Very interesting question. I did some desk research and here’s what I found.

Animal Welfare related findings 

1. Advertisers anthropomorphise animals to exploit them and convey the company’s messages i.e. animals want to serve humans. In this case, anthropomorphizing is used for the exact opposite of your purpose. But its successful application – it does work and makes people feel they have a license to continue their consumption unaltered – hints that it could also be used for good.
2. People respond more favourably, and are more influenced by, anthropomorphic portrayals of animals with a ‘high species similarity’ to humans than to non-anthropomorphic portrayals. However, participants responded more favourably to non-anthropomorphic representations of animals with a ‘low species similarity’. Thus, whilst demonstrating that anthropomorphism can be used to enhance the appeal of a product or brand, this study also shows that advertisers must work with its boundaries and limitations; anthropomorphism is most successful for animals or species that are perceived to be similar to ours.
3. Films such as ‘Chicken Run’ use anthropomorphism to reinstate animals as thinking, feeling beings, which could potentially subvert food norms and influence consumer perceptions of farm animals. Ironically, real chickens are not human enough for the film’s pro animal rights narrative to apply to them, whilst the chickens in the movie are not represented as animal enough to force consumers to reconsider the treatment of real chickens. So here we have a conundrum where anthropomorphism can help get a message across but people might not transfer these feelings in their every-day life decisions because in real life these animals have no human traits. The same could be true for nature conservation.
4. There’s evidence that anthropomorphizing animals increases prosocial behavior. Research has demonstrated that people have an affinity for non-human entities that appear to have human qualities. Relative to the non-anthropomorphism description of dogs, participants in the anthropomorphism representation of dogs reported more willingness to adopt dogs from a shelter and more support for animal rights, animal welfare, and vegetarian and vegan attitudes (2012. Butterfield Et Al. Anthropomorphism promotes animal welfare).

Saving Nature related findings

1. Whether anthropomorphism of nature has any impact on the way people relate to and behave toward nature has rarely been examined. This study shows that in general anthropomorphism of nature fosters conservation behavior. Moreover, when nature is anthropomorphized, people feel more connected to it; this sense of connectedness mediates the association between anthropomorphism of nature and conservation behavior (2013. Saving Mr. Nature/ Anthropomorphism enhances connectedness to and protectiveness toward nature).
2. Across three prosocial contexts, we found that individuals exposed to a message from an anthropomorphized social cause, compared with individuals exposed to a message relating to a nonanthropomorphized social cause, were more willing to comply with the message. This effect was mediated by feelings of anticipatory guilt experienced when they considered the likely consequences of not complying with the cause (2014, Ahn Kim, & Aggarwal. Helping fellow beings. Anthropomorphized social causes and the role of anticipatory guilt).
3. Anthropomorphic messages, relative to non‐anthropomorphic ones, appear to motivate more conservation behaviour and elicit more favourable message responses only among recipients who have a strong need for effectance or social connection. Among recipients whose such need is weak, anthropomorphic appeals seem to backfire (2014. Are anthropomorphic persuasive appeals effective? The role of the recipient’s motivations). Individual differences might explain why it works in some cases and not others.
4. The present research aimed to disentangle the effects of emotional and non-emotional anthropomorphism, and differentiating amongst other emotional mechanisms of the anthropomorphism-compliance effect (namely, anticipated pride and anticipated regret). Experiment 1 compared the effectiveness of positive, negative, and emotionally-neutral anthropomorphized campaign posters for boosting campaign compliance intentions against non- anthropomorphized posters. We also measured potential mechanisms including anticipated guilt, regret, and pride. Results failed to support the anthropomorphism-compliance effect, and no changes in anticipated emotion according to anthropomorphism emerged. Experiments 2 and 3 represented further tests of the anthropomorphism-compli- ance effect. No differences in compliance intention or anticipated emotion according to anthropomorphism emerged. The results of these three experiments suggest that the anthropomorphism- compliance effect is fragile and perhaps subject to contextual and idiographic influences (2015, Revisiting the Effect of Anthropomorphizing a Social Cause Campaign).We strongly recommend testing it before applying .
5. Literature regarding the effect of anthropomorphism on sustainability behaviors is contradictory, which suggests that that anthropomorphism is contextually sensitive. The current study seeks to add clarity to this domain by assessing the role of anthropomorphism on consumer sustainability behavior. Three experimental studies demonstrate that anthropomorphic cues (especially sad faces) activate a savior effect, which occurs when an anthropomorphic messenger is viewed as a victim and evokes feelings of sympathy. In turn, sympathy leads to enhanced sustainability behavior to save the victim from harm. However, when the desired sustainability behavior costs the consumer, this effect is suppressed – in such cases, the anthropomorphic messenger shifts from threatened victim to marketing agent, which reduces sympathy toward the messenger. Thus, companies seeking to promote sustainable behaviors and preferences for sustainable products could use anthropomorphism but only when the behavior does not result in additional payment to the organization (2019. Victim or beggar? Anthropomorphic messengers and the savior effect in consumer sustainability behaviour). It might be that anthropomorphism is more effective in increasing campaigning, volunteering, behavior change than giving. We recommend testing it with all these asks with your specific audience to determine where it’s most effective.

In short, the use of anthropomorphism seems to be promising and it might increase animal welfare or conservation behaviour but you need to test it with different audiences, different asks and different anthropomorhized species to determine which combination is most effective.