Influence of level of dried distillers grains with solubles on feedlot performance, carcass characteristics, serum testosterone concentrations, and spermatozoa motility and concentration of growing rams1

Abstract

The objective of this study was to evaluate the effects of dried distillers grains with solubles (DDGS) on ram lamb feedlot performance, carcass characteristics, serum testosterone concentration, and semen quality. One hundred twenty ram lambs (40.4 ± 9.1 kg; Suffolk × western white face) were used in a completely randomized design to determine the effects of DDGS on feedlot performance and carcass characteristics. Rams were allotted into one of three dietary treatments (n = 4 pens/treatment; 10 rams/pen): 1) 0DDGS: 85% corn and 15% commercial market lamb pellet, 2) 15DDGS: 15% DDGS substituted for corn (DM basis), and 3) 30DDGS: 30% DDGS substituted for corn (DM basis). Rams were weighed on consecutive days at the beginning (d 0 and 1) and end (d 96 and 97 and d 116 and 117) of the trial. Scrotal circumference was measured on all rams on d 84, 96, and 116. Semen and blood samples were collected on a subset of 48 rams (4 rams/pen; 16 rams/treatment; n = 4) to evaluate semen quality. Blood samples were collected every 14 d throughout the study. Semen samples were collected on d 84, 98, and 112. Rams were fed to market weight, shipped to a commercial abattoir, and harvested for carcass data collection. Initial BW, final BW, change in scrotal circumference, days on feed, carcass characteristics, serum testosterone concentrations, and spermatozoa motility score were not different (P ≥ 0.23) due to dietary treatment. However, DMI increased linearly (P < 0.001) as DDGS increased in the ration, resulting in a linear increase (P = 0.02) in ADG. Additionally, spermatozoa concentration decreased linearly (P = 0.05) as DDGS concentration increased in the ration. Increasing DDGS in the diet did not have a negative impact on ram feedlot performance or carcass characteristics; however, spermatozoa production may have been negatively affected, necessitating the need for additional research on the impact of DDGS on ram development.

Influence of distiller’s dried grains with solubles on ram lamb growth and reproductive traits

“…Van Emon et al (2013) did not observe any effects on ram lamb final BW as DDGS increased in the diet, whereas Schauer et al (2008) observed a tendency for DDGS to increase final BW compared with lambs receiving no DDGS. Van Emon et al (2013) observed a linear increase in ADG and DMI as DDGS increased in the diets from 0% to 30%; however, a linear decrease was observed for G:F. Previous studies have also shown an improvement in lamb ADG (Schauer et al, 2008;Van Emon et al, 2013) as concentration of DDGS in the diet increased, likely due to an increase in CP and crude fat in the diet. In the current study, CP increased from 16% to 27% and crude fat increased from 6.6% to 10.6% in the diets.…”

“…Semen was collected on days 84, 112, 140, and 168 of the study via electroejaculation. Immediately post-ejaculation, volume of the ejaculate was recorded in a conical vial, followed by a 10-µL subsample of semen being placed on a glass slide, and assessed via microscope (10× magnification) for spermatozoa motility scoring (Van Emon et al, 2013). The spermatozoa motility score, which is based on the rate of forward movement, was determined on a 1 to 4 scale, as previously described by Van Emon et al 2013: 1) no forward movement or all dead (0% to 24% live sperm cells), 2) slow forward movement (25% to 49% live sperm cells), 3) moderate forward movement (50% to 74% live sperm cells), and 4) fast forward movement (≥75% live sperm cells).…”

“…Five large squares were counted for each ejaculate sample: the 4-corner squares and the middle square. If the spermatozoa cells were on the top or right borderline of these squares, they were counted; however, if the cells were on the bottom or left, they were not counted (Van Emon et al, 2013). The below formula was used to calculate the spermatozoa concentration:…”

“…b DDGS = distiller's dried grains with solubles. c Commercial lamb pellet contained 0.22 g/kg chlortetracycline, 38.0% CP, 3.75% to 4.75% Ca, 0.6% P, 3.0% to 4.0% salt, 1.2 mg/kg Se, 52,863 IU/kg vitamin A, 5,286 IU/kg vitamin D, and 209 IU/kg vitamin E. (Van Emon et al, 2013). In addition, the percent of specific morphological abnormalities of the diluted spermatozoa in a nigrosin-eosin stain was determined on a prewarmed glass slide at 40× magnification.…”

Influence of distillers grains with solubles on bull growth and reproductive traits1

“…However, distillers grains with solubles can contain relatively high concentrations of S and crude fat, and although variability in new generation ethanol refineries has been decreased, excess crude protein (CP), crude fat, and S in the diet may be a concern. Van Emon et al (2013) reported a linear decrease in spermatozoa concentration of rams as distillers dried grains with solubles (DDGS) increased in the diet (0%, 15%, and 30%; dry matter [DM] basis). Additionally, Crane et al (2018) fed increasing concentrations (0%, 15%, 30%, and 45%; DM basis) of DDGS and observed decreased scrotal circumference but increased spermatozoa concentration and morphologically normal sperm of rams.…”