Feed compositions for animal health
Provided herein, inter alia, are compositions comprising oxygen tolerant strains of Megasphaera elsdenii and methods of making and using the same to promote improvement of one or more metrics in an animal, such as increased bodyweight/carcass gain, increased feed intake, decreased feed conversion ratio (FCR), decreased medical costs, decreased transition period, decrease use of antibiotics, and reduced mortality.
1 . A feed additive composition comprising a direct fed microbial (DFM) comprising at least one biologically pure strain of an oxygen tolerant Megasphaera elsdenii ( M. elsdenii ), wherein the oxygen tolerant M. elsdenii comprises at least one mutation (a) in a gene encoding a transcriptional regulator PerR comprising SEQ ID NO: 4; or (b) immediately upstream of a gene encoding the transcriptional regulator PerR.
2 . The feed additive composition of claim 1 , wherein the at least one mutation is (a) a nucleotide substitution resulting in an amino acid change in a transcriptional regulator PerR protein; and/or (b) an insertion of a nucleotide resulting in a frameshift mutation.
3 . The feed additive composition of claim 2 , wherein the nucleotide substitution is at a nucleotide position selected from the group consisting of 386, 155, 253, −99, and −125 corresponding to a gene encoded by the polynucleotide sequence of SEQ ID NO: 4.
4 . The feed additive composition of claim 3 , wherein the nucleotide substitution comprises G386T, C155T, C253T, T-99C, or G-125A.
5 . The feed additive composition of claim 4 , wherein the amino acid change comprises C129F, T52M, or H85Y relative to the polypeptide encoded by SEQ ID NO: 5.
6 . The feed additive composition of claim 5 , wherein the PerR protein comprises the polypeptide encoded by SEQ ID NO: 6.
7 . The feed additive composition of claim 2 , wherein the nucleotide insertion is at a nucleotide position selected from the group consisting of 30, 277, and 64 corresponding to SEQ ID NO: 4.
8 . The feed additive composition of claim 7 , wherein the insertion is an A at position 30, an A at position 277, or a G at position 64.
9 . The feed additive composition of claim 1 , comprising one or more of (a) an M. elsdenii strain having a 16S ribosomal RNA sequence displaying at least 97.0% sequence similarity to a 16S ribosomal DNA sequence of an M. elsdenii strain ACD1265 deposited at Westerdijk Fungal Biodiversity Institute (WFDI) under number CBS 146328; (b) an M. elsdenii strain having a 16S ribosomal RNA sequence displaying at least 97.0% sequence similarity to a 16S ribosomal DNA sequence of an M. elsdenii strain ACD1141 deposited at WFDI under number CBS 146325; (c) an M. elsdenii strain having a 16S ribosomal RNA sequence displaying at least 97.0% sequence similarity to a 16S ribosomal DNA sequence of an M. elsdenii strain ACD1141E deposited at WFDI under number CBS 146326; (d) an M. elsdenii strain having a 16S ribosomal RNA sequence displaying at least 97.0% sequence similarity to a 16S ribosomal DNA sequence of an M. elsdenii strain ACD1141F deposited at WFDI under number CBS 146327; (e) an M. elsdenii strain having a 16S ribosomal RNA sequence displaying at least 97.0% sequence similarity to a 16S ribosomal DNA sequence of an M. elsdenii strain ACD1265E deposited at WFDI under number CBS 146329; and/or (f) an M. elsdenii strain having a 16S ribosomal RNA sequence displaying at least 97.0% sequence similarity to a 16S ribosomal DNA sequence of an M. elsdenii strain ACD1265F deposited at WFDI under number CBS 146330.
10 . The feed additive composition of claim 1 , wherein the oxygen tolerant M. elsdenii remains viable after at least about 7-12 days of exposure to oxygen.
11 . The feed additive composition of claim 10 , wherein at least about 5.73×10 2 to about 1.16×10 8 cfu/mL of the M. elsdenii remains viable after 7-12 days of exposure to oxygen.
12 . The feed additive composition of claim 1 , wherein the oxygen tolerant M. elsdenii remains viable after at least 10 days after exposure to oxygen.
13 . The feed additive composition of claim 1 , further comprising at least one yeast strain and/or yeast extract.
14 . A method for treating, preventing, or decreasing incidence of rumen acidosis in a ruminant animal comprising administering an effective amount of the feed additive composition of claim 1 to the animal, thereby treating, preventing, or decreasing incidence of rumen acidosis in the animal.
15 . The method of claim 14 , wherein said administration raises or maintains the pH of the rumen of the animal above pH 5.6.
16 . The method of claim 14 , wherein the ruminant animal is a cow, goat, sheep, buffalo, deer or other member of the Ruminantia suborder of mammals.
17 . The method of claim 16 , wherein the ruminant animal is a dairy cow or a beef cow.