Effect of Rye Grain Derived from Different Cultivars or Maize Grain Use in the Diet on Ruminal Fermentation Parameters and Nutrient Digestibility in Sheep

Abstract

Six wether sheep with ruminal and duodenal cannulas were used in a replicated 3 × 3 Latin square to determine the effect of rye grain (from an open-pollinated or a hybrid cultivar) and maize grain from hybrid cultivar inclusion in the diet on ruminal fermentation parameters and nutrient digestion in different gastrointestinal tract compartments. The experimental diets consisted of meadow hay (800 g/day) and a concentrate mixture (300 g/day) that contained rye grain from an open-pollinated cultivar (OPRG), rye grain from a hybrid cultivar (HRG), or maize grain from a hybrid cultivar (MG) as a main energy source. Each experimental period lasted 17 days and consisted of 10 days for diet adaptation and 7 days for data and sample collection. Ruminal fermentation (pH, short-chain fatty acids, and ammonia concentration) and nutrient digestion up to the duodenum (in reticulorumen, omasum, and abomasum), in the intestine, as well as in the total digestive tract was investigated. Mean ruminal pH was higher for MG compared to HRG and OPRG (P<0.01) but did not differ between HRG and OPRG (6.45, 6.35, and 6.29 for MG, HRG, and OPRG, respectively). Treatment did not affect short-chain fatty acid concentration in the rumen, except for the molar proportions of valeric acid and of isovaleric acid of the total short-chain fatty acids, which was or tended to be higher (P≤0.06) for MG compared to HRG and OPRG. Less starch was digested in the gastrointestinal tract up to the duodenum and more in the intestine for MG compared to HRG and OPRG (P=0.01); however, total tract nutrient digestibility did not differ between treatments. In conclusion, usage of rye grain in sheep diets resulted in a lower ruminal pH compared to maize grain usage. No differences for ruminal fermentation, nutrient digestion up to the duodenum, in the intestine, as well as in the total digestive tract between rye grain from open-pollinated and hybrid cultivar usage in sheep diets were found.

Evaluation of Ruminal Dry Matter Disappearance and pH of Dry Corn, High-Moisture Corn, and Rye under <i>in Vitro</i> Conditions

“…Consequently, it is not surprising that RYE had reduced final pH compared to the two corn treatments and that the final pH for HMC was less compared to DRC given the increased IVDMD differences observed in the current experiment. These pH differences agree with those previously observed comparing rye to dry corn [8] and between HMC and DRC [10].…”

“…The increased IVDMD for rye grain agrees with other observations where rye grain was more rapidly available in the rumen compared to barley [6] or corn [7]. Differences in degradability between feed grains are related to the molecular structure of the protein matrix surrounding starch granules [6] [7] [8]. Another potential explanation for the increased IVDMD for rye grain is greater concentrations of alkylresorcinols in rye compared to other grain species, which could modify enzyme activity [6] [9].…”

Increased intake of mono‐ and disaccharides by Reeves's muntjac (Muntiacus reevesi). Effect on gastrointestinal tract structure and function and blood parameters

“…using a dedicated sets of regents (Biosystems S.A. and Diagnostic Systems GmbH). The SCFA and ammonia concentrations as well as the carbohydrate‐digesting enzyme activity in digesta were determined as described elsewhere (Miltko et al, 2016; Rajtar et al, 2020).…”

Breeding cereal rye (Secale cereale) for quality traits

“…Over 20 rye varieties were assessed for amino acid digestibility in hens, as measured by fecal matter, and the authors found that amino acid digestibility substantially varied (34%–71%) across varieties for lysine, methionine, threonine, and tryptophan (Zuber et al., 2016). Other workers have compared different rye hybrids or OPVs for differences in apparent ileal digestibility in pigs (McGhee & Stein, 2020), and ruminal fermentation in sheep (Rajtar et al., 2021), among other studies. Overall, it is clear that variation exists for important feed quality traits, and such traits could be targeted by rye breeders.…”