (CEL), cauda epididymal width (CAW), cauda epididymal thickness (CET), scrotal skin thickness (SST) and testicular volume (TV). Blood samples were collected to analyze glucose, urea, albumin, total cholesterol, total proteins, inorganic phosphate and magnesium concentrations. The body and testicular-epididymal measurements increased linearly with increases in the energy concentration in the diet. BW, BL, CW, RW, HG and BCS showed positive high correlations (r = 0.71 to 0.94) with all testis-epididymal measurements. The results of the metabolic profile study showed interactions between the addition of the concentrated feed and time of blood collection on total proteins, albumin, urea, cholesterol, phosphorus and magnesium concentrations. At the beginning of the trial, hypoproteinemia and hypoalbuminemia were verified in T3 and T4. However, the indices returned to normal over time with the continuity in the diet supplied. Hypomagnesaemia was verified in all treatments. The plasmatic phosphorus concentration was sufficiently high at the end of all treatments, except control. In conclusion, the BL, HG, CW, RW as well as the BCS may be used to estimate the development of the testes and epididymis. The metabolic profile results verified that adjusts are necessary in the amount of concentrated feed given to the lambs when Tifton 85 hay (Cynodon spp) is provided to the animals.