Ruminal protein degradability of sunflower cake, and effects of feeding sunflower cake on nutrient digestion, nitrogen balance, rumen fermentation, and blood metabolites compared with soybean meal

Abstract

The ruminal degradation parameters of sunflower cake (SFC), a by-product left after the mechanical extraction of oil from sunflower seeds, were estimated in an in situ experiment using a cow. And also the effect of feeding SFC on nutrient digestibilities, digestible energy, nitrogen balance, and ruminal and blood properties were investigated in a feeding trial using four Shiba goats compared isonitrogenously with soybean meal (SBM). The in situ results demonstrated that the SFC had high soluble protein (>70%) with 97% total degradable protein. The feeding trial revealed that the SFC had 85% crude protein digestibility and 65% total digestible nutrients on a dry matter basis in which the low carbohydrate digestibilities offset the advantage of high digestible fat (9.9%). The nitrogen efficiency (retained N/intake N) was lower for SFC than SBM, probably because of an inferior biological value of amino acids in SFC. Among the ruminal and blood properties, only the total ruminal acid concentration and blood urea nitrogen (BUN) differed significantly between the diets: The SFC diet showed lower values than the SBM diet. These findings indicate that SFC can safely replace SBM.

Sunflower cake versus soybean meal and alfalfa for nitrogen utilization when crude protein and non‐fiber carbohydrate levels are equivalent

“…These differences were derived from the differences in the analyzed values between the feeds used in advance for setting the levels and those collected during the trials. The SFC used in this study was higher in CP (32%) compared to the two SFCs in our earlier study (26% and 28%;Liu et al, 2022), and remained ether extract (EE) in the present study (12%) was midrange between the values in the earlier study (11% and 20%). Among the essential AA, Lys one of the most limiting AA, was the highest in number in the SBM diet and the lowest in the SFC diet, whereas Met, another limiting AA, was the highest in the SFC diet and the lowest in the SBM diet.…”

“…The reported Lys and Met contents of rumen microbes including bacteria and protozoa are 8.1% and 2.3% of total AA, respectively (Sok et al, 2017), which are nearly an ideal profile for both growth and lactation. The content of NFC, which is the main energy source for microbial synthesis, was 18% lower for the diet containing SFC than that containing SBM in our earlier study (Liu et al, 2022), whereas the NFC content in the present study was almost equivalent among the diets (although $8% higher for the SFC diet than the SBM diet), and the TDN contents did not differ significantly among the diets.…”

“…Our previous study (Liu et al, 2022) demonstrated lower N usage with a diet containing SFC compared to a diet with SBM, and as an explanation, we speculate that the biological value or amino acid (AA) composition of SFC is inferior to that of SBM for the formation of animal proteins. The reported Lys and Met contents are 6.4% and 2.0% of protein in animal tissues, and 7.6% and 2.7% in milk, respectively (O'Connor et al, 1993).…”

“…Sunflower cake (SFC), which is left after a mechanical extraction of oil from sunflower seed, become more popular with the development of organic farming and on‐farm oil production because chemically synthesized solvents are banned to be used for any feed materials used or processed in organic production in the European Union (EU, 2007). However, we have observed that compared to soybean meal (SBM), SFC showed lower nitrogen (N) utilization, probably due to amino acids' inferior biological values and/or a reduced ruminal synthesis of microbial crude protein (MCP) due to the lower non‐fiber carbohydrate (NFC) in SFC (Liu et al, 2022). We conducted the present study using Holstein cows to determine whether the N retention could be identical for SFC‐ and SBM‐based diets when the crude protein (CP) and NFC levels are nearly equivalent.…”

Antioxidant Capacity, Inflammatory Response, Carcass Characteristics and Meat Quality of Hu Sheep in Response to Dietary Soluble Protein Levels with Decreased Crude Protein Content

“…The antioxidant capacity of the digestive tract appeared to be the primary factor affecting meat quality in our results, and it was also correlated with SFA and n-6 PUFA. Rumen, duodenum, jejunum, and ileum are crucial for nutrient absorption and transport in ruminants, and the decreased antioxidant capacity in these organs may be linked to an imbalance in nutrient supply, such as the failure of simultaneous energy and N release in the rumen [43]. Therefore, our results highlight the importance of maintaining appropriate protein solubility in the diet for the body's antioxidant capacity and meat quality, offering a reference for the lower threshold of dietary SP levels.…”