Must one eat meat by one’s Purim meal?
Some Poskim rule it is an obligation for one to eat [animal] meat during the Purim meal. Other Poskim however rule it is not an obligation to eat meat. This is further proven by the fact this law has not been cited by the Tur or Shulchan Aruch. [Regarding the opinion of Admur see footnote] In any event, even if it is not an obligation to have meat on Purim, it is certainly a “Biblical” Mitzvah to do so. [Thus, everyone should endeavor to have a meat meal for his Purim Seudah.]
Is one to eat specifically animal meat on Purim, or does poultry also suffice?
The Mitzvah is to eat specifically animal meat. One does not fulfill the Mitzvah of meat through eating poultry. However, some Poskim are lenient in this matter. If one cannot afford animal meat, then at the very least he should eat poultry.
May a woman eat meat on Purim day if that coming night is her night of Tevila?
Yes. It is a Mitzvah for her to eat meat on Purim. However, in such a case she is to make sure to be extra careful in flossing and brushing her teeth before immersion.
 Rambam Hilchos Megillah 2:15 brought in Kaf Hachaim 695:6; Mor Uketzia 695; Beis Yaakov 73; Kaneh Bosem 1:102; Nimukei Orach Chaim 695:2 discusses this question and leaves the matter in doubt. He says that since Purim is a day of Simcha, and Simcha is fulfilled only with meat [see 529:7], therefore one should be obligated to eat meat on Purim.
Ruling of Michaber: The Michaber 695:4 rules that the Mishloach Manos is to include meat, hence implying that one is to eat meat during the meal. Likewise, in 696:7 the Michaber rules that an Onen may eat meat and wine on Purim as it is a Biblical command to rejoice on Purim, hence implying that one is to eat meat on Purim. This matter of eating meat however is omitted from his ruling in 695:1-2 regarding the meal customs. [See Toras Menachem 1991 2:294; Shulchan Menachem 3:321]
 As opposed to fowl. [See Nimukeiy Orach Chaim ibid]; See Q&A!
 M”A 696:15
 Igros Kodesh 5:256 [printed in Sefer Haminhagim p. 172 [English], Shulchan Menachem 3:320, Shaareiy Halacha Uminhag 2:291]; See Nimukei Orach Chaim 695:2
A Biblical Mitzvah despite not being an obligation: To note that although this law has not been cited in chapter 695:1-2, in chapter 696:7 the Michaber rules that an Onen may eat meat and wine on Purim as it is a Biblical command to rejoice on Purim, hence implying that one is to eat meat on Purim. At the very least one can learn from here that if one does eat meat on Purim, he is fulfilling a Mitzvah of rejoicing on Purim, irrelevant if it is an obligation or not.
 The Nemukei Orach Chaim ibid states that the above dispute in the obligation to eat meat on Purim is dependent on whether one is obligated to eat meat on Yom Tov. Hence, since the M”A holds one is exempt from eating meat on Yom Tov he also holds one is exempt on Purim. Accordingly, the opinion of Admur would be like the M”A that there is no obligation to eat meat on Purim, as Admur rules in 529:7 that there is no obligation of Simcha to eat meat on Yom Tov and it is merely a Mitzvah to do so. On the other hand, in 242:1 Kuntrus Acharon 2 Admur rules that eating meat and wine on Yom Tov is a Biblical command of Simcha. Vetzaruch Iyun! Perhaps however one can say that both rulings hold true without contradiction, as although one only fulfills his obligation of Simcha by drinking wine, as writes Admur in 529:7, nevertheless when he eats meat and other delicacies, he also fulfills the Biblical Mitzvah of Simcha, as he is merely increasing in the Mitzvah. In other words, the Mitzvah of Simcha begins with wine although extends as well to all other delicacies. Hence one who drinks wine can now extend and fulfill the Mitzvah with meat and all other delicacies and matters of Simcha. One can apply this likewise to Purim, as although there is no obligation to eat meat on Purim, nevertheless one who eats meat further fulfills a “Biblical” Mitzvah of rejoicing on Purim, as writes the Michaber in 696:7. [See Kaneh Bosem 1:102] Based on this it is also understood why many of the above Poskim wrote that the Michaber never mentioned an obligation to eat meat, when this is explicitly written by him in 696:7, as the ruling there does not obligate one to eat meat but simply rules that one who eats meat also fulfills the Mitzvah.
 See Michaber 696:7 that an Onen may eat meat and wine on Purim as it is a Biblical command to rejoice on Purim, hence implying that eating meat on Purim fulfills a Biblical Mitzvah.
The reason: As one is to have a lavish and festive meal on Purim [Rama 695:1], and this obligation is similar to a Biblical obligation, and meat enhances the meal. [Michaber 696:7] See the end of the previous footnote!
 M”A 695:6 in name of Kol Bo; Levush 695; Brought in Shaar Hatziyon 695:12
 Elya Raba 695:5; P”M 695 A”A 6; Kaf Hachaim 695:10
 See regarding Yom Tov, and the same would seemingly apply here: Chol Hamoed Kehilchasa 1:5; Piskeiy Teshuvos 529:10
 Nimukei Orach Chaim 695:2
 See regarding Yom Tov, and the same would seemingly apply here: Rambam Chagiga 2:10 “One does not fulfil his obligation with fowl and Menachos as they are not meat of joy”; Darkei Teshuvah Yoreh Deah 89:19; Chavos Yair 178; Yad Efraim Yoreh Deah 1; Divreiy Moshe 325; Terumos Hadeshen in Leket Yosehr “poultry is not called meat”; M”A 551:28 “There is no Simcha without animal meat”; Darkei Chaim Veshalom 395 that the Tzanzer Rebbe was particular to eat specifically animal meat on Yom Tov.
 Shagaas Aryeh 65
 Kaneh Bosem 1:102; Shiureiy Sheivet Haleivi p. 336; Taharah Kehalacha 19:33 footnote 92
Other Opinions: Some Poskim rule that women may not eat actual meat on Purim, if it is their day of immersion, and rather they are to eat meat soup. [Dvar Moshe 47; Ikarei Hadat 36:3; Ashel Avraham Openhaim 695; Orchos Chaim 695; Mishneh Halachos 7:96; 8:234; Kaf Hachaim 696:55] See Kaneh Bosem above which proves that it is permitted based on that all the above Poskim based their prohibition on the Dvar Moshe which holds that the custom is not to eat meat on Shabbos or Yom Tov if that night is her night of Tevila. However since practically it is our custom to eat meat on Shabbos and Yom Tov therefore even according to him it would now be permitted.
 The reason: As according to all it is a Mitzvah to eat meat on Purim, even if it is not an obligation [see previous footnotes], and women are obligated in all the Mitzvos of Purim just like men. [See Aruch Hashulchan 695:18; Kaf Hachaim 695:54]