Effects of Feeding System on Rumen Fermentation Parameters and Nutrient Digestibility in Holstein Steers

Abstract The purpose of this experiment was to study the effects of fattening Hu sheep diet with barley starch instead of corn starch in different proportions on the production performance, nutrient digestion, rumen fermentation parameters and rumen microbial of fattening Hu sheep. In this experiment, 72 Hu lambs (average BW:29.70 ± 1.70 kg) were selected and randomly divided into 4 treatments according to single factor block experiment. Each treatment included 18 replicates(n=18) and each sheep was raised in individual pen. Barely starch (BS) and corn starch (CS) were the starch source of the diets. Four treatments are BS-0 group(0%BS+100%CS), BS-33 group(33%BS+66%CS), BS-66 group(66%BS+33%CS), BS-100 group(100%BS+0%CS). The experiment lasted for 79 days with 7 days pre-feeding period and 63 days formal period(n=18), the last 6 days and 3 days were assigned to the digestibility(n=6) and sampled(n=10) after slaughter respectively. All dates were analyzed using the one-way ANOVE of SPSS 25.0. The results showed that the DM, OM, NDF and ADF digestibility of BS-0 group were higher than BS-100 group (P<0.05). the DM, OM and NDF digestibility of BS-66 group were higher than BS-100 group. Total VFA concentration of BS-66 and BS-100 is significantly higher than BS-33 and BS-0 (P<0.05). the propionate concentration of BS-33 is lower than BS-66 (P<0.05). The ruminal pH and NH3-N concentration of BS-33 are higher than BS-66 (P<0.05).BS-0 group has a higher ACE Chao1 and Shannon index than BS-100. At the phylum level, the abundance of Firmicutes increased and the abundance of Proteobacteria decreased in BS-100(P<0.05). At the genus level, the abundance of Ruminobacter in BS-100 is higher than other groups (P<0.05). These results indicated that the feeding efficiency of corn starch has positive affect than barley starch. 66% barley starch substitutes corn starch can improve nutrient digestibility and be good for rumen health.

Download Full-text

Effects of slow-release urea on in vitro rumen fermentation parameters, growth performance, nutrient digestibility and serum metabolites of beef cattle

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n4p1349 ◽

2020 ◽

Vol 41 (4) ◽

pp. 1399

Author(s):

Huan Liang ◽

Erlong Zhao ◽

Chunyan Feng ◽

Jianfei Wang ◽

Lanjiao Xu ◽

...

Keyword(s):

Beef Cattle ◽

Soybean Meal ◽

Dry Matter ◽

Slow Release ◽

Rumen Fermentation ◽

Nutrient Digestibility ◽

Serum Metabolites ◽

Fermentation Parameters ◽

Slow Release Urea

Two experiments were conducted to investigate the effects of slow-release urea (SRU) on in vitro rumen fermentation parameters, growth performances, nutrient digestibility, and serum metabolites of beef cattle. The single factor design was applied in both experiments. Three diets with different nitrogen sources including soybean meal (Control group), slow-release urea (SRU group), and common urea (Urea group) was designed (concentrate to forage ratio was 4:6). The diets were formulated to be isoenergetic and isonitrogenous, 75% of the soybean meal in the control diet was replaced by 1.41% SRU and 1.15% urea in SRU group and Urea group, respectively. In experiment 1, five healthy Jinjiang cattle (average body weight (BW) was 380 ± 17.1 kg) with permanent rumen fistulas were used in in vitro ruminal fermentation experiment. The results showed that supplementing SRU increased the dry matter degradation rate (DMD), digestible organic matter (DOM) and propionic acid concentration in cultivated fluid, and SRU supplementation decreased pH, NH3-N, total volatile fatty acid (TVFA), acetic acid, butyric acid concentration and microbial growth efficiency (MOEFF) in cultivated fluid. In experiment 2, eighteen Simmental crossbred cattle BW= 315 ± 5.2 kg) were stratified by BW and then assigned to the three groups to have equal BW among groups. The results showed that supplementing SRU reduced the average dry matter intake (ADMI), apparent digestibility of ether extract (EE), the activity of glutathione peroxidase (GSH-Px), the levels of IgG and IgA, and the production of thiiodothronine (T3) in serum, SRU supplementation increased the apparent digestibility of dry matter and organic matter (OM) and alanine aminotransferase (ALT) concentration in serum. These results indicated that some soybean meal could be replaced by SRU and urea in the production of beef cattle. In addition, compared with urea, SRU had a good sustained-release effect. The replacement of some soybean meal by SRU in the diet had no adverse impact on rumen fermentation, growth performance, and serum metabolites of beef cattle.

Download Full-text